All time-locked CSD epochs for each participant and condition were imported into EEGlab (version 11.0.3.1b; Delorme & Makeig, 2004) to generate normalized time-frequency averages (function timef.m). Event-related spectral perturbations (ERSP; Makeig, 1993) were obtained by computing overall fast Fourier transform (FFT) power spectra (zero-padding ratio of 8) relative to the pre-stimulus baseline. Relative increases (synchronization; ERS) and decreases (desynchronization; ERD) in event-related spectral power were quantified by the log10-transformed ratio of overall power and baseline power (multiplied by 10), yielding normalized ERS/ERD measures (i.e., positive or negative values) for 128 spectral frequencies (0.78125 to 100 Hz) at 200 time points (−122.5 ms to 922.5 ms) for each participant, condition, and recording site. Note that the length for the moving subwindow was set to 32 samples (2^5 = 160 ms) and padded with zeros to yield 256 samples (32 * 8), which determined both the FFT frequency resolution (sampling frequency/number of samples = 200/256 = 0.78125) and the resulting ERSP time interval (epoch start + subwindow length/2 .. epoch end subwindow length/2 = −200 + 80 .. 1000 – 80 =
