Defective somatic markers in sub-clinical psychopathy.

Damasio's somatic marker hypothesis is argued to be specifically applicable to psychopathy, though evidence has been meager until now. The principal evidence for the somatic marker hypothesis is based on findings in patients with orbitofrontal lesions, showing absent punishment learning on the Iowa gambling task. Interestingly, neuroimaging studies indicate orbitofrontal dysfunction in psychopathy also. Here we investigated the somatic marker hypothesis in subjects selected on low and high psychopathic behavioral characteristics from the outer extreme ranges of a large subject pool (n = 525). The low psychopathic subject group (n = 16) showed intact punishment learning, suggesting somatic markers came to guide their decisions in the course of the game. In contrast, such punishment learning was not observed in the high psychopathic subject group (n = 16), who mimicked the gambling behavior of orbitofrontal patients. These findings provide further evidence for the hypothesized link between psychopathy and orbitofrontal dysfunction.