essay on different ways of seeing species

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Dog ( Canis familiaris ), gecko ( Gekko vittatus ), garden snail ( Cornu aspersum ), Maxima giant clam ( Tridacna maxima ), jumping spider ( Salticus scenicus ). All but the snail image are © Shutterstock.com and (dog) The Dog Photographer, (gecko) Sebastian Janicki, (clam) Ingvars Birznieks and (spider) Ireneusz Waledzik

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How do other animals see the world?

Seeing through one eye or many, in technicolour or black and white, few animals experience the world as we do.

By analysing the properties of animals' visual systems, we can model what the world would look like through their eyes.

The images below each show a scene as viewed by a human. Drag the slider to the left to see how an animal would see the same scene.

Whereas human eyes contain three types of colour-detecting cells, called cones, dogs have just two. Their cone cells are specialised for picking up yellow and blue-to-ultraviolet light.

Each cone type contains a pigment sensitive to particular wavelengths of light. The range of colours an animal sees depends on the combination of colour-sensitive pigments in their eye and the processing by the brain.

With fewer cone types, dogs can't distinguish between as many colours as we can.

Gecko vision

Humans don't see colours very well, or even at all, in low light. This is because our cone cells function best in relatively bright light.

Other cells in our eyes, called rod cells, help us see in dim light. But because rod cells only have a single light-sensitive pigment, at night we see in shades of grey.

Geckos, on the other hand, have excellent colour vision at night - a useful advantage for a nocturnal hunter. Their eyes have evolved to be up to 350 times more sensitive to colour at night than ours.

Garden snail vision

Although the eyes of garden snails can't focus or see colour, they would just about be able to make out this other snail moving past, or a predator approaching.

The snail's ability to discern different intensities of light helps it navigate towards dark places.

Giant clam vision

Adult giant clams are completely stationary, having attached themselves to rocks or coral. They observe the world through several hundred tiny pinhole eyes along the edge of their soft bodies.

Pinhole eyes are the shape of a deep cup and have a narrow opening, but no lens. They are just one of an enormous variety of eyes owned by molluscs - animals such as slugs, snails, oysters and octopuses - which demonstrate different steps in eye evolution.

Although giant clams are sensitive to three different colours of light, they are unable to combine the information - instead, they see colourful but undefined images. However, their eyes are able to detect nearby movement, so that the clams can take action either by squirting a jet of water to startle a potential predator or by closing their shell .

Jumping spider vision

Excellent vision from four pairs of eyes helps these spiders hunt. When they spot potential prey, they pounce.

Their biggest pair of eyes face forward and give the spider high-resolution vision. The other, smaller eyes are used for peripheral vision and detecting motion.

Jumping spiders can see a broader spectrum of colours than we can. They even have pigments sensitive to ultraviolet light, so they are able to see more details in this flower's petals than we can.

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How Animals See the World: Comparative Behavior, Biology, and Evolution of Vision

Assistant Professor of Psychology

Professor of Psychology

Dewey B. and Velma P. Stuit Professor of Experimental Psychology

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The visual world of animals is highly diverse and often very different from the world that we humans take for granted. This book provides an extensive review of the latest behavioral and neurobiological research on animal vision, highlighting fascinating species similarities and differences in visual processing. It contains twenty-six chapters about a variety of species including: honeybees, spiders, fish, birds, and primates. The chapters are divided into six sections: perceptual grouping and segmentation, object perception and object recognition, motion perception, visual attention, different dimensions of visual perception, and the evolution of the visual system.

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The Millions Of Ways Animals Sense The World

33:18 minutes

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A shark tracks its victims by smell, but uses the unmissable signal of a fish’s electrical field to make its final strike. Fire-chaser beetles can detect the heat of distant forest fires with specialized cells in their heads. Baby tree frogs can detect the seismic signals of a striking snake from within the egg—and seem to hatch earlier in defense. And the prey-hunting visual system of one unassuming-looking Mediterranean fly, known as the killer fly, works faster than any other species we’ve observed.

All of these are examples of an animal’s umwelt , their specialized sensory bubble or window onto the world, as described by German biologist Jakob Johann von Uexküll over one hundred years ago.

As science writer Ed Yong writes in his newest book, An Immense World: How Animal Senses Reveal The Hidden Realms Around Us , our history of studying animals’ umwelten has been fraught with hubris, misunderstandings, and mistakes. But bit by bit, we’re learning to appreciate the truly spectacular perceptive abilities of the owl, the elephantfish, and the humble jumping spider.

Yong joins guest host Maddie Sofia to share stories of amazing animal sensory abilities and the challenges of both imagining and describing these other realms using human-centric language. Plus, the uniquely human capacity to imagine other animals’ umwelten , and how we can use it to make the world better for them .

Read an excerpt of Yong’s book, An Immense World: How Animal Senses Reveal The Hidden Realms Around Us.

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Segment Guests

Ed Yong is a science writer and author of An Immense World: How Animal Senses Reveal The Hidden Realms Around Us .

Segment Transcript

MADDIE SOFIA: This is Science Friday. I’m Maddie Sofia. Pop culture often imagines humans seamlessly entering the worlds of other animals. I mean, the Anamorphs books were big in my house. Or what about this classic? Spidey sense.

SPIDERMAN: Uh oh. My spider sense is tingling. I’m being watched. My spider sense tells me– Uh oh.

MADDIE SOFIA: But the worlds animals experience are vastly different from ours. We’ve never experienced the world through magnetic fields, flowing ocean currents, or high pitched vibrations.

How do you understand a fish that learns by sensing electric fields? Beetles that know no language except the heat of a distant forest fire. Mole rats that make their way around using touch sensitive teeth.

Science writer, Ed Yong, tries to translate for us. He’s interviewed manatees, treehoppers, and 100 different scientists to write his latest book, An Immense World– How Animal Senses Reveal the Hidden Realms Around Us. He’s here today to talk about what he’s learned about the worlds animals perceive that we can only try to imagine. Welcome back to Science Friday, Ed.

ED YONG: Hi. Thanks for having me.

MADDIE SOFIA: Absolutely. OK. So like I mentioned, there are plus different animals mentioned in this book. I saw you got punched by a mantis shrimp.

ED YONG: I did.

MADDIE SOFIA: Shocked by an electric eel. Spent time in deep freeze with hibernating ground squirrels. Tell me what your favorite animal interaction you had was during your research.

ED YONG: Oh, so I went to this lab in Missouri to meet a guy called Rex Cocroft who studies leafhoppers. And these are small insects that live on plants that I think most people have never heard of. But I guarantee you that if you’ve been to any park or green space, you will have been next to a leafhopper at some point.

They send vibrational messages through plants. They vibrate their abdomens and send these seismic signals through the stems and leaves of the plants on which they stand that other leafhoppers can then pick up. These vibrations are inaudible to us.

But if you clip a little microphone onto the plant, you can translate them into sound. And I went to this lab to listen to these vibrational calls myself. And they are astonishing. I saw this tiny little insects sitting on a leaf producing a sound that sounded almost like a lion’s roar, a very deep purring noise that you would never have thought would come from an insect.

And then we went on this prospecting expedition, going to a local park and clipping microphones onto like bits of plants– like little grass stems and so on– trying to find one of these things in the wild. And we eventually found– we heard this noise. It sounded like– I don’t know– it sounded like a fairy hyena laughing.

MADDIE SOFIA: Do you feel comfortable giving me a treehopper impression right now?

ED YONG: I do, because the treehopper is not going to be listening to this.

MADDIE SOFIA: Right.

ED YONG: I’m not going to get canceled for doing a bad treehopper impression.

MADDIE SOFIA: Go ahead, go ahead.

ED YONG: It sounded like [IMITATES TREEHOPPER]. It sounded like a weird snickering noise. And once I convinced myself that it wasn’t, in fact, the scientist just like standing behind me and teasing me, it just felt magical.

Like most of these insects are very rarely studied. Very few people go around clipping microphones onto bits of grass. But when you– so it means that when you do, you stand a reasonable chance of hearing something that no one has ever heard before.

MADDIE SOFIA: Yeah. Oh my gosh, I love that. OK.

I’m also just thinking about all these different sensory systems in your book of all of these animals– manatees, jumping spiders, your corgi, Typo. Was there a sensory system or like a perspective that you were like, oh I want that. That would be incredible.

ED YONG: Yes. I think there are quite a few. And they’re all my babies, so it’s a little hard to pick between them. I think that in terms of the more exotic senses that we really don’t have access to, dolphin sonar would be truly incredible.

So dolphins have the ability to echolocate. So they [INAUDIBLE] high-pitched calls and they sense the world by bypassing the rebounding echoes. But because of the way sound moves through water, dolphin sonar also penetrates through flesh. An adult dolphin echolocation on you can probably perceive your skeleton, your lungs.

MADDIE SOFIA: I don’t know how I feel about that.

ED YONG: Right. Suddenly– I don’t know, have you ever swum with a dolphin?

MADDIE SOFIA: Yes, I have.

ED YONG: It probably knows stuff about you that even your close friends don’t know, probably.

ED YONG: So I think that experience of essentially being a swimming, living, medical scanner would be the absolutely incredible.

MADDIE SOFIA: I love that.

ED YONG: And then there are also– even for more familiar senses– birds have access to this entire dimension of colors that we can’t see. And if we could, flowers, the feathers of other birds, much of the world would look very, very different.

ED YONG: And I think just being able to briefly get that sense of like a more kaleidoscopic reality would be incredible.

MADDIE SOFIA: Absolutely. OK. So one of the things that you emphasize is the importance of studying animals in their own right. Not just how we can use them or mimic them. Why is that so important, Ed?

ED YONG: I think for a few reasons. I think sometimes our relationships with animals do become a little bit transactional. Scientists study them as model organisms, as windows into our biology. Or they might study them as sources of inspiration, things that could point us to words better technology.

But I don’t really care about any of that. An Immense World is about animals– is about trying to understand animals for their own sake. And I think that’s important, just because they are kind of miraculous. And because their ways of sensing the world are so different from ours.

Our senses give us a perception of the world that feels complete. And that sense of completion is an illusion, we actually are only perceiving a very thin sliver of all there is to perceive. Our world is just a small fraction of the immense world surrounds us. And we can’t access that, unless we really think about what other animals are doing.

So if we ignore them or if we allow them to go extinct, we lose a way of understanding the world around us. And I think our reality becomes a little bit narrower and a little bit more constrained as a result. So it’s really a sort of philosophical argument. I think that if we really want to know what is happening around us, we have no choice but to try and consider the perspectives of other creatures.

MADDIE SOFIA: All right, Ed. So let’s try to consider some of those perspectives of other creatures. And I want to start by talking about that sensory bubble that you alluded to, that all animals live in. The parts of the world that an animal can actually sense. It’s called the umwelt. Where did this word come from?

ED YONG: It was popularized by a German biologist named Jakob von Ueskull. And I’m very sorry to all German speakers for absolutely butchering that. It’s hard, all right.

And so he used the word umwelt comes from the German for environment. But von Ueskull wasn’t using it to talk about the physical environment, not like the plants or the mountains or what have you. He meant the sensory environment, the part of that world that the animal can perceive through its own unique set of eyes, ears, noses, or other sense organs.

The umwelt is the slice of reality that each creature has access to. And it differs radically from one species to another.

MADDIE SOFIA: Yeah. How would you describe the umwelt of your smell-focused pet dog, Typo, for example. Take us into Typo’s brain.

ED YONG: So Typo can see further to the sides than I can, as a simple example. His color vision is more limited than mine. So while my visual spectrum runs from red to violet, his goes from yellow to blue.

But through his nose, the world is far richer than I could possibly imagine. And that’s evident whenever we go for a walk. He sniffs furiously as we trundle along the same streets that I walk along, day in and day out.

And every time we do that, it’s a new adventure to him. He sniffs the plants that he encounters. He sniffs patches of dried pee from dogs that have walked those streets before.

And when he does that, he gets biographical information about those dogs. He knows who’s been there. He knows what they’ve been up to. Maybe he has an idea about their health or what they’ve recently been eating.

To me, Typo sniffing like dog pee on our walk is a little bit like me checking my social media feed. it’s a way for him to connect socially with the other dogs in his world, even when they’re not immediately next to him.

And the parallels between that and me scrolling through Instagram and seeing what my far friends are doing are actually pretty exact. I think that those two things are incredibly comparable.

MADDIE SOFIA: I want to talk about actually studying this stuff, because I can imagine it’s really challenging to study these sensory systems so different from ours. Especially when even our terminology, like ultrasonic, is defined by human sensory ranges and limitations. So talk to me a little bit about that.

ED YONG: Yeah. It’s really hard to escape our own biases. And you touched on a great example. Ultrasonic is almost like anthropomorphic by definition.

That just refers to frequencies over 20,000 Hertz, which is the top of the human hearing range. Actually, most animals– most other mammals certainly– can hear just fine into that range. For them, it’s not ultrasound it’s just sound.

MADDIE SOFIA: Yeah, right.

ED YONG: Right. And similarly ultraviolet, a color that we can’t see but that exists is just beyond the violet end of the rainbow. It’s not really ultra to most of the sighted animal kingdom, which actually can see ultraviolet.

The limitations of our senses then create limitations in our science. So for a long time, scientists kept thinking that seeing ultraviolet was special. That it was the province of just a very narrow range of the animal kingdom. And that it might be used for sending secret messages that most other creatures could not see.

So you might have ultraviolet markings on your face that were only perceptible to your species. But it turns out that if most other animals actually can see ultraviolet, it’s not very secret at all.

MADDIE SOFIA: Absolutely.

ED YONG: It just happens to be another color.

MADDIE SOFIA: Quick reminder that I’m Mattie Sofia and this is Science Friday, from WNYC Studios. Talking to science writer Ed Yong, who has a new book about the amazing sensory worlds of animals. So how do we actually study this stuff. Like give me an example of studying a sense that we don’t remotely have. How we’ve managed to try.

ED YONG: So echolocation is actually a great example of this. And it turns out to be a sense that, despite feeling exotic to most people, is one that is remarkably easy to study. Because to echo-locate, a bat– for example– must produce sound.

So it’s listening for the echoes of its own calls. And without the call, there is no echo. So the bat, to sense the world around it, needs to be making noise. And by changing the nature of those calls, their frequency, their duration, the bat can wrest different information from the world around it.

So a scientist can look at where the bat is aiming its sonar pulses. They can look at the frequency of those pulses. And they can get a sense of what the bat is trying to detect.

Whether it’s trying to search for an insect in open air. Whether it’s trying to navigate around obstacle. Whether it’s homing in for the kill.

MADDIE SOFIA: Yeah.

ED YONG: And that’s sort of incredible.

ED YONG: It means that by recording a bat’s calls, you can almost get at the bat’s intent. And that makes things like echolocation reasonably easy to study. But it also– there’s always going to be a gap.

You’re never going to fully appreciate what exactly is going on in the bat’s head, even though it’s calls give you a sense of what the bat is trying to do with its echolocation.

MADDIE SOFIA: Right. Can I ask you, in a similar vein as how it’s kind of difficult to study these sensory systems. Was it difficult to write about this research? Would you write a sentence and be like, oh, what a human way to write that sentence. You know what I mean?

ED YONG: Right. Yes, very much so. It certainly, in that way, it’s quite hard to avoid anthropomorphisize– isn’t that the right word?

MADDIE SOFIA: That’s right.

ED YONG: It’s quite hard to avoid viewing these creatures through human terms. And I’ve just done it there, right. I’ve used the word “view”, which is a visual term. We are a species whose sighted members rely on vision very heavily.

And our terminology for perceiving the world is heavily influenced by vision. Just that word there, using “view” to mean “perceive” is symptomatic of that. So in writing the book, I tried really hard to not use visual language when I’m talking about non-visual senses.

To not foist human terms on these creatures. And it’s difficult. Because sometimes, there just isn’t an obvious alternative. Especially when you think about sensors like, say, electroreception, so sensing electric fields.

There, the lingo is all stuff like potential, and voltage, and current. Stuff that feels, I think, abstract to most people. It doesn’t come– electroreception doesn’t come with the rich lexicon that sight or sound might have.

MADDIE SOFIA: We have to take a short break. When we come back, more from science writer Ed Yong, author of the new book An Immense World– How Animal Senses Reveal the Hidden Realms Around Us. All about the smell, vision touch, and unique senses animals use to perceive the world.

I’m Maddie Sofia, this is Science Friday. We’ve been talking with science writer Ed Yong this hour about how animals, and I mean non-human animals, sense the world around them. From seeing colors we can’t even imagine, to the faint electrical fields generated by all living things.

He’s written all about it in his new book, An Immense World– How Animal Senses Reveal the Hidden Realms Around Us. There’s an excerpt on our website if you want to take a look, sciencefriday.com/senses. That’s sciencefriday.com/sense.

So let’s dig into some of these sensory systems. And I want to start with I think my favorite that was in the book. You write that animals have been sensing seismic vibrations since they crawled out of the ocean. How is this different than sound, which is like vibrations of the air?

ED YONG: Right. So what we usually think of as sound are waves of pressure moving through the air. But similar vibrations can also course through the ground. Most of these examples are when an earthquake happens, you feel that rippling of the ground.

But that also happens to a much, much smaller extent through more regular activities. Like whenever we walk we send seismic vibrations along the ground beneath us. And if you have the right sense organs, you can detect those vibrations.

And many animals absolutely do that. This world of seismic sensing is often neglected. We tend to focus on the airborne stuff and we neglect all the stuff that goes on beneath our feet.

Like the leafhoppers I talked about at the start of this interview are a prime example of that seismic sense. But there are lots of other creatures– from earthworms to elephants– that also detect these surface-borne vibrations.

And spiders are absolute masters of this. The spiders that build their own webs are effectively extending their sensory systems into the world around them through the architecture that they make with their own bodies.

MADDIE SOFIA: Yeah, absolutely. In one example of seismic sensing that completely blew me away. I was like– I had to put the book down for a second. Baby tree frogs can sense the vibrations of predators while they are inside the egg. I– can we talk about it?

ED YONG: Yes, we can. So this all comes from a long body of work by Karen Warkentin, who is an amazing biologist. So they worked out that at a time when everyone thought that embryos were just passive entities, Warkentin showed that in fact, they are still actually actively sensing the world around them and can sometimes react to that world.

So these baby tree frogs inside their eggs can detect the vibrations of a snake that’s trying to chew on this cluster of eggs. And they will react by releasing an enzyme from their face that dissolves the eggs and allows them to break free and plop into water.

MADDIE SOFIA: I just–

ED YONG: That’s right. That is incredible.

MADDIE SOFIA: Evolution, you know what I mean?

ED YONG: I know, absolutely. This is– good job evolution.

MADDIE SOFIA: Yeah, smart.

ED YONG: It’s solid, solid work, yeah. So these are creatures that are maybe four days old. They might technically– they’re sort of 0 days old, right. They haven’t even hatched yet.

They’re still inside the egg. But they still have an umwelt. They still have an awareness of their surroundings.

And they can differentiate between the kinds of vibrations created by a chewing snake and those created by say, the patter of rainfall or the shaking of the ground. It’s not just that any kind of vibration sends them busting out of the egg. It’s very specifically the vibrations created by predators.

MADDIE SOFIA: Yeah. OK, OK. And then this chapter also– can tell how jazzed I am about this chapter– and then, and then. This chapter also had a really good example of how predators have evolved to exploit the senses of their prey. Kind of the reverse, including their seismic senses. And you have kind of a funny story about some Florida residents who have been unknowingly mimicking the way moles hunt earthworms?

ED YONG: Right. Yes, that’s right. So there is this practice called “worm grunting”, where you create seismic vibrations in the ground by rubbing like iron against a stake. This happens in Florida.

People go out into the woods and they create strong vibrations in the ground. And earthworms start rising up from the ground and then can be collected and used as bait. And it turns out that these vibrations mimic the stimuli created by burrowing moles.

And so the earthworms essentially are trying to flee from what they think is a mole-quake.

ED YONG: But that is, in fact, the work of Floridians inadvertently mimicking a mole.

MADDIE SOFIA: Oh my gosh. OK. So let’s move on to a different chapter, which is a chapter that you wrote about pain. Which I thought was really unique and I hadn’t thought that much about.

