I have been curious about the amygdala , if it is over responsive/reactive , it is not regulated or controlled.I found it tends to overreact in positive situations by overexposure based on positive sentiment ,it subconsciously(like human autopilot) takes over and place larger trades.
Technically, the amygdala is an ancient part of the emotional brain that governs responses to threat -- usually fear responses. It also, interestingly enough, is involved in letting down our guards so that pro attachment kinds of behavior can occur. The amygdala (fear response) is governed by the hippocampus -- as interpreter of in incoming information related to past experience embedded into limbic memory. It is the signal from the hippocampus that activates the amygdala.
This "positive sentiment" you speak of is probably what I would call a dopamine fix associated with reward. This is more about the impact euphoria (feeling good) has on perception rather than an amygdala related event. Euphoria, while trading, leads to over trading. Trading is about managing the emotions and meanings of assessments that create the mind that engages uncertainty.