Color Congruent Odorant is Perceived Prominently in Mixture Odor

This study examined how olfactory perception is influenced by visual cues (ie, color). In Experiment 1, fourteen participants judged perceived mixture ratio of the binary odor (citrus fruit and aromatic tree) by using ratio estimation method under one of two color conditions (yellow and purple). Each color was congruent with one of odor components. Perceived mixture ratios for the odorant congruent with the presented color were higher than those for the odorant incongruent with the color. Experiment 2 was conducted to confirm the possible response-bias effect on their judgment with the same participants. Conditions were same as Experiment 1 except that only one odorant was presented at a time. The effect of color was not observed, indicating that their judgments were not contaminated with response-bias. Thus, these results indicate that the odorant congruent with the presented color was perceived dominantly in a mixed odor, but this could be observed only when the odor stimuli contained that odorant. This study suggests that particular odorant congruent with a color cue is perceived selectively from a mixture odor. This finding may reflect the olfactory selective attention in mixed odor, attracted by the color as a cue to the specific odorant