You call it the unwanted sense. Give us some pain 101. It turns out there’s a difference between the sensory perception of hurt and the emotional thing we call pain.

I think everybody who’s ever broken a bone or had a chronic illness kind of knows what I mean. We all know the sensation is telling us information. But it’s also different from the great deal of suffering around that information.

ED YONG: Right, totally. So if I touched a hot pan, for example. My arm is going to start recoiling before I realize that I have touched something hot. And that reflex is fueled by what’s called nociception.

There are receptors in my hand that detect that something harmful has– that I touch something harmful. And that forces me to recoil. Then afterwards, shortly afterwards, I feel the pain of the injury.

You know it sucks. I am suffering. That negative emotion is pain.

And there is a distinction between those two, the actual detection of the harm and then the emotional response to it. Now there has been a lot of debate about whether animals have the latter. Like all animals seem to have the former, right. They all do nociception.

They can all recoil from something that’s going to hurt them. But whether they have that emotional suffering or not is something that is very hotly debated. But I think in the middle is where a lot of the reality lies. I think a lot of animals do have an experience of pain.

ED YONG: From fish to crustaceans. But I don’t think that it’s going to be exactly the same as what we experience.

ED YONG: I think there’s going to be a lot of variety there. And that’s a little weird, right. I think we think of pain as universal.

But it isn’t. If I get chili oil all over my hand, that’s really going to sting.

ED YONG: The same chemical that causes that sting doesn’t cause pain at all in birds, for example.

ED YONG: Or like naked mole rats. And even closely related animals can experience pain in very different ways. If an octopus injures a tip of its arm, it’ll know oh, arm number 6 is injured. I’m going to look after that.

If a squid has an injury on part of its body, it doesn’t seem to understand which part of its body has been injured. It just seems to have this whole body hypersensitivity.

ED YONG: So even there what we– this idea of pain is going to manifest in very different ways–

ED YONG: In animals that we think of as being closely related.

MADDIE SOFIA: OK. This is good, because I want to ask you about something you wrote in your chapter about pain as this unwanted sense. You write that this quest to understand animal pain is a another conversation driven by our own biases.

We’re often asking questions like can I eat this animal, morally. What can I do to this animal. What should we be asking instead?

ED YONG: The more interesting questions, rather than just do animals feel pain or not or, are what kinds of pain do they feel. Like how does that manifest to them. Under what conditions have different types of pain evolved.

You’re right that this is such a charged topic. And it I think makes us forget the nuances that we understand in some different senses. So some people have argued that this distinction between nociception and pain is actually quite artificial.

And it’s not that we make that distinction for things like vision, for example. People aren’t talking about the distinction between photoreception, the detection of light, and vision, the subjective experience of the visual world. Except that distinction absolutely exists. We can very much talk about it. And people do.

It just doesn’t have that same moral charge that talk of pain does. And I think that moral charge is absolutely vital. it shapes the ways we think about caring for animals, like our responsibilities to them. But it shouldn’t stop us from asking these more interesting nuanced questions about exactly what their experience really is like.

MADDIE SOFIA: All right. OK. So we don’t have time to talk about all the chapters and the animals in your book, unfortunately. But we have to talk about the beetles.

ED YONG: I love the beetles.

MADDIE SOFIA: Yeah. OK, more specifically, the beetles that chase forest fires.

ED YONG: Right. So there are a few species of beetles that fly towards forest fires. Which seems to be like the wrong direction, right. Like usually you fly away.

But they fly towards the fires because a charred forest actually is a pretty sweet place to lay your eggs, if you’re a beetle. Your grubs will hatch in an environment where there are no predators, where the trees have been weakened and make for easier meals.

And so these beetles fly towards fires. And have probably the most dramatic sex in the animal kingdom, where they mate amid the flames in this slide amazingly metal way.

MADDIE SOFIA: Yes.

ED YONG: But this ability is contingent on their ability to detect forest fires. And they do that by sensing the heat from those fires, the infrared radiation that those fires give off, over truly incredible distances.

People have documented these beetles arriving at like barbecues, or like a sports stadium at the time when people were smoking cigarettes a lot and you had these thousands of points of heat for these beetles to be distracted by. And, yeah, it’s an absolutely incredible ability.

MADDIE SOFIA: Just a quick reminder that I’m Maddie Sofia and this is Science Friday from WNYC Studios. Talking to Science writer, Ed Yong, who has a new book about who has a new book about the things animals feel that we can’t.

OK. So your book starts with the senses of other animals, but ultimately ends with humans, with us. And what you say is that we, unlike the octopus or the owl, can glory in worlds we cannot perceive with our own senses. That ability is actually our greatest sensory skill. Tell me more about that.

ED YONG: Yeah. If I was in a room with a rattlesnake, a dog, an elephant, an owl, firstly you might question my life choices. But also, you might realize that all of us are going to be experiencing that room in a very, very different way even though we share the same physical space.

But the one thing that I, the human, has that I think is unique is the ability to ponder about what those other creatures are experiencing, the knowledge that their sensory worlds are different to ours. Now there’s a long history of people claiming, wrongly, that humans have some skill that no other animals have. But I think this is a reasonable claim to make in this instance.

Because thinking about other sensory worlds doesn’t come naturally even to humans. It took a lot of philosophy and research to actually get to the point where I can write a book like this. So we have, now, this ability to ask.

Like what does an electric fish sense. What does a bat sense. What does a rattlesnake sense. And that ability to go on these sensory voyages– to try and jump into the umwelt of another creature–

ED YONG: –is a profoundly human gift, and I think that one that we really ought to cherish and not throw away.

MADDIE SOFIA: Yeah, absolutely. Just as a final note, how do we use that gift responsibly? How do we use that gift– that power– for good?

ED YONG: Yeah. At the end of the book I write about the problem of sensory pollution. The fact that we have flooded the world with light and sound in a way that distracts and waylays and harms the other creatures around us. And paradoxically, we– despite the fact that this kind of pollution is very obvious to us– we neglect it.

Because we don’t think of light and sound as possible pollutants. We think of them as good things, part of our lives. But by forcing other creatures to exist in our umwelt we neglect the ways in which they live their lives. And sometimes we end those lives as a result.

I think that thinking about other umwelts allows us to be better custodians of the world, better carers for the other creatures around us. I think it also makes us more profoundly connected to that world. We understand the creatures in it better.

If we remove unwanted sources of light and sound, we can see those creatures better. It’s not for nothing that early on in the pandemic people really realized that they could suddenly hear lots of birds around them that they couldn’t hear before. Because the world was a quieter place.

I think by respecting other umwelts, we become better connected to nature. We recognize that nature is something that exists in our backyards rather than something distant. And I would hope then that we feel a more profound call to care for it and to appreciate it.

MADDIE SOFIA: All right. That’s all the time we have. Ed Yong, thank you so much for joining me today.

ED YONG: Thank you for having me.

MADDIE SOFIA: Ed Yong is a science writer and author of An Immense World– How Animal Senses Reveal the Hidden Realms Around Us. There’s an excerpt on our website if you want to take a look sciencefriday.com senses that’s sciencefriday.com senses.

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The Strange and Secret Ways That Animals Perceive the World

One evening almost sixty years ago, a Tufts University researcher named Roger Payne was working in his lab when he heard a radio report about a whale that had washed up on a beach nearby. Although it was a cold, wet March night, he decided to drive to the shore. When he arrived, he discovered that the animal had been mutilated. Two passersby had carved their initials in its flanks. Someone had hacked off its flukes, and another person, or perhaps the same one, had stuck a cigar butt in its blowhole. Payne stood in the rain for a long time, gazing at the corpse. He had been studying moths; now he decided to switch his attention to cetaceans.

Aside from the dead one, Payne had never actually seen a whale, nor did he know where whales could be observed. At the suggestion of an acquaintance, he made his way to Bermuda. There he met an engineer who had worked for the United States Navy, monitoring Soviet submarines via microphones installed off the coast. While listening for enemy subs, the engineer had chanced upon other undersea sounds. He played a tape of some of them to Payne, who later recalled, “What I heard blew my mind.”

Payne took a copy of the tape home with him. The sounds—made, the engineer had determined, by humpback whales—ranged from mournful wails that evoked the call of a shofar to high-pitched cries that resembled the squeals of piglets. Payne found the tape mesmerizing and listened to it hundreds of times. Finally, it dawned on him that what he was listening to had a structure.

With the help of a machine called a sound spectrograph, Payne converted the voices on the tape into a series of squiggle-like notations. The exercise took years, but eventually it confirmed what he had suspected. The humpbacks always made their wails, squeals, and grunts in a particular order—A, B, C, D, E and never A, B, D, C, E, in Payne’s formulation. The paper in which he announced his discovery appeared in Science in the summer of 1971. “Humpback whales ( Megaptera novaeangliae ) produce a series of beautiful and varied sounds for a period of 7 to 30 minutes and then repeat the same series with considerable precision,” Payne wrote. Each series, he argued, qualified as a “song.”

While the paper was in the works, Payne arranged to have the humpbacks’ songs released as an LP. The album spent several weeks on the Billboard 200 and sold more than a hundred thousand copies. This was a particularly impressive feat, as one commentator noted, for a “work with no musicians, no lyrics, no danceable beats and actually no singers either. (Humpback whales do not possess vocal cords; they make sound by their pushing air out through their nasal cavities.)” The humpbacks inspired many terrestrial performers; Judy Collins incorporated some of their calls into her album “Whales and Nightingales”; Pete Seeger wrote “Song of the World’s Last Whale”; and the New York Philharmonic played “And God Created Great Whales,” a piece composed by Alan Hovhaness.

In 1977, when NASA launched Voyagers 1 and 2, designed to probe the far reaches of the solar system, the songs of the humpbacks went with them. The agency outfitted each craft with a “ golden record ” that could be played using a stylus (also included) by any alien who happened to intercept it. The recording featured greetings in fifty-five languages—“Hello from the children of planet Earth,” the English speaker said—as well as a sequence from one of Payne’s whales.

At the time the Voyagers set out, no one knew what, if anything, the humpbacks were trying to convey. Today, the probes are more than ten billion miles from Earth, and still no one knows. But people keep hoping.

Imagine the following scene: You are in a room with an owl, a bat, a mouse, a spider, a mosquito, and a rattlesnake. Suddenly, all the lights go off. Instead of pulling out your phone to call an exterminator, you take a moment to ponder the situation. The bat, you realize, is having no trouble navigating, since it relies on echolocation. The owl has such good hearing that it can find the mouse in the dark. So can the rattlesnake, which detects the heat that the rodent is giving off. The spider is similarly unfazed by the blackout, because it senses the world through vibrations. The mosquito follows the carbon dioxide you’re emitting and lands on your shin. You try to swat it away, but because you’re so dependent on vision you miss it and instead end up stepping on the rattler.

Ed Yong, a science writer for The Atlantic , opens his new book, “ An Immense World: How Animal Senses Reveal the Hidden Realms Around Us ” (Random House), with a version of this thought experiment. (His version also includes a robin, an elephant, and a bumblebee, though not the potentially fatal encounter with the snake.) Yong is interested in what animals might communicate to us if they could, which is to say, what they perceive. Humans, he points out, see the world one way. Other species see it through very different eyes, and many don’t see it at all. Attempting to exchange one world view—or, to use the term Yong favors, Umwelt —for another may be frustrating, but, he argues, that’s what makes the effort worthwhile. It reminds us that, “for all our vaunted intelligence,” our Umwelt is just one among millions.

Consider the scallop. (What’s sold at the supermarket fish counter is just the muscle that scallops use to open and close their shells; the entire animal resembles a fried egg.) Some species of scallop have dozens of eyes; others have hundreds. Inside them are mirrors, composed of tiny crystals, that focus light onto the retina—retinas, really, since each eye has two. A scallop’s eyes are arrayed around the edge of its body, like spikes on a dog collar.

Our brains combine the information gathered by our two eyes into a single image. With dozens (or hundreds) of eyes, scallops face a steeper challenge. But they don’t have much brainpower to devote to the task. (In fact, they don’t have brains.) In an effort to figure out what the scallops were doing with all their eyeballs, Daniel Speiser, a biologist at the University of South Carolina, developed an experiment he called Scallop TV. He strapped the animals onto little pedestals, planted them in front of a computer monitor, and forced them to watch images of drifting particles. Scallops are filter feeders, meaning that they consume plankton they strain out of the water. Speiser found that if the computer-generated particles were big enough and were moving slowly enough the scallops would open their shells. “It’s wild and creepy to see all of them opening and closing at the same time,” he tells Yong. He thinks that their eyes function independently, like motion detectors. When one eye senses something potentially tasty, it sends a signal to investigate. If Speiser is correct, Yong notes, then even though scallops’ eyes are both numerous and complex, the animals don’t possess what we would think of as vision. They see, he writes, “without scenes.”

“An Immense World” is filled with strange creatures like scallops and strange experiments like Scallop TV. Harbor seals have a fringe of vibration-sensitive whiskers jutting from their snouts and eyebrows. To gauge how sensitive the whiskers are, a team of marine biologists at the University of Rostock, in Germany, trained two harbor seals to follow the path of a miniature submarine. Then they blindfolded the animals and plugged their ears. To study how moths elude bats, scientists at Boise State University cut off some moths’ tails and fitted out others with fake wing extensions. To ascertain whether hermit crabs experience pain, a pair of researchers at Queen’s University Belfast prodded them with electric shocks, and to figure out the same thing for squid a biologist at San Francisco State sliced them with scalpels. When I got to the story of Kathy, a bottlenose dolphin who refused to don a sound-blocking mask that researchers wanted her to wear, I silently cheered for her.

The black ghost knifefish is, as its name implies, a nocturnal hunter. By firing a specialized organ in its tail, a knifefish creates an electric field that surrounds it like an aura. Receptors embedded in its skin then enable it to detect anything nearby that conducts electricity, including other organisms. One researcher suggests to Yong that this mode of perception, known as active electrolocation, is analogous to sensing hot and cold. Another posits that it’s like touching something, only without making contact. No one can really say, though, since humans lack both electric organs and electroreceptors. “Who knows what it’s like for the fish?” Malcolm MacIver, a professor of biomedical engineering at Northwestern, asks.

The most famous iteration of this question comes from the essay “What Is It Like to Be a Bat?,” published in 1974 by the philosopher Thomas Nagel. Bats are closely enough related to humans, Nagel noted, that we believe them capable of what we’d call experience. But how can we get inside their furry little heads? The difficulty is not just that they can’t tell us. It’s that their Umwelt is utterly foreign.

One might try to imagine, Nagel wrote, “that one has very poor vision, and perceives the surrounding world by a system of reflected high-frequency sound signals,” or that “one has webbing on one’s arms, which enables one to fly around at dusk and dawn catching insects in one’s mouth.” But that wouldn’t help much.

“I want to know what it is like for a bat to be a bat,” Nagel insisted. “Yet if I try to imagine this, I am restricted to the resources of my own mind, and those resources are inadequate.” The question “What is it like to be a bat?,” he concluded, is one that people will never answer; it lies “beyond our ability to conceive.”

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Yong’s response to Nagel, who makes several appearances in his pages, runs along the lines of “Yes, but . . .” Yes, we can never know what it’s like for a bat to be a bat (or for a knifefish to be a knifefish). But we can learn a lot about echolocation and electrolocation and the many other methods that animals use to sense their surroundings. And this experience is, for us, mind-expanding. Yong speaks to Christopher Clark, a Cornell researcher who in the nineteen-seventies worked with Roger Payne, listening for whales. Whale songs lie at the opposite end of the spectrum from bat calls; they are very low frequency and can travel vast distances. If whales are using their songs to communicate with one another, they are doing so not just across space but also across time. A call made by a humpback near Bermuda would take twenty minutes to reach a humpback swimming off the coast of Nova Scotia. If the Canadian whale answered immediately, it would be forty minutes before the Bermuda whale heard back. To imagine what it’s like to be a whale, “you have to stretch your thinking to completely different levels of dimension,” Clark says.

Meanwhile, you don’t have to understand what it’s like for a bat to be a bat to appreciate what might mess with a bat’s way of being. Yong pays a nighttime visit to Grand Teton National Park with Jesse Barber, a biologist at Boise State University. Barber is concerned about what’s become known as “sensory pollution.” Even in the Tetons, lights now illuminate the darkness. Insects are drawn to the lights; bats are attracted to the insects; and, the worry is, owls pick off the bats. To test this hypothesis, Barber and his students spend the night tagging bats in a campground parking lot. The lot, Barber complains, is “lit up like a Walmart because no one thought about the implications for wildlife.”

Yong wants us to think more about these implications, which can upset entire ecosystems. He offers the example of Woodhouse’s scrub jays, which are native to the western United States and central Mexico. The birds are important to the survival of piñon pines because they spread the trees’ seeds. But they’re bothered by the noise of compressors, so they avoid spots where natural gas is being extracted. Researchers found that, where the jays still find quiet, piñon-pine seedlings are four times more common than in noisy areas the birds have abandoned.

“Through centuries of effort, people have learned much about the sensory worlds of other species,” Yong writes. “But in a fraction of the time, we have upended those worlds.”

In September, 2015, a British documentary filmmaker named Tom Mustill was vacationing in California with a friend when the two decided to take a kayak trip in Monterey Bay. The aim of the trip was to see whales up close, but Mustill and his friend got more than they had bargained for. As they were paddling about, a humpback shot up out of the water just feet from their boat. (Mustill later compared the experience to watching the space shuttle take off.) The whale, which weighed thirty tons, came down more or less on top of them. The two kayakers were sucked under, along with their boat. Mustill thought that he had been torn apart and attributed his lack of pain to being in shock. But he and his friend both resurfaced in one piece. They made it to shore, where the company that had rented them the kayak offered them free hot chocolate.

Mustill continued with his vacation, which included a camping trip in Big Sur. When he got back in cell-phone range, he learned that someone on a nearby boat had captured his whole whale encounter on video , and that the video, posted to YouTube, had gone viral. By the time Mustill returned to London, it had been viewed four million times. The story was picked up around the world. “ Baleia de 40 toneladas quase esmaga casal de canoístas ” (“ Forty-ton whale nearly crushes couple of kayakers ”), the Cape Verdean newspaper Expresso das Ilhas reported. “ ‘ How am I not dead ?’ ” the headline in the Daily Mail ran.

As a result of his newfound fame, Mustill became, in his words, “a lightning conductor for whale fanatics.” Everyone, it seemed, had a story about whales. Many involved interspecies communion. A member of the British Navy told him about how whales had sung to him in his submarine. A book publisher told him about how a pregnant dolphin—both dolphins and porpoises belong to the group known as toothed whales—had indicated that she, the publisher, was also pregnant, something she herself had not known at the time. A scientist recounted locking eyes with a gray whale that approached her in a Mexican lagoon and let her rub its enormous tongue.

Mustill himself couldn’t shake the experience. A whale researcher told him that the only reason he had survived was that the humpback, upon noticing him and his friend, had purposefully turned its body so that it wouldn’t kill them when it landed. Mustill decided to make a documentary, “The Whale Detective,” which ran a couple of years ago on PBS. Now he has written “ How to Speak Whale: A Voyage Into the Future of Animal Communication ” (Grand Central).

Like Yong, Mustill is interested in animals’ perceptions. But he wants to push beyond mere Umwelt -switching to an exchange of what might, broadly speaking, be called ideas. Early in the book, he goes to visit Payne, who’s now eighty-seven. Why, he asks, do humpbacks sing? And what do their songs mean? Payne says he can’t say: “I would desperately love to know.”

Mustill isn’t deterred. He delves into the latest research on animal communication. Many species have been shown to have highly complex systems of conveying information—so complex that they probably deserve to be called languages, though people tend to reserve the word “language” for themselves. Chimpanzees in the Budongo forest of Uganda, for instance, have a repertoire of at least fifty-eight gestures, which they combine in sequence much the way we combine words. Prairie dogs in the American West make distinctive cries to indicate different predators, and they seem to be able to incorporate descriptions into them: a big dog, for example, will elicit one sort of cry; a small dog, another sort. Chestnut-crowned babblers, sweet-looking brown-and-white birds native to Australia, respond differently when elements of their calls are played in different orders, much as we would respond differently when offered, say, a cake pan rather than a pancake.

