The Gods Must Be Crazy 2 Dailymotion

[Ceola Roefaro]

NARRATORThese people are not crazy. They have all suffereddamage in tiny sections of their brains that has profoundly distorted the waythey perceive themselves and the world around them. In the past, these bizarrecases would have been dismissed by science, but today one neuroscientist tracksthem down with the dogged persistence of a detective.

V.S. RAMACHANDRAN (University of California, San Diego): Whatexcites me is I can go in there and pretend I'm Sherlock Holmes and try andfigure out what has gone wrong in this patient's brain, what's changed thataccounts for the strange symptoms. And this, of course, is a lot of fun to dobecause you're learning a lot about the brain; learning a lot about what causesthe symptoms in that particular patient. But more importantly, it's telling youabout how the normal human brain works, and how the activity of neurons in thenormal brain gives rise to conscious experience and gives rise to the wholespectrum of abilities that we call human nature.

NARRATOR: Can the misfortune of brain injury shed light on theworkings of the normal brain, perhaps even help solve some of the eternalriddles of human nature? Understanding the human brain is one of the ultimatechallenges in science.

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NARRATOR: Dr. Vilanyur Ramachandran is revolutionizing ourunderstanding of how the brain works. His efforts to solve some of the mostbaffling neurological mysteries take him from the hospital bed to the outerlimits of brain science.

V.S. RAMACHANDRAN: The human brain is without any doubt the mostcomplexly organized form of matter in the universe. The brain is made up of 100billion nerve cells or neurons. Someone has calculated that the number ofpossible permutations and combinations of brain activity exceeds the number ofelementary particles in the universe. And this gives you some idea of thestaggering complexity one is faced with in trying to understand the functionsof this mysterious organ. So the question is, "How do you even begin?"

NARRATOR: Ramachandran began his investigations with a strangephenomenon called "phantom limb syndrome." It's not uncommon for amputees tofeel the vivid presence of a missing limb long after it has gone.

DEREK STEEN:Thirteen years ago, I was involved in a motorcycle accidentand I pulled the nerves out of my spinal cord up in my neck. They told myparents directly that I would never use my arm again.

V.S. RAMACHANDRAN: The reason we think it happens is that in the brainthere is a complete map of the surface of the body. The entire left side of mybody, the skin surface, is mapped on to the right side of my brain along avertical strip of cortex which we call the "somatosensory cortex." Similarlythe right side of my body is represented on the left side of my brain. So everypoint on your body surface has a corresponding point on this body map. Now, itturns out that the representation of the face on this map is right next to therepresentation of the hand. Now, that's a bit surprising, as you'd expect themap to be continuous and faithfully represent the left side of my body. But itdoesn't. Now imagine what would happen if the left arm were amputated. The partof the brain corresponding to the hand no longer gets any input, and it'shungry for new sensory input, so to speak. The sensory signals from the facenormally activate only the face area that's right next to the hand area. Butthey now invade the vacated territory corresponding to the missing hand andstart activating the hand region of the brain.

And so, whatever is reading those signals higher up misinterprets thosesignals. It says those signals are coming from the missing hand. So youexperience the sensations as coming from the missing fingers even though I'mtouching your face. This is showing there's been a massive reorganization ofthe sensory pathways in your brain after the amputation. And it's as thoughthere's been a cross-wiring in your brain.

V.S. RAMACHANDRAN: One of the dogmas in neurology has always been thatconnections are laid down in the fetus in early infancy and once theseconnections are laid down, there's nothing you can do to change them.

NARRATOR: As a scientist, Ramachandran knew that such aradical proposal needed scientific proof. It was time to give Derek a brainscan. Hopefully this would show what was actually going on in his brain. Butwould it prove that Ramachandran's hunch was correct?

This is a scan of Derek's brain. The green spot shows the brain's responseto the stimulation of Derek's existing right hand. Next to it, the red spotshows that the right side of Derek's face is also being stimulated. So far,everything is normal.

But in the right hemisphere the green spot has disappeared, because Derek'smissing right arm can no longer send signals to his brain. Remarkably the redarea, which corresponds to his left cheek, has now taken over the whole space.

V.S. RAMACHANDRAN: It's as though now the sensory input from the face isinnervating a completely new part of the brain. And this means new pathwayshave been opened up. Whether this is because there's been an actual sproutingof new nerve fibers or there have been pre-existing silent pathways, which arenow suddenly active, we're still working on. We suggested that maybe theconnections are already there like reserve troops ready to be called intoaction, and when you amputate the hand, these latent connections suddenlybecome active.

