Fig. 3
From: Mu rhythm motor–auditory delay in imagined speech mirrors overt speech timing
Sensor space power decrease time course in the beta and alpha frequency bands. Grand average Hilbert transformed band-filtered power decrease with respect to the baseline in the alpha (a) and beta (b) frequency bands. The lines represent the 157 axial gradiometers. MEG sensors are color-coded according to their spatial location on the scalp that is shown in the topography in the upper left. The topographies of most salient events in the time course are shown on top together with their timing. (c) The average across sensors of the baseline normalized envelope in the beta (red) and alpha (blue) frequency band is represented. The solid lines represent the mean and the shaded area surrounding the solid lines represent the standard error of the mean. The vertical dashed black line represents the expected speech onset measured in the behavioral pretest. The colored stars and vertical dashed lines represent the group-level beta (red) and alpha (blue) ERD onsets. (d) The distribution of individual subjects’ beta and alpha ERD onsets are represented in the red and blue histograms, respectively. The colored vertical dashed lines represent the median beta and alpha ERD onsets across participants. (e) The distribution of individual subjects’ temporal difference between beta and alpha ERD onsets is represented in the grey histogram. The black vertical dashed line represents no temporal difference; the grey vertical dashed line represents the median temporal difference between beta and alpha ERD onsets. A negative value indicates that the beta onset precedes the alpha onset, a positive value indicates that the beta onset follows the alpha onset.
