AUTHOR=Tsushima Yoshiaki , Nishino Yurie , Ando Hiroshi 

TITLE=Olfactory Stimulation Modulates Visual Perception Without Training

JOURNAL=Frontiers in Neuroscience

VOLUME=Volume 15 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2021.642584

DOI=10.3389/fnins.2021.642584

ISSN=1662-453X

ABSTRACT=Considerable research shows that olfactory stimulations affect other modalities in high-level cognitive functions such as emotion. However, little known fact is that olfaction modulates low-level perception of other sensory modalities. Although some studies showed that olfaction had influenced on the other low-level perception, all of them required specific experiences like perceptual training. To test the possibility that olfaction modulates low-level perception without training, we conducted a series of psychophysical and neuroimaging experiments. From the results of a visual task in which participants reported the speed of moving dots, we found that participants perceived the slower motions with a lemon smell and the faster motions with a vanilla smell, without any specific training. In functional magnetic resonance imaging (fMRI) studies, brain activities in the visual cortices (V1 and hMT) changed based on the type of olfactory stimulation. Our findings provide us with the first direct evidence that olfaction modulates low-level visual perception without training, thereby indicating that olfactory-visual effect is not an acquired behaviour but an innate behaviour. The present results show us with a new crossmodal effect between olfaction and vision, and bring a unique opportunity to reconsider some fundamental roles of olfactory function.