Abnormal interhemispheric connectivity in male psychopathic offenders.
BACKGROUND
Psychopathic offenders inevitably violate interpersonal norms and frequently resort to aggressive and criminal behaviour. The affective and cognitive deficits underlying these behaviours have been linked to abnormalities in functional interhemispheric connectivity. However, direct neurophysiological evidence for dysfunctional connectivity in psychopathic offenders is lacking.


METHODS
We used transcranial magnetic stimulation combined with electroencephalography to examine interhemispheric connectivity in the dorsolateral and motor cortex in a sample of psychopathic offenders and healthy controls. We also measured intracortical inhibition and facilitation over the left and right motor cortex to investigate the effects of local cortical processes on interhemispheric connectivity.


RESULTS
We enrolled 17 psychopathic offenders and 14 controls in our study. Global abnormalities in right to left functional connectivity were observed in psychopathic offenders compared with controls. Furthermore, in contrast to controls, psychopathic offenders showed increased intracortical inhibition in the right, but not the left, hemisphere.


CONCLUSIONS
The relatively small sample size limited the sensitivity to show that the abnormalities in interhemispheric connectivity were specifically related to the dorsolateral prefrontal cortex in psychopathic offenders.


CONCLUSIONS
To our knowledge, this study provides the first neurophysiological evidence for abnormal interhemispheric connectivity in psychopathic offenders and may further our understanding of the disruptive antisocial behaviour of these offenders.
Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, the Netherlands.
Sylco S
SS
Hoppenbrouwers
Centre for Addiction and Mental Health, Schizophrenia program, Toronto, Ont.
Danilo R
DR
De Jesus
Centre for Addiction and Mental Health, Schizophrenia program, Toronto, Ont.
Yinming
Y
Sun
Correctional Service of Canada, Central Ontario District (Parole), Psychology Department, Toronto, Ont.
Tania
T
Stirpe
Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, the Netherlands.
Dennis
D
Hofman
Centre for Addiction and Mental Health; Law and Mental Health Program, Toronto, Ont., Canada.
Jeff
J
McMaster
Correctional Service of Canada, Central Ontario District (Parole), Psychology Department, Toronto, Ont.
Ginny
G
Hughes
Centre for Addiction and Mental Health, Schizophrenia program, Toronto, Ont.
Zafiris J
ZJ
Daskalakis
Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, the Netherlands.
Dennis J L G
DJ
Schutter
D000328:Adult; D000987:Antisocial Personality Disorder / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000187:drug effects / Q000503:physiopathology*; D057237:Criminals; D004569:Electroencephalography; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D050781:Transcranial Magnetic Stimulation