Owing to advances in recording technologies and artificial intelligence, researchers in the burgeoning field of bioacoustics can now download thousands of hours of animal sounds and leave the work of sifting through them to a computer. This has opened up tantalizing new possibilities, including that of translating animal-communication systems into English —or Arabic, or Xhosa. Six years after Mustill was nearly killed by the humpback, a group of scientists from, among other institutions, Harvard, M.I.T., and Oxford formed the Cetacean Translation Initiative, or CETI , to try to decipher whale communications. (The team is working with sperm whales, which, instead of singing, issue patterns of clicks, known as codas, that have been compared to Morse code.)

“Is it too much of a leap to think we might someday decode the sperm whale click for ‘mother’?” Mustill writes. “For ‘pain’? For ‘hello’? The answer is, of course, that we cannot know until we try.”

No less than “An Immense World,” “How to Speak Whale” is dogged by the “what is it like” question. Mustill suggests that decoding whale-speak could finally produce an answer. The problem, or perhaps the paradox, is that to decipher whales’ songs or clicks we would need to have access to the experiences they’re referring to. And this is precisely what we lack. Wittgenstein was even blunter than Nagel. “If a lion could speak, we could not understand him,” he maintains in “Philosophical Investigations.”

Mustill never addresses this problem directly. “How to Speak Whale” is borne along by his faith that whales have something intelligible to tell us and his hope that one day soon we’ll figure out what that is. “Songs of the Humpback Whale,” the album that Payne released in 1970, helped bring about the end of commercial whaling, Mustill notes. Think how transformative it would be if we could chat with whales about their love lives or their sorrows or their thoughts on the philosophy of language. “The more we learn about other animals and discover evidence of their manifold capacities, the more we care, and this alters how we treat them,” Mustill writes.

This seems to be true, or at least it seems as if it should be true. And yet every year the outlook for nonhuman species grows grimmer. In the case of marine-mammal species, the International Union for Conservation of Nature now classifies a third as endangered. A recent study by a team of European researchers concluded that even many of those species which seem to be doing all right, such as gray whales, are threatened by climate change. As Mustill himself observes, “To be alive and explore nature now is to read by the light of a library as it burns.”

So what message would the world’s remaining whales deliver to us if they had the chance? How do you click “What the #@ ϟ ⚛︎!”? ♦

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Journal reference:

PLOS Biology DOI: 10.1371/journal.pbio.3002444

Article amended on 24 January 2024

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• Published: 12 August 2022

Making sense of animal senses

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An Immense World: How Animal Senses Reveal the Hidden Realms Around Us

Our senses define our reality; they are the window through which we perceive just a small part of a vast and complex physical environment. Our perceptual world differs in unimaginable ways from the perceptual worlds of the millions of other animals with which we share the same physical reality. Trees of green and roses of red are not part of the wonderful world of a tick, which does not sense colour, but instead senses body heat and odors emanating from skin. This perceptual world was coined ‘umwelt’ (from the German word for environment or surroundings) by Baltic–German zoologist Jakob von Uexküll in 1909. In a new popular science book, Pulitzer Prize-winning science writer Ed Yong uses the concept of umwelt as a uniting theme, and takes us on a journey into the sensory worlds of animals.

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How Animals See the World

Each type of animal on earth has evolved a range of senses and skills which allow it to live successfully in its environment..

Vida Systems

Many of these adaptations are very different from how humans have evolved, and compared to humans some of these adaptations feel like they belong in a superhero comic. Senses such as ultraviolet vision, extra color receptors, and echolocation are very hard for humans to imagine, yet are part of the everyday life of hundreds of species of animals. 

Dragonflies

The most efficient hunter on the planet is not the lion or shark. In fact, lions only successfully capture around 15% of animals they hunt, and sharks catch around 47%. One animal has an astounding capture success rate of 95%: the dragonfly.

Much of its success rate is attributed to its eyesight. A dragonfly’s world looks very different from the human world, so much so that it is impossible for humans to see what it sees.

Compound Eyes

Dragonflies have compound eyes, which consist of a number of smaller visual units. While houseflies have 6000 compound eyes, dragonflies have up to 30,000. These units present the dragonfly with one picture, not 30,000 little ones. 

Multidirectional

The dragonfly eyes wrap almost all around its head, allowing it to see in all directions at once. With this 360 degree vision, it can see without moving its head. This includes behind it as well as underneath it.

The colors humans see are detected by 3 color photoreceptors: red, blue, and green. Most species of dragonflies have many more color photoreceptors, up to 30 in fact. This means they are able to see colors humans cannot even imagine.

As well as being able to see more colors than humans, dragonflies are able to see ultraviolet light. These rays of light from the sun are invisible to humans, however the dragonfly’s ability to see them helps it hunt its prey.

Slow Motion

Due to their incredible eyesight, dragonflies experience time differently than humans. Insects like flies and mosquitoes actually move very slowly for dragonflies. They can track a flying object and decide whether it is prey or not in less than 5 hundredths of a second. 

Dragonflies can also see through a polarizing filter, much like when humans wear polarized sunglasses. This ability allows them to view prey that may be hiding underwater even if sunlight is hitting the water.

Dolphins have pretty good eyesight underwater. As their eyes are located on either side of their head, the dolphin’s range of vision is wider than a human's, including being able to see objects located behind them.

It is still relatively unknown how detailed dolphin vision is, or how many colors they can see. However, dolphins have another way to see the world, echolocation.

Seeing with Sound

Echolocation, also called sonar, is the act of sending out sound waves and listening to the changed sound waves bouncing back. Dolphins and bats are 2 species that regularly use echolocation to find food and navigate. 

What They See

Recent studies have been looking into the visual picture a dolphin builds using echolocation. It is thought that dolphins are able to detect the shape of prey using echolocation, giving them an extra edge while hunting.

Echolocation is also believed to give the dolphin a 3–D picture. When combined with regular sight, dolphins can determine shape, size, and the internal structure of objects near them. Research suggests that even details such as a diver’s belt can be seen using echolocation.

How Do We Know?

In order to test dolphins’ echolocation abilities, researchers blindfolded dolphins for a mimic game. The dolphins then had to copy a trainer’s actions.

Despite being blindfolded the dolphins were able to copy the trainer, suggesting that their echolocation skills could build a detailed picture. 

Despite popular opinion, dogs can actually see some color. They have 2 photoreceptors, blue and yellow. This means they are unable to see red and green, so finding a red ball on green grass is a very difficult task for a dog.

What dogs lack in color vision they make up for using another sense; their sense of smell.

Without their acute sense of smell this is what the world looks like to a dog. With just 2 photoreceptors in the eye, a dog sees its surroundings mostly in the colors of blue, violet, and yellow.

A Dog's World

This is a stylized version of the world perceived through a dog’s nose. Its nose has over 300 million olfactory, or smell, receptors, and a human nose has only 6 million, meaning its sense of smell is at least 10,000 times better. 

Long Distance

A dog can smell potential prey from long distances. This ability has been harnessed by humans in unusual ways. Researchers studying whale hormones use dogs to find orca feces. Dogs pick up the scent of the feces in choppy water over a mile away. 

Dog Bulletin Boards

When dogs leave their mark on a fire hydrant or a pole they are providing a wealth of information. Like online profiles, the marks provide information including age, sex, whether they have been neutered, their stress levels, and even their social standing. 

A large part of a dog’s brain is dedicated to analyzing smells. This area is about 40 times larger than in a human brain. Dogs are able to smell and remember things that have already passed, allowing them to see back in time.

Snakes in general have relatively poor vision compared to humans. Some species can only detect light, dark, and movement but others have quite keen eyesight. Snakes that live in trees tend to have the strongest eyesight, while burrowing snakes tend to have the weakest.

Several species of snake have independently evolved special heat pits which are used in conjunction with their vision to hunt their prey. 

Pit vipers, pythons, and some boas have evolved a set of infrared sensitive receptors located in the nose of the snake. This allows them to see the body heat of prey species, much like night vision goggles.

No Visual Input

These heat pits operate without any input from the eyes. In one study researchers blindfolded snakes and discovered their ability to find prey was not hindered. Researchers also covered the heat pits and discovered that the snake was still able to hunt for prey. 

It is unknown just how detailed the world is when using these heat pits. Spitting cobras can still aim venom at a human's eyes even when blindfolded, suggesting that the heat pits may give the snake more detail than previously thought. 

Human Applications

It is thought that these heat pits are the most sensitive infrared detection receptors on Earth. Learning how they work could be key in developing new technology for use in defense, space exploration, and wildlife management.

Researchers believe that sharks are either completely colorblind or can only see a few colors. Sharks rely heavily on other senses to detect and hunt prey, using their incredible sense of smell and an organ called the ampullae of Lorenzini.

These make the shark quite an efficient predator, as the white pointer shark, for example, has a hunt success rate of 47%.

Low Light Vision

Sharks have a layer of crystals located behind their retinas called the tapetum lucidum that allows them to see around 10 times better than a human in low light. However, their depth is limited, as sharks can only see clearly about 50 feet ahead.

Popular legend says a shark can smell a drop of blood in an Olympic–sized swimming pool. Research suggests that while the shark can detect blood at a low level, it's more like detecting a drop of blood in a backyard–sized swimming pool (still impressive!).

Electromagnetic Field

Sharks have an unusual organ called the ampullae of Lorenzini. This organ detects electromagnetic fields emitted when animals move. It allows them to see prey hiding in the sand as well as locate swimming prey very efficiently. 

Surfer vs Seal

Unlike what is shown in the movies, sharks in general do not hunt humans. Many surfers have been attacked by sharks and research suggests this is because from below a surfer looks very much like a shark's preferred meal, seals.  

Polar Bears

Polar bears live in an environment with no trees, caves, or other landmarks. Hills can become higher or lower due to snowfall and lakes can freeze. So how does a polar bear find its way around?

Although little research exists, it is believed that they see about as well as humans. Although they do have a protective membrane covering their eyes to protect them from ultraviolet light, polar bears rely on their sense of smell to find prey and live in their featureless environment.

Smelly Feet

One study showed that the feet of the polar bear have large sweat glands which could be used to mark a trail for other bears to follow. Another theory is that the bears track through their urine, also leaving a trail.

Seal Detection

A polar bear can smell a seal sitting on the ice from 20 miles away. With that same sense of smell, it can also detect carcasses and gladly feeds on the remains of beluga whales, grey whales, and walruses.

Under the Ice

Polar bears can also smell seals that may be buried in 3 feet of snow from over a mile away. While in the ice, the seals use a breathing hole, which the polar bear can detect. 

Color Vision

It may seem surprising given the white–dominated landscape polar bears live in, but research suggests that polar bears have full color vision, similar to humans. With dichromatic vision, they do not see green, but they have good vision in low light conditions.

A.J. Campbell

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See the World Through the Eyes of Animals With These Stunning New Videos

By making ultraviolet light accessible to our eyes, a novel camera system reveals how insects, birds and other creatures experience color

Christian Thorsberg

Daily Correspondent

The expression “a bird’s-eye view” has taken on a brand-new meaning this week, after an international team of researchers released a new video technology that allows humans to experience the world as birds and other animals might see it.

Advances in both camera hardware and software programs allowed the team to record clips that approximate how the world is perceived by myriad creatures. Birds, butterflies, honeybees and mice were among the first animals to have their color vision made accessible to human eyes. Their views of the world were recreated on camera and published Tuesday in the journal PLOS Biology .

“Traditional techniques for measuring these colors often told only part of the story,” senior author Daniel Hanley , a sensory ecologist at George Mason University, tells Popular Science ’s Laura Baisas. “The scientific community lacked adequate tools for studying colors in motion… now, we can record color signals as they would appear to wild animals.”

Seeing beyond visible light

On the electromagnetic (EM) spectrum —the entire distribution of light in our universe, from gamma rays to radio waves—human beings can only see a small portion: a sliver of the spectrum called visible light that consists of our familiar rainbow of colors.

For a bird—which, unlike a human, can see ultraviolet rays—vision is quite different. A cloudless day, for example, doesn’t seem so blue to birds. “Their sky will be essentially an ultraviolet sky,” Hanley tells the New York Times ’ Emily Anthes.

Should a rainbow appear, birds would see a much wider arc of color than what humans see, extending lower on the spectrum to show more indigo and violet, which have shorter wavelengths. For a mouse, a rainbow consists of only two bands: green and ultraviolet.

The new camera technology can capture these differently colored views of any scene: To honeybees, as one clip shows, our skin appears rather unremarkable until white sunscreen is applied—then, it absorbs more ultraviolet light and pops, to the insects, as a vibrant yellow.

Animals’ visual abilities are determined by their total number of photoreceptor channels, or the total types of eye cells that capture light and send it to the brain, Jan Hemmi , an animal vision expert at the University of Western Australia and a Smithsonian Institution research associate, tells Smithsonian magazine in an email.

“Different photoreceptors have different sensitivity to different wavelengths of light, therefore it matters greatly how many channels we have to work with,” he says. “Humans have three; dogs have two; bees, many insects and birds have four; and some reptiles have five.”

With four photoreceptor channels, Hemmi says, “[birds’] color perception has three dimensions. What that actually looks like? We have no idea—but it must be amazing.”

Capturing color on video

The science behind the study combines new video technologies that can isolate light of various wavelengths with the existing biological understanding of the different types of light animals are able to process.

To “see through” animal eyes, the team uses two cameras—one sensitive to ultraviolet light and one sensitive to visible light. Together, they capture light in four distinct wavelengths: blue, green, red and ultraviolet. Using a novel software that the researchers created in Python, the videos are converted into data and broken down into what they call “perceptual units”—values that correspond to colors animals can see, based on what is already known about different species’ photoreceptors.

One of the key breakthroughs in the process was developing the camera hardware to capture ultraviolet light, a challenge that had plagued scientists in the past. Likewise, consistently capturing the perceived color of a moving object or scene hadn’t been reliably achieved. But this new software can predict the colors animals see with 92 percent accuracy, per the paper.

According to Hemmi, the researchers have done “an amazing job” in producing these videos. The catch, though, is that we are still viewing them through our human eyes. “There is no real solution to this, however, but the videos do a good job at highlighting which aspects of images and scenes appear different to the animals and which do not,” he says.

Opportunities for research

The team made their Python code open-source and built their cameras using commercially available parts, which allows scientists around the world to more easily reproduce their technique. They hope others will continue to develop the technology and share footage in unique ways , such as in film, conservation and natural history projects. The research, partly funded by the National Geographic Society, may one day influence how nature documentaries are presented.

Some scientists are already dreaming of new research possibilities. “I can’t wait to get my hands on the video camera,” Eunice Jingmei Tan , an evolutionary biologist at the National University of Singapore who studies the color displays and signaling behaviors of spiders and insects, tells Scientific American ’s Lauren Leffer.

In the future, researchers might be able to find out how animals use their perception of colors to make decisions and interact with the world. That kind of breakthrough, Hemmi says, would be a “game changer.”

“What the cameras can show is how the animal’s eyes see the stimuli,” he says. “The next step is to find out how the brain sees and uses them.”

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Christian Thorsberg is an environmental writer and photographer from Chicago. His work, which often centers on freshwater issues, climate change and subsistence, has appeared in Circle of Blue , Sierra  magazine, Discover  magazine and Alaska Sporting Journal .

Seeing Species: A New Book Looks at Animals in Media

Debra merskin brings together sociological, psychological, and historical views..

Posted April 9, 2018

When media claims violent humans are acting "like animals" they're wrong

Nonhuman animals (animals) appear in all sorts of media each and every day. However, they're often misrepresented as individuals or objects in detached, impersonal, and objectified ways from our points of view, and not as who they truly are. The ways in which they're portrayed often makes them more aggressive than they truly are (as when people who commit violent acts are called "animals"), and often they're portrayed as "others" which contributes to distancing them from humans. This can have impacts on how people view them and come to treat them. 1 Just today an essay titled " Trump blames Putin, Obama for 'Animal Assad,' tweets 'big price' after reports of Syrian chemical attack " appeared on CNN news.

Because of these errors in representation, often done out of ignorance or to be "cute," I was thrilled to learn of the University of Oregon's Dr. Debra Merskin's new book titled Seeing Species: Re-presentations of Animals in Media & Popular Culture. I was pleased that she was able to answer a few questions about her most important work. Our interview went as follows.

Why did you write Seeing Species ?

After more than two decades of teaching and research about the impact of mass media and popular culture on human beings who are marginalized, it became increasingly clear to me that animals other than humans are similarly discriminated against. Unlike most humans, however, animals cannot speak for themselves, at least not in ways we have learned to understand. They can neither give nor withhold consent for what happens to them. But this does not mean they do not communicate. As a media studies scholar, I saw the parallels and impact of portrayals on groups who do not control their own image and wanted to write about it. Thus, just like people of color, those with different physical or mental abilities, or with other markers of difference, animals are stereotyped either positively or negatively, in media content. Those with the power, usually not of the represented group, create the portrayals which influence attitudes, behaviors, public policy, and law. I was influenced as well by your article with Carrie Freeman and Sarah Bexell in which journalism ethics were challenged to include animals amongst those for whom one provides voice (" Giving Voice to the 'Voiceless': Incorporating Nonhuman Animal Perspectives As Journalistic Sources "). In visual media, one-dimensional portrayals such as all wolves are evil; polar bears are cuddly; all pit bull dogs are vicious significantly impact animal lives and ours. [MB: And sometimes the references to nonhumans are simply inane and meaningless. As an example, a few days ago when I was watching a basketball game between the Boston Celtics and the Toronto Raptors, one of the commentators made the absurd and idiotic comment that one of the players was "a pitbull...a pitbull with glitter." Some people also argue that we aren't really the "voice for the voiceless" because nonhumans do talk to us in their own ways. In her essay called "You Aren't a 'Voice for the Voiceless'," Amanda Houdeschell writes, " Let us not claim to be the voices of the voiceless but to amplify the voices of the silenced ."]

How does your book follow up on your past work?

Exposure to media content about a person or animal follows the same theory that predicts if we only know someone different from ourselves (whether it be on the basis of skin color, nose shape, or species) is via the media, we will come to think of that individual in only a limited way. I use the theory of intersectionality to argue to which species one belongs is a predictor of treatment—whether that is discrimination , marginalization, or exclusion from moral consideration.

What are some of your major messages?

Making appearances in advertisements, television programs, movies, books, internet memes , and art, symbolic animals do tremendous work for us selling goods, services, ideas, and as stand‐ins for our interests and ideas. Yet, does knowing animals only symbolically impact their lived experiences? Research about children’s most important first friends routinely points to animals but thus far has ignored, these important others. I examine this as a foundation for the development of empathy. In addition, the book explores several questions:

-- Where does thinking of other beings in a detached, impersonal, objectified way come from?

-- Do the mass media contribute to this distancing?

-- When did humans first think about animals as other Others?

The book’s main themes include examining the persistence of the human/animal divide, parallels in the treatment of Otherized human beings and animals, and the role of media in either liberating or limiting real animals lives. Ecopsychology locates and identifies the connections between how we re‐present animals and the impact on their lived experiences in terms of distancing, generating a false sense of intimacy , and stereotyping. Representations of animals are discussed in terms of the role the media do or do not play in perpetuating status quo beliefs about them and their relationship to and with us. Through a series of case studies about animals such as polar bears, prairie dogs, cats (large and small), elephants, and ravens the book applies media theories to the deconstruction of communication that usually has nothing to do with real animals but is entirely about humans.

Who is your intended audience?

Of course, like any academic, I hope people outside the academy will find the book interesting. However, the primary audience is students, undergraduate, and graduate, in media, animal, environmental studies, and philosophy courses.

What are some of your current and future projects?

I continue to study representations of animals by species in different forms of media. At present, I am working on the effects of film and television shows on the adoption and often abandonment of animals as a media effect. Furthermore, the website I, along with my colleague Dr. Carrie Freeman created, animalsandmedia.org, is an ongoing project designed to connect working media professionals with an ethics of representation by offering a style guide, similar to that used when seeking ethical and factual representations of human minorities.

Is there anything else you'd like to tell readers?

It is important when considering the treatment of animals other than humans, and making comparisons with human beings, that this isn’t an exercise in “the oppression Olympics” as Pattrice Jones calls it. Rather compassion, care, and concern for all beings, in my view, is a fundamental obligation. One does not become a species traitor by advocating for the moral inclusion of others. Rather, an intersectional approach posits that all systems of oppression must be confronted, all social and cultural institutions interrogated, including the mass media and its ancillary serves such as advertising and public relations. What benefits any one of us benefits us all.

