
The thinking brain versus everything else
Psychiatry deals with the supratentorial. Supratentorial? you’re wondering.
A quick anatomy lesson: there’s a thick sheet of tissue that stretches horizontally through the brain, dividing it into a top and a bottom. The sheet is called the tentorium.

The part of the brain below the tentorium handles the basics, like breathing, hunger, hormones, and heartbeat. That’s called the infratentorium. It’s not the interesting part. Forget about it.
Now if you’re looking for thought and emotion and language, the top section of the brain is where you put your money. This part is called the cerebrum or supratentorium, and it should be splashed in neon colors or dipped in gold, or both. This is where we find the human soul. This is the land of dreams, passions, goals, and imagination. Here you find movies like the Matrix and Avatar and the English Patient. This is where Martin Luther King found his speech and started a movement. Herein lies the Italian Renaissance.
If you’re going to be a psychiatrist, you must swear an allegiance to the supratentorium.
Sort of.
Supratentorial Humor

In medicine, the joke goes like this: “The patient presented with a sore toe.” It can be a cough, burning sensation across the abdomen, problem walking, rash,anything. All you need is an unexplained symptom. “Upon examination the toe is fine. The problem isn’t physical. The problem is supratentorial. Therefore, the plan is to refer to psychiatry.”
What? you’re thinking. How can a sore toe be above the tentorium?
A toe can’t be supratentorial. Thar’s the rub, mate! A supratentorial toe means the sore toe isn’t real. The patient is imagining it. No, no, they’re not faking the pain. They really feel it, but there’s no physical reason for the toe to hurt. Since the pain is felt and thought about but not real, it’s supratentorial. It lies in the realm of movies and art (and psychiatry), not physical medicine.
There are other words to describe a “symptom without a cause,” like functional and idiopathic. “His inability to walk is functional,” or “she’s struggling with idiopathic pain behind the right ear.” We doctors like to use big words to hide the truth. Sometimes we don’t know what’s causing the problem. It’s easier to imagine it’s not real.
I’ll let you in on a few clues:
- When faced with a set of symptoms the doctor doesn’t recognize, something outside our circle of knowledge or that doesn’t exist in our textbooks, we often call it supratentorial (or functional or idiopathic).
- If a doctor says your problem is supratentorial, consider seeking a second opinion.
- If you’re a psychiatrist with a supratentorial problem… oh, never mind.
Psychiatry, Tentorium, and Contradiction
So psychiatry deals with the supratentorial. What is psychiatry but the realm of thought, emotion, behaviors, memory, and speech? What is humanity but the gathering of knowledge, feeling, and the ability to express? That’s cerebrum all the way. Absolutely psychiatry is supratentorial.
Unfortunately that’s all wrong. This damned tentorium has everyone confused.

Some psychological symptoms masquerade as physical disorders. Some physical problems look psychiatric. Both types are called false masqueraders. They look and act like ducks but they don’t quack.
- A college student’s panic attacks turn out to be a rare tumor on his adrenal gland called a pheochromocytoma. The tumor spurts out Adrenalin, causing his blood pressure to fly and his body to catapult into a panic dozens of times/day. Pheochromocytoma is typically labelled a panic disorder before it’s diagnosed properly. It’s rare and looks like a duck.
- An elderly woman with severe depression and a 100-pound weight loss turns out to have pancreatic cancer. Pancreatic cancer is often diagnosed as “severe depression” before doctors realize the truth. It’s another duck that isn’t a duck.
- A businessman in the emergency room complains about chest pain, racing heart, problems breathing, tingling in his left arm, nausea, and dizziness. He’s concerned he’s having a heart attack, but it’s a panic attack.
- A morbidly obese man with a dozen medical problems presents to your office with depression, anxiety, attention problems, and memory problems. He’s getting divorced. He just lost his dog. He’s been taking his medications wrong. He recently started using heroin. Where did it all start? His body doesn’t know he’s supposed to be supra OR infratentorial, not both.
Oh boy. Humans have spent thousands of years drawing a line between mental and physical, between the spiritual and material. The soul is separate from the body, right? This distinction is important to us. In medicine it gives us permission to be “scientific.” Providers like things well-defined and well-delineated. We know who needs to see whom for what. The emotional, illogical side of humanity is reserved for psychiatrists. Everything fits nicely into place.
Do you think the universe agrees? Nope. It taunts us with the tentorium and laughs at us for reaching the wrong conclusion. It bypasses our “duck is a duck” rule. It adds geese, turkeys, swans, sparrows, and poodles to our duck mix and asks us to come up with better rules. “The tentorium is a fluke,” it says. “Your distinction between body and soul? Buuuuzzzz. Wrong.”

Take home point?
So you want to be a psychiatrist, play one on TV, or something like that?
One day you’ll meet a teenager whose nastiness is caused by a brain tumor no one recognizes; after all, her symptoms appear supratentorial. Teenagers can be nasty. No one thinks to look below the line. A woofing duck is accepted as a duck, and the teenager is left to die. That’s how you learn to look past psychiatry. You look for everything.
You’ll encounter a mother who breaks her son’s arms in a fit of confusion. She says she had a seizure. She has temporal lobe epilepsy, a clear infratentorial reason for her behavior, but there are doubts. When is a duck really a vulture? That’s how you learn to keep your wits about you.
You’ll meet a serial killer who murdered twenty people because all twenty were inhabited by demons. You’ll treat his depression and speak kindly to him. Sometimes ducks do horrible, horrible things, but they’re still ducks. That’s how you learn compassion.
You ready for this? Can we call you Doctor?
Welcome to psychiatry.
Afterward/food for thought:
“Is psychiatry a medical enterprise concerned with treating diseases, or a humanistic enterprise concerned with helping persons with their personal problems? Psychiatry could be one or the other, but it cannot — despite the pretensions and protestations of psychiatrists– be both.”
–Thomas Szasz.
Do you agree?

This is the first article in an e-book originally written for medical students. I’m currently adjusting it for the general public. Other articles in the book include vocabulary, ethical dilemmas, how to do evaluations, how to deal with difficult situations, the rules of psychiatry, and note writing. If you’re interested in a copy of the book, please sign up and shoot me a message. Thanks!
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