In the February 2000 issue of the ARCHIVES, a methodologically refined study by Raine et al1 demonstrated reduced prefrontal gray matter accompanied by a reduction in autonomic activity in patients with antisocial personality disorder (APD). An important additional expected observation concerned the dissociative pattern on the indexed indices of autonomic activity: a reduction in prefrontal gray matter was linked to a reduction in electrodermal, but not cardiovascular, activity. Low arousal as indexed by reduced electrodermal activity is argued to indicate insensitivity to punishment or poor fear conditionability. This results in difficulties learning to inhibit antisocial acts.1,2 Although it was not possible to be more specific regarding the localization of gray matter reduction within the prefrontal cortex, Raine et al and Damasio3 in his commentary suggest that the orbitofrontal cortex constitutes the most likely candidate.
van Honk J, Schutter DJLG, d'Alfonso A, Kessels RPC, Postma A, de Haan EHF. Repetitive Transcranial Magnetic Stimulation at the Frontopolar Cortex Reduces Skin Conductance but Not Heart Rate: Reduced Gray Matter Excitability in Orbitofrontal Regions. Arch Gen Psychiatry. 2001;58(10):973-974. doi: