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We basically over come what we would call discomfort, and I think you might, a lot of people might call p. We're going to find out how we can all learn to combat p by controlling our sense of touch to an astonishing degree. We use touch to explore the world. Instantly we can tell how something feels to us. Frozen and grungy. But our sense of touch does much more than just tells us what's there. But touching something smooth and soft feels lovely. Ooh that's very nice. I could sleep in a in a large mattress of this stuff. So why do we care so much about how things feel? We've come to Jodhpur in Northern India, to pay a visit to some distant relations, a troop of hanuman Langers. These monkeys hold clues to the origins of our sense of touch. For most animals the occasional touch is part of normal life. But monkeys adore touching and being touched. We come from a long line of touchy feely ancestors and for them like us touch is more than just simply exploring the world. It's not about keeping clean. Touch is how they get along. Scientists have shown that grooming releases endorphins in to the blood stream. Endorphins are feeling good chemicals. So it's a stress reliever for the monkey that's being groomed. And even for the monkey that's doing the grooming. Grooming just about anything makes them feel good. And from our monkey ancestors we've inherited the same strong feelings about touch. And ingenious way of telling well from bad. Embedded in the surface of the skin there are millions of touch receptors. And it's those that relay the sensation of touch right to the brains. Sensing what's touching us is actually a remarkable piece of detective work. Because there are no specific sensors telling us whether something are wet or dry, or rough or smooth. So how can we tell if it's a drop of oil or the stroke of a hand? Touch receptors only monitor basic things like pressure temperature and minute vibrations on the skin. They feed this information as nerve signals to the brain. It's the exact combination of signals coming from them skin that allows the brain to work out what's touching us. But our sense of touch does more than just tell us what's there. Our skin is also designed to protect us from damaging ourselves. When a firm touch gets too much it suddenly feels very different. It hurts. This is hurting because special p receptors are firing. Our p receptors, they do nothing except scream at us when things get just too rough, arch. There's actually a lot more to p than you, might think. This is just the beginning, arch. If we're such touchy creatures how do people like Jim Rose do things which look so pful Well curiously back in India, there's a another animal that provides a useful tip Much of an elephant's hide isn't very sensitive at all, just as well. If you spend you life being scratched and scraped by thorns. A forest of spiny lantana catches on your skin, and your clothes. To go through stuff like this you need a hide as thick as old boots. And that's why, elephants, aren't offended if you call them thick-skinned. In fact zoologists refer to elephants as pachyderms. Which literally means thick skinned. So while this lantana thorn scrub would tear your legs to shreds these elephants hardly seem to notice it. Their skin is so thick it takes a lot to scratch an itch. That sound it's enough to make you wince. But not all of an elephant's skin is so tough the finger like tip of the trunk is extremely sensitive. And has the highest density of touch receptors anywhere on the elephant's body. Where they're most sensitive to touch they're also most sensitive to p. So elephants approach things very gingerly with their trunks. Thank you. The sensitivity of the elephant's skin to touch and p varies enormously over its body. From the delicate soft snout to its thick leathery hide. We probably seem as strange to an elephant as they do to us. We look so different but when it comes to our sense of touch we've actually got a lot in common. Their touch receptors are concentrated where they interact most with the world. And so need to have the best sense of touch. And in that respect we humans are exactly the same. And generally we feel less p in areas, which are less sensitive to touch. A tiny paper cut on your finger is excruciating. But you can cut your leg and it doesn't hurt nearly as much. So we feel things very differently across our bodies. But that's not just because of the number of touch receptors in the skin. Each area of the body sends touch signals to a particular area of the brain. If the size of your body parts reflected how sensitive they are, you'd be in for a shock. Our extremely sensitive hands would be huge. Your feet would be as big as your chest, and half of their length would be your toes. It's no wonder they're so ticklish. And your face is much more sensitive than your chest and back so that too would be bigger. Your lips would put Mick Jaggers to shame. Your tongue would be as big as your already oversized hands. Put it all together and you'd have something that even a mother would find hard to love. So because we feel things so differently in different areas of our bodies. Things are always going to hurt a lot less on your back and your legs. But when it comes to confronting p there's another vital aspect of our sense of touch that can help. Sometimes we completely ignore the touch signals coming from our bodies. It happens all the time. And one man who knows how is at Stamford University in California. Professor David Spiegel. He's studying how hypnosis can sometimes help reduce chronic p that can't be treated with drugs. Hypnosis is a naturally occurring state of highly focused attention coupled with physical