Multisensory Interactions between Olfaction and Touch: The Influence of the Trigeminal and Olfactory Sensation of an Odourant on Roughness Perception

In this study we investigated the influence of the olfactory and trigeminal sensation of an odourant on roughness perception. We expected that people would judge the tactile surface roughness of four sandpapers as higher when they were exposed to a substance with a trigeminal component (alcohol), and lower when they were exposed to Phenylethylalcohol (PEA, rose odour), compared to a no-odour (clean air) condition. Our results indicated that the participants could discriminate all four sandpapers on basis of their perceived roughness. However, there was no significant main effect of chemosensory and no significant interaction between chemosensory and sandpaper roughness. Despite the lack of significance, the results revealed that the mean rating responses on roughness were higher in the alcohol condition, and lower in the PEA-condition, compared to the no-odour condition. We also found a significant effect of gender for the roughness ratings in the PEA condition. Alternative explanations for the found results and suggestions for further research are discussed.