Fig. 2

Comparison of electroencephalogram (EEG) frequency activities obtained from unmatched and matched odor stimulation-evoked EEG responses, respectively, under the condition of tasting chocolate. a–c Profiles of mean occupancy rates obtained by Fast Fourier Transform (FFT) analysis of EEG signals. a, b Mean occupancy rate of the respective frequency bands (4–23 Hz) under conditions of unmatched (garlic) odor stimulation (a) and matched (chocolate) odor stimulation (b) while tasting chocolate (mean ± standard error [SE]). c Profiles of mean occupancy rates for the two cases are superimposed, and the three frequency bands under study are shown (mean ± SE). d Mean areal occupancy rates in the case of unmatched and matched odor stimulations are shown (mean ± SE). Differences in areal occupancy rates between cases are compared among the three frequency bands. Asterisk indicates that the difference in areal occupancy is significantly greater in the theta frequency band than in the other frequency bands (alpha, beta) under study