Visual search performance depends on the congruency of olfactory sensations.

We here provide evidence for a benefit of congruent olfactory sensations during a challenging visual search task. Using a four-channel olfactometer, we exposed our participants to one of three suprathreshold fruit odorants (lemon, apple, or strawberry) or neutral room air (no odorant) while they searched for an image of a cued-target fruit presented among fruit distractors. Congruent odorants (e.g., exposure to a lemon scent while searching for a lemon among other fruits) led to greater performance levels and faster responses compared to trials where the participants were exposed to an odorant that was incongruent to the searched-for target fruit or to neutral room air, respectively. Post-hoc correlations across our n = 22 participants suggest that low performers in the baseline (no-odorant) search task benefited most from the congruent odorant-visual object coupling, whereas the visual search of high performers was impaired most by incongruent couplings. A control task points to large individual differences in olfactory discrimination across our healthy participants and their discriminative ability correlates with the amplitude and sign of the congruency effect. Our findings point to a multisensory congruency effect of odorant processing while participants visually search for a nutritional item among other food choices, suggesting that your nose knows what you are looking for.