Brain Structure - Brain Theory from a Circuits and Systems Perspective - page 7

Amygdala
The amygdala is a pair of complex parts the size of a cherry that activates primal
fears and other emotional responses. It has been called the fear button. Each
amygdala is about 4 cm into your brain from either temple. A sudden movement
or loud sound will cause the amygdala to signal the hypothalamus to initiate a
standard response, for example, to fight, to take flight, or to freeze.
The amygdala is important to memory because it adds emotional content to an
impression. Emotion is an important cue for creating and for retrieving long-term
memories. We usually remember details associated with emotional events, such as
our first romance, or where we were when Kennedy was assassinated, or where we
were on September 11, 2001.
Cingulated Gyrus
The cingulated gyrus aids in retrieving and analyzing memories of prior situations
and developing responses for future use. It is reserved for challenges that do not
require an immediate response. It helps us to make up our minds about what to do in
the presence of ambiguous information. It also determines the emotional strength of
sensory information and presents a result to the cortex. The cingulated gyrus is on
top of the corpus callosum.
Corpus Callosum
The corpus callosum is a major part of a network that connects the left and right
brains.
Forebrain Structure
The upper forebrain is a layer of neurons, or gray matter, and the underlying
connections, or neural white matter.
Gray Matter
Gray matter refers to dendrites, which do logical processing.