The Breathtaking Diversity of the Human Mind

“We think there’s a monoculture of the mind,” neuroscientist Anil Seth told me. “There’s astonishing diversity.”

Neuroscientist Gerald Edelman likened the lushness of the mind to a rainforest. I love to talk to people about how they think. I hear about imaginary conversation partners, mental elevators that creak from floor to floor, and inner governments that debate and vote (and fall from power over bad decisions). For many people, thoughts come nonverbally—as mathematical equations, flowers, colors—before translating into language.

I write about neurodiversity. Anil Seth, the author of Being You: A New Science of Consciousness, writes about “perceptual diversity.” Seth was kind enough to talk to me last week about just how individual our perceptions are. Necessarily, the brain is an organ locked in a dark shell, responding to streams of often incoherent sensory information with, as Seth puts it, best guesses.

It feels as if, as conscious beings, we interact directly with the world. But our brains interact with sensory signals. The parts of our bodies in direct contact with the physical world aren’t the ones that think. My favorite color is blue; my retinas' is not.

Perception is kind of like playing telephone—trying to create coherence out of messages that whisper through a string of intermediaries. The world we experience emerges from a “dance,” in Seth’s words, of perception and correction. We predict what input means, but get stung into revising our guesses, when, for instance, the sofa cushion is really my sweet but rightfully annoyed cat.

Seth writes, “Next time you go for a walk by the sea, or through a town, try to imagine all the unique, personalized inner universes in the minds of all the people around you. There isn’t just one beautiful world out there; there are many.”

Yes, there are. And yes, do.

In Being You, Seth calls consciousness a “controlled hallucination.” Humans build worlds, our social protection being whether others build ones roughly similar—whether that means agreeing the sky is blue or that lizard people run the government. (You just don’t want to be the first one talking about lizard people!)

One of Seth’s recent projects was called Dreammachine—an immersive art-science hallucinatory experience created in collaboration with musicians, architects, and engineers. The project saw 40,000 people hooked up to a device that hit their closed eyes with strobe lights and a rhythmic soundtrack. One user saw a twisting funnel like the “maw of a wormhole” followed by kaleidoscopic honeycombs. The fact that flashing white lights—a simple if striking input—can create deeply individual visions shows how unique the work of consciousness really is.

The variety of perceptual responses was “extraordinary,” Seth told me. Even for the same person, “different days could be very different.”

The last three decades have seen a blossoming of research and philosophical speculation about consciousness. Tools like brain imaging yield information, but no clear answers about why and how subjective experience exists. To be conscious, to feel that “there’s something it’s like to be you,” is both the most real and least knowable thing you’ll ever do. It is New Scientist's "great wonder and strangeness."

I wrote several decades ago in my book A Mind Apart, “How does everyone resist the lusciousness of others’ minds, moving around us, with us, all the time, like a gallery of veiled art?”

You who read this are part of that gallery. Stop for a second, now, and appreciate that wonder.

I’m describing ways science and philosophy consider consciousness.

Medicine, for the most part, considers what it prefers to call the mind very differently. In the late 1800s, a German psychiatrist named Emil Kraepelin declared that madness was a brain disease, and there were varieties of this brain disease, for instance, bipolar disorder and schizophrenia.

“So-called psychic causes, unhappy love, business failure, overwork,” wrote Kraepelin, “are the product rather than the cause of the disease; they are merely the outward manifestation of a pre-existing condition.” As a madwoman, in Kraepelin thinking, my failed loves are the product of a bad brain, a malfunctioning machine.

Around the 1980s, a group of American psychiatrists who called themselves the neo-Kraepelinians revived this faith in biological, classification-based psychiatry. Their major work, the Diagnostic and Statistical Manual of Mental Disorders or DSM, is now central to medical practice. It lists more than 600 varieties of mental “disorders,” each with a checklist of symptoms.

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One of the neo-Kraepelinians, psychiatrist Gerald Klerman, declared that there exists in the human mind a clear boundary between "the normal and the sick." Another neo-Kraepelinian, Nancy Andreasen, wrote this very Kraepelinian statement: that though mental illness can be "sometimes triggered by unfortunate life events, the basic causes [of it] lie in the biology of the brain."

But the term “mental illness” really means “consciousness illness,” and within the framework of what we know about the mind, that term makes no sense. Humans can’t have both extraordinary diversity and reductive similarity. It’s impossible to parse terms like “out of touch with reality” when no one knows what the thing being touched even is. “Normal” is a difficult standard, and "boundaries" is an even more difficult one.

I wonder what mind care would look like with reverence for the great wonder: amor mentis, love of the mind. With dialogue, which needs to take place with the person holding the prescription pad. As a teenager, I heard I had schizophrenia and would live my life in an institution. When the diagnosis changed to bipolar, doctors said I was lucky—that diagnosis “held hope.” No one at the time of the diagnosis asked me what was happening in my life or what might help me. That would have held hope.

Anil Seth told me that the one thing his research has taught him is some “humility” towards other people’s different perceptions of the world, and their inner lives. And that he believes “bringing to light our inner diversity could be as transformational for society as recognition of our externally visible diversity has been.”