VEP(視覚性誘発電位)および脳波へのラベンダーおよびペパーミントの効果

The effects of the two kind of odors, Lavender and Peppermint, on the human VEP (Visual Evoked Potential) were studied with 15 healthy male subjects aged 22~39 years. EEGs containing VEPs evoked by flash stimuli once every 5 sec were derived from the two derivations (2 ch : O1→A1+2, 5 ch : O1→Cz) and recorded on magnetic tapes. Reproducing the tapes, VEPs with 1024 msec of analysis time were obtained by averaging 100 responses, and EEGs were subjected to the frequency analysis. In each experimental session, EEGs containing VEPs were recorded before, during and 15 and 30 minutes after the inhalation of air containing odor. Consecutive changes were observed with group mean VEP. Indivisual VEPs were subjected to the component analysis, and to the statistical assessment together with EEG frequency analysis. The following results were obtained.
1. During and after inhalation of Lavender, latencies of the short and long latency components increased, and peak-to-peak amplitudes decreased significantly. In EEG, the power % of α2 frequency band increased, and then that of θ increased significantly with EEG slowing. These findings indicate that Lavender inhibits the visual system on the lateral geniculate body and visual cortex, probably through GABA neuron system. The effect of Lavender on CNS might be relaxation at first, and then up to sedation.
2. During inhalation of Peppermint, the latencies significantly increased and the peak-to-peak amplitude significantly decreased with the long latency components of VEP, but not those of short latency components. These findings indicate that Peppermint does not inhibit the visual system at the subcortical level, and the inhibitory effect on CNS is mild, moreover it might have some effect of the thymoleptic.