Gateways To The Mind

The Bell Telephone System brings you another of its series of programs on science, man's effort to understand nature's laws. [Music] Heat. Heat. [Music] [Music] The sound stage with its gadgets and equipment will serve as a sort of workshop in the telling of our science story. The human senses, how they work and what they mean to man. And to help us along, we'll have the assistance of various members of the crew who work here. [Music] Thanks for the tour, Bill. Quite a place, this sound stage. Yeah, they're ready on the Aristotle set, doctor. Oh, thanks. Let's go. Oh, doc. I always thought this Aristotle was a real old guy with a long beard. You know, real ancient. Well, Bill, although Aristotle lived about 2500 years ago, he wasn't always an ancient. When he was a young man, like many other people of his time, he was interested in trying to learn about the human senses. But here he is getting a shave and surrounded as always by some of his students. [Music] [Applause] [Music] Certainly, there is nothing more distressing to the human senses than a dull razor. Master, continue. Udeis, what are your thoughts concerning the human senses? As meat and wine are nourishment to the body, the senses provide nutrient to the soul. All knowledge must come through the senses. all that we perceive and all of the awareness of our daily existence. Then we may summarize thus these senses bring us touching, seeing, hearing, tasting, smelling, and all that we know of the world comes to us through these five senses. So Aristotle was the first guy to figure it out, huh? Not the first maybe, but Aristotle wrote some very interesting things about the census. Well worth reading today. Yeah, but everything comes to us through our senses. Yes, indeed, Bill. Now you think about it. Without the information your senses bring you, you'd be like a man locked in a dark cave. Now, in one big respect, Aristotle was wrong. We have many more than five senses. And for another thing, we don't hear with just our ears alone. We don't smell just with our noses. We don't taste just with our tongues. Hey, wait a minute, Doc. After 20 years behind this camera, you're not going to tell me I don't see with my eyes, are you? Well, in a strict sense, you don't, Hal. Your eyes, like your other sense organs, simply receive impressions from the outside and send them on to the brain. And that gets into my department, doctor. Good. It's always interesting to see what you animators come up with. Well, trying to draw a character that represents a sense. Pretty tough assignment, huh? You bet. But we have to show how they work. So we finally came up with our old friend Mercury, messenger to the gods, but a kind of a a wiry electrical Mercury. Very quick, responsive. Number one supplies us with a big percentage of our information. Reacts to the air vibrations we call sound. One of the two chemical senses. Another chemist taste specialist reacts only to salty, sweet, bitter, and sour. Responds to changes in surface or or skin conditions. So there they are, the familiar five, but not like messengers really. More like dispatchers dispatching information through the network of the sensory nervous system. Let's see how touch does it. Okay, now let's take the tip of the finger. That's where the sensory endings of touch are most plentiful. When the skin touches something, our friend here dispatches a sort of signal to headquarters. Well, in very simple terms, that's about what happens. But how that signal gets to headquarters in the brain, that's the first part of our big story. Within our bodies is a marvelous network of nerves. Nerves that carry the signals and carry them to the brain. Carry the signals. But how do by electricity? See the nerves of this network are made up of the long thin fibers of living nerve cells. Nerve cells that can make their own electricity. Luigi Galvani experimenting with what was then known as animal electricity accidentally touched the big muscle in the leg of a frog with two pieces of metal that were in contact with each other. The electrical stimulus caused the frog's leg to jump. That was almost 200 years ago. The arguments that grew out of Galvani's experiment led to Valta's discovery of the principle of the electric battery. Doc, don't tell me I got an electric battery somewhere inside of me. No, not batteries, but nerve cells. Hundreds of millions of them, each capable of making electric charges. Bill, turn on this machine, will you? This is an actual recording of the electrical impulses going from a living eye to a living brain. HK Hartline of the Rockefeller Institute for Medical Research, who made this recording, is studying patterns of impulses in the optic nerve fibers and how these patterns serve as information for the brain. These impulses race through our sensory system whenever sense receptors trigger electrical discharges into the nerve fibers. Each nerve cell passes the impulse along by discharging its electricity to fire the next cell in the chain. The impulses jump along