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 Hz) and alpha/beta (8–35 Hz). The ROI time intervals correspond to the P1/N1a ERP component (0 – 50 ms), N1b/P3a components (50 – 350 ms) and the P3b component (350 – 800 ms). The duration of time windows for delta, theta and alpha/beta frequencies were as follow: 50 ms for the P1/N1a ERP component, 300 ms for the N1b/P3a component and 450 ms for the P3b component. ROI frequencies and time intervals are consistent with our previous ERP studies (Ehlers and Somes, 2002, Slawecki et al., 2003).
