Humans live in a multisensory world and as a consequence, the brain dedicates considerable resources to multisensory processing. Olfaction is a modality in which multisensory processing is particularly important. For example, odor, taste, color, and texture are strongly associated in food and drink. Despite many studies demonstrating associations between odors and other sensory modalities, the strength of these associations across sensory modalities is unknown. Furthermore, it is unclear what odor dimensions are relevant in odor crossmodal associations. To investigate this we presented 50 British participants with 16 odors spanning two odor dimensions: pleasantness (pleasant vs. unpleasant) and edibility (edible vs. inedible). Participants were asked to rate to what extent associations with vision, sound, taste, or texture came to mind when they smelled an odor on a 0 (not at all) to 5 (very much) scale. Vision was the modality most strongly associated with odors, followed by taste and texture, with sound the least associated. Using linear mixed effects models with participants and odors modeled as random effects, we found associations in all modalities except taste were stronger for pleasant compared to unpleasant odors. Surprisingly, associations in all modalities except vision were stronger for inedible compared to edible odors. Our results suggest the strength of odor associations varies across sensory modalities. Importantly, odor pleasantness and edibility are two key factors driving crossmodal associations, supporting suggestions made elsewhere that they are primary dimensions in the perceptual space of odors.

Fundings: This work is supported by BA/Leverhulme Small Research Grant SG2122\210743to LS and DC.