at speeds up to a 100 miles an hour or more. These living cells are self-charging. They recover and are ready to fire again in a tiny fraction of a second. Doc, then this nerve network can carry all the different signals from all the different senses. Yes, that's a funny thing. The senses are all different. The signals are all alike. Yeah, but then how could the brain know which sense is sending the message? Bill, you've just asked the big question. That brings us up to the brain. It's the areas in the brain, the specific areas where the signals end up that tell us whether we are touching, seeing, hearing, tasting, or smelling. Ever since Johannes Mueller, a German physiologist of the 19th century, recognized this, scientists have been trying to understand how the brain transforms information it receives into action, sensation, and thought. After all, it's not the easiest thing in the world to look in on the actions and workings of a living brain. Maybe that's where the animator has an advantage. He can invent one. That's an interesting idea. Look, here's just a few of the hundreds of sketches that we waited through trying to make our drawings agree with your facts. Couldn't find a place for those 12 billion nerve cells, huh, Gene? No. We soon realized that the best we could hope to do was map a part of it into a kind of a electronic headquarters. This is our latest try. It shows up pretty well on this enlarged drawing. Most of the nerve impulses enter here from the spinal cord. Uh-huh. And they pass through here to this relay center at the base of the brain. Yes. That would be what is called the phalamus. And the impulses go on upward to their destination. Yes. Their destination in the gray outer layer of the brain called the cortex. We've drawn electronic tubes to indicate the areas where the messages come in. Oh, here's a better view. Now, you see, if the impulses came from the eye, they'd come down through here. In the same way we've set up tubes for the ear, nose, tongue, touch, and all the rest. And these electrical impulses come alive as pictures on what we call the master receiver. And I suppose the smaller screen represents the memory section, right? Impressions are recorded and stored there for later reference. Now here on the master dispatching board, we transform sensory information into conscious action, walking, talking, and so on. All right, let's see this electrical headquarters of yours in operation. Well, Lou is in charge of the making it work department. So Lou's the one who really has to make these drawings move, huh? Well, I do the thinking and he does the work. Thanks, Dad. Well, doctor, we've animated a little sequence here about a character we call Joe Commuter. Here he is, undisturbed by any outside uh stimulus, like that 7:15 special he takes five mornings a week. [Laughter] Who's the little man? He's new around here, isn't he? Well, he represents the thinking part of Joe's brain. He checks things against memory and past experience and decides Joe's actions on the probabilities of the future. Joe Joseph. Next on the agenda, breakfast. [Music] Good morning, dear. And so the day begins. [Music] [Music] What a beautiful day. It's nice to live in the country. I think I'll walk to the station. Well, what do you know? Wild strawberries. They used to taste wonderful when I was a kid. Hold it. Hold it right there. Now, let's back up and break that action down into slow motion and see what happened. The first thing Joe has to decide is whether these really are strawberries. Well, that's where the eye comes in. [Music] H, they look familiar. Let's check. [Music] Strawberry, huh? Of course. [Music] Well, what about the other senses? Not much action here. Strawberries aren't very noisy. [Music] Meanwhile, touch is checking up on everything coming in contact with the skin. [Music] And so, headquarters is informed. The Mary is picked. Wait a minute. How about checking with the lab sense of smell? Uhhuh. And that worried look is natural. After all, how do you describe the smell of a strawberry? Stimulus dispatched. Analyzed. Okay. Bed by headquarters. Go ahead, eat it. Taste it. Another chemist gets into the act. Taste this time. How is it? Should be sweet. [Music] Sour. Sour. Well, a lot happened in those few moments. And Lou, what was it that triggered all those little sensory characters into action? Well, the light from the strawberry carried the stimulus to the eye. BB buzzing stimulated the ear and the chemical reaction on the nose and tongue stimulated the sensory endings of smell and taste. Stimulus. That's the key word. Stimulus. Is that film ready? All set, doctor. Fine. Let's take a look at it. It's the key word because all forms of life respond to a stimulus. It's one of the things that all living creatures have in common. Turn it on, Bill. [Music] Just as human beings with their complicated sense organs and nervous systems respond to the stimulus of touch, so do the simplest one- cellled animals which can be seen only with a microscope. This is an amoeba. These