Implicit in this and related methods is the assumption that the trial being analyzed is preceded by and followed by identical trials. To reduce consequences of resulting discontinuities, we use a cosine window over the initial and final 100 msec of the input time series of each trial. The output of the transform for each stimuli and electrode site was calculated by averaging the individual trials containing the time-frequency energy distributions. To quantify S transform magnitudes, a region of interest (ROI) was identified by specifying the band of frequencies and the time interval contained in the rectangular ROI. ERO energy was determined as the measure of the energy values in the ROI. PLI was determined as the peak amplitude of the PLI in the ROI. These analyses are similar to what has been previously described (Schack and Klimesch, 2002; Jones et al., 2004). Baseline corrected post-stimulus activity (900 ms) was calculated by subtracting pre-stimulus ERO energy values (100 ms) from the post-stimulus ROI values, as previously described (Padmanabhapillai et al., 2006b). The ROI frequencies were: delta (1–4 Hz), theta (4–8