Thank you, Debra, for taking the time to answer my questions. I hope your important book will enjoy a broad global audience made up of academics and others who are interested in seeing nonhuman animals being represented as who they truly are. Not only is it misleading to misrepresent nonhumans, but, as you point out, there are major ethical issues as well. By correcting the ways in which animals are portrayed in media, Seeing Species will be a real game-changer for the wide variety of animals who need all the help they get in an increasingly human-dominated world.

1 For more discussion please see " Animals in media: Righting the wrongs ," " Animals in the Media: Guidelines for Accurate Representation ," " Animals Are Not Warmongers: An Important Media Corrective ," " Do Less Harm: Ants and a Simple New Years Resolution " in which an NPR report referred to cutting off an ant's legs as an ant "makeover," " 'Are You with the Right Mate?' The Media's Misuse of Chimpanzees, " and links therein. Please also see Carrie Packwood Freeman and Dr. Merskin's website called " Animals and Media: A Style Guide For Giving Voice to the Voiceless " where you'll find guidelines for how animals are represented in journalism, advertising, public relations, and entertainment and also tips for the general public and extremely valuable resources including Online Resources and a Glossary of Animal-Related Terms. The style guidelines were created for media practitioners in the professions of journalism, entertainment media, advertising, and public relations to offer concrete guidance for how to cover and represent nonhuman animals in a fair, honest, and respectful manner in accordance with professional ethical principles. Also relevant to discussions of how animals are represented in media are these two research essays, " Specific Image Characteristics Influence Attitudes about Chimpanzee Conservation and Use as Pets " and " Use of 'Entertainment' Chimpanzees in Commercials Distorts Public Perception Regarding Their Conservation Status " and a recent essays on the brutal killing of bunnies in New Zealand (" It's a Ghastly Time to Be a Bunny in New Zealand " and " Bye bye Easter bunnies ."

Carrie Packwood Freeman, Marc Bekoff, and Sarah Bexell. Giving Voice to the 'Voiceless': Incorporating Nonhuman Animal Perspectives As Journalistic Sources . Journalism Studies 12(5), 590-607, 2011.

Marc Bekoff, Ph.D. , is professor emeritus of ecology and evolutionary biology at the University of Colorado, Boulder.

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Animal senses: how do they perceive the world and what important things can they sense that we cannot.

Professor Keith Kendrick

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The way the world is perceived by any species is dependent upon how sense organs and the nervous system interpret cues. The same world can appear very differently to other species. This lecture considers how the world is experienced by other animal species, and how and why the visual and auditory senses have taken over from smell during the course of mammalian evolution.

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Animal senses: How do they perceive the world and what important things can they sense that we cannot?

Introduction

In the next three lectures I will consider how we and other species experience the world around us and in particular how, as social beings, we and they recognise each other and have a capacity for self-awareness. All this, of course, requires at the outset some appreciation of how the senses work and how they differ between species.

An important starting point in considering the way we and other species sense the world is the simple statement that whatever sense is being used it is merely providing an interpretation of the outside world. In short we do not sense the world as it is but merely as our sense organs interpret it within the limitations of their design. One might even say that our senses provide us with the comforting illusion of experiencing an absolute reality that is, in effect, only relative and highly subjective. This illusion makes it difficult for any individual to appreciate the fact that the same world can, and does, appear very different to other species and indeed even to other individuals of one’s own species.

From an evolutionary standpoint of course any species develops only the specific senses, ranges of detection and levels of sensitivity that are required for its members to interact successfully with the environment and survive. Only humans have taken the step of developing sophisticated artificial sensors to detect chemical molecules, light particles, sound waves and electromagnetic energy beyond our own biological sensory capacities. The amusing fact however is that for all our amazing inventiveness in many cases other species have evolved equivalent, or even superior, biological abilities to sense cues from the environment that are only available to us with the aid of machines.

We have come to accept the existence of five primary senses in most species. These are divided into those which require some aspect of the environment to achieve physical contact with the individual (touch and taste) and those which detect remotely either at close range or at variable distances (smell, hearing and sight).

Our experiences through the different senses are effectively our point of contact with the outside world and allow our sense of individuality with respect to it. It therefore comes as no great surprise that sensory deprivation is one of the most effective human-devised tortures. Cut off from its sensory input the brain simply loses control.

We are all well aware that different species have different capacities to use these five primary senses and we will examine some of these in detail in a moment. Most of us are also aware of claims that other senses may exist that allow detection of objects by echolocation (or biosonar as it is now called) and electric fields, direction guidance using sun compasses, celestial maps and detection of electromagnetic fields. Finally, and most controversially, are the claims of being able to sense telepathic signals at distances beyond those where other senses can be utilised. Indeed, as far as the telepathic sense is concerned it is often claimed to be prevalent in species who have continued to stay close to the natural world but has been lost in humans whose progressive detachment from things natural has rendered this ability vestigial.

Even a casual look at special sensory abilities that have been claimed for other animal species is pretty impressive:

· Dogs and cats who know the moment their owners form an intention to return home (even if hundreds of thousands of miles away in some cases). · Dogs detecting previously undiagnosed illnesses such as cancer or being able to give their owners warning of an impending epileptic attack or high blood pressure. · Animals being able to detect hormonal changes in other animals or humans. · Animals being able to sense emotional states in humans or other animals either in their presence or even when physically separate from them. · Dogs being able to detect the presence of humans even when they are buried. · Dogs and cats being able to trace their owners and making long journeys to be re-united with them. · An impressive range of species being able to find their way back to a particular place from a distant and totally unfamiliar location. · Animals being able to detect electromagnetic fields, infrared and ultraviolet, use sun compasses and read celestial maps. · Animals having the ability to locate objects and individuals by sonar. · Animals able to sense impending storms, earthquakes etc.

There are, of course, many more such claims. As we will see, many of these phenomena can easily be explained by understanding the different sensory abilities of other species. However, before examining in more detail the different ways that animals experience the world in comparison with us, and whether there are in fact more than five senses, it will be useful to illustrate the general principles upon which the primary senses function. This will hopefully provide a useful guide to understanding both the nature of individual sensory experiences and the defining criteria required for establishing additional sensory modalities.

General principles of sensory systems

Whatever sensory system one considers the most important first component to identify is the receptor device that converts, by transduction, the relevant external signals from the environment into electrical impulses that can be conveyed to, and interpreted by, the brain. To date we know of five basic types:

(1) Chemoreceptors - which are activated by the shapes of specific chemicals through receptors on their cell membranes (i.e. smell and taste receptors) (2) Mechanoreceptors – which are activated by forces displacing physical sensors, such as hairs, attached to the cell membrane (touch and hearing receptors). (3) Thermoreceptors – in the skin which sense temperature (4) Nociceptors – in the skin which sense pain (5) Photoreceptors - which are activated through surface receptors and absorb light (visual receptors).

There are also likely to be magnetoreceptors for detecting magnetic fields although it is still unclear as to what, or even where, these receptors might be (I will return to this question later).

All these receptors are located external to the brain and the electrical signals they produce, when activated by the relevant external stimuli, are conveyed to the brain by bundles of nerves. Sensory acuity is mainly associated with the number of receptors dedicated to sensing a particular aspect of a sensory stimulus – i.e. a specific wavelength of sound or light, the sensitivity of any particular body region to touch or the ability to detect the taste or smell of a particular chemical. It has less to do with how sensitive specific sensory receptors are since they are usually able to respond to the minimum unit of an energy source - one or two particles of light, decibels or chemical molecules. However, in many cases receptors vary in the duration of their response to a particular stimulus with some adapting very quickly and others more slowly. This adaptation is important since one of the main uses of our senses is to detect changes in the different energy sources around us (whether in location, intensity or type) and so invariant exposure to the same energy source will result in the receptors initially detecting but gradually adapting to it by adjusting their thresholds upwards. Indeed this makes our sensory systems less than optimal for performing repetitive tasks (bulk wine or food tasting or quality control of mass produced identical objects). This is why robotic sensors can offer advantages since this adaptation component can be omitted.

In general the organisation of the neural projections from the sensory receptors through the sensory nerves to the brain faithfully maintain the same spatial representation as the pattern of sensory receptor activation. This means that the initial spatial and temporal pattern of activation within the brain regions receiving the information picked up by the sensory receptors is reproduced so that the brain can start off its interpretation of the sensory cues using the same physical map as the receptors themselves. To further complicate matters some senses (particularly vision) have multiple maps dedicated to the extraction and analysis of the different components of information conveyed by the receptors.

Of course, not all things are of equal importance as far as sensory detection is concerned. The general principle is therefore that where a particular sensory modality, part of the body, light or sound wavelength, or chemical molecule is of greatest importance for some aspect of survival then not only will more receptors be employed for detection but also correspondingly more of the brain. So even if you knew relatively little about the preferred habitat and behaviour of any particular animal species, you could deduce much simply from knowing what kinds and numbers of sensory receptors they have evolved and the amount of brain dedicated to analysing the information received from them.

One conceptual problem that arises is that the initial representative maps of the different sensory modalities within the brain are all physically separate – that is as far as the brain is concerned our immediate experiences of the sight, sound, smell, taste and feel of any particular object are independent of one another. Even though sensory information from these specific sensory processing regions does eventually become integrated, particularly in those areas involved with controlling some form of behavioural action, we are likely to be aware of what the different senses are detecting before this happens. Thus we have the vaguely schizophrenic conclusion that, to a large extent, the brain can allow us to be independently aware of our experience of the world through each of the different senses.

While we are left with the uncomfortable general conclusion that our brains through the different senses are capable of simultaneously experiencing multiple independent illusory interpretations of reality it is clear that the separatist principles that have evolved when dealing with multiple senses are there to avoid confusion (a point I will return to later on when I consider synaesthesia).

Let us now examine how these principles work with some specific senses.

The sense of touch

The skin is our largest sensory system and if unfolded has an approximate area of 50 square feet. It has different receptors for heat, cold, pain, itching and pressure and this is the case in mammals in general. If we just concentrate on the pressure sensitive receptors, which effectively represent the sense of touch, and how these send projections via spinal nerves to somatosensory maps (somatotopic maps) within the brain, then we can see immediately how both we and other animals have vastly different touch sensitivity from different body regions.

In humans, the surgeon Wilder Penfield was the first to map the human somatosensory and motor cortices. What he found was firstly that the most sensitive body regions were disproportionately represented. Thus, more of the brain is devoted to touch stimuli from the genitals, lips, tongue hands, face and feet than the whole of the rest of the body. Indeed, as far as the brain is concerned our body representation of touch sensitivity is a very strange looking homunculus with these regions disproportionately enlarged!

A second point of interest is the way the different body regions are juxtaposed in terms of their representation in the brain cortex. In humans the somatosensory cortex is a narrow band extending the whole width of the cortex with the left and right sides of the body being represented respectively in the right and left hemispheres of the brain. If we move along this cortical band from the most lateral point of the brain towards the middle of it the batting order is throat, tongue, jaw, lips, face, nose, eyes, thumb, index, middle, ring and little fingers, hand, arm, shoulder, head, body trunk, hip, leg, foot, toes and genitals. For the most part, whatever species one considers there is a similar kind of juxtaposition of body-parts although the shape of the somatotopic map is often more like a huge blob on the cortical surface of the brain in highly tactile-dependent species rather than a narrow band.

An important principle is that this touch map within the brain is very much use-dependent and it has been shown in monkeys that preferential use of specific fingers can double their cortical representation. One shudders to think what generations of hand-held computer-game devotees may have done to the cortical representations of their thumbs!

From the other side of this scenario there is the question of what happens when limbs are amputated. Here juxtaposition is an important consideration since the body parts represented adjacent to the missing part tend to invade its space within the cortex. This can result in bizarre phantom limb experiences – for example individuals with a missing hand may report an apparent sensation in it when part of the face is touched. In another instance an individual missing the lower half of his left leg reported his experience of sexual orgasm as extending to include this phantom limb. Indeed, since there is a least some overlap between the brain representations of different body regions it has been argued that foot fetishes are particularly prevalent since the feet are represented immediately adjacent to the genitals!

The increased importance of touch in mammals that rely more on this sense than vision and hearing (particularly those that are mainly nocturnal or live underground) is illustrated by the large amount of brain dedicated to processing touch information relative to areas dealing with sight and sound. It is also reflected in the huge numbers of receptors, and associated brain processing, in their noses and whiskers which are the areas of most importance for navigating their world and locating other individuals and food. A primary example of this is the famous star nosed mole that has 100,000 touch receptors in its nose and over half of its entire somatosensory cortex dedicated to them (indeed this represents around 20% of the entire brain cortex!). To put this in a human context this represents six times the maximum touch sensitivity of the human hand.

Similarly nocturnal animals such as the raccoon mainly use their hands to locate food and other individuals and also have high receptor numbers and disproportionate representation of their hands within the brain.

Animals with such enhanced sense of touch in specific body regions are likely to have a corresponding enhanced sensitivity to pain in them since nociceptor numbers should also be increased. They are also likely to able to detect low-level earth vibrations and subtle alterations in the environment that we would be unable to detect. This could, for example, help them to identify the start of earthquakes and storms well before we would be able to.

Smell and taste

These two chemical senses do clearly work in conjunction with one another since the experience of flavor is a combination of activation of taste and smell receptors (and indeed touch sensations on the tongue) although the sensitivity of those responding to odorants is much higher than those responding to tasteants. This explains why having a bad cold can dramatically impair one’s experience of food flavors and why you can’t taste the difference between a potato and an apple with your nose plugged!

The sense of taste As far as the sensation of taste is concerned there are five or possibly six different receptor types and the exact experience is determined by the respective pattern of activation that occurs across these different receptors. Broadly speaking all of these receptors are distributed in the tongue (and indeed other mouth areas – epiglottis and soft palate) although there is some enhanced regional sensitivity to specific tastes (most text books illustrate distinct spatial locations for the different receptors but they are not correct – indeed no area of the tongue is sensitive to less than four different taste qualities). The receptors detect salty, sweet (sugars), sour (acids), bitter (alkaloids) and umami (glutamate receptors, i.e. detects monosodium glutamate and meat-like tastes). Recent research suggests that there may be fat receptors as well. These receptors are aggregated in groups of 30-100 in taste-buds embedded in the surface of the tongue with access to the chemicals on the tongue via pores.

The sense of taste both promotes appetite for safe foods and immediate rejection of toxic ones. Life being what it is, the system is biased towards detecting potential poisons so receptor detection thresholds are better for sour and bitter tastes (which suggest potential poisons) than for salty and sweet ones!

Taste information is relayed via several cranial nerves to the brainstem and then to the somatosensory cortex adjacent to the region dealing with the sense of touch in the tongue. At this time there is no reported meaningful topographical representation of the different tastes in this region although it is likely to turn out that there is one.

As with the sense of touch, experience can increase the number of taste receptors so food and wine tasters can enhance this sense. Similarly, other animals can presumably adapt to local conditions by varying the representation of their taste receptors, although less is known about how other animal species have adapted their taste systems in comparison with ours. However, many other mammals have greater total numbers of taste buds than us (rabbit – 17,000; pig – 15,000; human – 9000) suggesting they may actually have superior taste sensitivities!

Interestingly, there are also large general variations in taste receptor numbers with about 25% of individuals (mostly female) having around 1100 taste buds/cm2 (who readily detect bitter substances and often consider sweet food has too much sugar and are rarely overweight), 50% with around 500 and incredibly 25% with fewer than 100 (mostly men – in this case individuals like bitter foods such as coffee and cheddar and eat more salt and sugar than on average and therefore are more likely to be overweight). It has been proposed that enhanced taste sensitivities in females may be used to protect them from ingesting toxic foods during pregnancy. Indeed, the period of morning sickness in pregnant women corresponds to the most vulnerable period that embryos have during development (when the internal organs are being generated and the foetus is very sensitive to damage by even low levels of toxins) and represents the result of increased sensitivity and aversion to foods that are particularly likely to contain some toxins (vegetables and meats). Miscarriages are actually less likely to occur in women who experience severe morning sickness.

The sense of smell This is the sense where the popular view is that most animals are superior to us. This view is largely correct with some dogs being claimed to have 1000-fold better detection levels for odours than us. Indeed, many breeds can identify individuals or food even when enclosed or buried or perhaps 100 metres or more away (provided the wind is in the right direction).

To complicate matters, smell detection is carried out by two different sets of detectors and brain pathways that have probably evolved separately. This is because the chemicals that compose particular odours are either air borne or in liquid form (i.e. urine, saliva or glandular secretions – often referred to as pheromones).

Both systems are remarkable in having huge numbers of specific chemical receptors, 100 or so for liquid-borne odours and 1000 or so for air borne ones. The air-borne odour system can use these to detect an incredible 10,000 or more different smells. Detection of pheromones This is an ancient sense which is likely to mainly evoke involuntary behavioural or hormonal changes in response to specific smells.

The receptors are located in a small organ located in between the roof of the mouth and the nose (Jacobson’s organ or the vomeronasal organ). They send their projections via a nerve to a small specialised processing region in the brain (accessory olfactory bulb) and then onwards to parts of the limbic system controlling emotion and the hypothalamus controlling sex and the release of hormones into the blood. Thus the right smell evokes an immediate and unconscious emotional, sexual or hormonal reaction. The stuff of dreams as far as the perfume industry is concerned!

For some species of mammals such as hamsters and pigs, the male sexual response depends on female pheromones activating this system. In mice it is used by females to recognise the male that has mated with them. If the female is then exposed to a strange male his novel pheromones will cause her to abort her pregnancy.

For some time it was thought that humans did not possess this ancient form of chemical detection but it now appears that it does exist and many of the receptors have now been identified. However, despite repeated attempts to demonstrate that this detection system can unconsciously provoke sexual or other emotional or endocrine reactions in humans no clear evidence has been provided. This has not stopped it being referred to as the potential 6th sense and the subject of intense speculation.

Detection of air-borne odours For detection of air borne odours the 1000 different types of receptors are located in the olfactory epithelium of the nose. The huge increase in olfactory sensitivity seen in some other mammals compared to us is reflected in the area of the olfactory epithelium and the numbers of receptors involved. Thus the dog has 150 cm2 of epithelium, the cat 14 cm2 and humans only 4 cm2.

These receptors send projections via the olfactory nerve to a primitive region in the front of the brain, the olfactory bulb. Here the nerves from the same type of receptor converge giving this brain region a form of spatial map where each different chemical odour activates a separate region. This map can however vary with intensity which may help explain why the same odour can be perceived differently at different intensities. Most biological odours are made up of a number of different chemical components and so their representation ends up as a complex pattern of all the different individual elements. This representation of complex odours can also be increased as a result of learning.

After the olfactory bulb signals are processed by a small cortical structure, the piriform cortex which still maintains some of the spatial information patterns. From there it is sent to parts of the limbic brain dealing with emotion (amygdala) and memory (hippocampus). It then reaches the frontal region of the neocortex which integrates it with other senses and is also important for aspects of memory and controlling attention and behavioural action as well as linking into brain centres mediating reward.

The organisation of this sensory system, like the pheromonal one, is thus relatively simple compared with hearing and sight but it does involve areas of the brain that allow it to be a sense that we, and probably other species, can be conscious of. The other important aspects associated with it are that its direct links into brain regions controlling both memory and emotion, make it both a highly memorable sense and one where recognition almost invariably evokes an immediate emotional reaction (whether pleasure or disgust).

The survival value of this sense is therefore obvious in that it provides a highly sensitive means of detecting, remembering and locating things that can make you feel good or bad with the minimal amount of thought and even when there is not much light!

Although the larger numbers of odourant receptors in many other mammalian species, by comparison with humans, allow them to detect concentrations at levels where objects can be detected at great distances down-wind, a major use of this sense is more proximal – i.e. nose down, following trails left on the ground or for detecting buried food.