various single-sellled animals have of course no specialized sensory cells or nervous systems, but they lead a busy life in their microscopic world. The first important groups of multis-selled animals have a simple nerve network connecting individual sensory cells and are particularly sensitive to touch. [Music] Jellyfish have notches around the perimeter of their bodies in which there are sense organs sensitive to light and to food. This inquisitive looking animal uses his tentacles for touch, but also has an eye at the base of each of them. These more complex animals have the sensory cells grouped together into sensory organs connected by a nervous system with a primitive brain. In the insect world, you may find many surprises. The hearing organs of the grasshopper are on the side of his abdomen, and he tastes food even before he eats it with small appendages outside his mouth. Most insects have organs for both touch and smell on their antenna. In some insects, sight is more important. The dragonfly has unique compound eyes that practically cover his head. Fish can taste all over their bodies. Like other animals, their sense organs developed according to their particular needs. The chameleon can look in two directions at once because each eye works independently of the other. The alligator has an extra eyelid to protect his eyes when he opens them underwater. Some snakes, like the pit viper, have a special sense on their faces that detects the heat of warm-blooded prey at a distance. Among the birds of prey, the faul and especially has a keen eye. The cat, whose senses are all quite well-developed, is highly sensitive to the stimulus of touch on the tips of his whiskers. In each instance, the pattern of each animal's sensory development is reflected in the development of its unique brain structure. Compared to those of many animals, man's senses are much less acute. He can't see like a falcon, smell everything a dog smells. But man, lives by his wits as well as his senses. Man, and only man possesses a brain that gives him the capacity of imagination and thought far beyond the limited mental activity needed for daily survival. And only man has developed a singular ability to speak, to reason, and to plan far into the future. [Music] George, I know that this is your office, but what exactly happens here? My job is to control the strength of the electrical currents coming from the microphones and bring them into balance on this console. It's called mixing and then it's recorded on film. Not anymore. Magnetic tape. Now, in other words, these sounds are first converted into electrical impulses and then they're balanced and amplified in this console and then recorded. That's correct. That's a lot like the ear works. Vibrations, electricity, sound. So, it is. But George's ear is a much more complicated instrument than the equipment he operates. How does the inside of the human hearing apparatus look to an animator, Jean? Well, I'll tell you, doctor. Let's find out by following the sound of chopsticks right into George's ear. The outer ear is shaped somewhat like a funnel ending at the eardrum. The surface of the eard drum is pushed back and forth by the vibrations of the sound waves. The movement of the eard drum sets the oicles in action. Three little bones commonly known as the hammer, anvil, and stur. This film shows the human eard drum which is only about a/4 of an inch across. These are the oicles at work within the human ear. The tiny steerup works with a rocking motion creating pressure on the fluid of the inner ear, the coccia. Driving back and forth, this little lever mechanism increases the pressure about 10 times. And now we discover what really happens to chopsticks. Here's a simplified view of the coccia. It's lined with a thin baselor membrane which contains 24,000 hairlike cells. In this illustration, they somewhat resemble the keyboard of a piano. The sound waves, now transformed into fluid pressure waves, disturb the hairike cells along the baselor keyboard according to the pitch of the notes. Each pitch vibrates a particular group of tiny hair cells, triggering electrical impulses that proceed along the auditory nerve and form a brain pattern, which to us means music. Now, those nerve impulses we heard a while ago, they're the same for uh well, seeing or hearing? Well, to answer your question, Bill, come and help me, will you? Here again is Dr. Hartine's recording of optic nerve impulses. Dr. Lloyd Bidler, Florida State University, has made these recordings of impulses originating in the taste buds. Recordings have also been made to smell for impulses from the alactory nerve. They're all the same. Yes, the impulses for all the senses are the same. There's another interesting thing a little further on this roll here. As the stimulus from outside increases, the number of impulses goes up accordingly. These things were first demonstrated in the 1920s by Ed Adrian of the University of Cambridge. It's the same with all of our senses. taste. For instance, this time the