Amygdala

Binge drinking can damage the amygdala.

And young people who described themselves as conservative had an amygdala (the brain structure associated with emotional processing) that was larger.

The amygdala is a mass of gray matter, similar in shape to an almond, existing in each of the cerebral hemispheres, that is involved in the experience of emotions.

Researchers also found that people with the highest amygdala activity, in other words those who were the most stressed out, had the highest levels of inflammatory markers in their blood.

There is experimental evidence showing that cortisol restrains the intensity and duration of the emergency reaction to stress, and catecholamines have been shown to enhance emotional memory in the amygdala (see subsection on "Noradrenaline"). Thus, individuals lacking cortisol would overstore traumatic memories .

Cognitive scientists distinguish between normal risk-assessment decisions, which activate the reward-prediction regions of the brain, and decisions made amid extreme uncertainty, which generate activity in the amygdala.

In the study, led by Ryota Kanai of the University College London, people who identified themselves as liberals generally had a larger anterior cingulate cortex — a comma-shaped region near the front of the brain that is involved in decision-making. By contrast, those who identified as conservatives had larger amygdalas — almond-shaped structures that are linked with emotional learning and the processing of fear.

A decreased amygdala response, in other words, may help explain the “slippery slope” of lying, said Sharot, one of the authors of “The Human Brain Adapts to Dishonesty,” just published in the journal Nature Neuroscience.