Natural Odor Inhalers (AromaStick®) Outperform Red Bull® for Enhancing Cognitive Vigilance: Results From a Four-Armed, Randomized Controlled Study

Abstract

Two recent publications demonstrated that specifically designed essential odor inhalers can enhance performance through (a) better selective attention and scanning speed and (b) physiological changes of increased heart rate variability and blood oxygenation. In this study, we compared two natural odor inhalers with a popular energy drink (Red Bull®) with regard to their ability to improve vigilance on a computerized attention test. We employed a four-armed, randomized controlled experimental design and used a modified version of the CompACT-Vi test module to investigate whether deep inhalations of essential oil scents improved vigilance. Both inhalers markedly improved the number of correctly identified targets and participants’ reaction time when compared to a control condition and consumption of Red Bull® (0.9 < d < 1.3). Additionally, the number of correctly solved mathematical sums during the second half of the vigilance test was substantially higher (d = 1.3) with the use of inhalers than for the control and Red Bull participants. Inhaler use was also associated with relatively increased heart rate variability (d = 1.0) as a mechanism of adapting to the experimental demands. Thus, short and deep inhalations of essential oil scents delivered directly to the nose improved vigilance, while a popular energy drink failed to show an effect beyond that of a control group receiving no stimulant.