Effects of a pleasant ambient fragrance on simulated driving performance - The sweet smell of ... safety?

Eighty undergraduates performed a simulated driving task that required them to keep a moving target within defined boundaries (compensatory tracking); they also performed this task while responding to randomly occurring visual stimuli (stop signs). They performed these tasks in the presence or absence of a pleasant fragrance and after receiving or not receiving a small gift. A significant Fragrance x Gift interaction indicated that performance on both tasks was significantly enhanced by pleasant fragrance but only when participants did not also receive a gift. A main effect of gift condition indicated that performance on both tasks was significantly reduced by receipt of a small gift. In a follow-up study, 5 minutes of exposure to a pleasant fragrance was found to produce significant increments in participants' positive affect and alertness. Results were interpreted as suggesting that in the absence of other sources of positive affect, exposure to a pleasant fragrance can enhance some aspects of driving performance.