The human sense of smell should still not be underrated and since the way our brains are organised to detect odours is very similar to that of other mammals we can, to some extent, use our own experience to consider what it must be like for a dog with a threshold 1000-fold lower than our own. For us smell is also a highly emotive sense. As Rudyard Kipling put it: “Smell are surer than sights or sounds to make our heartstrings crack”

The whole field of aromatherapy is also centred around this concept with large numbers of smells being claimed to influence our general alertness, stress and mood:

Chamomile: calming and soothing. Eases anger and anxiety Clary sage: relaxing, euphoric. Eases anxiety, tension and stress Eucalyptus: fresh cooling and invigorating. Promotes alertness Jasmine: alleviates anxiety and depression Lavender: calming. Helps relieve pain. Lemon: refreshing and energizing. Eases tension. Heightens mental clarity Mandarin: relaxing and calming. Relieves insomnia Neroli/Orange blossom: relieves stress, anxiety and insomnia Peppermint: refreshing and stimulating. Increases alertness. Relieves pain, indigestion, nausea and headaches. Rosemary: a stimulant that promotes mental clarity and alertness. Sandalwood: warm, sensual aroma. Euphoric and seductive. Ylang-ylang: alleviates anger, anxiety and stress (Hammers, 1995)

Like us, and in line with the principles of all sensory systems, the receptors will adapt to constant exposure to particular odours by becoming less sensitive to them and so there is not a constant experience of information overload. However, when new smells are present they will probably be experienced with the intensity of a physical blow and an immediate feeling of pleasurable attraction, fear or disgust. Thus, when a dog is following the odour trail left by a rabbit , another dog or its owner it is probably constantly being encouraged to continue doing this through a strong experience of pleasure and excitement.

For the majority of humans we are only infrequently aware of changing smells in our environment but for animals like dogs it seems likely that life is made up of a constant experience of detected changes in smells.

Our body chemistry is altered by what we eat, or by whether our immune system is trying to fight off disease, by hormonal changes and by different emotional states. This is then reflected in altered chemical compositions of our excretions (saliva, sweat, urine, faeces) which can be detected by those animals with a super-sensitive sense of smell (notably dogs). From an evolutionary standpoint this is a very useful advantage to have in deciding who to reproduce with, whether to fight with or escape from an individual, whether another animal is dead or not and if meat is good to eat or not. Doctors used to use their sense of smell to aid diagnosis in their patients before it became simpler to send of blood or urine samples for analysis of chemical changes. However, a number of labs around the world are working on perfecting artificial nose technologies to aid in rapid, non-invasive diagnosis of human disease. Death, of course, also results in a dramatic biochemical changes which animals with a keen sense of smell could detect.

Hearing and biosonar

In mammals hearing different sounds across a range of different intensities is initially the result of pressure waves entering the ears and vibrating the large surface area of the ear drum (tympanic membrane). This in turn vibrates the three small middle ear bones (malleus, incus and stapes) at the same frequency which transmits and amplifies them via the oval window (15-30 times smaller than the ear drum) into the cochlear of the inner ear. Here the waves mechanically activate hair receptors embedded in the basilar membrane through the vibrations setting up a shearing force along it in conjunction with the tectorial membrane. Different frequencies are detected by the hair cells along the length of the basilar membrane. This membrane varies in width and thickness so that different frequencies effectively vibrate the hair cells in different portions of it. Sound intensity is signalled by altered wave amplitudes more strongly (high amplitude) or weakly (low amplitude) activating the receptors. The highest frequency sound waves resonate the part of the membrane nearest the oval window (where it is thickest) and the lowest frequencies resonate the portion furthest from the oval window where it is widest and thinnest.

The greater hearing sensitivities of many other mammals (notably dogs and cats) compared to us is once again mainly the result if having more peripheral receptors dedicated to the task. Indeed, turning up the gain in this way also means that such animals are going to be detecting changes in the sound environment almost constantly rather than just periodically. It also means that loud noises are more likely to be avoided since the levels of vibration they cause in the ear membranes and receptors will actually cause pain.

The bones of the middle ear are held in place by small muscles, which, if contracted, will stiffen the structure, and reduce hearing sensitivity. We, and other animals, do this when we vocalise, making it harder to hear anything else when we speak (Don’t speak when I’m speaking to you!). For this reason we actually hear the noises we make ourselves mainly through the bones of the skull and these can directly vibrate the final ear bone, the stapes. This is why when we hear recordings of our own voice (detected mainly through the ears and all three ear bones) they sound different from the way we sound when we hear ourselves speak. In marine mammals such as the dolphin the ear has become vestigial and sounds, whether self produced or externally derived, are actually detected through vibrations set up in the lower jaw being transmitted into the cochlear via the stapes.

As with the other sensory systems the spatial arrangements of the different frequencies in the receptors of the cochlear are faithfully maintained in the auditory nerve projections into the brain. Thus different portions of the auditory cortex contain cells tuned to different frequencies and larger regions are dedicated to processing the most common frequencies. There are also associated maps responding to frequencies detected by both ears (binaural).

Direction of sound is computed using the time difference for it reaching the two ears and the shadowing effect of the head reducing the intensity of sound reaching the ear screened by it. Ideally, detecting phase differences in sounds arriving at the ears requires the size of the sound waves to be twice the distance between the ears. For a mouse this equates to 12-20Khz whereas for humans it is 1Khz. Thus animals with small heads are bound to be more sensitive to higher frequencies than us.

As with the other senses, experience can have dramatic effects on the cortical representation of different frequencies so you can become better attuned to hear sounds that have particular importance.

The two main differences between our own sense of hearing and that of some other mammals lie both in its sensitivity and the different frequencies that can be detected. Thus large land mammals such as elephants can detect infrasound frequencies as low as only a few Hz whereas we can only go as low as 20-40Hz. Indeed, elephants communicating with each other use low pitched sounds that are very hard for us to detect and allow them to hear other animals calls 8 or more kilometres away!. On the other hand many other mammals are capable of detecting ultrasonic frequencies well beyond our maximum range of 20kHz. This includes most rodents (mice up to 100KHz), dogs (up to 45KHz), cats (up to 64KHz), bats (up to 120KHz) and dolphins (up to 100KHz).

Advantages of infrasound Low frequency sounds penetrate virtually everything and as such are transmitted incredible distances. Whales, elephants, giraffes, lions, hippos and rhinos all communicate with one another using this frequency range (which is mostly inaudible to us). For this reason they can communicate with each other over huge distances. So at least in some species this explains their ability to locate and communicate with each other at what seem to be impossible distances. This low sound frequency is transmitted well through the ground and elephants can apparently detect other elephants stamping the ground in fear 50 kilometers away. It has been calculated that elephants may routinely be able to be identify these sounds over an area of 100 square kilometres. With cetaceans they have the added advantage that sound travels four times faster in water than air and this may explain their ability to locate each others calls even when hundreds of kilometres apart.

Even the smallest earth tremors (low frequency seismic waves) preceding earthquakes should be detectable by animals with good hearing in the infrasound range. Similarly low-frequency noise transmitted from distant thunderstorms or rain falling on the ground would give considerable notice of imminent weather changes in the area where the animal is.

As humans we appreciate the advantages of stealth technology for being able to approach enemies undetected. Another evolutionary advantage of both infrasound and ultrasound capabilities is to mask communication from the ears of other species that you may want to catch or stop from catching you.

Advantages of ultrasound High frequency sounds are better for short-range communication since they are easily reflected by objects and localised. Large numbers of mammals use ultrasound frequencies to communicate and in many cases (apart from echolocation) to indicate some form of distress (babies calling to their mothers or adults in pain). One exception to this is in male rodents where they emit ultrasonic vocalisations after having sex with a female. Clearly this is not pain although whether it is a sign to the female to back off until he is ready to have sex again or the consequence of physical exertion is open to speculation!

It seems likely that predatory species such as members of the dog and cat families have evolved ultrasound detection abilities to help detect the presence of prey species since they do not seem to use these frequencies to communicate with one another.

Biosonar The evolution and use of biosonar (echolocation) in animals is a remarkable story and its complexity makes it impossible to go into detail here. Many consider biosonar to be a distinct additional sense although I prefer to see it as a specialised adaptation that utilises the sense of hearing. The superstars of biosonar are insect catching bats (Microchiroptera) and dolphins, although the fact that these species use biosonar differently and lack common evolutionary ancestry suggests that they have evolved this ability independently.

Most is known about echolocation in bats. These animals live together in caves in vast numbers (often many millions) and come out at night to hunt insects. They can use echolocation to detect even the smallest moving insects at distances of 3-4 metres and can catch 300-600 of them every hour. They can do this in absolute darkness and don’t seem to need their eyes at all. This is high speed hunting carried out at 20-30 mph and from detection to capture takes less than 0.5 seconds.

They do this by emitting frequent, brief ultrasound calls which have a constant fundamental frequency of 30KHz with three integer harmonics at 60, 90 and 120KHz. When an insect is detected there also a downward-sweep frequency modulated component at the end of the call. The intensity of the 60KHz component is the loudest and so this is the most important for detection. Indeed, the intensity of this is so loud that it has been equated to the level of sound we might expect to experience at a Rock concert. Amazing to think that several million bats could be flying around making more noise than one could almost possibly imagine but as far as we are concerned they appear to be mute!

The bat’s calls are focussed by structures on the head and are perfectly designed to bounce back from even the smallest of objects. The flies are moving in relation to the bat and so the echoes bouncing back from the calls are subject to a Doppler effect which shifts their frequencies upwards. The bats compute the differences in time and sound intensity of the echo arriving in the two ears to determine directional changes. Differences in the magnitude of the Doppler shift are used to calculate distance. Greater localisation accuracy is also achieved by systematically increasing the frequency of calls as the bat closes in on the fly

Their auditory cortex has a linear map of the different frequencies in the bats auditory range but large amounts of cells are dedicated to precise detection of 30, 60 and 90KHz. The problem with this is that Doppler-shifted echoes might differ from this by as much as 0.5KHz and the system would not detect them very well. So in addition to increasing the frequency of its calls as it catches up with the fly the bat systematically alters the pitch of its call so that the Doppler-shifted returning echo is always at 30,60 and 90KHz (this requires remarkable vocal control that would be the envy of any opera singer!).

The wing-beats of insects affect the patterning of the returning echoes and the bats are even sensitive enough to such minute changes to allow then to determine what sort of fly it is they are chasing. After all, we all have diet preferences and bats would not want to be disadvantaged by not knowing what exactly was going to be in their next mouthful!

One other major problem is that with several million competing bats firing off calls all around you how can each individual know which echoes belong to its calls? The solution is truly simple, but still remarkable. In the first place echoes from ultrasonic calls can only be detected over 3-4 metres so that limits the number of possible competing sounds from other animals. Just like us, when the bat vocalises it contracts the muscles on the bones of the middle ear and therefore cannot hear the low intensity 30KHz signature frequency of other bats. Like us it hears this frequency from its call through the skull linking to the stapes bone and not through its ears. It will also sound different and have a highly personalised specific frequency which will differ from the other 30KHz sounds perceived by the ears. In its auditory cortex it has another map of auditory frequencies where cells only respond if a 30KHz frequency is either followed by a 60 or 90KHz one with a particular time-difference. Since the bat can’t hear the 30KHz component of any other bat when it makes its call, and can tune these brain cells to register only to the precise frequency with which it hears its own voice, then it can be sure its call has started the activation sequence. Having located its prey it also has a pretty good idea when a 60 or 90KHz echo should be received and so the cells guiding the animal will only be those which are activated by a subsequent 60 or 90 KHz echo arriving at the right time. In this way it is unlikely that the animals will be confused by the calls and echoes from dozens of other bats flying near them

Dolphins probably differ only in that they use broader band calls (or clicks as they are often called) which are effective over longer distances (they can detect a 5cm ball at 120 metres). They also differ in that they produce the clicks through the nose rather than the larynx and hear the echoes through their lower jaw linked to the stapes bone (the dolphin’s ear opening seems to be largely vestigial). They also focus their ultrasound using a structure called the melon in their nose and have adapted amazing ways of using fat encasing their hearing apparatus to prevent problems of impedance matching when sound transmitted through water moves into air in the middle ear.

Thus, the different hearing ranges experienced by other species, or the use of biosonar, can give them information from the world that we can appreciate only through machines. In particular they can allow long-distance communication and localisation of even the smallest objects in complete darkness. Once again they may also aid detection of environmental changes well before our own senses can.

Vision and magnetoreception

The visual sense is of course the one that we are most reliant on and where, to a large extent, we have considerable advantages in terms of acuity and ability to interact with the environment in daylight compared with other mammals. It is also the most complex sense and I will only describe it in a fairly superficial way (see Zeki, 1993 for more detail) and concentrate on differences between us and other mammals. Light entering the eyes is focussed onto the retina by a lens. The retina has two types of light-sensitive receptors: rods (which are sensitive to low levels of light at all frequencies), and cones (which are sensitive to light at specific frequencies).

The fact that the visual sense can interpret the world through so few receptors compared with some other senses is perhaps surprising but it has the important consequence that the brain does much more interpreting work than with the other senses. This conclusion is easily demonstrated by the host of visual illusions that can be shown to trick or confuse the system. The eye also focuses the world upside-down on the retina but, the brain turns it back the right-way up. Finally, even though we have blind spots where our optic nerves leave the eye to take visual information into the brain, the brain fills in the gaps for us so that we are not aware of this gap in our visual world.

All animals have some form of central area of highest sensitivity in the centre of the retina and the eyes are directed to bring important objects into the central field of vision which allows the light from their image to fall on the densely packed receptors in this region.

Humans, other primates and many predators have eyes that are mainly located facing forwards in the head which improves the degree of binocular overlap and visual acuity in a limited field of view. Primates also have developed the most sophisticated control in being better able to move the eyes independently of the head so that light from the salient features of any particular scene or object can be more quickly brought into the most accurate field of view. On the other hand most prey species have more laterally placed eyes which, in many cases, can almost give a full 360 degree range of vision although a more limited field of binocular overlap. Thus the field of view experienced by a rabbit or sheep is much wider than for us or monkeys.

Most other mammals are better adapted to a nocturnal existence than ourselves and have more rod receptors in the retina and many have a structure called the tapetum in the eye which reflects captured light back onto the retina for a second time to further enhance sensitivity. In such animals this makes their eyes shine brightly in the dark when exposed to light.

Humans and other primates perceive colours by having cone receptors which are sensitive to light of three different wavelengths, red, green and blue (trichromatic vision). However, a number of mammals only have two such receptors (dichromatic). Dichromatic vision is considered to have advantages for the detection of movement (which is clearly important for most animals) and while trichromatic vision is not as good in this respect it may have evolved to allow primates to improve visual resolution and to distinguish between different coloured fruits and leaves more easily.

The way that the brain processes the visual signals reaching it from the eyes is remarkably complex and has been the subject of huge amounts of research. However, the general principle is the same as other senses in that the spatial pattern of light influencing the receptors in the eye is reproduced in the primary visual cortex. This performs a first-pass analysis of light intensity and direction and then sends this on to other regions that are specialised for analysing motion, colour and shape and even some regions where specific objects, such as faces, are encoded (an area I will cover in my next lecture). The connections between this primary visual area and all the others is mainly parallel in nature with the same region of cortex connecting with multiple other regions. Thus visual experience is mainly the result of different aspects of the visual stimulus being assessed by physically separate parts of the brain simultaneously, and this gives rise to an integrated and synthesised perception. For this reason damage to different parts of the system can result in highly specific deficits such as the ability to see colours, movement and shapes although other aspects of visual cues are still experienced.

There is little doubt that other animals experience the visual world somewhat differently to ourselves. Many have considerably less cone receptors and nerve projections to the brain which downgrade both visual acuity and the vividness of color perception (for example the dog optic nerve has 167,000 nerve fibres compared to 1.2 million in a human). On the other hand many mammals (cats, dogs and sheep for example) have up to six times better visual sensitivity than us in the dark since they have many more rod receptors. These latter receptors are probably also responsible for giving these species greater sensitivity to visual movement than us.

If we express daylight visual acuity in other animals as a percentage in relation to humans, horses and sheep have 50-60%, dogs have 40% and cats have 20% of our acuity. Put another way the acuity of a cat viewing an object placed 20 feet away would be the same as that for a human viewing it from 100 feet away (i.e. a cat has 20:100 vision compared with human 20:20 vision).

In contrast to us many other mammals only have cones sensitive to two (dichromatic) rather than three (trichromatic) wavelengths. This greatly reduces the numbers of colours than can be seen (similar to humans with colour blindness due to the lack of a particular cone receptor). For the most part it is the long-wavelength cone (red) that is not represented giving the animals similar experience to humans who are red-green colour blind. As trichromats we can distinguish four basic hues (red, blue, green and yellow) which can be seen as a continuum of hues through proportional mixing. For dichromatic animals (and red-green colour blind humans) only two hues can be distinguished (blue and yellow) and rather than mixing intermediate hues are either achromatic (white or gray) or a desaturated version of one of the two basic hues (i.e. pastel blue or yellow). Thus the world is likely to appear slightly blurred with a predominance of pastel yellows, greens, blues and greys (Carroll et al., 2001).

Of course humans are not the most sophisticated species for either visual acuity or colour. Some birds (especially birds of prey) and insects have more types and numbers of photoreceptors giving them a much more sophisticated colour sense and greatly enhanced acuity.

Some animals (notably some birds, ants, bees and some fish) have also developed photoreceptors that are sensitive to extremely short wavelengths in the UV range. This allows these species to calculate the position of the sun by detecting patterns of polarised light at different times of day (allowing compass navigation using the sun even when the sun is not actually visible – see Hughes, 1999). It also allows some birds of prey to detect small rodents whose urine trails have a UV content. At the other end of the spectrum some snakes have receptors that can detect longer wavelengths in the infrared region of the spectrum which allows them to detect the heat generated by potential prey. Mammals however do not seem to have adapted to detect either UV or infrared frequencies.

Magnetoreception It is now well established that many migratory species of birds and fish have sophisticated abilities to detect the earth’s magnetic fields to allow them to find their way across hundreds or even thousands of miles without having to rely on either the position of the sun or the stars (see Hughes, 1999). Indeed all these species are unable to perform this feat if they have magnets attached to them that prevent them from detecting the weak magnetic fields of the earth.

For many years the nature of the magnetoreceptor has been the subject of considerable debate and the main stumbling block to accepting this as a bona fide sense. Much of the initial focus has been on the possibility that we have biological magnets in our heads capable of transducing magnetic fields into electrical activity to be processed by the brain. This initially received support from the demonstration that such a material, magnetite, was indeed present in simple organisms such as some bacteria and allowed them to orientate north (in the northern hemisphere) or south (in the southern hemisphere) in response to magnetic fields. Bees also appear to have such magnetic receptors linked in with their nervous systems. Elegant studies in trout have also now established similar connectivity between magnetite-based receptors and the brain via a branch of the trigeminal nerve. Most mammals, including humans have such magnets in their heads, particularly in the nasal area but to date no connectivity with the brain has been established although mammalian brains, including our own, do show altered activity in response to magnetic stimulation.

A number of recent proposals have suggested that magnetic fields may actually be detected through their known influences on photoreceptors in the retina (Ritz et al., 2002). This idea has received recent support from a study in the mole rat showing that a primitive visual area in the brain, the superior colliculusis strongly activated by magnetic fields with the direction of the magnetic fields being represented in different layers (i.e. another potential example of a map)(Nemec et al., 2001). This makes a lot of sense because this brain structure is important for controlling the way we immediately change our orientation (i.e. turn towards or away from) in response to both visual and touch cues. This same system could obviously do the same thing for responding to magnetic fields.

In humans one study has concluded that many of us can tell which is North and South without the aid of visual directional cues although we are apparently better at it if we are either naked or wear cotton than if we wear synthetic static-producing substances like nylon. We are also better at it apparently if we normally sleep in a North/South orientation (Baker, 1995).

There is little doubt that many mammals are better able to detect changes in magnetic fields than ourselves. This ability may not only give directional guidance but also advance warning of electric strorm. Electrical activity in our bodies also sets up local magnetic fields and so it is conceivable that just as we can used magnetic resonance imaging to view activity in our brains, other species may have the ability to detect changes in our physiological or emotional states by detecting changes in the magnetic fields we, or other animals, produce.

It is likely that the sensing of magnetic fields is a very primitive biological system, rather like the pheromonal one, and involves brain regions that do not promote significant awareness. In this case it may be more like either travelling unconsciously down a homing beam where alarms are only raised when there is a mismatch between intended and actual directions, or feeling comfortable, or not, through being in the presence of another individual.

