The pleasant odor reduces the brain activity and enhances behavioral performance during kanji word-color stroop task: A multi-fiber NIRS study

The purpose of this study was to investigate that the effect of sensed pleasant odor on the increased psychological loading and brain activity due to the confliction and intervention by the difference between meaning of kanji words and word color. During word-color stroop task, brain activity was estimated by oxy-hemoglobin concentration (ΔO₂Hb) and psychological loadings, i.e., status of the autonomic activity, was measured by ECG signal and peripheral blood flow. As a result, when the lavender aroma sensed, ΔO₂Hb was decreased and mean response time was significantly shortened as compared with non-odor. The results indicate that the pleasant emotion evoked by the pleasant odor and further the calling effect by lavender aroma inhibited the over activity due to stoop task, and thus facilitate precise reading of the logographical kanji word and word color.