Lower Brain Function Versus Higher Brain Function
The important concept to grasp is that there are two general paths for thought in the brain. Neuroscientists generally refer to these as 'lower' brain functions (instinct, memory, emotion, and subconscious thought associations) and the 'higher' brain functions (cognitive thought, conscious reasoning). The lower brain areas work faster than the high road, and so they serve as the foundation for conscious thought. Another way to think of it is the Daddy brain and the kiddie brain. The big Daddy brain is the part that thinks rationally, reasons, and makes decisions. The lower brain is like the impulsive, hyperactive 3-year-old... rambunctiously tugging us in different directions without thinking or acting rationally. It feels rather than thinks.
Whenever you encounter anything, be it a new experience or idea, the thoughts that emerge are a combination of hese two "channels" of the mind interacting. Lower brain functions often get a bad rap, because they're responsible for most human problems; everything from irrational thinking to the impulsive murders and crimes that plague our society. "We have stone age emotions, medieval institutions and God-like technology, that's the source of all our problems," comments Edward O. Wilson (2008, p. 32).
It's not all bad, though, so long as we understand how our mind works. The lower brain areas also enrich our lives in numerous ways. When we feel happy, when we feel loved, when we feel affectionate, when we reflect upon a fond memory; all these emotions originate from the low road. The problem arises when people aren't able to keep their lower brain functions in check, which is quite often. Worse yet, they make decisions from these impulsive feelings and use the lower roads to think. The lower-brain functions are great for feeling, but terrible for thinking.