Are our experiences of the different sensory modalities always separate?

Imagine what it would be like if music was not just heard but could also be seen in terms of colours and felt in different parts of your body, or alternatively if specific words always triggered a simultaneous sense of a particular flavor or colour. Life might be seen as a rich and complex experience but would also be more than a little confusing and an exhausting state of sensory overload at times.

This condition can indeed happen in humans and has been called “synaesthesia” (literally syn = together + aesthesis = perception) and was first reported by Francis Galton in 1880. Most recent reports suggest that it occurs in between 1 in 200 and 1 in 20,000 individuals, depending upon how strict a definition is used. In its most common form individuals see specific graphemes (numbers or letters) as coloured (even though they are not) although which colour is seen varies from individual to individual. However, the 5 senses allow for up to 20 different varieties of synaesthesia involving two senses and most of these have been reported. The main examples are sounds evoking visual experiences of colours although some bizarre combinations have been reported such as a man who experiences tastes as shapes and a woman who experiences different musical instruments as tactile experiences in different parts of her body (see Cytowic, 1993).

One thing that is most common is that visual experience is evoked by one or more of the other senses rather than the other way around.

Not suprisingly this condition has often been associated with artistic individuals – Vladimir Nabokov, Olivier Messiaen, David Hockney, Alexander Scriabin for example. A recent report has even suggested that 23% of 358 fine-arts students surveyed reported experiencing synaesthesia.

It is clear that synaesthesia is likely to result from a number of different causes and at a number of different levels in the brain (both perceptual – low-level synaesthesia and cognitive – high level synaesthesia – Ramachandran and Hubbard 2001). Although it is difficult to provide definitive principles for what is going on, the most likely explanation is that in most cases there is cross-wiring between adjacent areas dealing with analysis of different sensory information. Thus our sensory maps within the brain may occasionally overlap.

Simon Baron-Cohen at the University of Cambridge has hypothesised that intermixing of the senses is actually normal in human babies in the first year of life and this is supported by brain imaging studies which show broad overlapping patterns of activity with different sensory stimuli. In both humans and other animals there is a physical pruning of brain connections during early development that reduces interactions between sensory areas of the brain.

While one can understand from the reported experiences of individuals with synaesthesia that this can lead to confusion as well as creativity, it remains an intriguing possibility that for some animal species their experiences of the world might be more likely to be routinely multisensory than our own. This might especially apply to nocturnal animals that appear to have almost redundant visual senses and enhanced senses of smell and hearing. In this case it might be useful for specific smells or sounds to be reinforced through the experience of a corresponding visual sensation. This might actually help to improve discriminatory performance without providing confusion with information being detected by the eyes. The idea is, of course, pure speculation but has some support from humans where recent studies on the blind have shown that when they read Braille by touch this can activate areas of the visual cortex!

Is there a telepathic sense?

I deliberately left this to the end so that it could be shown that a number of observations about animals being able to detect earthquakes, storms, emotions and disease, communicate with one another over long distances and find their way home could be shown to be explained easily though their superior abilities to detect specific different forms of known and measurable energy.

While we still have a large amount to learn about detection of electromagnetic energy produced by humans or other animals one would still be hard pushed to consider that this will explain all of the claims that have been made for special abilities in animals and some humans.

The catalog of often quite rigorously controlled observations provided by Rupert Sheldrake in his book “Dogs that know when their owners come home” for dogs, cats, horses and a number of other species is persuasive and hard to explain at present by detection of energy forms that we accept and for which there are known biological receptors.

In humans we also have a number of documented cases of remote viewing where individuals show themselves capable of describing pictures or other items sealed in containers in a remote location. A famous example is the artist Ingo Swann.

Many would like to believe in the existence of extrasensory perception and postulate the existence of other forms of communication via psychic energy which we may, with practice, be able to detect and which other animals may consider second nature. However, without being able to measure the energy or define how we are able to detect it physically, all observations will remain phenomenological. Of course our understanding of many currently accepted biological sensory capacities started out in exactly the same position.

Since we still have not established the full potential of sensory systems we do at least partly understand it would seem more politic to concentrate our efforts on completely understanding the capabilities of these.

General conclusions

What we can conclude is that at this stage the different sensory capacities of other species can explain many of their apparent supernatural abilities such as communicating over incredible distances, finding their way to distant places, locating small objects even in the dark, detecting buried objects, human or animal diseases or hormonal or emotional changes and detecting environmental changes such as storms and earthquakes long before we can. It is also clear that not everything that has been claimed either other animals or humans are capable of (communication intentions over very long distances or use of remote vision for example) can currently be explained by what we know of the sensory systems that are known and accepted.

What is also clear is that the different sensory equipment, detection sensitivities and ranges make the experience that other species have of the world rather different from our own. The same world can, and does, seem very different to a dog compared with a human. Equally, it can be experienced in a very different way by some humans compared with others.

Some selected references:

Baker, R (1985) Magnetoreception by man and other primates – in “Magnetic Biomineralization and Magnetoreception in organisms” eds Kirschvink, Jones and MacFadden, Plenum, New York. Carroll J et al., (2001) Photopigment basis for dichromatic color vision in the horse. Journal of Vision 1: 80-87. (see www.journalofvision.org/1/2/2/) Cytowic RE (1993) The Man Who Tasted Shapes: A Bizarre Medical Mystery Offers Revolutionary Insights into Reasoning, Emotion and Consciousness. New York, Putnam (available through Amazon). Galton F (1880) ‘Visualised Numerals’ Nature 22:494-495. Hughes HC (1999) Sensory Exotica. MIT Press, Cambridge MA.(available through Amazon). Nemec P et al. (2001) Neuroanatomy of magnetoreception: the superior colliculus involved in magnetic orientation in a mammal. Science 294:366-368. Ramachandran VS and Hubbard EM (2001) Synaesthesia – A window into perception, thought and language. Journal of Consciousness Studies 8:3-34. Ritz, T et al (2002) Shedding light on vertebrate magnetoreception. Neuron 34:503-506. Sheldrake R (1999) Dogs that Know when their Owners are Coming Home and Other Unexplained Powers of Animals, Hutchinson, London (available through Amazon). Zeki S (1993) A vision of the brain. Blackwell, Oxford

This event was on Thu, 23 Jan 2003

Professor of Physic

Professor Keith Kendrick is Systems and Behavioural Neuroscientist and was Gresham Professor of Physic between 2002 and 2006.

He has been a member of the...

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You have read a passage from “Different Ways of Seeing Species” that explains the benefits and drawbacks of relying on remote sensing data. Write an essay arguing whether or not the pros outweigh the cons. Use evidence from the passage to support your response. Your writing will be scored based on the development of ideas, organization of writing, and language conventions of grammar, usage, and mechanics.

The definition of an essay is ambiguous and overlaps with that of a letter, a paper, an article, a pamphlet, and a short fiction.

General terms, an essay is a piece of writing that presents the poster's own argument. The ability of this approach of gathering data to do so without the researcher's presence makes it particularly valuable , according to an essay that weighs the benefits of this kind of information. You must choose a side in this essay in order to write it. Choose one key fact about remote sensing data that makes study work easier if you are analysing the pros. You could alternatively choose to make an argument against this form of data collection. Regardless of your position, make sure your argument is supported by relevant facts and ends with a restatement of your thesis .

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Related Questions

What is one central idea of tecumseh’s speech? indigenous people do not believe in signing any treaties. indigenous people hope to restore their trust in white settlers. harrison should stop holding councils without getting input from indigenous peoples. harrison should stop taking land from indigenous peoples and should return what was taken.

Harrison should stop taking land from indigenous peoples and should return what was taken is one central idea of Tecumseh's speech . So the option D is correct.

One of the main points of Tecumseh's speech is that Harrison should cease taking territory from indigenous peoples and should return what was taken.

He argued that Native Americans should not be cheated out of their land and that they should be respected and their rights respected.

He also called for unity among all Native Americans and urged them not to fight each other but to unite and fight against the settlers who wanted to take their land. So the option D is correct.

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The complete question is:

What is one central idea of Tecumseh’s speech?

A. indigenous people do not believe in signing any treaties.

B. indigenous people hope to restore their trust in white settlers.

C. Harrison should stop holding councils without getting input from indigenous peoples.

D. Harrison should stop taking land from indigenous peoples and should return what was taken.

Answer:A & C

Explanation: Took the test

The passage suggests that small children should wash their hands ________ in the rainy season since they have lower immunity

The passage does not specifically recommend how often small children should wash their hands in the rainy season.

However, it suggests that it is particularly important for small children to wash their hands during this time because they may have lower immunity and be more susceptible to infections and illnesses. Regular handwashing is a simple but effective way to reduce the spread of germs and help prevent illness, regardless of the season.

Handwashing is one of the most important habits that small children should learn and practice regularly. Children are more vulnerable to infections and illnesses due to their developing immune systems. During the rainy season, when there is an increase in moisture and humidity, the risk of infections and illnesses is even higher. Therefore, it is essential that small children take extra precautions to stay healthy during this time.

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Which statement about the passage best reflects the influence of a totalitarian dictator? the inability of the animals to sleep at night the increased discomfort the animals feel the continued belief that the key was stolen the refusal to capture Snowball

The refusal to capture Snowball reflects the influence of a totalitarian dictator, as the dictator has established and enforced an oppressive rule that prevents any action against Snowball.

He persuades the other animals Snowball's idealistic outlook is fake. Napoleon eventually evicts Snowball from the farm and takes over using only brute physical power when the animals become uneasy. Napoleon succeeds in persuading the others that Snowball betrayed their cause. Napoleon eventually gives up on his use of deceit and political manipulation in favour of direct suppression, just as Snowball appears ready to persuade the other animals to adopt his viewpoint on the windmill. He starts establishing a totalitarian dictatorship after using the dogs to chase Snowball away from the farm.

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Fix any punctuation or capitalization errors below. Click "Submit Answer" if there are none. 06 Luke Skywalker told the travel agents he wanted to fly around the world in a hot air balloon. They just rolled their eyes and laughed at him. What is wrong with this sentence?

According to the question Nothing is wrong with this sentence .

A sentence is a grammatically complete unit of words expressing an independent statement, question, exclamation, or command. It typically begins with a capital letter and ends with some form of punctuation. Sentences can be simple or complex, depending on their length and the number of clauses they contain. A simple sentence typically consists of a single clause, while a complex sentence may contain several subordinate clauses. Sentences help us communicate ideas, thoughts, and feelings in a clear and concise manner.

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which location/battle served as inspiration to francis scott key in writing the star spangled banner?

Answer: Fort McHenry

Explanation:

Roosevelt, churchill and stalin discussed the future of europe and the world after the war at the… question 12 options: potsdam conference council of trent versailles conference yalta conference

Roosevelt, Churchill and Stalin discussed the future of Europe and the world after the war at the Yalta conference . So the option C is correct.

At the conference, they discussed the creation of the United Nations and the post-war reorganization of Europe. They also discussed the reparation of Germany and the Soviet Union's role in the war against Japan. Additionally, they discussed the Soviet Union's role in a future government of Poland.

Other topics discussed at the conference included the foundation of the World Bank, the International Monetary Fund, and the United Nations Security Council . The conference also discussed the establishment of the United Nations Atomic Energy Commission and the International Court of Justice. So the option C is correct.

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Roosevelt, Churchill and Stalin discussed the future of Europe and the world after the war at the…

A. Potsdam conference

B. council of Trent versailles conference

C. Yalta conference

D. Teheran conference

You will now write a paragraph describing TWO QUALITIES you believe were highly valued in this new nation. What characterized a strong American, and why do you think these qualities were so important in our early American history? Are these qualities still important today?

The idea that the United States is different from other countries or is an example of excellence is known as American exceptionalism.

Why is it crucial to understand early American history?

Knowledge of American history is essential for comprehending the development of the nation and what it means to be an American. Knowing history can provide people a deeper understanding of current affairs and how society can advance, in addition to providing them with a knowledge of important facts and figures.

What qualities best characterize the American Revolution?

Unquestioning certitude is the path to dictatorship. Meacham noted that empathy, humility, and curiosity were the three defining features of the American Revolution . Meacham asserted that if we are not enthralled by the powerful forces at work, we disintegrate.

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QUICK!!! Read the following excerpt from Narrative of the Life of Frederick Douglass. Then, answer the question that follows. …after some reflection, he granted me the privilege, and proposed the following terms: I was to be allowed all my time, make all contracts with those for whom I worked, and find my own employment… In this sentence, what is the purpose of the colon? A)To introduce a formal business greeting B)To indicate time C)To join two sentences D)To list information that follows

HELP! Choose which of these is a true statement A: Reasons are quotes about why the claim is true and evidence shows the writer's ideas. B: Evidence is an explanation about why the claim is true and reasons show facts to prove what is true. C: Statements are explanations about why the opinion is true and claims show facts to prove what is true. D: Reasons are explanations about why the claim is true and evidence shows facts to prove what is true. I need big help! Please I’m new also and help me!

Option D: Reasons are explanations about why the claim is true and evidence shows facts to prove what is true is the correct answer.

In writing, a claim is a statement that a writer believes to be true, and it serves as the central argument of the piece. It is the writer's position on a particular topic or issue . A reason, on the other hand, is a statement or explanation that supports the writer's claim. It provides evidence, justification, or support for the writer's position. Essentially, claims and reasons work together to persuade the reader of the writer's argument or point of view.

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Which of the following would provide the best subject for a reflective essay? Select one: a. a trip to the ocean when I was nine b. when my big brother left to become a soldier c. a summary of the plot of Feed. d. my plans for the future

Explanation :

They don't actually know if you experienced any of the other options. while if you writing about you plans for the future you can talk about it and reflect on it.

B. when my big brother left to become a soldier

I took the test and got 100. This is the only thing you can really reflect about since nothing else happened that makes you think.

Aschoff and Weber designed an experiment in which participants were shielded from external cues about the time of day and were free to choose the times they were active and the times when they slept, over a month of observations. This procedure allowed Aschoff and Weber the unique opportunity to observe:Please choose the correct answer from the following choices, and then select the submit answer button.A. free-running rhythms.B. circadian rhythms.C. ultradian rhythms.D. infradian rhythms.

Free-running rhythms were able to be seen in the experiment created by Aschoff and Weber,

in which subjects were insulated from outside cues regarding the time of day and given the freedom to determine when they were awake and asleep.

When biological processes , like the sleep-wake cycle, are operating on their own and are not influenced by outside cues like light-dark cycles, they are said to be "free-running rhythms." In this study, participants were free to develop their own natural rhythm without being influenced by other influences because there were no external cues.

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Refer to Inside Out and Back Again for a complete version of this text. In the story, Hà’s family waits to be sponsored, but no one comes for them. When Hà’s mother learns that Americans prefer to sponsor Christian families, she changes the family’s religion on their application for sponsorship. How does this response develop a theme in the story?

It demonstrates how families will do everything it takes to give their kids the best chance of success. A moral lesson on how life is ever-changing, as well as the numerous individuals one encounters along the way, is conveyed in the book.

The book's introduction claims that Hà's father, a Vietnam Former soldier, was kidnapped either by North Vietnamese Army while she was barely twelve years old. Inside the end, Hà's family discovers that their dad had tragically passed away while being in North Vietnamese custody .

The protagonist and narrator of Thanhha Lai's book "Inside Out & Back Again" is ten-year-old Kim-Ha, also known as Ha. Quang, Vu, & Khoi's younger sister Ha, the child of their parents, is also their cousin.

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the book ultimate gift characters questions please answer all the questions 2 Are the main characters believable?/// 3 Who did you like the most and why?/// 4 Could you relate to any of the characters in the story?/// 5 Have you done any of the things in the things in the story or felt the same way as the characters did///

It was a charming and amusing tale with well-rounded performances and likable characters. You could bring the whole family to see it because it was clean enough.

3.  Who did you like the most and why?

Drew Fuller plays wealthy and privileged Jason Stevens . Jason is anticipating a substantial inheritance upon the death of his grandfather, James Garner. Jason, on the other hand, must embark on a journey of self-discovery in order to obtain the genuine present that his grandfather intended for him to receive.

5.  Have you done any of the things in the things in the story or felt the same way as the characters did?

Jason is tasked with bringing the Golden Fleece back from a land called Colchis, which is now Georgia and is in Southwest Asia. This place is far from the known world. The tale of the fleece is fascinating on its own.

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The amount of time covered by the narrative of a film is referred to as story time. T/F

story duration. The amount of time that the entire narrative arc of a movie's story—whether explicitly presented on-screen or not—is implied to have taken to occur. Compare plot duration and screen duration.

What is the MOST effective first step in creating a rational and easy-to-process presentation? State the key message up front. State each main point as if it's a separate idea. Include many visuals without context. Summarize all the evidence that supports the key points.

Option D is the best first move to make a logical and simple-to-understand presentation : Compile a summary of all the arguments in favour of the main topics.

The typical goals of a presentation are to inform , persuade, inspire, and motivate, or to present a novel concept or item. Together with lectures or demonstrations, presentations can also contain speeches and introductions.

A good presentation should be succinct and narrowly focused on the topic. It shouldn't stray from the path. Strong presentations should be able to effectively convey the required information. The anxiousness should be channelled into inspiration throughout the presentation.

So, take note that effective presentations leave a lasting impression . They are easy to remember due to the pictures, drawings, and data they contain, thus one must first explain the summary of the message.

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write a letter to your friend explaining reasons why we should preserve our Jamaican cuisine ​

Dear [Friend],

I hope this letter finds you in good health and spirits. I am writing to you today to talk about the importance of preserving our Jamaican cuisine.

Jamaican food is an essential part of our culture and identity as a people. Our cuisine has a rich history that is intertwined with our African, European, and indigenous roots. It is a reflection of our resilience, creativity, and resourcefulness as a nation.

Preserving our Jamaican cuisine is crucial because it helps to promote our local agriculture and food industry. Many of the ingredients used in our traditional dishes are grown and produced locally. By supporting our Jamaican cuisine, we can also support our farmers and producers, which can help to boost our local economy.

Moreover, our Jamaican cuisine is a tourist attraction that draws visitors from all over the world. Many people come to Jamaica to experience our food and culture. By preserving our cuisine, we can continue to share our unique cultural heritage with the world.

Lastly, our Jamaican cuisine is a source of pride and identity for Jamaicans everywhere. Our food has become a symbol of our national pride and a way for us to connect with our roots. Preserving our Jamaican cuisine is essential to maintaining our cultural identity and passing it on to future generations.

In conclusion, preserving our Jamaican cuisine is critical to promoting our local agriculture, boosting our economy, and maintaining our cultural identity. Let us continue to celebrate and cherish our Jamaican food as an integral part of who we are as a people.

[Your Name]

Answer:your lazy if u cant do this lol

Explanation:lazyyyyyyyyyyy

According to the essay, the author dreads questions about teaching geography from thegeneral public because ___

According to the essay , the author dreads questions about teaching geography from the general public because they often reveal a lack of understanding about what geography is and what geographers do.

The author explains that many people view geography as simply memorizing place names and locations on a map, but it is actually a complex and multifaceted field that includes studying human-environment interactions, spatial patterns and processes, and global interconnections .

The author also notes that many people have a narrow view of geography as only pertaining to physical features, when in fact it encompasses a wide range of social, economic, and cultural aspects as well. This misunderstanding can lead to frustrating and unproductive conversations with the general public about the importance and relevance of geography.

