Fig. 4

1/f slope and PSD during inhalation of aromatic oil within 10 min inhalation. 1/f activity was shown to be gentler when participants exposed with the aromatic oil comparing with the unscented condition. This phenomenon may occur under the influence of dopamine. When humans like something, they release the hormone dopamine, which causes an increase in vibrational activity in the brain. The larger the oscillation, the greater the force, and the slope tends to be gentler.