As attempts combining movies with smell have been increased in movie industries, interest of visual-olfactory cross-modal studies has been increased. According to previous studies, high congruency condition by odors could modulate perceptual responses of visual stimulation and neural activities as well. However there were limited evidences regarding perceptual response to visual stimulation with context-related smell. These evidences may be crucial to screening cheaper and safe odorants with evoking similar perceptual effects. Therefore, we studied how context-related smell may affect the perceptual responses to visual stimulation.
To understand effects of context-related smell, we performed questionnaires and EEG studies. For the visual stimulation, two video clips were used: high valence and low valence. Four odorants were used in this experiment: lavender, geranial, 2-furanmethanethiol and 2-ethyl-3,5-dimethylpyrazine. Odorants were divided into two categories: category A (lavender, geranial) and category B (2-furanmethanethiol, 2-ethyl-3,5-dimethylpyrazine) by structural similarity. Odorants were offered with a video clip simultaneously during measuring about 10 s. There were 53 participants (27 men, 26 women) divided into 4 group depending on category conditions.
We found that context-related smell induced similar congruency with video clips. As predicted, proper match between the smell and videos showed high congruency. In our EEG studies, alpha asymmetry was changed depending on odor category and congruency only in low valence video clips. High valence video clips did not show similar results as low valence video clips. Taken together, our studies suggested that context-related smell can induce different brain activities, although their behavioral outcomes were similar in video clips.