This Is What Makes The Brain Control The Body

This question originally appeared on Quora. Answer by Fabian van den Berg.

As humans we really like the idea that we are in control, that our decisions are our own, that “we” are free and call the shots. Silly humans, always lying to themselves.

Everything influences the brain, some things have a stronger influence than others, and what determines your choice changes depending on the circumstances. We are bombarded with input all the time.

What we do, think, decide, everything is the result of many factors. These are often more basic than we would like to admit (and I mean things like, because it was on the right or it was my favorite color). Our subjective/conscious experience only plays a part in that decision process. The amount of biases really is staggering! And these are already rather advanced influences on the brain, caused by the brain itself.

What about external factors? What controls the brain? everything. From the bacteria in your gut, to the people around you, the weather, what you see/hear/smell, the signals it gets from your own body.

Imagine you go to the supermarket, how strong are you when you walk through the candy-isle? Normally you can resist the allure of chocolate, cookies, and chips…but what if you are really hungry? Will you buy an extra loaf of bread? some lettuce? or are you more tempted to buy some cookies. It’s just this once, and you haven’t eaten that much so how bad can it be?

This is a simple example where the sensation of hunger affects the thought-process. Even if you decide not to buy that candy, the way you got to that decision is different when you are hungry. More subtle things go on. We make different choices when we are with other people, friends, family, or a possible mate. We make different choices when we are tired than when we are awake. Our thoughts are different when we are angry, sad, or happy.

Our brains aren’t isolated systems, it’s a system that’s always in flux, going with the waves of the environment. It constantly changes its output based on the information it gets and the information it has stored.