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100 POINTS & BRAINLIEST ONLY IF U... READ AND SUMMARIZE THE FOLLOWING PASSAGE!!! PLEASE!!!! TITLE: From Relationship of smartphone use severity with sleep quality, depression, and anxiety in university students Background and aims: The usage of smartphones has increased rapidly in recent years, and this has brought about addiction. The aim of the current study was to investigate the relationship between smartphone use severity and sleep quality, depression, and anxiety in university students. Methods: In total, 319 university students (203 females and 116 males; mean age = 20.5 ± 2.45) were included in the study. Participants were divided into the following three groups: a smartphone non-user group (n = 71, 22.3%), a low smartphone use group (n = 121, 37.9%), and a high smartphone use group (n = 127, 39.8%). All participants were evaluated using the Pittsburgh sleep Quality Index, Beck Depression Inventory, Beck Anxiety Inventory; moreover, participants other than those in the smartphone non-user group were also assessed with the Smartphone Addiction Scale. Results: The findings revealed that the Smartphone Addiction Scale scores of females were significantly higher than those of males. Depression, anxiety, and daytime dysfunction scores were higher in the high smartphone use group than in the low smartphone use group. Positive correlations were found between the Smartphone Addiction Scale scores and depression levels, anxiety levels, and some sleep quality scores. Conclusion: The results indicate that depression, anxiety, and sleep quality may be associated with smartphone overuse. Such overuse may lead to depression and/or anxiety, which can in turn result in sleep problems. University students with high depression and anxiety scores should be carefully monitored for smartphone addiction. ANSWER RULES/CONDITIONS: Says the correct answer: FIRST = Brainliest, Thanks, 5 stars, and praise. Correct answer: Thanks, 5 stars, and praise. Incorrect answer: 2 stars (Nothing personal). Odd answers like GPUOLFYG or answers that don't make sense: 1 star and report. Links: 1 star and report.

Here is a summary of the passage:

This passage is a formal test, examining if females or males have higher smartphone usage and the impacts it causes. We are told that the result from this test represents those female smartphone users have higher rates of depression, anxiety, and daytime dysfunction users. With percentages higher than 100% this passage shows that over usage of phones can cause a major impact on the health and well-being of an individual!

Hope this helps, have a lovely day! :)

It's the statistics of phone usage in university students

according to the boston consulting group matrix we should do this with products that have high relative market share in low growth industries

According to the Boston Consulting Group (BCG) matrix, products that have high relative market share in low growth industries are categorized as " cash cows. " These products generate significant revenue and profit for the company, but their growth potential is limited due to the low-growth nature of their industry.

To effectively manage cash cows, companies should adopt a strategy of maximizing profits and cash flow from these products. This can be done by reducing costs, increasing prices, and improving operational efficiency. Companies can also consider investing the profits generated by cash cows into other areas of the business that have higher growth potential, such as "stars" or "question marks" in the BCG matrix.

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determining the earliest start time (es) and earliest finish time (ef) for each activity is known as the _______________ through the network.

Determining the earliest start time (ES) and earliest finish time (EF) for each activity is known as the forward pass through the network .

The forward pass  is used to calculate the earliest start and finish times for each activity in a project schedule. This helps to determine the critical path and the earliest possible completion date for the project.

The forward pass is an important step in the critical path method (CPM ), which is a project management technique used to plan and schedule projects. The forward pass is typically performed after the project network diagram has been created and the activity durations have been estimated.

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Which of these directly resulted from the event announced in this headline? 8.7(C)The abolitionist movement gained momentum in the North.Members of the U.S. Senate sought to end Black Codes in the southern states.The federal government allowed the expansion of slavery into all new western territories.Abolitionists moved to the South to avoid living under the new law.

The event announced in the headline is the passing of the Fugitive Slave Act, which was part of the Compromise of 1850. This act made it a federal crime to assist runaway slaves and mandated that escaped slaves be returned to their owners.

This resulted in a number of significant consequences, including the following:The abolitionist movement gained momentum in the North, as many people were outraged by the Fugitive Slave Act and the federal government's support of slavery. Abolitionists became more vocal in their opposition to slavery and organized protests , rallies, and other events to raise awareness of the issue.Members of the U.S. Senate sought to end Black Codes in the southern states, which were laws that restricted the rights of African Americans and enforced racial segregation. Some senators believed that the Fugitive Slave Act was a violation of the Constitution and that it should be repealed.The federal government allowed the expansion of slavery into all new western territories, which was a direct result of the Compromise of 1850. The compromise included provisions that allowed for the admission of new states to the Union as either free or slave states, depending on the desires of their residents.Abolitionists did not move to the South to avoid living under the new law. In fact, the Fugitive Slave Act made it more dangerous for abolitionists to operate in the South, as they could be arrested and punished for assisting runaway slaves. Instead, many abolitionists focused their efforts on supporting the Underground Railroad, which was a network of safe houses and secret routes that helped enslaved people escape to freedom.

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5.why does this expression cause an error? how can you fix it? (3 points) 'i have eaten ' 99 ' burritos.'

This expression causes an error because the numbers are not in quotes . To fix the expression, you need to put the numbers in quotes like this: 'I have eaten '99' burritos.'

This expression causes an error because it is trying to concatenate a string and a number without using the proper syntax. In Python , you cannot simply combine a string and a number with a space in between. You must either convert the number to a string using the str() function or use the format() function to insert the number into the string. To fix this expression, you could use either of the following methods: Method 1: Convert the number to a string with the str() function: ```python 'I have eaten ' + str(99) + ' burritos.' ``` Method 2: Use the format() function to insert the number into the string: ```python 'I have eaten {} burritos.'.format(99) ``` Both of these methods will produce the same output: `'I have eaten 99 burritos.'`

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Which would BEST develop the claim that more nutritious food in the cafeteria would help students do better in school. Responses A Better food is better for a student's overall health and wellness.Better food is better for a student's overall health and wellness. B Many people are starting to see that eating better food can have a positive effect on health.Many people are starting to see that eating better food can have a positive effect on health. C Fruits and vegetables are full of vitamins and minerals that the body needs.Fruits and vegetables are full of vitamins and minerals that the body needs. D More nutritious food will improve overall health, and healthy students are successful students

The ideal solution is (D). More nutritous food will enhance general health, and successful pupils are those who are healthy.

Lean meat, fish, chicken, eggs, beans, lentils, chickpeas, tofu, and nuts are examples of protein-rich foods. These foods are crucial for the growth and muscle development of your youngster. Together with these beneficial vitamins and minerals, these meals also contain omega-3 fatty acids, iron, zinc, and vitamin B12.

Food served at schools is healthy. According to studies, students who take part in school meal programmes eat more whole grains, milk, fruits, and vegetables during meals and have higher overall diet quality than nonparticipants. According to research, children can learn to notice how a good diet affects their mental wellbeing by participating in nutrition education.

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In Fools Crow , write one paragraph describing how Yellow Kidney’s family see him since his return, as well as a paragraph describing the lead up to the coming battle with the Crows.

After Yellow Kidney's return, his family is overjoyed to see him. They welcome him with open arms and are relieved that he has survived his journey. However, they also see that he has changed. He is no longer the carefree and happy-go-lucky person he used to be. His experiences have made him more serious and reserved, and he seems burdened by the weight of his responsibilities. Despite this, his family is proud of him for completing his quest and for becoming a man.

As tensions between the Pikunis and the Crows escalate, preparations for battle begin. The Pikunis are aware that the Crows are planning an attack and are determined to defend their territory. The war party is led by Fast Horse, a skilled warrior who is eager to prove himself. Many young men, including Yellow Kidney, join the war party. The women and children are left behind in the camp, where they prepare for a possible attack. The Pikunis are well aware of the dangers they face, but they are also fiercely committed to defending their way of life. The lead up to the coming battle is filled with a sense of urgency and tension, as the Pikunis prepare for what could be a fight for their very survival.

when / We / use / writing/ must/ few /as / words/ as/ a/ telegram/ possible ​

This essay on Telegram's role in communication was authored by another student and turned it to the class. You are welcome to use it as a resource and for research.

Telegraph style, telegraph style, telegraphic style, or telegraphese is a shortened writing style that condenses information into the fewest words or characters possible.

Response and justification The telegram writing format consists of brief sentences or phrases that are separated by the word stop at the end of each sentence. Telegrams did not contain extraneous words, articles, punctuation, or certain conjunctions.

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when you are fully present with others-paying close attention to their gestures, manner, and silences, as well as to what they say, you are listening

for the first time in history. The a list of the a little bit more, and a little bit of the same.. It entails giving your whole attention to the speaker , absorbing not just what they are saying but also their nonverbal .

signs and general communication style. Active listening may promote better interpersonal relationships and mutual understanding as well as more efficient communication and problem-solving. A crucial communication ability is active listening , which entails not just hearing what someone is saying but also comprehending its underlying meaning and expressing it to the speaker. Giving the speaker your complete attention, being fully present in the conversation , and employing strategies like paraphrasing and asking clarifying questions to assure understanding are all necessary. When there are strong emotions present, active listening is extremely crucial.

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help with these questions pls it’s due today

2. It is not safe to process the animals because the farmer should make sure that the parasite is completely out of the swine's system before sending the animals out for consumers to ingest.

3. It is safe to process the animals because the animals have undergone multiple vaccinations and a quarantine period of 90 days which is usually enough for the cattle to be cleansed of the parasite before being consumed by the public with no risk of catching the parasite.

2. Processing the animals is unsafe since the farmer should ensure that the parasite has been totally eliminated from the swine's system before releasing them for human consumption.

3. The animals are safe to process since they have had many vaccines and have been quarantined for 90 days, which is typically long enough for cattle to be parasite-free before being consumed by the general population without risk of contracting the infection.

What is Republic in West Africa on the Gulf of Guinea and the most populated African country?

Nigeria is a country in West Africa and it is the most populated African country.

With an estimated population of more than 200 million, Nigeria is the most populous nation in Africa and is situated in West Africa. Together with Benin, it has borders with Niger, Chad, Cameroon, and the Gulf of Guinea. With more than 250 different ethnic groups, each with its own culture and language, it is a diverse nation . Although Yoruba and Hausa are among several languages that are frequently spoken, English is the official language.

It is the largest economy in Africa and a significant oil producer. Moreover, it belongs to the Organization of Petroleum Exporting Countries. Despite its abundance of natural resources, Nigeria still faces severe economic and social issues such as poverty, corruption, and inequality. Nigeria has a lively literary world as well as a rich cultural past. The nation's political history is complicated, with periods of military dictatorship, democratic transitions, and problems related to ethnic and religious groups.

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A good personal narrative uses the senses to describe things. The reader wants to _____ the story unfold be able to visualize and see O smell, touch, taste, hear and see be able to understand All of the above. the story unfold.

Answer: be able to visualise and see

what activity would best create awareness of substitution as a cohesive device?

A sentence completion exercise might be a good exercise to raise awareness of replacement as a coherent device .

One activity that could create awareness of substitution as a cohesive device is a fill-in-the-blank exercise . This exercise could involve providing sentences with missing words, which students must then fill in with appropriate substitutions that maintain the cohesion of the sentence.

For example:

Original sentence: John went to the store to buy milk.

Fill-in-the-blank sentence: John went to the store to buy ________.

Possible substitutions: bread, eggs, cheese, cereal.

Students would need to choose the substitution that makes the most sense in the context of the sentence, while also maintaining its cohesion. This exercise would help students recognize how substitution can be used to create connections between different parts of a sentence, and how it can contribute to the overall coherence of a piece of writing .

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How John Berger changed our way of seeing art

Reader in Sociology, Goldsmiths, University of London

Professor of Sociology, Goldsmiths, University of London

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Vikki Bell receives funding from Economic and Social Research Council

Yasmin Gunaratnam does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

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The opening to John Berger’s most famous written work, the 1972 book Ways of Seeing , offered not just an idea but also an invitation to see and know the world differently: “The relation between what we see and what we know is never settled,” he wrote.

Berger, who died on January 2 at the age of 90, has had a profound influence on the popular understanding of art and the visual image. He was also a vibrant example of the public intellectual, using his position to speak out against social injustices and to lend his support to artists and activists across the world.

Berger’s approach to art came most directly into the public eye in four-part BBC TV series, Ways of Seeing in 1972, produced by Mike Dibb and which preceded the book. Yet his style of blending Marxist sensibility and art theory with attention to small gestures, scenes and personal stories developed much earlier, in essays for the independent, weekly magazine New Stateman (between 1951 and 1961) and also in his first novel A Painter of Our Time , published in 1958.

The BBC programmes brought to life and democratised scholarly ideas and texts through dramatic, often witty, visual techniques that raised searching questions about how images – from European oil painting to photography and modern advertising – inform and seep into everyday life and help constitute its inequities. What do we see? How are we seen? Might we see differently?

“Berger’s theoretical legacy”, the Indian academic Rashmi Doraiswamy wrote recently , “is in situating the look in the context of political otherness”. Berger’s idea that looking is a political act, perhaps even a historically constructed process – such that where and when we see something will affect what we see – comes across most powerfully in the second episode of Ways of Seeing – which focused on the male gaze.

Here Berger showed the continuities between post-Renaissance European paintings of women and imagery from latter-day posters and girly magazines, by juxtaposing the different images – showing how they similarly rendered women as objects. Berger argued that this continuity constrained how certain forms of femininity are understood, and therefore the terms on which women are able to live their lives. He identified a splitting of the European woman’s consciousness, in which she:

has to survey everything she is and everything she does because how she appears to others, and ultimately how she appears to men, is of crucial importance for what is normally thought of as the success of her life.

Historical context, scale, and how we see were recurring themes in Berger’s writing, films, performance and in his collaborative photographic essays with Jean Mohr , Anne Michaels , Tereza Stehliková and others.

Berger’s essays and books on the photograph worry at the political ambiguity of meaning in an image. He taught us that photographs always need language, and require a narrative of some sort, to make sense.

He also took care to differentiate how our reaction to photographs of loved ones depends on our relationship to the person portrayed. In A Seventh Man , a collaborative book with Jean Mohr on Turkish migrant workers to Germany in the 1970s, he put it simply:

A photograph of a boy in the rain, a boy unknown to you or me. Seen in the darkroom when making the print or seen in this book when reading it, the image conjures up the vivid presence of the unknown boy. To his father it would define the boy’s absence.

Under the skin

Because he had been a painter, Berger was always a visual thinker and writer. In conversation with the novelist Michael Ondaatje he remarked that the capabilities of cinematographic editing had influenced his writing. He identified cinema’s ability to move from expansive vistas to close-up shots as that to which he most related and aspired.

Certainly Berger’s work is infused with a sensitivity to how long views – the narratives of history – come alive only with the addition of “close-up” stories of human relationships, that retell the narrative but from a different angle. For instance, writing about Frida Kahlo’s compulsion to paint on smooth skin-like surfaces, Berger suggested that it was Kahlo’s pain and disability (she had spina bifida and had gone through treatments following a bad road accident) that “made her aware of the skin of everything alive —- trees, fruit, water, birds, and naturally, other women and men”.

The character in Ondaatje’s novel, In the Skin of a Lion, to whom he gave the name Caravaggio, was partly inspired by Berger’s essay on the painter . In that essay, Berger wrote of a feeling of “complicity” with the Renaissance Italian artist Caravaggio, the “painter of life” who does not “depict the world for others: his vision is one that he shares with it”.

Berger’s writerly inclinations and sensitivities seem to echo something of the “overall intensity, the lack of proper distance” for which Caravaggio was so criticised – and which Berger so admired. This intensity was not a simple theatricality, nor a search for something truer to life, but a philosophical stance springing from his pursuit of equality. He gave us permission to dwell on those aspects of our research or our lives that capture us intensely, and to trust that sensitivity. His was an affirmative politics in this sense. It started with a trust in one’s intuitions, along with the imperative to open these up to explore ourselves as situated within wider social and historical processes.

Reflecting on his written work, Berger wrote in the recent Penguin collection Confabulations :

What has prompted me to write over the years is the hunch that something needs to be told and that, if I don’t try to tell it, it risks not being told.

He knew very well that writing has its limitations. By itself, writing cannot rebalance the inequities of the present or establish new ways of seeing. Yet he wrote with hope. He showed us in his work and – by example – other possibilities for living a life that was committed to criticising inequality, while celebrating the beauty in the world, giving attention to its colour, rhythm and joyous surprises. We remain endowed and indebted to him.

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Evolution: Changing Species Over Time

Evolution is the process by which species adapt over time in response to their changing environment. Use these ideas to teach about the water cycle in your classroom.

Biology, Ecology, Genetics

Photograph by James L. Amos

Evolution is an important field of study for scientists. It covers the study of changes organisms have undergone over time in response to different factors in their environment. All organisms, including humans, evolve over time. Evolution occurs through natural selection, and is a force that has shaped every organism living today.

Darwin’s Finches

Have the students read about and research the finches Darwin studied on the Galapagos Islands . Darwin noticed that different finches had differently shaped beaks. He also noticed that the various beak shapes were each best suited for handling certain types of food. Darwin knew that the finches had come from continental South America originally, but those that he saw on the islands were unlike the ones on the mainland. Darwin wondered what caused these finches to change when they made it to the Galapagos Islands. Have students test the ability of different beaks to get different types of food. Provide students with spoons, forks, metal binders clip, and tweezers to represent different types of beaks and food bowl with foam packing peanuts, small bird seed, large bird seed (sunflower seeds), and toothpicks. Have student try the different tools and identify which tool works best with which foods.

National Geographic Explorer Jingchun Li: Evolution of “Living Solar Panels”

The first thing you notice when visiting a healthy marine coral reef is the number of different fishes and the many bright colors of both the fishes and the corals. Marine biodiversity refers to the richness of different species living together in a community. Have the students read about National Geographic Explorer Jingchun Li and her research on marine biodiversity and biologically productive coral reef ecosystems . Li is studying how coral reefs and other organisms are undergoing macroevolution to cope with the stresses created by human disturbances to their ecosystem.

Divide students into groups. Ask the students what stresses are taking place in the marine environment that coral reefs and other marine organisms need to adapt to. Have them divide into small groups and research these changes and design solutions to address these disturbances.

Human Evolution

Scientists who study early humans depend on fossil evidence to help them sort out how our ancestors evolved over time. When looking at the fossils, scientists look for clues to changes in different characteristics such as brain size, skull shape, locomotion, and jaw size. Have the students learn about human evolution , then have them work through the Mystery Skull Interactive  to use clues to identify fossils.

Evolution in Isolation

Have the students watch the video about the birds living on the island of Papua in Indonesia. This isolated island is a paradise with a lush and resource-rich habitat. Male birds of many different species have evolved elaborate ways of attracting mates. Ask the students, why is it important for a species to have the strongest males mate with the females and how does this affect the species?

National Geographic Explorer Jeremy Emiland Martin: Evolution of Crocodiles

Have the students read about Jeremy Emiland Martin’s work on the evolution of crocodiles  and then have them research how modern crocodiles have been evolving since the time of the dinosaurs. Because crocodiles are found in so many different areas of the world, it is important to go back to where they first emerged to learn about their evolutionary beginnings. Ask the students, how have crocodiles evolved since the Cretaceous Period? What might have caused crocodiles to evolve? Why were these traits favorable in this particular environment?

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July 30, 2024

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Related Resources

• Animal vision: seeing through different eyes
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Making sense of all the visual information we receive every second we're awake uses about a quarter of the brain's processing power at any one time. The human eye, our primary sensory organ and source of information, is often seen as highly advanced, so it might be surprising to learn that we may have only a quarter of the colour vision capability of a mantis shrimp and are at least six times slower in visual reaction time than a fly.

Mantis shrimp have the most complex retinal visual system known to science, says Professor Justin Marshall , from UQ's Queensland Brain Institute, an expert in animal vision. The crustaceans use polarised light for attracting a mate, with only males reflecting this light. Mantis shrimp also see colour and have 12 input channels, or sensitivities, in their eyes for this. Humans only have red, green and blue, and yet we can distinguish millions of different colours.

"How mantis shrimps use colour remains shrouded in mystery," says Professor Marshall, whose research has uncovered these amazing findings. "At the moment, we understand more about how their vision system works than how they use it. There is a lot of exciting research to come."

Many animals out-perform humans in some form of vision and some, including the octopus, can see forms of light that humans cannot. Octopuses also see polarised light, a form of light that humans only see with the aid of sunglasses and other optical devices. Surprisingly, they are also completely colour-blind and seem to have swapped colour for polarised information from the world around them. How do they manage their feats of amazing camouflage, blending perfectly with the ocean floor? And why do some, such as the blue-ringed octopus, use colours they don’t see themselves?

These cephalopods are very sensitive to contrast patterns and even the texture of their surrounds; they can mimic their environment almost perfectly and have evolved to ‘know’ the colour of the ocean bed. The iridescent blue of the tiny blue-ringed octopus is likely there to warn animals that can see colour that its bite is laden with potentially lethal toxins.

"Instead of colour, cephalopods have developed polarisation vision for tasks that mostly remain obscure to us," says Professor Marshall. "Some certainly communicate with polarised light but the meanings of those messages are yet to be decoded.”