chemicals of food or drink excite the hairlike cells of the taste buds which line the crevices of our tongues. The remarkable thing is that taste is not just one sense. It's actually four. Sweet, salt, sour, and bitter. Seems to me I taste more different ways than just four. That's because when you're tasting things, you're also smelling things. The range of smell seems to be boundless. seem to be about as many different smells as there are things to smell. And of course, taste plus smell equals flavor. Jean, come on. We have to go over the West Tricks. Sure. You know, a fellow told me that if you hold your nose, you can't tell whether you've got a little piece of apple or onion on your tongue. Yeah. How about that? That's right. When we taste something, the chances are we also smell it. Hey, doc, this pop tastes cold. Am I smelling that? Oh yes, that's another thing. In our mouths, we have temperature senses which react to ice cream, hot coffee, hot and cold things. Certainly, we find that the sense of smell is most useful to man. Perhaps primitive man like the animals made much greater use of it. For most animals, smell is still the most trustworthy sense. Turn on the machine, will you? The delicate thawn uses his sensitive nose as well as his ears to warn of approaching danger. Many stories are told about the moth's extraordinary sense of smell with receptors located on its most remarkable antenna. Ants, too, have receptors for smell on their antenna. Now, we know about the rabbit. Big ears, always cocked, and a busy nose, always alert. And speaking of a busy nose, [Music] Bill, in the case of the dog, do you know what he was smelling? A bone. Molecules. You mean to say we smell molecules? Whatever we smell is in the form of tiny molecules that being volatile take off into the air. We smell them as odors, aromas, for example. They bring us the first sweet scent of new spring blossoms. [Music] Rich and long remembered experiences come to us through the air as tiny molecules. And wafted free on the clear morning breeze, they can smell mighty good. We help the molecules get to the right place by sniffing. They wind up in a chemical laboratory for that's what the upper chamber of the nose actually is. When the molecules reach this chamber, they chemically stimulate the millions of cell filaments on the alactory patch. And from here, as in the case of the other senses, messages races, electrical impulses to the brain where we experience the sense of smell. [Music] Doc, before you get to the science of how we see, I'd like to introduce you to the big eye. Well, it's true. The human eye has often been compared to the workings of a camera. You step right this way, Doc. Now, suppose we start with a lens. You can see inside the sunbox. The light coming through the lens is focused on the film. Now, this is the iris, and we can regulate the way it opens and closes to admit various degrees of light. Now, suppose we look at the side. Now the film moves down here where the light coming through the lens strikes it. So this is where the negative is exposed. Yes, that's right. Hal, your camera is a fine machine for taking moving pictures. Now let's look at something much more remarkable. [Music] This is a closeup of a normal human eye. The periodic blinking of our lid keeps the outer eye surface moist. Up under the lid and at each corner of the eye are tiny glands manufacturing tears which wash away dirt particles and contain an antibiotic to combat germs. The iris opens and closes automatically to control the amount of light admitted through the pupil to the inner eye. Ever wonder what a doctor sees when he looks inside your eye? Well, here it is. The retina. The only place in a living man where some of his nervous system can be seen. This part of the eye compares to the film in the camera. It's on this delicate screen that all objects of our vision are transformed into myriad electrical impulses. This is the blind spot where the nerve fibers of the retina come together to form the optic nerve which bundles them out to the brain. There are no light receptors at this point. So it is literally a blind spot. Now in this diagrammatic side view, light reflected from an object strikes the transparent surface of the eye, the cornea. The iris opens or closes to the correct aperture. The light passes through the lens which brings it into focus on the retina. This curved screen contains over 125 million tiny light sensitive cells, each capable of dispatching an individual message to the brain. In this photo microraph of the cross-section of the retina, we can actually see some of these cells. This depression is the phobia. Here we have our sharpest vision concentrated in an area the size of a pin head. This is the visual center of the eye. Looking at something means catching its image on the phobia. We have two kinds of light sensitive cells, cones and rods. The cones in bright light transmit our color vision. In dim light, they cease to work and the rods take over. Rods transmit our vision only in black