Left Anterior Insular Lesions Result in Impaired Recognition of Facial Expressions of Negative Emotions

Abstract

Single case studies about patients with unilateral insular lesions reported deficits in emotion recognition from facial expressions. However, there is no consensus about both the actual extent of impairments and the role of lesion lateralization. To investigate associations of brain lesions and impairments in a facial emotion recognition task, we used voxel-based lesion-symptom mapping (VLSM) in a group of 29 stroke patients in the chronic stage, 16 with left and 13 with right hemispheric lesion. Recognition accuracy was impaired for fearful and angry expressions in patients with left hemispheric lesions compared to 14 matched healthy controls. VLSM analyses revealed that lesions centered around the left insula were associated with impaired recognition of emotional facial expressions. We here demonstrate a critical role for the left insula in decoding unpleasant emotions from facial expressions and therefore present further evidence for a broader role for the insular cortex not restricted to disgust processing.