Among the vertebrates, even the goldfish with its tiny brain can detect more colours than a human, and it can see ultraviolet (UV) wavelengths, a range of light that humans cannot normally see. Many reef fish, birds, lizards and mantis shrimp use UV light, some for covert communication among themselves, most likely for attracting and choosing mates.

Studying how these small-brained animals can see and process such complex visual information helps us understand more about how our brains process our visual world. Scientists, inspired by this vision in nature, are also working on developing better underwater navigation and camera technologies .

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John Berger at home in Quincy in the Haute-Savoie, France, in 2008. Photo by Franck Courtes/Agence VU

Ways of living

John berger’s ‘ways of seeing’ exploded a discipline. but his greatest legacy might be a quieter project of re-enchantment.

by Joshua Sperling   + BIO

At the start of the first TV episode of Ways of Seeing , John Berger takes a scalpel to Botticelli’s Venus and Mars . The opening beat of the programme is the audio of the incision – the blade’s rough abrasion on canvas – before the soundtrack settles into voiceover. ‘This is the first of four programmes,’ Berger says, ‘in which I want to question some of the assumptions usually made about the tradition of European painting. That tradition which was born about 1400, died about 1900.’

Ways of Seeing first aired on Sunday evenings on BBC2 at the start of 1972. It attracted few initial viewers but, through rebroadcasts and word of mouth, the show gathered steam. By the end of 1972, it had gone viral. People in London and New York argued about Berger’s ideas. When Penguin commissioned a paperback adaptation, the first two print runs sold out in months. Regularly assigned in art schools and introductory art history courses, Berger’s project has never really waned in popularity. That first episode now has close to 1.4 million views on YouTube, and the paperback regularly sits atop Amazon’s Media Studies bestseller list.

For decades, Berger’s name has been shorthand for the series, which has been shorthand for a certain style of combative, materialist art criticism. Often presented as a riposte to Sir Kenneth Clark’s TV series Civilisation (1969) – Berger himself spoke of it as a ‘partial, polemical reply’ – the show attacked Clark’s school of connoisseurship ‘with a razor’. Suave, moneyed, knighted at 35, Clark was the embodiment of the high-cultural mandarin: art existed for the pleasures it afforded those refined enough to feel them. Berger was a self-styled outsider: he had run away from boarding school as a teenager, and left England for France in his 30s. Art was best, he said, when it was born of struggle and inspired belief. At its worst, it was little more than a luxury good. The difference extended to the very mode of aesthetic response – appreciation or critique? This is the significance behind the act of vandalism that opens Ways of Seeing . Viewers soon learn that the painting Berger cut was a facsimile, but the metaphor of the scalpel is plain: to question is to dissect. It is to cut past the scrim of beauty, and reveal more fundamental anatomies: capitalism, colonialism, patriarchy, mimetic desire.

It is a move that has only grown in ubiquity ever since. The feminist art historian Griselda Pollock remembers the ‘moment’ of Berger’s appearance – 1972 – as a kind of methodological primal scene: after the show, the humanities began to turn away from connoisseurship toward what Pollock has called the ‘analysis of power and the deconstruction of classed, raced, and gendered meanings’. Ways of Seeing became an urtext of critique, a work that captured young imaginations, and changed the way that people saw and understood the world. Close to 50 years on, Pollock’s description still applies to most of the work done by humanities scholars and, more and more, mainstream cultural journalism too. From the arts and culture pages of The Guardian or The New York Times to the latest hot takes on Twitter, what criticism has come to mean is what Berger pioneered. In an age of open media, the implications are vast. If the internet has made all of us critics, that means we are all now foot soldiers in a culture war: self-armed semioticians and practiced deconstructors of political signification.

As is the case with most viral content, nobody expected Ways of Seeing to travel so widely, least of all its authors. Kept to a tight budget, the show was filmed in a rented electrical goods warehouse in Ealing, a west London suburb. Berger worked on his voiceover at his parents’ apartment on Hallam Street, in the imposing shadow of the BBC’s Broadcasting House. After the series aired, the arrangement of the book was anything but streamlined. Berger worked with his creative partners (Mike Dibb, Richard Hollis and Sven Blomberg) in a manner more closely resembling the bricolage of a zine than the strategic making of a bestseller. It was a principled if madcap route to fame, part of a broader revolutionary mood. Later that same year, on receiving the Booker Prize for his novel G. (1972) – a sexual bildungsroman set in prewar Europe – Berger announced on stage that he was sharing half the prize money with the London-based Black Panthers. Of course, fame can be secretly coveted only for the privilege to cast it off afterwards. But the one-two punch of Ways of Seeing and the Booker scandal were decisive. Taken together, they turned Berger into a star.

L ike beauty, provocation can hide as much as it reveals. Time brings new colour to old materials, and what makes Ways of Seeing so enduring might not be the same as what made it so electrically influential when it first appeared. We are now more aware of the fissures in the show, in its slight hesitations and indecisions, and in the hedges to what was otherwise such a freight train of an argument. The pictorial tradition of the female nude, Berger argues throughout the second episode, was not a celebration of humanist virtue but a fantasy of the acquisitive ‘male gaze’ (the term was coined a year later by Laura Mulvey). But then, as if in a footnote, he adds a hushed caveat, noting the ‘few exceptional nudes’ that were expressions of the painter’s love. There are similar equivocations at the end of nearly every episode. What of the masters of the tradition? What of its rebels? What of the mystery – beyond the ideology – of art? What of those anonymous works not held in any museum but exchanged between friends and partners? And what of the most modern art form of all – the art that comes to us on a screen?

In retrospect, Ways of Seeing was not only about painting but also television. More specifically, it was about painting-as-seen-on-television, which is to say it was about the transition from one medium to another, one tradition to another, maybe even one epoch to another. In short, it was about the severing of roots. Just after Berger cuts out the head of Venus from the Botticelli, we see her cropped portrait run through an industrial printer, multiplied ad infinitum and set in motion along the circuits of mass exchange. The movement finds its outward echo in the following shot: the silhouette of a television monitor against a blue screen.

From the oil painting to the printing press to the cathode-ray tube of TV: beyond the simple aggression of a razor, the opening of Ways of Seeing presents a filmic reenactment of the argument of Walter Benjamin’s essay ‘The Work of Art in the Age of Mechanical Reproduction’ (1936). (One of the chief legacies of the show was helping to launch Benjamin to the front of the critical canon.) Writing during the terrifying onrush of fascism, Benjamin saw the crisis of European liberalism as, in part, a result of the emergence of new media. The advent of photography, the phonograph and other machines of automated replication had produced a more disturbing change in social consciousness than others had recognised. The CliffsNotes version of the essay focuses on Benjamin’s notion of the aura , the idea that reproduction severs artworks from their anchors in space and time, that facsimiles lack something that originals possess. But this was only half of his argument. Benjamin was just as interested in the entire network of mass mediation (as a replacement of art) and the new, seemingly unanchored artform of film. These, he believed, were part of a broader shift that meant nothing less than ‘the shattering of tradition’ and the ‘liquidation of the value of tradition in the cultural heritage’. As new forms of technological culture replaced the old – and the argument will be familiar to anyone who has paid attention in the past several years to discussion of the internet – civilisation moved into a halfway house of mediation, susceptible to new modes of political adventurism and mass behaviour.

Benjamin’s essential concept of remediation has come to denote the process by which an older medium is represented in, or mimicked by, a newer one (as well as the inverse). The yellow sticky notes on your laptop or the painting app on your phone are common examples. Ways of Seeing was itself one of the most ambitious, self-reflexive projects of remediation of the entire postwar period. Building on André Malraux’s concept of a ‘museum without walls’, Berger built a museum of the airwaves. He presented at an often dizzying pace: Botticelli, Leonardo, van Eyck, Bruegel, Rembrandt, Van Gogh, Caravaggio, Goya, Hals (all in the first episode). Berger was bringing painting into what Raymond Williams called ‘an irresponsible flow of images’ characteristic of television. It was an early harbinger of the waterfall scroll of Instagram or Google Images.

Remediation has been theorised by contemporary scholars in relation to adaptation, translation, perspective, realism, transparency, sampling, recyclage and the user interface. For Berger, it was always connected to something more fundamentally human: the experience of migration. What does it mean to be uprooted, removed from an original source, and placed into new surroundings? And what does such an otherwise intimate experience reveal of the creative-destructive engines of modernity?

Berger’s best essays convey a miraculous gratitude that the world comes into view at all

At the start of the 20th century, a number of Central European critics raised these questions with special force. From the Leftist philosopher Georg Lukács (who spoke of the modern era as one of ‘transcendental homelessness’) and his friends Béla Balázs and Karl Mannheim, to the Heidelberg circle around Max Weber, including Ernst Bloch, to Benjamin, Theodor Adorno and the other members of the Frankfurt School, the generation coming of age amid the crises of fin-de-siècle Europe excelled at feeling (and analysing) the disorienting, everyday effects of capitalist progress: alienation, solitude, fragmentation, a sense of spiritual orphaning. (The style also captured the imaginations of many on the Right, including Martin Heidegger and Mircea Eliade.)

Born a generation later, Berger became perhaps the most important critic to extend their intellectual project into the postwar English-speaking world, and then into the postmodern era of high globalisation. He worked within what might be called a ‘warm current’ of the European Left: an anticapitalist humanism less interested in structural analyses of exploitation (though Ways of Seeing had its dose of structuralism) than in ground-level questions of meaning and experience. In a modern world that Weber described as disenchanted, the qualitative virtues of traditional societies had been replaced by a ‘machine mentality’ whose metrics of self-advancement had to be expressed in numerical terms – money, productivity, efficiency. This was part of a larger desire to reduce all of nature to figures and formulae, eliminating the first-hand power of the senses: the visible and the audible, the palpable and the ineffable.

On a formal level, Berger was obsessed by the arts of sight: drawing, painting, photography, cinema. He often wrote about appearances directly, conjuring small physical presences as few others could: the way that a lizard shimmies as it moves, the warmth of grass in the sun, the ‘red of young eyelids shut tight’. His best essays convey a miraculous gratitude that the world comes into view at all. Berger was anything but pedantic. He was friends with academics, including famous ones, but his style was anathema to the learned and world-weary. The renowned literary critic Frank Kermode once wrote to Berger remembering a stay in his ‘peculiar paradise’ in the Vaucluse in southeastern France, so different from the ‘low morale’ and ‘vanity’ of Cambridge.

Ways of Seeing has had its impact on the discipline of art history – as both grenade and leveller – even as Berger remained uninterested in the kinds of questions that art historians tend to pose. He was drawn instead to far more religious themes: longing and exile, encounter and estrangement, leave-taking and return. His greatest legacy might lie in the unique ways in which he combined these two spheres – the visual and the existential – both of which have their roots in evolutionary biology. (Visual areas account for a large portion of the cortical surface of the human brain, while the prefrontal cortex deals in memory and those cognitive processes that help to found a coherent self.) Berger was one of the few modern writers to have trafficked so regularly between the world of ideas and the world of things. As he later reflected, it was perhaps his early work in television, with its voiceover and film track, that helped him to synthesise his love of both words and images, thinking and seeing.

‘The way in which human perception is organised,’ Benjamin wrote, ‘is conditioned not only by nature but by history.’ For Berger, the changes to visuality in the 20th century must be understood in relation to the qualitative dimensions of its historical watersheds. Close to 20 years after Ways of Seeing , he wrote of the advent of cinema in relation to the experience of exile. He saw cinema and exile as intertwined, part of an intimate dialogue between presence and absence. To film anything is to safeguard it for the future, and so to foresee its eventual loss. It is to watch a set of moments pass into a separate realm both inside and outside of time. ‘In the sky of cinema,’ Berger wrote, ‘people learn what they might have been and discover what belongs to them apart from their single lives.’ The century of film was also a century of transport, emigration, disappearance, uprooting. ‘Painting brings home,’ he concluded. ‘The cinema transports elsewhere.’

That distinction emerges as the heart of Ways of Seeing . As a film about painting, it was the hinge on which the programme was built: between locomotion and stillness, sound and silence, a blue screen and canvas. ‘With the invention of the camera everything changed,’ Berger tells us in the first episode. European painting once gathered the visible world into fixed scenes of static permanence. But film meant ‘we could see things that were not there in front of us’. Appearances entered a state of motion and flux. They began to travel across the world. ‘It was no longer so easy to think of appearances always travelling to a single centre.’

‘A single centre . ’ This might be another word for a home – that place, as the poet W H Auden put it in ‘Detective Story’ (1937), ‘where the three or four things/that happen to a man do happen’. For Berger, the need for a home was part of human nature, dating back thousands of years, at least to palaeolithic dwellings and the transition from nomadism to agriculture. In an essay first published as ‘A Home Is not a House’ (1983), curiously prompted by Steven Spielberg’s film ET (1982) and its global popularity, Berger considered more archetypal beginnings. The term ‘home’, he admits, has been long taken over by the moralising of conservatives and xenophobes, both representatives of the ruling class, who have worked to hide its more original meaning. He writes:

Originally home meant the centre of the world – not in a geographical but in an ontological sense … home was the place from which the world could be founded … Without a home at the centre of the real, one was not only shelterless, but also lost in non-being, in unreality. Without a home, everything was fragmentation.

Though expressed in straightforward prose, Berger’s essay slaloms through a conceptual minefield, one that has confused (and intimidated) most thinkers on the Left for at least a century. No other baby has been as perpetually thrown out with the bathwater of politics as has the concept of home – perhaps due to its presumed relation to the ‘national question’ or the desire for property. On each of these scores, Berger drew fundamental distinctions. Along with only a handful of postwar critics, most of whom were refugees, he wanted to acknowledge the atavistic pull that an original home can exert. To long for one is not incipient fascism, but a desire perverted by the ideologies of patriotism and patriarchy.

Though aware of the very real contradictions, Berger would have agreed with Edward Said, who wrote in ‘Reflections on Exile’ (1984) of the ‘unhealable rift forced between a human being and a native place, between the self and a true home: its essential sadness can never be surmounted.’ And yet he would have also agreed with Vilém Flusser, the Czech-Brazilian philosopher, who spoke of the migrant not only as a challenge to the native’s self-centredness but as holding the capacity to enlighten. Flusser, who (like Berger) wrote extensively on both photography and emigration, in ‘The Challenge of the Migrant’ (1985) suggested that the migrant should be seen as a ‘vanguard of the future’, an emissary of a new mystery: not the old mystery of a lost homeland but rather ‘the mystery of living together with others’.

The two groups for whom Berger came to advocate, the Zapatistas and the Palestinians, were both stateless

In Berger’s work, the figure of the foreigner represents promise more than threat. This was true in his first novel, A Painter of Our Time (1958), about a Hungarian émigré in London. It was also true for A Seventh Man (1976), his collaborative account of migrant workers in Europe, and his trilogy of peasant fiction, Into Their Labours (1991). In Flusser’s words, the migrant can be ‘both a window through which those who have been left behind may see the world and the mirror in which they may see themselves, even if in distortion’. Much critical thought has examined those distortions. Said reframes the question, asking how we might ‘surmount the loneliness of exile without falling into the encompassing and thumping language of national pride, collective sentiments, group passions?’ At a political moment that has seen the stunning rise of Donald Trump, Narendra Modi, Jair Bolsonaro, Viktor Orbán – the list goes on – this might be the million-dollar question of our time.

Unlike other social theorists, Berger never tried to reason his way through the contradictions of nation-state or the citizen/non-citizen distinction. He preferred instead to disown any affinity at all with state power. The two groups for whom he came to advocate, the Zapatistas and the Palestinians, were both stateless. Perhaps this was a cop-out – but maybe not. In an otherwise sympathetic review of Berger’s From A to X (2008), Ursula K Le Guin pointed to the absence of political complexity in the novel: the allegorical universalism of its revolutionary lovers effectively ‘exonerated [their people] from bigotry and political folly or factionalism’. The charge of sentimentalism was often levelled against his later work.

In 2007, aged 81, Berger published Hold Everything Dear , about the War on Terror and the global migration crisis. In a phone interview with an Australian radio host, he was asked to directly confront the contradiction that immigrants can put pressure on the native poor, making them ‘nervous and even angry’. Berger drew back. ‘I don’t deny the difficulties,’ he said, but he added that the problems were often distorted by the vested interests of the national press, and by cynicism:

You ask me as though I can find a solution. No, I can’t find a solution in theory like that, of course not. The solutions … we’re not really talking about solutions, we’re talking about finding a way to live, to survive, to perhaps discover forms of mutual aid … All that can only happen in practice, in particular situations in the way that people associate or don’t associate in terms of some small project or in defence of some small thing which is in the area where they live. It’s not for somebody talking on the radio abstractly about the world who will find that kind of solution.

The answer reflected Berger’s distrust of theoretical remedies to human problems. Perhaps even more so, it accorded with his respect for practice and social knowledge. He never tried to gain the ear of power. He was more concerned with everyday gestures and decisions: the choices people either make or fail to make in their own lives.

A choice about a way to live presented itself to Berger shortly after he made Ways of Seeing . He was in his late 40s and had achieved an international level of fame. The invitations started coming in. He could have taken a position at a museum or university. He could have entered a world of sinecures and fellowships, residencies and agents, conferences and airports. He turned down almost all of this.

The reasons were historical as well as personal, and might relate, however indirectly, to our own contemporary impasse: our inability to see more than one generation into the future, the dissolving legitimacy of the metropolitan and academic elite, the seeming incapacity to move beyond a politics of negativity and despair. Just as we are hitting the limits of critique as a culture, Berger was hitting them as a writer – and a person. With Ways of Seeing (and his Booker-winning novel G. ), he had reached a tipping point that was also a midlife crisis and a fork in the road. ‘I can be only by destroying,’ Lionel Trilling once wrote of a certain modern attitude, ‘I can know myself only by what I shatter.’ But where is there to go when the demolition is complete?

There is a photograph of Berger from the 1973 Frankfurt Book Fair. Taken by Jean Mohr, a lifelong friend, it shows a middle-aged writer, exhausted and detached, lying on the floor as others walk past him in a blur. What was Berger thinking about? What was he longing for? It was at this fair that Berger met a young American, Beverly Bancroft, then an assistant at Penguin Books. Within a year, they were married. Two years later, they had a son. Soon they moved to a small farming village in the foothills of the Alps. The chalet they rented lacked central heating and running water. The outhouse was across the driveway.

The question, he once said, was of ‘continually learning to be embedded in life’

It would be easy to romanticise Berger’s third act as a rural storyteller. Even while haymaking, he was still a renowned writer with famous friends. But it would be just as easy to cynically write it off. Throughout the neoliberal era, most intellectuals have lived in a social world that is urban, cosmopolitan, cutthroat and status-oriented. Berger went someplace very different. He remained politically committed though his conception of the political shifted and enlarged, absorbing a broader sense of history and experience.

The question, he once said, was of ‘continually learning to be embedded in life’. During the 1970s and ’80s, as Ways of Seeing made the rounds in British and American classrooms, Berger was discovering his own need for roots – what Simone Weil called ‘the most important and least recognised need of the human soul’ – even if they were freely chosen and across the English Channel. Embeddedness, in this way, was about the double anchors of community and place. It required, on the one hand, the help of others – not primarily because of their material aid but because ‘they are real and therefore looking at them, being with them, you become real in that moment’ – but it also required an individual openness to the physicality of the world: the seasons, the rising and setting of the sun, the trees and animals and rain.

How this ontology would map onto urban experience is an open question that Berger never fully answered. How it would map onto digital experience is something we have yet to answer. Yet there is in his late work a kernel of something perhaps visionary. At a time when E M Forster’s humanist mantra – only connect – has come to sound like a slogan for an internet provider, Berger’s more numinous, earthly communions might be the most useful. Ways of Seeing remains the way he came to the attention of millions, and the hinge in his life. His long trajectory after the dividing line of Ways of Seeing still has much, maybe even more, to teach us.

In the conversation with the Australian interviewer, Berger felt compelled, if only for a moment, to leave the sphere of ideas. ‘Now I live here,’ he said of the village where he had settled:

I’m looking out of the window, the sky is grey, it’s got to be about 13 degrees … The hay is getting browner and browner, less and less nutritious, so there will be less and less milk this winter when the cows are fed hay because of the snow outside. So I’m sitting here in front of that window, and now, after all those years, I’m sitting at home …

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