Abstract
In our previous experiments, it was shown that odors (rose, sandalwood) might influence the haptic perception (stiffness, roughness). In particular, subjects felt a smooth surface even smoother with rose odor and a stiff surface even harder with sandalwood odor. This study investigated whether the effects of odors could be explained by their categories that are derived from the verbal descriptions of odors. We used jasmine that is categorized as “flower”, which includes rose, and peppermint that is categorized as “herb” close to sandalwood for our experiments. Subjects were requested to adjust the roughness or stiffness of a test surface to match that of a standard surface just shown before it using a force-feedback device. Standard surfaces were presented with different odors (jasmine, peppermint, odorless) which was projected to the noses of subjects. The results showed that jasmine made subjects feel the surfaces softer than those in odorless condition, but had no effect on roughness perception. Meanwhile peppermint did not show significant effect on either stiffness or roughness perception. According to the inconsistency between the results of present and previous experiments, we argue that odors in similar categories do not necessarily influence haptic perception in the same way.