Figure 4. EEG time-warping procedure.
A. As shown in this representative trial of the finger-tapping to the beat task, the inter-tap interval (ITI) fluctuated from tap to tap, with a mean ITI of 800 ms. B. The time-warping procedure consists in compressing or dilating the EEG signals recorded within each ITI such as to scale it to a fixed target ITI of 800 ms. The compression and dilation of the EEG segments was computed by linear interpolation of the non-time-warped signals.