Insular Cortex Response to Static Visual Sexual Stimuli

Abstract. According to previous research, the insula is important for processing salient and emotional stimuli, but its precise role remains elusive. By combining high spatial and temporal resolution, intracranial electroencephalography (iEEG) might contribute to filling this gap. Four drug-resistant epileptic patients with intracranial electrodes in the insula were instructed to watch and rate pictures with sexual content and neutral pictures. Event-related potentials (ERPs) were computed separately for both types of stimuli. Ninety-three percent of the anterior insula (AI) and 85% of the posterior insula (PI) contacts showed differences between ERPs. AI-positive deflections tended to have an earlier onset than PI-positive deflections. The results suggest that the AI generates a P300-like response and contributes to the early phase of the late positive potential, both components found enhanced while viewing emotional stimuli in the ERP literature. The present findings are interpreted as congruent with the role of the AI in maintaining attention to salient stimuli.