Tahani Karrar at Reuters:
Researchers from the Institute of Psychiatry, King’s College London monitored the emotional responses of six men who had committed repeat offences such as attempted murder, rape with strangulation and grievous bodily harm.
“We’ve never been able to look directly in the brain before and what we found is that when psychopaths were exposed to frightened faces the distress cue didn’t increase the psychopath’s blood flow. It decreased it,” Declan Murphy, a professor of psychiatry at the institute, told Reuters.
He added psychopaths might not stop their attacks because they may have learned to dampen their brain’s response to other peoples’ distress signals.
All six subjects scored highly on the Hare Psychopathy Checklist, a test which looks for the presence of cunning, manipulative or exploitative behaviors as well as lack of guilt or remorse.