and white. This is why, as daylight deepens into dust, colors dim and fade away. Here's a diagrammatical closeup of the rods and cones. Each rod and cone is sensitive to light because of a pigment contained in its tip. When this colored substance is struck by light, it's chemically changed. This excites the nerve, sending messages to the brain which enable us to see. This then is the human eye, an organ which inspires poets as well as scientists. For it is the eye that gives us the colorful, everchanging world of vision. In order to examine the last of Aristotle's five senses, the sense of touch, let's drop in on this gentleman to whom we have already been introduced. Return again to that road map of his sensory system and out to that suburb we visited before. And it's a well populated place because in one tiny area we find not only the sense of touch but at least four other senses. These are true senses just like Aristotle's major five for each has its own signal system and nerve endings that can be individually identified. For example, these are the free nerve endings of pain. There are millions upon millions of these tiny filaments throughout our bodies. Well, Jean, why don't you try one of your real life dramas to show how this team of senses operates? Okay, let's take the situation of a lady testing a hot iron. Bill here has consented to act the exacting role of housewife. I'm one of those modests to science you hear about. Okay, let's run through the whole act. Oh, bravo. And here's the way it works. Now, in slow motion, when the tip of the finger touches that hot surface, a number of things happen and happen fast. Hundreds of pain endings charge into action. [Music] Touch sends out information on surface conditions. Heat and cold report the temperature changes on the skin. Pressure reacts to the sensation of finger against iron. So these sensory messages race up the finger and the arm and reach the spinal cord where there's something like oh an automatic switchboard where pain triggers an immediate reflex action as well as continuing to the brain. Now the reflex signal races back and activates the muscles of the arm and the finger is jerked away from the iron. And it's only when the other sensory messages report in on the master receiver and the pain impulse finally reaches the phalamus that our little man knows the finger has been hurt. Well, isn't it true doctor that some people are more sensitive to pain than others? Oh yes. Yes, that's very true. People differ greatly in this. Doctor, when you sit down? Thank you. Really enormous variations in what we call the threshold of pain. Some people are born with no sense of pain at all. No toothache. That bad? It was really very serious to touch a hot iron, cut yourself badly, and feel no pain. Imagine a child who would have to be watched every second because he would never know when he'd hurt himself. What about the other senses, Doc? Sense of humor, sense of balance, common sense, horse sense. Well, these are everyday expressions, common places, figures of speech, except the sense of balance. And that's a very real sense. Without the sense of balance, you couldn't stand up. Certainly, you couldn't walk. And behind this sense of balance is a most interesting mechanism. Deep within the inner ear, we have the semic-ircular canals, which are filled with liquid. Associated with the lining of these curved channels are minute hair cells. Now, it's generally believed that when we move our heads, the liquid disturbs these hair cells which send signals to the brain. We also have sense receptors in our muscles and tendons to tell the brain of any change in muscle tension. When Bill stands on one foot, he can feel this automatic interplay of the different muscles of his leg. And of course, his eyes tell him what he does. Coordinating all of this information from ears, muscles, and eyes at assembly points, the nervous system sends back reflex motor impulses to the right muscles, telling them to tighten or relax to keep the body in balance. This automatic feedback between the incoming signals and the outgoing compensating actions is what enables a cat to land on its feet or an acrobat to spin through the air to a precise landing. Now in slow motion, we can see what happens when a cat is dropped from an upside down position. His eyes and equilibrium organs in his ears cause him to write his head. This puts an uneven tension on the neck muscles and their tension receptors excite reflexes which bring the body back into alignment with the head. Like the falling cat, we too are constantly getting sensory reports which themselves induce the next motion. This series of reflexes involving what is known as feedback results in controlled and accurate motion. Hey doc, what have they got to say about tickling? Well, seriously, some physiologists say that tickling should be considered a real sense. I'd like to see you make a character out of that one. You know, the more we talk about the senses, the more characters we seem to be getting. It's getting to