On the outside, they all seem like normal people. You have a motel manager, a police detective, a doctor and a banker. But they hide a dark side. Just how does the brain of a real psychopath work?

He seems calm, even normal -- until he lifts his hands ... cortex above the eyes and the amygdala deep in the brain. But Kiehl says when psychopaths like Dugan see the KKK picture, their emotional ...

Many psychopaths show a distinctive pattern of ... substance to measure brain activity. Here's a scan of a normal brain (top) and Fallon's brain (bottom). Notice that the normal scan shows much ...

Cancer cells follow the same genetic programs found in normal brain cells, but in a distorted way, he said. Some cancer cells seem to repeat the pattern of early brain development, almost growing ...

The kaleidoscopic whirl of colors they recorded is essentially a heat map of brain changes, with the red, orange and yellow hues reflecting a significant departure from normal activity patterns.