Inside the rare disorder that makes you think you’re brain dead

brainDan Kitwood/Getty

Humanity’s greatest conflicts emerge from two parties looking at the same thing and each insisting, with the utmost confidence, that only he or she sees it correctly.

More fundamentally, each party insists that there is a correct way to see it — that the issue is a matter of fact, not opinion. Same-sex marriage or flying the Confederate flag is simply wrong, end of discussion. Your co-worker is stuck-up, not shy. The dress is white and gold, not blue and black — are you blind?

The notion that you see the world objectively, that you have unmediated access to reality, is called “naive realism.” Few fields have made greater strides in combatting naive realism (and by strides I mean baby steps) than neuroscience. We now know the layers of filtration, computation and interpretation that lie between incoming photons and the image of a rainbow. Colors — and opinions and morals — are constructed in our heads, not in the world.

Neuroscience doesn’t stop at blurring our certainty in the world around us. It turns our questioning inward, toward our supposed core. We all know René Descartes’s proposition “I think, therefore I am,” the first step in establishing what exists and what doesn’t — a stomp on the rock at the center of our universe. But once you understand the brain, even the “I” in “I think” is up for grabs. And so goes “I am.”

In “The Man Who Wasn’t There,” science writer Anil Ananthaswamy smartly explores the nature of the self by way of several mental conditions that eat away at patients’ identities.

We read about Alzheimer’s, autism, schizophrenia and less-common experiences such as ecstatic seizures or the certitude that one’s brain is dead — and not just in the hangover or brain-fart sort of way. Following in the steps of Oliver Sacks’s “The Man Who Mistook His Wife for a Hat” (1985) and V. S. Ramachandran and Sandra Blakeslee’s “Phantoms in the Brain” (1999), Ananthaswamy uses neuropsychology and narrative to take us inside the heads of people experiencing realities very different from our own.

Central to the sense of self is the feeling of free will — the impression that you make decisions and conduct behavior of your own volition. You are not a pre-programmed or remote-controlled robot. But in schizophrenia, this experience can go haywire.

Normally, your brain registers the decision to act, immediately followed by the feeling of actually acting, and it concludes that you must be responsible for initiating the action. But in schizophrenia, mistimed feedback mechanisms can make behavior and thought seem to appear out of nowhere. Suddenly your internal monologue becomes a foreign voice. In both ill and healthy brains, our explanations for much of what happens in the world — including our own behavior — are manufactured after the fact. This insight leads to a concise definition of the self. As Ananthaswamy puts it, “You may be your brain’s best guess as to [the] causes of all your internal and external sensory signals.” Something is causing these thoughts and actions, and when the internal timing is tuned, that thing is what we call the “self.”

Another way of viewing the self is as a model, a simplified representation of the entire brain and body (and sometimes the surrounding environment), so that different parts of the brain can coordinate to predict and control what the organism as a whole will do next.

Sometimes parts of this model become so wildly inaccurate that you have, say, body integrity identity disorder, in which you feel as if a limb does not belong to you. In one stirring chapter, Ananthaswamy travels with a man to Asia to have his leg voluntarily amputated, the only reliable remedy for such a mismatch.

Intelligent organisms such as humans don’t like disorder, and so we try to organize information into models or stories. As Ananthaswamy says about long-term memory, it’s “less constrained by fidelity and is more concerned with the need for ‘coherence.’ ” The closest available coherent story is often an absurd one. When the brain’s temporoparietal junction, which integrates touch, vision, balance and body position, suffers a glitch, the brain weaves an alternative tale and produces the convincing experience that you have a doppelganger sitting next to you or that you are floating outside your body.

Similar out-of-body experiences can be produced by researchers using virtual reality or brain electrodes.

“What’s clear from these studies,” Ananthaswamy writes, “is that aspects of our sense of self that we take as given and immutable — a sense of body ownership, a sense of where the self is located, and even the perspective from which the self observes — can be disrupted, even in healthy people.” If such basic elements of our experience are malleable, how can we expect to see the truth about anything else?

Selves are malleable because they’re contingent on their neural wetware. Reading these case studies, you just want to tell people, “No, you’re not dead!” Or, “Your wife is not really a hat!” It’s hard to grasp that people can’t reason themselves out of such delusions. This frustration reveals the extent of our mind-body dualism. Despite our intuitions, the mind can’t tell the brain how to operate. It, and all of its reasoning capacity, are as dependent on the brain’s moving parts as running is on our legs.

A recent study found that explaining naive realism to people and showing them visual illusions reduced their certainty in their judgments of others’ behavior — whether Donald is being hostile or just assertive. Maybe neuroscience education can help alleviate social strife. (Who knows how many wars the dress-color controversy has averted by highlighting the subjectivity of experience — not counting the ones it’s sparked online?) One might start by explaining how the self is fabricated and that it is a fabrication, just like everything else we experience.

“The man who wasn’t there” is an evocative term for a particular pathological self-negation. But, according to neuroscience, none of us are here.

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