The Brain

When we’re using our brains, we have System 1 and System 2.

System 1 is our fast-thinking, unconscious brain. It takes care of comfortable, familiar tasks, such as quickly reading some text or typing on a keyboard. The effort level is low, but this is due to having a pre-existing library of information to pull from (this is part of the reason why a second brain can be useful — to give yourself more information to quickly pull from).
System 2 is our slow-thinking, methodical brain. This takes significantly more effort and energy to use than System 1, but is where new thoughts can be processed and more complicated tasks can be performed. It is for this reason why context-switching should be avoided, and deliberate practice encouraged.

Amygdala

Considered the “emotional centre” of the brain (from “Peak Performance”).
A study conducted out of the University of Wisconsin-Madison ^{(which
study?)} compared brain activity in the Amygdala when exposed to stress. The study looked at those that were experts in meditation, and those that were not. The experts were able to acknowledge and then turn off the Amygdala’s response (referred to as an amygdala hijack).
This concept of turning off the Amygdala is used to help people “turn off” after a long day of focused work.
While not covered in the study, similar behaviour has been seen in professional athletes.

Handles rational decision-making