Our brains are made of “three pounds of the most complex material we’ve discovered in the universe,” David Eagleman informs us in Incognito: The Secret Lives of the Brain (Pantheon, 304 pages, $26.95). Still, if you remove half of a child’s brain before he is “about 8 years old,” the child will be fine. “Let me repeat that: the child, with only half his brain remaining, is fine.”
There is a lot of this kind of thing in Incognito. The learned specialist is also a popularizer of impressive gusto, and his book is a barrage of bizarrerie. “Strap in,” the author advises us, twice. Our hearts, it turns out, are alliterative: People whose forenames start with the same letter are more likely to marry each other. Davids disproportionately wed Donnas. People are also more likely to establish a home in cities whose names echo their birthdates: “People born on 3/3 are statistically overrepresented in places like Three Forks, Mont., as are people born on 6/6 in places like Six Mile, S.C., and so on.” In 2001, Eric Weihenmayer, a blind man, ascended Mt. Everest. He managed this feat by affixing a device to his mouth that enabled him “to see with his tongue while he [climbed].”
And so we range, from the outré to the recherché to the borderline risqué. “What does this research tell us? It tells us that fiscally concerned strippers should eschew contraception and double up their shifts just before ovulation.” The journey to the heart of neurological darkness is also a kind of safari, and we spend a lot time taking in the marvelous birds.
Incognito proposes a grand new account of the relationship between consciousness and the brain. It is full of dazzling ideas, as it is chockablock with facts and instances, but the big one is unexpected: consciousness is not all that important. Consciousness, Mr. Eagleman writes, “is the smallest player in the operations of the brain.” It is like a “stowaway,” hitching a ride on a “transatlantic steamship … without acknowledging the massive engineering underfoot.” We tend to think that consciousness is the dominant attribute of the mind, and thought the main event of mental life. We are wrong. “To the extent that consciousness is useful, it is useful in small quantities, and for very particular kinds of tasks.” You could say the same of cumin.
Mr. Eagleman likes to quote Pascal: “Man is equally incapable of seeing the nothingness from which he emerges and the infinity in which he is engulfed.” The situation inside our skulls is analogous. Consciousness does not see reality, as it does not see the brain. “What we perceive in the outside world,” Mr. Eagleman writes, “is generated by parts of the brain to which we do not have access.” With experience, we think we are getting the real thing. This is what we think, but in fact we are getting almost none of it. “When the world is successfully predicted away, awareness is not needed because the brain is doing its job well.” By the time consciousness goes to work on the puzzle of new information, most of the pieces of that puzzle are already in place.
“Waking perception is something like dreaming with a little more commitment to what’s in front of you,” Mr. Eagleman writes. “It’s easy to spot a hallucination only when it’s bizarre. For all we know, we hallucinate all the time.” If we fail to distinguish the influence of the brain on our experiences, it is not because it is too faint. It is because it is too pervasive. “Almost all of our actions–from producing speech to picking up a mug of coffee–are run by alien subroutines.” Still, if consciousness can’t grasp how it gets where it goes, it usually credits itself for where it ends up. As Mr. Eagleman notes, “We are constantly fabricating and telling stories about the alien processes running under the hood.”
“We tell ourselves stories in order to live,” said Joan Didion. Consciousness tells itself stories in order to persuade itself that it controls itself. But consciousness doesn’t control itself. These are tall tales, and Mr. Eagleman thinks that it is time for us to take an axe to some of the tallest ones. “Many of us like to believe that all adults possess the same capacity to make sound choices. It’s a nice idea, but it’s wrong.” Incognito is a book about brains, but where it wants to make waves is the courts.
A crux of many criminal trials is intention: did the defendant intend to break the law? The legal term for this is mens rea, which translates as guilty mind; its admission as a concept licenses courts to factor in the “blameworthiness” of criminals in formulating their sentences. Mens rea is not a category that applies to all criminals, though. If a criminal is declared insane, this means that he does not satisfy the preconditions of mens rea–i.e., that he cannot make free conscious choices. His sentence will, accordingly, be mitigated. Most criminals are not so lucky, and receive their sentences as mentally competent before the law.
This distresses Mr. Eagleman. He thinks that the representation of a criminal mind as mentally adequate can only mean that the neurological evaluation of it has been inadequate. “The criminal activity itself should be taken as evidence of brain abnormality, regardless of whether measurable problems can be pinpointed.” What is important in assessing punishments for crimes isn’t culpability. It’s modifiability–whether the deviant neurological processes can be corrected. “The one thing nobody can take away from you is the freedom to fuck up your life whatever way you want,” wrote Jonathan Franzen (in, of course, Freedom). According to Mr. Eagleman, this is not true. “Free will may exist–but if it does, it has very little room in which to operate.” Even our fuckups are neurochemically choreographed.
Ideas start out unsentimental, but people form sentimental attachments to them, anyway. Free will is an idea to which many people are fiercely attached. It may yet die. Copernicus unseated us from the center of the universe, Milton exposed God as a bore, and Darwin traced our parentage to pond scum. Then Nietzsche killed God. Then Freud told us that all of it, in the end, was about our mothers. These things have happened before. What revolutionary ideas give with one hand, they take away with a pickaxe. “Maybe an unexamined life is not worth living,” as Saul Bellow wrote. “But a man’s examined life can make him wish he was dead.” Mr. Eagleman is our latest pickaxe-wielding radical. He aims, grandly, to do for the study of the mind what Copernicus did for the study of the stars. “We are not at the center of ourselves,” Mr. Eagleman writes, “but instead–like the Earth in the Milky Way, and the Milky Way in the universe–far out on a distant edge, hearing little of what is transpiring.” With Incognito, Mr. Eagleman has given us a hearty shove in the direction of that distant edge. Will we leap, or step back?
Mr. Eagleman is already several steps ahead of us. In 2009, he published a book of fiction called Sum: Forty Tales From the Afterlives. In one tale, “Blueprints,” he envisions an afterlife in which God has initiated the dead into all the secrets of creation. But it is an ambiguous gift. God thinks that the knowledge will dazzle mankind, but Satan is sure that it will hurt it. Both are in for a letdown. It turns out that “being let into the secrets behind the scenes has little effect on our experience. The secret codes of life–whether presented as a gift or a burden–go totally unappreciated.”