be like a regular three- ring uh circus. Yeah. Tada. [Music] Heat. Heat. Heat. Heat. Heat. Heat. Heat. Heat. [Music] [Music] seems to stop and and go back again, but it doesn't. It goes all the way around. It's an optical illusion. But even though you you tell me, my eyes still won't believe it. Well, let's attach a bar to the framework and see what'll happen. [Music] The trapezoid still appears to move back and forth, but the bar goes around. No, I'm really mixed up. Well, let's move up to an overhead view and see what happens. [Music] Plainly, it does go all the way around and the bar moves with it. Reason we are fooled from this angle is that the trapezoid and its windows are not rectangular in shape, but we expect them to be because we have learned by experience that windows are rectangular. And even though we know it's turning all the way around, our brain still interprets the visual image in terms of past experience. The yellow scarf hung on a short wire from one end of the trapezoid moves around in a ghostlike circle. While again, in spite of what we know, the window seems to stop, move back and forth. [Music] [Laughter] [Music] [Music] I'll never trust another trapezoid. Now, let's go to Princeton University where the trapezoid experiment and others relating to perception and past experience were done. It's here in the demonstration laboratory that these windows were constructed. Why do the two heads seem to change size? Answer: The windows are distorted and this appears to be a normal room. Man, watch now. The man and boy are greatly distorted in size. The answer is obvious if we look at the room from another angle where we see that the room is distorted. The people are normal. Professor Hadley Cantrol, Princeton psychologist, can tell us the significance of what we have seen. The demonstrations you have just seen were devised by the scientist Adelbert Ames. While they are amusing illusions, they are much more than that, for they demonstrate some rather profound psychological principles involved in all of man's experience. They show that our experience is much more than a simple reaction to something outside and that we have to learn through our own past behavior the significance of the impressions our sense organs bring to us. And again this leads us to understand that the world we know is created in large measure from our past sensory experience. An interesting experiment that shows how the brain reacts to sensory stimulation can be shown here on the oscilloscope. And this instrument can be used to detect the impulses that reach the brain from the sensory organs. Now this brain is resting and the pattern of response is smooth. But if the eyes are suddenly stimulated by a flashlight, we see a violent variation in the pattern. Now let's observe what happens when a sudden loud noise is heard. So outside stimulation activates the brain. The screen's ready, doctor. Thank you. We wonder how human beings would react in situations where there was a near absence of things happening. What happened to him? Well, in a way, nothing. Looks to me like he's been in an accident. No, this is an experiment that took place at McGill University. Students volunteered to participate in this study of human behavior under extreme and prolonged monotony. Their hands and arms were softly covered to muffle the sense of touch. All harsh lights subdued by a mask, comfortable beds, quiet. And yet it was impossible for most of these students to take it for more than 24 to 48 hours. The psychologist Dio Heb and his associates who conducted these experiments found that deprived of ordinary everyday sensory experiences, the subjects began to lose touch with reality. Those who stuck it out began to see things, hear things. Distortions set in. hallucinations. Some began to see dots of light, lines, simple geometric patterns. Then the patterns became distorted. Another described hallucinations of little yellow men with black caps with their mouths open. One said he saw the recurring vision of eyeglasses passing in a procession like an animated movie cartoon. As the time went on, these visions became more disturbing, unreal, often frightful. Deprived of normal sensory bombardment, the brain may cease to function in the usual way. For instance, studies in France and at Harvard University have shown that hallucinations are fairly common among long-d distanceance truck drivers after long monotonous hours on the road. [Music] The cockpit of a jet aircraft droning along in the stratosphere can duplicate very closely the hypnotic monotony experienced by the students at McGill. Lack of change, little stimulation to the senses, illusion, distortion, hallucinations may set in. What happens to men in an Antarctic white out when they lose all sense of distance and all objects seem to float in midair? What is the strange exhilaration known as rapture of the deep that can cause divers to discard their breathing apparatus? These are problems that scientists in and out of the armed services are studying. This centrifuge