Impaired emotional processing in a patient with a left posterior insula-SII lesion

The present case-report investigated the influence of a lesion in the left posterior insula-SII cortices on the processing of emotions. MB and 16 normal controls explicitly rated the valence and the intensity of both facial expressions and emotional words. In addition, they had to perform a number comparison task and a lexical decision task without focusing their attention on emotional components of stimuli. MB identified the valence of emotional words as well as the control group. Nevertheless, she provided higher intensity scores for disgusted words and her responses in the lexical decision task were significantly delayed for these stimuli. In addition, MB’s response times were not differently influenced by the presence of irrelevant emotional faces. However, she explicitly identified fewer facial expressions of disgust and she assessed them as significantly less intense. This pattern of results contributes to highlight the psychological and behavioral disorders observed after a left posterior insular stroke.