Supplementary Figure 7: Asymmetry of auditory entrainment results in neurophysiological study.
From: Spontaneous synchronization to speech reveals neural mechanisms facilitating language learning
(a) Auditory asymmetry: comparison between groups. Asymmetry was computed as: (PLVright—PLVleft)/0.5(PLVright + PLVleft). The asymmetry of auditory entrainment was significantly different between groups (r = 0.42, Rank-Biserial Correlation; Mann-Whitney-Wilcoxon test, two-sided p = 0.029). Right inset: ROIs, left and right early auditory regions. (b) Brain-to-stimulus synchrony in each hemisphere averaged within temporal ROIs. The data show that, while the typical rightward lateralization in tracking the speech envelope was present in low synchronizers, this was reduced in the high synchrony group (Wilcoxon signed-rank test, two-sided plow = 0.0013 and phigh = 0.089). (c) Scatter plot of the correlation between structural and neurophysiological values. Mean FA laterality as a function of the auditory entrainment’s asymmetry. There was a significant relationship (N = 36, Spearman r = 0.36, p = 0.026; Skipped Spearman r = 0.38, t = 2.40, CI = 0.04, 0.66) between the neurophysiological auditory asymmetry and the structural laterality of the white matter cluster (see Fig. 3 for the cluster) that differentiates between groups. While the structural leftwards laterality and the reduced rightward asymmetry shown by the high synchronizers might seem counterintuitive, in both cases high synchronizers show a more leftwards pattern of results as compared to low synchronizers (the correlation between structural laterality and auditory asymmetry is positive). Orange/light blue correspond to high/low synchronizers respectively. ** p < 0.005 (Wilcoxon signed-rank test), * p < 0.05 (Mann-Whitney-Wilcoxon test). Dots: individual participants. Black lines: mean across participants. Shadowed region: SD.
