[Insula and disgust]

Abstract

The disgust emotion is elicited by a variety of stimuli ranging from rotten food to immoral persons. When we encounter such disgusting stimuli, whether they are physical or social, we commonly experience rejection responses by the body such as nausea and revolt. In fact, since the time of Darwin, it has been argued that disgust has its origins in a rejection response to offensive food, and that the sensations of tastes and odors play a crucial role in the experience of disgust. This view predicts that the insula is closely related to disgust because it serves both gustatory and visceral motor functions including the control of vomiting. Indeed, the insula is activated by a broad range of disgust-related stimuli such as disgusted facial expressions, unpleasant odors, pictures of rotten food, and unfair acts. However, increasing evidence indicates that the insula plays an important role in the experience of not only unpleasant but also pleasant bodily feelings. In brief, the insula seems to be involved in the conscious perception of emotional bodily feelings in general, or somatic markers, and assist in our decisions as to approach vs. avoidance.