machine, for example, helps to determine how the human senses function under abnormal conditions. Moreover, we are living in an age when man is extending his senses into farreaching realms that he once only imagined to the sources of meteors and cosmic rays. In England, a radio telescope like a huge electronic ear can catch faint radio waves broadcast from the distant galaxies and nebula of outer space. [Music] [Music] Electronic senses circling the earth send information to man's waiting brain. All these magnificent tools are nothing in themselves. They are really only extensions of man's basic senses so that he can see further, hear better, feel more delicately. The simple truth is no matter how much man may extend his senses, the more he must depend upon the ones he has. And so inevitably we return to our basic theme. We exist through our senses. We are bound to reality through our senses. We learn, we survive, we grow through our senses. In laboratories, hospitals, universities, young men and women, many of them still studying for their degrees, are investigating, exploring, dedicating their minds and imaginations to the adventures of research. studying the science of our senses. The mechanism of taste and smell and the brain itself, the center to which the senses report, is being studied in every country of the civilized world. The final wonder is that the experience brought to our brains by the senses is recorded there for the rest of our lives. Dr. Wilder Penfield, director of the Montreal Neurological Institute, will tell us of one of the truly great physiological discoveries of the 20th century. Thank you, Dr. Baxter. During my life as a brain surgeon, it has been necessary to operate on good many men and women, good many hundreds, and to expose the brain under local anesthesia with the patient conscious. In those operations, it is a useful practical procedure to stimulate the cortex electrically. These are not experiments. In that process, we have stumbled quite accidentally on the fact that there is recorded in the nerve cells of the human brain the complete record of the stream of consciousness. All those things of which a man was aware in any moment of time are are recorded there and all the sights and sounds which he ignored and the thoughts which he ignored are absent from that record. The operations are carried out under local anesthesia so that the patient is conscious and can talk. He does not feel anything when the electrode touches the brain with its gentle electrical current. It is as though the electrode touched a wire recorder or a or a strip of film and he reles a period of time. When I talk to him afterwards about how it seemed to them, they say it is much more real than any remembering. It is as though they were reexperiencing it. I believe you're about to hear the actual words of patients in response to this stimulus which they were quite unaware of while they were in the operating room. You will hear them as I heard them. I have a sudden feeling as though I lived through all this before. Now I see them. They're laughing. my friends and I'm with them in a house in South Africa. They're my old friends. I hear children's voices. I hear them down along the river. I'm sitting in a railroad station in a small town, small town in Kentucky. It's winter and the wind is blowing outside and I'm waiting for a train. I see the whole thing. a guy coming through the fence at a baseball game. I was watching these two teams play when this fell came through the fence. I hear a song. I haven't heard it since I was in high school. There it is again. The brain of man contains a record of his past, a living storehouse of remembered moments of all his days. What we do, what we feel are registered there. are multiple sensations. The whole awareness of the wonderful world in which we live. [Music] So is recorded the total spectrum of human experience. A tapestry woven from the memories of past sensations, ever growing and unique in each of us. [Music] [Applause] This has been a story of the human senses and how their signals relay to the brain of man all his knowledge. Knowledge indispensable in understanding his world. How man chooses to use this knowledge in shaping his world will determine the future of mankind. Oh yeah. Oh yeah. [Music] Heat. [Music] Heat. [Music] [Laughter] [Music] [Music] The Bell Telephone System takes pride in bringing you this program and its series of shows on science. We acknowledge our gratitude to the distinguished board of adviserss covering the broad range of modern science, biology and genetics, medicine, bacteriology and botany, [Music] chemistry, geoysics, physics, anthropology, electronics and acoustics, mathematics, engineering for the program you have just seen. Our thanks to the special advisers who have suggested and checked the scientific material. The Bell Telephone System is indebted to all these men and to many institutions for the generous support they've given this venture in public education through entertainment. Heat. Heat. [Music]