Here’s one theory. This is a side view of the #brain below. Normally, prefrontal cortex activity, here shown in blue, regulates our thoughts, actions and feelings by influencing other brain areas:
These areas include the amygdala and hippocampus, here in orange, which manage emotions and memory. The green motor and sensory regions, responsible for body movement and sensation, are also moderated by prefrontal cortex action.
When #stress hormones arrive in the bloodstream, such as noradrenaline, things change. Activity in the body and emotional centres lose their prefrontal cortex control.
Their unchecked activity can also bring down prefrontal activity more, which spoils working memory and our ability to make decisions. The brain becomes fearful and confused under stress.
Adapted from a highly referenced Nature Portfolio Neuroscience Review from 2009 by Dr Amy Arnsten: https://www.nature.com/articles/nrn2648
Stress on his brain – AI image courtesy of Microsoft Designer.