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

“Yes,” I said. “He suggests that in a normal child’s brain, lower visual areas create sophisticated three-dimensional representations of a horse or any other object. After all, that’s what vision evolved for. But as the child gradually learns more about the world, higher cortical areas generate more abstract, conceptual descriptions of a horse; for example, ‘it’s an animal with a long snout and four legs and a whisklike trail, etc.’ With time, the child’s view of the horse becomes dominated by these higher abstractions. He becomes more concept driven and has less access to the earlier, more visual representations that capture art. In an autistic child these higher areas fail to develop, so he is able to access these earlier representations in a manner that you and I can’t. Hence the child’s amazing talent in art. Snyder presents a similar argument for math savants that I find hard to follow.”

“What do you think of his idea?” the reporter asked.

“I agree with it and have made many of the same arguments,” I said. “But the scientific community has been highly skeptical, arguing that Snyder’s idea is too vague to be useful or testable. I disagree. Every neurologist has at least one story up her sleeve about a patient who suddenly developed a quirky new talent following a stroke or brain trauma. But the best part of his theory,” I continued, “is a prediction he made that now seems obvious in hindsight. He suggested that if you were to somehow temporarily inactivate ‘higher’ centers in a normal person’s brain, that person might suddenly be able to access the so-called lower representations and create beautiful drawings or start generating prime numbers.

“Now, what I like about this prediction is that it’s not just a thought experiment. We can use a device called a transcranial magnetic stimulator, or TMS, to harmlessly and temporarily inactivate portions of a normal adult’s brain. Would you then see a sudden efflorescence of artistic or mathematical talent while the inactivation lasted? And would this teach that person to transcend his usual conceptual blocks? If so, would he pay the penalty of losing his conceptual skills? And once the stimulation has caused him to overcome a block (if it does), can he then do it on his own without the magnet?”

“Well, Dr. Ramachandran,” said the reporter, “I have news for you. Two researchers, here in Australia, who were inspired in part by Dr. Snyder’s suggestion, actually tried the experiment. They recruited normal student volunteers and tried it out.”

“Really?” I said, fascinated. “What happened?”

“Well, they zapped the student’s brains with a magnet, and suddenly these students could effortlessly produce beautiful sketches. And in one case the student could generate prime numbers the same way some idiot savants do.”

The reporter must have sensed my bewilderment, because I remained silent.

“Dr. Ramachandran, are you still there? Can you still hear me?”

It took a whole minute for the impact to sink in. I have heard many strange things in my career as a behavioral neurologist, but this was without doubt the strangest.

I must confess I had (and still have) two very different reactions to this discovery. The first is sheer incredulity and skepticism. The observation doesn’t contradict anything we know in neurology (partly because we know so little), but it sounds outlandish. The very notion of some skill being enhanced by knocking out parts of the brain is bizarre—the sort of thing you would expect to see on The X-Files. It also smacks of the kind of pep talk you hear from motivational gurus who are forever telling you about all your hidden talents waiting to be awakened by purchasing their tapes. Or drug peddlers claiming their magic potions will elevate your mind to whole new dimensions of creativity and imagination. Or that absurd but tenaciously popular factoid about how people only use 10 percent of their brains—whatever that’s supposed to mean. (When reporters ask me about the validity of this claim, I usually tell them, “Well, that’s certainly true here in California.”)

My second reaction was, Why not? After all, we know that astonishing new talent can emerge relatively suddenly in frontotemporal dementia patients. That is, we know such unmasking by brain reorganization can happen. Given this existence proof, why should I be so shocked by the Australian discovery? Why should their observation with TMS be any less likely than Bruce Miller’s observations of patients with profound dementia?

The surprising aspect is the timescale. Brain disease takes years to develop and the magnet works in seconds. Does that matter? According to Allan Snyder, the answer is no. But I’m not so sure.

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