Fig. 3.

Variable-pace experiment: coherence spectra and directionality results. A (active) and C (passive): Coherence spectra and associated topographic distribution in the frequency range of significant coherence. B (active) and D (passive): Renormalized partial directed coherence (rPDC). The smaller insets display the phase–frequency plots of the Fourier coefficients of the multivariate autoregressive model, which were used to estimate the delay through linear regression (red line). The gray horizontal lines indicate the threshold of statistical significance. Acc: accelerometer. SM1: primary sensorimotor.