We often talk about the brain as if it were a single unified computer. We think that our Self which is that conscious voice in our head is the CEO making all the decisions. But neurology tells us a very different story.

Consider the eye. In the very center of your retina there is a blind spot. It is the place where the optic nerve and the blood vessels enter the eye so there is no room for photoreceptor cells. You literally cannot see the thing you are looking directly at.

But you do not see a black hole in your vision. Why? Because your brain runs a Photoshop filter over it. It takes the information from the surrounding area and inpaints the missing data. What you see in the center of your vision is not reality. It is a guess. It is a simulation based on probability.

This is the perfect metaphor for the Self. The thing we think of as Me is often just a simulation stitched together by a much deeper and older part of the brain that we rarely acknowledge.

The Democracy of the Body

You cannot run a country by having every citizen vote on every single issue every day. You would never get anything done. You have to elect representatives.

The brain works the same way. You cannot consciously decide to beat your heart or digest your food or dilate your pupils. The amount of data required to run a human body is like drinking from a fire hose. If your conscious ego had to manage it you would collapse.

So the brain stem acts as your representative government. It manages the vast majority of your life without you ever knowing about it. It decides if a room is safe. It decides if a person is trustworthy. It decides if you should fight or flee. And it does this milliseconds before your conscious mind even knows what is happening.

The GPU vs. The CPU

If we have to use a computer metaphor think of the cortex or the thinking part of your brain as the Central Processing Unit or CPU. It is great at doing complex novel math problems one at a time. It is great for logic.

But the brain stem is the Graphics Processing Unit or GPU. A graphics card is designed to do millions of very simple math problems simultaneously. It has to render every pixel on the screen at once.

The brain stem is processing millions of bits of sensory data like light and sound and temperature and micro expressions and tone of voice all at the same time. It is running a massive parallel calculation to answer one question. Am I safe?

This is why you cannot talk someone out of trauma. Talk therapy targets the CPU. It tries to use logic and language to change how a person feels. But trauma lives in the GPU. It lives in the brain stem’s rapid fire assessment of danger.

Implicit Memory and the Body

This deep processing creates what we call implicit memory. These are not memories you can tell as a story. They are memories you feel. They are the tightness in your shoulders when your boss walks in. They are the sudden drop in your stomach when you hear a certain song.

When we try to treat these with Cognitive Behavioral Therapy we are essentially telling the CPU to yell at the GPU. We are telling the conscious mind to demand that the body stop feeling what it is feeling. But the body has more data. The body is reading the room in a way the mind cannot.

This is why tools like pupillometry are becoming so important. The pupil dilates based on cognitive load and emotional arousal and it does so involuntarily. It is a window into what the GPU is doing. By watching the eye we can see when the brain stem detects a threat even if the patient says they are fine.

A Therapy for the Hardware

If we want to heal trauma we have to stop treating the software and start treating the hardware. We need therapies that speak the language of the brain stem.

This is why I use methods like Brainspotting and Somatic Experiencing. These are not woo woo magic tricks. They are ways of accessing the event related potentials in the deep brain. We are using eye position and body sensation to locate the files that the GPU is currently processing and help it resolve the error.

We have to respect the wisdom of the body. We have to understand that our irrational reactions are actually highly rational responses to a set of data that our conscious mind just has not seen yet. When we stop fighting our biology and start listening to it real healing becomes possible.