relaxation. People go in to it all the time, every day. When you're in a movie and you get so caught up in the movie that you start to think it's the real world. That's a hypnotic like state. To demonstrate the power of hypnosis to control p, Prof. Spiegel is going to hypnotize our volunteer and then stick pins in to his left hand. And then close your eyes slowly, let your body float. The volunteer is told to imagine his left hand is in numbingly cold water. I want you to imagine that your left hand is dipped in to a bucket of ice water. His right hand should be a sensitive as normal. Feel a bit of breeze on it. I'm feeling that yeah. Ok so now we're going to see how your hand feels when we test the sense of pleasant cool tingling numbness. How's you hand feeling now? Research from brain scans has shown how hypnosis affects the brain. The p from the needle triggers two areas in the brain. The first tells us that our hand is hurting. The second controls just pful it feels. Hypnosis turns down the brain activity in both these areas so reducing the amount of p the subject feels. So what does it feel like in you left hand and arm? Any discomfort? Amazingly in his left hand which he's been told to imagine is numb this volunteer doesn't mind the needles sticking in to his hand. But in the right hand, which he's not imagining is numb; the needles are unbearable causing shooting ps up the arm. Sorry how is it now? Yeah that's better. Alright so now we're going to remove the needles, that of your left hand. Out they come. Do you feel anything now? No I feel nothing at all. Deep breath and we'll come out of this state of self-hypnosis, feeling relaxed and refreshed. You really didn't feel it in here huh? No not at all. That's great that's great you did very well it was there for quite a while yeah. All hypnosis is really self-hypnosis, it's just a way of teaching you how to use your capacity that you have naturally, but focus it on a certain strategy to deal with p. So basically you can go into the self hypnotic state by anything that gets you to turn inward to pay attention, turn inward cut out your awareness of outside cues and that you can learn to do all by your self. So is our guinea pig now ready to lie on a bed of blades. Jim wife had a plate broken with a cannon ball. But now he's thoughtfully lined up something else. We've discovered several ways to help cope with the p. Just like the elephant some areas of our skin are much less sensitive. So lying on your back should make it less pful. Expectation has a lot to do with the amount of p we feel. Despite our keen sense of touch we can actually reduce the amount of p we feel. If you can relax and focus on something else, than the theory goes lying on a bed of blades should be a breeze my friend you're going to have to take of that T-shirt. You're going to do this bare backed. That's right. That's right I told you he had hair in places monkeys don't obviously there's a degree of showmanship with Jim's act. So this can't be as nasty as it looks. But even so it's not something to try at home. One other thing, you can never be too safe. There you go. Swim doesn't be there. Take a look at that back. Take a look at that back Come on. So with our minds we have astonishing power to control how pful things feel to us. Our brain decides what touch sensations we register and what we ignore. And in that respect our sense of vision is surprisingly similar. In the second half of the program we're going to reveal the fabulous things our visual systems can do. But we'll also discover why our brains can fail to register the blindingly obvious. Would you spot this change over? Get your video recording now and at the end of the program you'll discover how much you missed of what was happening right in front of your eyes. The South African Bush. We're here in search of a deadly animal whose vision is just like ours in one extraordinary way. She's a cobra, and has to be approached very carefully. Her flared hood is a warning. If provoked she could unleash a venomous strike, which could k me in minutes. But there's a little known fact about snake's eyes. If you stay still enough she shouldn't be able to see me. Because the light sensing cells in her eyes tire if what's they're looking at doesn't change. Faced with a static person the snake relaxes. But any sudden movement and the cobra attacks. Like all animals this snake has evolved to see just what she needs to see to survive and not much more. We're just the same. The human visual system is superbly good at some things, but we can also miss an amazing amount of what's happening right in front of our eyes. We're in the skies above Los Angeles, one of the few places where they'll let you play tag with real planes. We're about to put the co pilots eyes through a high-speed work out. Forget video games this is the way to test just how much our visual can cope with. The co pilot's job is to stop the other plane closing in at over 300 miles an hour. Then he has to get him in his sights and keep track of him as his plane hurtles around the sky. All he's looking for is a tiny spec in this empty sky. This takes real concentration. There he is, the planes caught the co pilot's attention because it was moving. So his eyes were automatically drawn to it. He knows he's been spotted so now he tries to loose the chasing plane. Even at speed the co pilot can follow him as the chase plane banks and spins his visual system has no trouble keeping track of which way the target plane is moving, and how far away it is. If the chasing team can get their laser on the other plane will have to surrender and let off a smoke trail. This 3 dimensional high-speed pursuit shows what we can do with our eyes. But how does our visual system