Fig. 7: Pre-movement phase and connectivity.

a Average functional connectivity changes from the left SMA to all other cortical regions, computed in the 0.2–1.2 sec window from movement onset, when contrasting trials in which the movement started in the optimal vs. non-optimal alpha phase. Shades indicate standard errors. The black line indicates the cluster of frequencies (9–12 Hz) in which significant changes occur after multiple comparisons correction. b Connectivity changes in the significant cluster’s frequency range (9–12 Hz) for individual subjects (N = 25). The vertical bar indicates the standard error. c Cortical maps of uncorrected log p-values (t test, two-sided) for the connectivity changes in the 9–12 Hz range induced by the pre-movement alpha phase on 8 cerebral macro-regions, using the left SMA as a seed. d Cortical map of regions surviving cluster-based correction across ROIs when the same connectivity analysis is performed at the level of 114 ROIs, based on a two-sided t test. e Directionality changes in connectivity from the left SMA to left temporal regions depending on the pre-movement alpha phase. The y-axis represents the 9–12 Hz phase coherence between signals from the seed region and delayed signals from the left temporal regions. The result is plotted as a function of the delay on the target region so that more coherence at positive delays suggests connectivity from the left SMA to left temporal regions, and vice versa. The blue curve is obtained from trials starting in the optimal phase, and the red curve from trials starting in the non-optimal phase. Shades indicate standard errors. f Results of the directionality analysis at single subject level (N = 25). The dots indicate the peak of the individual delay-coherence curves (averages are shown in panel (e)) Again, positive values indicate connectivity mainly from the left SMA to temporal regions, and vice versa. Black error bars indicate standard errors. g Uncorrected log p-values for the directionality analysis from a two-sided t test, as in panel (f), performed only within the temporal lobe at the finer spatial scale of 114 ROIs. Dark blue areas indicate ROIs outside the temporal lobe, not analysed at this parcellation level.