Stimulation with an Intermittent Fragrance Relieves the Sleepiness of a Driver

In this study, we showed that the presentation of an intermittent fragrance by using a driving simulator was effective in relieving the sleepiness of a driver. The driver who stepped on the simulator run continually for 52 minutes. We used an air cannon for intermittently presenting a peppermint fragrance to the driver at intervals of 24 min and 36 min. The driver performed a visual search task after the driving simulator was turned on. Additionally, we measured the perclos (extent to which the eyelids are closed), which is considered an index of sleepiness. The results of our study showed that the driver was not very efficient in performing the visual search task. The subject was relieved of sleepiness after the intermittent presentation of the fragrance at 36-min intervals. On the other hand, when the fragrance was presented continuously, the sleepiness increased at time, and over 48 min, the subject felt very sleepy. We showed that the intermittent presentation of an appropriate fragrance to a driver relieves the sleepiness of the driver