Left-hemisphere activation and deficient response modulation in psychopaths

Psychopathic offenders have difficulty processing contextual or secondary c ues once they have initiated goal-directed behavior or allocated attention to a primary task. To test the hypothesis that this deficit in response mod ulation is specific to conditions in which psychopaths' left-hemisphere res ources are engaged, we administered a serial recall task to 21 incarcerated psychopaths and 21 control subjects. Subjects were instructed to memorize eight words that were presented one at a time, each in one of the four corn ers of the visual display. Subjects' primary task was to recall the words i n serial order Then, without forewarning, they were asked to recall the wor ds' locations. As predicted psychopaths performed as well as control subjec ts in recalling words from the left and right spatial fields, but recalled significantly fewer locations from the right spatial field. Thus, psychopat hs' deficient response modulation was specific to conditions in which their left-hemisphere resources were actively engaged.