Social and emotional functioning following bilateral and unilateral neurosurgical prefrontal cortex lesions

Abstract

Alterations in emotional and social functioning such as impaired ability to recognize emotions in others, a lack of empathy and poor insight have commonly been reported following prefrontal cortex damage. This study sought to investigate the subtleties of such difficulties in 34 individuals with discrete unilateral and bilateral neurosurgical lesions encroaching on the orbitofrontal, medial, and dorsolateral regions of the prefrontal cortex. A specifically devised self- and informant report measure, the social-emotional questionnaire was used to examine five factors of functioning: emotion recognition; empathy; social conformity; antisocial behaviour; and sociability. There were some specific significant differences between the clinical and control groups' informant-ratings in certain domains of social and emotional functioning. Individuals with damage involving the orbitofrontal region were reported to display elevated levels of antisocial behaviour. Individuals with bilateral orbitofrontal lesions were rated as showing significantly reduced social and emotional functioning in comparison with individuals with unilateral lesions and controls. In addition, individuals with bilateral lesions had significantly less insight overall regarding their social-emotional abilities. The right unilateral lesion group showed significantly less insight into their abilities to recognize emotion in others in comparison with the left unilateral group. In conclusion, these results suggest that specific social-emotional and insight deficits may form separate constellations of impairment. The findings also indicate that marked changes in social and emotional functioning are more likely following bilateral damage, and unilateral lesions do not inevitably lead to impairments.