The Tell-Tale Brain: A Neuroscientist's Quest for What Makes Us Human

by V.S. Ramachandran

(Volvox, I learned, is the only biological creature on the planet that actually has a wheel.)

Science needs a variety of styles and approaches. Most individual researchers need to specialize, but the scientific enterprise as a whole is made more robust when scientists march to different drumbeats.

Homogeneity breeds weakness: theoretical blind spots, stale paradigms, an echo-chamber mentality, and cults of personality.

Getting trapped in narrow cul-de-sac specializations and “clubs” whose membership is open only to those who congratulate and fund each other is an occupational hazard in modern science.

Maybe someday we will even answer the most difficult question of all: How does the human brain give rise to consciousness? What or who is this “I” within me that illuminates one tiny corner of the universe, while the rest of the cosmos rolls on indifferent to every human concern? A question that comes perilously close to theology.

Highly complex processes can emerge from deceptively simple rules or parts, and small changes in one underlying factor of a complex system can engender radical, qualitative shifts in other factors that depend on it.

sometime about a hundred and fifty thousand years ago there was an explosive development of certain key brain structures and functions whose fortuitous combinations resulted in the mental abilities that make us special in the sense that I am arguing for. We went through a mental phase transition.

same old parts were there, but they started working together in new ways

lack of empathy, moral standards, and self-restraint are also frequently seen in sociopaths, and the neurologist Antonio Damasio has pointed out they may have some clinically undetected frontal dysfunction.)

Victor said he had never discovered this virtual hand on his face before, but as soon as he knew about it he found a way to put it to good use: Whenever his phantom palm itches—a frequent occurrence that used to drive him crazy—he says he can now relieve it by scratching the corresponding location on his face.

Think of what happens when an arm is amputated. There is no longer an arm, but there is still a map of the arm in the brain. The job of this map, its raison d’être, is to represent its arm. The arm may be gone but the brain map, having nothing better to do, soldiers on. It keeps representing the arm,

orphaned brain map continues to represent the missing arm and hand in absentia, but it is not receiving any actual touch inputs. It is listening to a dead channel, so to speak, and is hungry for sensory signals.

when one of our patients, Ron, took the mirror box home and played around with it for three weeks in his spare time, his phantom limb vanished completely, along with the pain.

notion that you could amputate a phantom with a mirror seemed outlandish, but it has now been replicated by other groups of researchers, especially Herta Flor, a

We usually think of pain as a single thing, but from a functional point of view there are at least two kinds of pain. There is acute pain—as when you accidentally put your hand on a hot stove, yelp, and yank your hand away—and then there is chronic pain: pain that persists or recurs over long or indefinite periods, such as might accompany a bone fracture in the hand.

Although the two feel the same (painful), they have different biological functions and different evolutionary origins.

If this sort of optically mediated anesthesia could be shown to work on an intact hand, it would be another astonishing example of mind-body interaction.

Far from being wired up according to rigid, prenatal genetic blueprints, the brain’s wiring is highly malleable—and not just in infants and young children, but throughout every adult lifetime.

We can now say with confidence that the brain is an extraordinarily plastic biological system that is in a state of dynamic equilibrium with the external world. Even its basic connections are being constantly updated in response to changing sensory demands.

Even though our picture of the world seems coherent and unified, it actually emerges from the activity those thirty (or more) different visual areas in the cortex, each of which mediates multiple subtle functions.

Exactly how many of our visual areas are unique to humans isn’t clear. But a great deal more is known about them than about other higher brain regions such as the frontal lobes, which are involved in such things as morality, compassion, and ambition. A thorough understanding of how the visual system really works may therefore provide insights into the more general strategies the brain uses to handle information, including the ones that are unique to us.