The Ecology of Humans (27-4) Amygdala


High childhood anxiety is associated with enlarged amygdala, and with increased connectivity between the amygdala and distributed brain systems involved in attention, emotion perception, and regulation. ~ Chinese American behavioral psychiatrist Shaozheng Qin et al

The amygdala is the brain’s emotive center, remembering emotionally charged events. It is also instrumental in relationships and sociality.

The amygdala is necessary for processes that involve updating representations of value. ~ American neurobiologists Sara Morrison & Daniel Salzman

All sensory information goes to the amygdala to create mental sensation. From that first impression emotively based valuation of experience is determined in the amygdala. This then factors into motivation for action.

The amygdala extensively interfaces with the prefrontal cortex: the mind-brain’s executive system control center at the front of the frontal lobe.

Human response to animals, either affine or fearful, is hardwired in the amygdala.

Juveniles largely rely upon the amygdala for decisions, as the prefrontal cortex is still developing.

Once the amygdala is over-reactive, people tend to behave in an anxious, over-reactive way to things they see as a potential threat. ~ American psychologist Luke Hyde

The amygdala’s importance cannot be overstated. It is well connected to other brain regions involved with sensation and cognition.

In association with the hypothalamus and thalamus, the amygdala is part of the limbic forebrain. From an evolutionary perspective, the limbic system is relatively primitive. All vertebrates have limbic systems which perform similar processing. The limbic system is particularly well developed in social species.

The human amygdala is enlarged compared to other primates. Our amygdala is responsive to emotive content expressed by the whites of the eyes (sclera), such as fear. Other primates have dark eyes, and so lack this communication conduit.

The amygdala matures during puberty. Its response to visual sexual stimuli differs between women and men.