A deficit in attentional set-shifting of violent offenders.
BACKGROUND
Recent brain imaging studies suggest that proneness to violence and antisocial behaviour may be associated with dysfunction of the prefrontal cortex. The present study. therefore, examined aspects of prefrontally guided executive functions in a group of criminal violent men.


METHODS
Violent offenders undergoing forensic psychiatric examination by court order undertook computerized tasks for planning, visual working memory and attentional set-shifting from the Cambridge Neuropsychological Test Automated Battery. Their performance was compared to that of subjects with marginal mental retardation and normal controls.


RESULTS
Violent offenders performed well on tasks for spatial and figurative working memory, as well as on a test for planning. A marked impairment was observed in the attentional set-shifting task: offenders made significantly more errors than the other groups when required to shift attention from one perceptual dimension to another. Reversal learning was also deficient. Correlational analyses within the offender group revealed that poor performance on the perceptual shift problem was associated with fewer errors in tasks for working memory and planning.


CONCLUSIONS
The present results suggest that violent offenders show dual impairments in inhibitory cognitive control. First, they are deficient in shifting attention from one category to another. Secondly, the ability to alter behaviour in response to fluctuations in the emotional significance of stimuli is compromised. These deficits might constitute cognitive reflections of the biological prefrontal alterations observed in this group of people.
Bergvall
A H
AH
Department of Psychiatry (National Board of Forensic Medicine), Göteborg University, Sweden.
Wessely
H
H
Forsman
A
A
Hansen
S
S
D000293:Adolescent; D000328:Adult; D000987:Antisocial Personality Disorder / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D001288:Attention / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology; D003936:Diagnosis, Computer-Assisted; D005555:Forensic Psychiatry; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000503:physiopathology*; D012720:Severity of Illness Index; D014754:Violence