measure up to the rest of the animal kingdom? There are plenty of exotic creatures equipped to see in truly fabulous ways. The mantis shrimp has remarkable eyes on stalks, which scan the world in 12 different colors. Chameleons have eyes, which can swivel independently. So one eye can be on the look out for danger, while the other lets them grab their supper. And some animals have much sharper eyes than us. From over 4 miles away an eagle can spot prey that would be completely invisible too us. These animals all have eyes suited to their needs. So what have ours evolved to be good at? We are group living animals and our real specialty is looking at the people around us, especially if we fancy them. In a busy nightspot we've decided to test exactly what people's eyes get up too. With the help of psychologist Ben Tatler and Cathy Hughes. Some volunteers have agreed to put on a headset that will record every move made by their eyes. Our eye track it gives us the opportunity to see where we're actually looking. This kind of important to record. Because the eyes are moving about all the time. They're darting around 3 times a second. And we're certainly not aware of this. So we need some kind of piece of equipment that's going to show us what's happening. Our volunteers think they're going to the back of the bar to be tested by the psychologists. But the real test is actually before that. They're asked to wait next to 2 women and a man who've been planted there. All attractive models. How much will our volunteers ogle them? And if they do will they know they're doing it? Time to play back the tape and our first victim is in for a surprise. Checked this guy as you went by. Did you realize that you were looking at him? No I noticed someone over there, they were laughing at me. That's all I did. Not that particular person she was very interested in our male model in the sleeveless T- shirt. And it's not just his face she's checking out. Next she takes a look at the bloke's bottoms along the bar. And she had no idea she was doing it. It's an eyes opener for me I'm amazed, absolutely, absolutely. In fact all our volunteers claim they weren't aware of where they were looking. Did you realize how much you were looking at them? Cause you were looking at these 2 girls quite a lot. No. In our test the women actually ogled more than the men. Our last volunteer just thought she was talking to her friend. But her eyes were all over the guy in the camel coat. I'm really embarrassed. I don't even know there's a guy in the bar with a camel coat on. And yet I must've been sat looking at him. Oh my god, oh no. Our brains are so good at people watching that we do it automatically without even realizing. So I guess the great thing at looking at eye movements and looking at where we look. Is that it does give us a window in to the way that the brain is working. What the brain is interested, at some kind of subconscious level. Even though it never gets through the point of us being aware. Our eyes never settle, and there's a good reason why they're constantly darting around. It's all to do with the basic design of the eyeball. Ophthalmologist Dr Bill Aylward takes a snap shot of the back of the eye. What you can see here are blood vessels, running over the surface of the retina. And beneath them are light sensitive cells, which allow you to see. Lining the inside of each eyeball there are over a 100 million light sensing cells. But only the bigger cone cells see in color. And amazingly only in one tiny area of each eye are there enough of these cone cells jammed packed tightly together for sharp color vision. Most of the retina gives you vision which is quite blurry, apart from this very small area in the middle. Just that smudges that we can see there. This little smudge here that really gives you really fine detailed vision. And that bright spot is even odder. An area which is completely blind. That's where all the blood vessels come in and out, and where all the optic nerve fibers go back to the brain. There's so much going on there that there aren't actually any light sensitive cells in that area. And that corresponds to your blind spot. So it is a very odd design. So if our eyes are designed with a blind spot and a mostly blurred image, how do we see the world in such intricate detail, and such vivid color? The patchy image made at the back of the eye is just the beginning of how we see. As our eyes dart around we make sure that anything interesting is lined up on our sharp spot, so we get a good look at it. And you don't know you're doing it. Because the brain takes these jerky snapshots and creates a nice smooth movie of the world. And the brain also compensates for the blind spot. Because our eyes give us slightly different images we can combine them to give one complete picture. Our visual system is constantly keeping track of what's out there and where it's moving. But it goes way beyond that. Some times we can even see things before they've happened. Scientists have recently discovered that baseball hitters do something quite extraordinary. The ball is moving so fast that the hitter can't simply watch the ball as it comes towards him, and then adjust his swing. So how does his bat end up in the right position? Your average novice tries to follow the ball through the air and then take aim that's disastrous. It's impossible I don't even know how you catch it? Top baseball stars like Gabe Kapler don't even try to watch the ball. You know they say that it's almost impossible for us to track the ball actually from the pitchers hand all the way in to the catcher's glove. Or when we make contact with the ball. But you know I don't know if that's true or not all I know is that natural ability tends to take