It’s All in Your Head

My belief in mind-body dualism ended in a doctor’s office one day in my 20s. After a routine allergy shot, my arm unexpectedly swelled and turned red. They gave me a shot of adrenalin and had me stay till the reaction subsided. While I waited, my mind went into semi-panic, as if my final exams were tomorrow and I hadn’t begun to study. Knowing that the adrenalin gave my feelings a purely physical cause didn’t calm me. Mind and body were inseparable.

“It’s all in your head” implies your idea isn’t real. But if mind and body are one, isn’t your brain where all your ideas exist, I wondered? It’s all in our heads. That’s where experience happens. The physical world outside us is knowable only through what our senses pass on to the brain. And in a world where dogs hear whistles inaudible to us, and most birds can see ultraviolet light we can’t, why assume human perceptions are the best match for what’s out there?

My thoughts evolved further when my optometrist told me recently that glaucoma could advance a lot before I noticed any loss of vision. I asked what I’d see in the blank where the vision is gone. “Oh, your mind just makes it up,” she said. It turns out many gaps in sensory input get filled with the brain’s best guess. Happily, most brains manage amazingly sound guesswork most of the time. “All in your head” is a pretty good place to explore the reality of ourselves and our world.

Image: Allergy shot such as the one that triggered my long-ago reaction. United States Air Force, 2015.
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