it's the amygdala again. 
in animals the sensitivity depends on the level of neurotransmitter serotonin.
low serotonin makes us hyperreactive to stress.
high serotonin dampens fear.
dominant male monkeys have high serotonin—but the level drops when they lose eye contact with the monkeys who fear them. 
if the low ranking monkeys serotonin rises their position in the hierarchy rises.

there's either some anomaly in my brain and sensory system or there is exhaust coming in here. i'd rather be confused than poisoned, but what if i'm confuse and poisoned.

anyway there's a lot to think about in this book of trauma about stress and anxiety and it's  paradoxical in nature. like we may be traumatized and not be able or know how to escape, and returning to the scene of stress may quell the anxiety.