over and the repetitive action that you do on a day to day basis as a hitter tends to take over. After facing thousands of throws Gabe has learnt to see in to the future. Scientists have discovered that within a few thousands of a second of the ball leaving the pitchers hand, Gabe's brain analyses the speed, spin and angle of the ball. And then he predicts where it's likely to end up. So he's swinging at the ball before any normal human being would know where it was going. And he does it with astonishing accuracy. Most of us aren't quite that sked. But every time we cross the road, we all use our eyes to predict where things will move. With each glance our brains are warring away. Working out where cars will be so we can dodge the traffic. We rely on our eyes to guide ourselves around the world. It's all about co-coordinating our sense of vision with our bodies. But we've not even born with the basics. Babies have to learn where things are and what they have to do to grab them. And until they get it right it can be a frustrating process. As adults we take it all for granted. But In Chicago Physiologist Hubert Dolizal has devised a bizarre way to test how well our brains can adjust. When everything we've spent years learning is turned on his head. He's built a set of goggles that flip the world up side down. Hello Hubert. Hubert has been wearing his goggles non-stop for 2 weeks now. We're going to see how well our human guinea pig learns to cope after just a few hours. That is so weird. At first it's totally disorientating, but at the end of the day we're going to see whether it's possible to ride a bike with the goggles on? Where are you its? I'm right here. Now here we go, Look at you lets shake hands. Argh ha First its back to Hubert's flat. And to start with a simple task that any child could do. It's so weird and my hand it just you know disembodied. It's back to square one. Tell you what I'm going to have a new admiration for babies now. When you see them playing and trying to stack things.
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![]() When it comes to touch we'll reveal why we love the feel of some things |
![]() It's all about co-ordinating our sense of vision with our bodies |
Good for you there is a great gaping fridge there. And I can't work out how to get my hand in. Everything that normally happens automatically is now a real struggle. You have to think about what you're seeing, work out where things are, and then move your hands. It makes you realize how even the simplest movements depend on accurate guidance from our eyes. Where is my hand? At first anyone entering this strange upside world has the hand eye co-ordination of a toddler but after a few hours there are signs of improvement. Hubert seems to have no trouble, but then he's spent weeks wearing the glasses, and to begin with he was just as bad. Whoops, whoops I just realized that I'm going to drink it with my forehead. I'm sorry. As the days went by Hubert adapted brilliantly. His brain started to make sense of this topsy-turvy world. Making the right movements automatically without having to think about it. Ooh. After 8 hours. Its time for our volunteer to attempt riding the bike. It takes a monumental effort of concentration not to fall off, but he's just about hanging on. |
![]() Embedded in the surface of the skin there are millions of touch receptors |
![]() Cone cells jammed packed tightly together for sharp colour vision |
The human sense of vision is superbly good at some things. Spotting attractive people in a crowd, guiding us around the world. And even predicting where things will end up. Doing all that takes a lot of brainpower. Almost a third of the brain is taken up with vision. But there's a limit to how much we can see without overloading the system. So something has to give, which is why we sometimes miss things happening right in front of us. A shopping centre in London. This man is going to go up to people and ask for directions. Then a door comes through and he swaps with some one else. Sorry what were you saying? They don't look that similar, so do you think people would notice the swap? There are 4 cameras hidden around the shopping centre so we can secretly film how people react when some one they're talking to suddenly changes. After a bit of practice its time to start the experiment. |
![]() Each area of the body sends touch signals to a particular area of the brain |
![]() Watch the tape again but this time just watch it as you would a normal piece of television |
Excuse me do you live around here? Sorry where? So did the unsuspecting members of the public notice that they'd been speaking to 2 different people? No I didn't and I think I walked away thinking damn I can't help that guy. And he's gone off in the wrong direction. I really don't know where he's going. Where? Less than half the people noticed the swap, which is exactly what happens whenever, this experiment is done. Even though the first person who stopped them swapped with someone different did they think they were still talking to the first person? Yeah I did. Excuse me sorry to trouble you; do you live around yep, you haven't heard of west, West Street? What and what about? They're looking right at the experimenter's faces. But their brains are too busy to register what their eyes are telling them. Most of the time our vision does a wonderful job. But there's a limit to how much our brains can cope with. So we just pay attention to one thing at a time. And we're blind to the rest. The brain has a huge amount of information being delivered to it by the eyes. It has to make the decision; it has to decide where to place its attention. What information it should scrutinize, what information it should ignore. |