The amygdala acts as a 'lumper,' generalizing sensory events rather than being ultra-precise about details.

“This has a wonderful side and a kind of dark side. The dark side is that PTSD and traumas of various kinds often involve an increase in adrenaline because whatever it was that caused the PTSD was indeed very stressful. Caused these big increases in these chemicals. And because the amygdala is rather general in its functions. Right, it's not tuned or designed in any kind of way to be specifically active in response to particular types of sensory events, or perceptions. Well, then what it means is that we can start to become afraid of entire city blocks where one bad thing happened in a particular room of a particular building in a city block.”