Valence processing differs across stimulus modalities

Although it is often assumed that valence processing in the prefrontal cortex (PFC) is similar for stimuli originating from different sensory modalities, evidence supporting this view is lacking. To address this, we recruited 20 male participants and used a delayed-response fMRI design to test whether perceived pleasantness of flavors and images is similarly processed in the PFC. As predicted, significant correlations were observed between image and flavor pleasantness ratings, and PFC response to these stimuli; however, these responses were spatially different, with flavor pleasantness reflected in more ventrally located PFC regions than image pleasantness. These results indicate that, contrary to the general assumption of a singular circuit representing pleasantness, distinct PFC circuits are recruited depending upon stimulus modality. We argue that the ventral-dorsal distinction may be attributed to a difference in proximal versus distal stimulus representations.