V.S. RAMACHANDRAN: But in fact, you can get a phantom with almost anypart of the body. You can get phantom menstrual cramps after a hysterectomy.You can get phantom appendix pain even after the appendix has been removed.Theoretically, you can have a phantom of almost any part of the body, except ofcourse, the brain. You can't have a phantom brain by definition, because that'swhere we think it's all happening.

JAMES PEACOCK: A few days after I woke up...you know...it might havebeen under a week to eight or nine days, something like that, before the painreally started getting bad, you know? To where it was like your hand is justcrinched up real tight and stuff, and balled up, you know? And you can't moveit. To unclinch it's just...you can't. You try in your mind.

V.S. RAMACHANDRAN: One answer might be that the brain is sending signalsto the arm and trying to clench it. But in you and me there's messages goingback from the muscles of the hand telling you you're clenching too much or toofast and this damps the command signals so you can slow down. But the patienthas no feedback because he doesn't have an arm so the brain says, "send evenmore signals, okay?" And this goes on and you get into a sort of positivefeedback loop. So I said, "Well if you give him some other source of feedback,such as visual feedback, maybe that'll trick the brain into thinking that thehand is clenching or unclenching and maybe you can interrupt this loop." So Isaid, "Well why don't we put a mirror there and have James look inside themirror?" It's just as though you have visually resurrected the phantom limb.And of course the patient knows it's an illusion, but it's very, verycompelling.

JAMES PEACOCK: Right. Now as you look in there and you move your hand,your phantom does the same thing as your left hand is doing. The first time Igot in here and I'd done this, it was just like it relieved the phantom painand unclenched it, you know? It was just so intriguing, you know? Sometimesit's just hard to explain how you felt, you know?

NARRATOR: Ramachandran believes the mirror box needs to beevaluated with many patients before he can be sure that it really works. Butits undeniable success in uncramping James's phantom hand suggests that evenpain can be a construct of the mind. The phenomenon of phantom limbs revealshow our brains can delude us into being conscious of something that isn'tthere.

Ramachandran found Graham Young in Oxford, England. He is one of theworld's few known blindsight patients. This paradoxical condition shows justhow much our brains run our lives without our being aware of it.

GRAHAM YOUNG: When I was eight, when I had the accident...it was a roadaccident that caused the brain damage...I literally used to walk into lampposts. I ran into, you know, these huge great pillars you get in stations? Iran into one of those one day.

NARRATOR: The main visual centers in humans occupy nearly halfthe brain in a large region towards the back of the head. Graham's vision wasdevastated by the accident. Today, he can see to the left but is blind toeverything on the right, in both eyes.

COLIN BLAKEMORE: I think blindsight is extraordinary when you see it.It's shocking. I think it's shocking because it brings home the fact that wecan actually manage our brains without consciousness to some extent and thatleads to the question, "Well then...

GRAHAM YOUNG: Right. I'm aware of individual functions of sight.Sometimes I am aware of a motion, but that motion has no shape, no color, nodepth, no form, no contrast. Sometimes I can tell you what orientation it's at,but then we lose everything else.

COLIN BLAKEMORE: If there's one thing that this phenomenon of blindsightteaches us, it is that vision is not entirely seeing, that there can be adisconnection from the capacity to respond to visual information and the actualact of being visually aware of something. Those two things can be separated andprobably are in our everyday lives. But the problem is that, obviously, we'renot aware of the things that we're not aware of. We just don't know the extentto which they play a part.

V.S. RAMACHANDRAN: It's almost as if the patient is using ESP. He cansee and yet cannot see. So it's a paradox, it's almost like science fiction.How is this possible? Well, if you look at the anatomy, you can begin toexplain this curious syndrome. It turns out from the eyeball to the highercenters of the brain where you interpret the visual image, there's not just onepathway. There are two separate pathways, which subserve different aspects ofvision. One of these pathways is the evolutionarily new pathway, the moresophisticated pathway, if you like, that goes from the eyeball through thethalamus to the visual cortex of the brain. Now, you need the visual cortex forconsciously seeing something. The other pathway, which is older evolutionarily,and is more prominent in animals like rodents, lower mammals, birds andreptiles, goes to the brain stem, the stalk on which the brain sits. And, fromthe brain stem, gets relayed eventually to the higher centers of the brain.Specifically, the older pathway going through the brain stem is concerned withreflexive behavior orienting to something important in the visual field, makingeye movements, directing your gaze, directing your head toward somethingimportant.

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