Brain Processing of Fearful Facial Expression in Mentally Disordered Offenders

Emotional facial expressions are important cues for interaction between people. The aim of the present study was to investigate brain function when processing fearful facial expressions in offenders with two psychiatric disorders which include impaired emotional facial perception; autism spectrum disorder (ASD) and psychopathy (PSY). Fourteen offenders undergoing forensic psychiatric assessment (7 with ASD, and 7 psychopathic offenders) and 12 healthy controls (HC) viewed fearful and neutral faces while undergoing functional magnetic resonance imaging (fMRI). Brain activity (fearful versus neutral faces) was compared both between HC and offenders and between the two offender groups (PSY and ASD). Functional co-activation was also investigated. The offenders had increased activity bilaterally in amygdala and medial cingulate cortex as well as the left hippocampus during processing fearful facial expressions compared to HC. The two subgroups of offenders differed in five regions compared with each other. Results from functional co-activation analysis suggested a strong correlation between the amygdala and anterior cingulate cortex (ACC) in the left hemisphere only in the PSY group. These findings suggest enhanced neural processing of fearful faces in the amygdala as well as in other facial processing brain areas in offenders compared to HC. Moreover, the coactivation between amygdala and ACC in the PSY but not the ASD group suggested qualitative differences in amygdala activity in the two groups. Since the sample size is small the study should be regarded as a pilot study.