EEG Changes in Odor Effects after the Stress of Long Monotonous Work

Odor effects after the stress task (Uchida-Kraeppelin test) were evaluated by EEG changes in 8 normal adults. The subjects were exposed to 4 odors (peppermint, bergamot, lavender, sandalwood) and the control (air). The amplitude of the slow alpha amplitude increased just after the stress task, which may indicate cortical deactivation. When exposed to the 4 odors or control (air), the latter had increased delta and theta amplitude, while the former had no increase. Peppermint significantly increased beta1 and beta2 amplitudes compared with the other odors. These results suggest that the odor stimuli may prevent reduction of arousal level after the stress task, peppermint especially raised the arousal level, which may indicate an excited effect.