Reward responses to food stimuli across sensory modalities: Hunger modulates wanting differentially for pictures and odors

Food reward responses are guided both by hunger as a homeostatic need state and by the perceptual evaluation of food cues. Whether interactions between the two vary depending on the sensory modality through which food cues are presented, however, remains unclear. In a preregistered within-subject study, we tested whether modulations of food reward valuation by hunger are more pronounced for food odors compared to food pictures. Participants (N = 43) rated visual and olfactory presentations of food, non-food, and disgusting stimuli in both fasted and sated states across the separable reward dimensions of liking and wanting. Our results showed that hunger selectively increased wanting for food cues (p < 0.001) while food liking was not significantly affected (p = 0.063). Contrary to our hypothesis, this hunger-induced increase in wanting was less pronounced for food odors than for food pictures (p < 0.001). Liking and wanting ratings of non-food stimuli were largely unaffected, regardless of state (p = 1.00; p = 0.208). Overall, our findings indicate that hunger selectively modulates motivational rather than hedonic components of food reward in a modality-dependent manner. The present study establishes a methodological framework for examining how metabolic state and perceptual factors jointly shape food reward evaluation, highlighting the importance of multi-modal approaches for understanding both normative appetite regulation and maladaptive eating behaviors.