Hedonic stimulus properties significantly influence food reward processing. The underlying mechanisms remain poorly understood, warranting precise delineation of the contributing processes. This is complicated by the fact that consummatory and anticipatory perceptual reward properties of food stimuli (pleasant and appetizing) are correlated in real world settings, processed in parallel, and across several sensory modalities. In this study, we test whether consummatory and anticipatory hedonic processing of visual and olfactory stimuli can be separated by comparing food stimuli (pleasant, appetizing), to non-food (pleasant, unappetizing), and disgusting (unpleasant, unappetizing) stimuli. In two separate experiments, participants rated content-matched sets of 28 odors (N=37) and 50 pictures (N=42) for consummatory reward properties and appetitive food reward value. Our results indicate that participants differentiate clearly between the anticipatory appetitive value and the consummatory reward value for both odors and pictures (p<.001). Hedonic properties were higher for visual than olfactory stimuli in the food category, but lower in the non-food category (p=.004), suggesting a higher risk for odor misidentification compared to pictures. The same is true for the consummatory part of the disgusting category (p=.013), indicating a need for stimulus matching in multisensory batteries. Our data demonstrate reliable separation of consummatory and anticipatory evaluation by category for both the olfactory and visual domain. Stimulus sets that vary these factors independently may provide novel insight into food reward processing, such as their integration with gastrointestinal feedback and their independent roles underlying disturbed processing of food reward in individuals with eating disorders.
AS is the recipient of a GIRACT European PhD in Flavor Research Award. JS is funded by Vetenskapsrådet (VR2018-1384) and ERC StG OLFLINK 947886. CB is funded by VR-538-2013-8864.