Overlapping activity in anterior insula during interoception and emotional experience

Classic theories of emotion posit that awareness of one's internal bodily states (interoception) is a key component of emotional experience. This view has been indirectly supported by data demonstrating similar patterns of brain activity - most importantly, in the anterior insula - during both interoception and emotion elicitation. However, no study has directly compared these two phenomena within participants, leaving it unclear whether interoception and emotional experience truly share the same functional neural architecture. The current study addressed this gap in knowledge by examining the neural convergence of these two phenomena within the same population. In one task, participants monitored their own heartbeat: in another task they watched emotional video clips and rated their own emotional responses to the videos. Consistent with prior research, heartbeat monitoring engaged a circumscribed area spanning insular cortex and adjacent inferior frontal operculum. Critically, this interoception-related cluster also was engaged when participants rated their own emotion, and activity here correlated with the trial-by-trial intensity of participants' emotional experience. These findings held across both group-level and individual participant-level approaches to localizing interoceptive cortex. Together, these data further clarify the functional role of the anterior insula and provide novel insights about the connection between bodily awareness and emotion. (C) 2012 Elsevier Inc. All rights reserved.