ERSP in decibels relative to baseline. A, Spectrogram of the action trial separated by group (top, native group; bottom, foreign group), averaged across trials and channels (E30, E36, E37, and E42), and grand-averaged across participants in each group. The vertical line at Time 0 indicates the start of the WoA. The red rectangle defines the frequency (5–7 Hz) and time (0–500 ms) limits over which the analyses were computed (WoA). B, Topographic maps showing the average amplitude for all channels within the μ frequency range and 0–500 ms time window (WoA). The black circle delimits the four sensorimotor channels selected for the statistical analysis. C, Bars represent the averaged ERSP over the WoA with ±1 standard error, separated by trial type (x-axis) and group (color). A paired-sample t test found a significant difference between groups in the action trials; a one-sample t test found a significant decrease of μ only in the native group, but not in the other conditions (the symbol “*” indicates a p < 0.05). See Extended Data Figure 2-1 for details about the no-action trial.