Figure 3.

Changes in perceptual oscillations as a function of the sensory entrainment frequency within the alpha band (Experiment 1: between-subjects design). A, B, Power spectrum of the perceptual oscillation after the 11.5 Hz (A) and after the 8.5 Hz (B) sensory entrainment. Gray horizontal insets above the peak show the frequency bins for which the observed spectrum (average of the individual power spectrums) has been found to be significantly higher relative to the spectrum obtained from the permutation test. C, D, Phase angle histograms for the 11.5 and 8.5 Hz entrainment, respectively, with both perceptual oscillations that showed significant phase concentration across participants (mean phase angle vector across participants depicted in red). E, F, Smoothed data (i.e., moving average applied) with the shaded area representing ±1 SEM and the continuous line depicting the best sinusoidal fit in the frequency range of interest (see Materials and Methods). As evidenced from the histograms on the right, in both cases, the observed adjusted R² (continuous vertical lines) was higher than the critical adjusted R² value (dashed vertical line) representing the 5° percentile in the null distribution obtained from the permutation of the original data. ISI, Interstimulus interval (between the end of the entrainment and the onset of the target stimuli).