Participants underwent brain scans while watching videos of people having their foot stepped on, having a heavy bowl fall on their hands, or the like. The scanning system was of a widely used type known as functional Magnetic Resonance Imaging, which measures brain activity based on where blood is flowing.
Aggressive adolescents showed a “specific and very strong activation” in a brain area called the ventral striatum, known from previous studies to respond to pleasurable events, Decety said. Unlike the control group, he added, the more aggressive youth didn’t activate brain areas involved in self-control, called the medial prefrontal cortex and the temporoparietal junction.
The findings are reported in the current issue of the research journal Biological Psychology.