This CSD component structure was modulated in both groups by the different response requirements (Figure 2). Most notably, CSD waveforms revealed marked button press effects over medial-central sites (C3/4), shifting the contralateral CSD waveforms in a negative direction for most of the recording epoch. By comparison, silent count responses had arelative smaller P3source over mid-parietal sites (e.g., Pz). Thus, overall CSD waveforms were highly comparable in controls and patients across task and response mode, despite notable reductions of prominent CSD components (N2 sink, P3 source) in patients. Importantly, eye movements were also comparable across group, task, and response mode (see bipolar eye activity traces included in Figures 1 and 2), and evidently did not affect the corresponding CSDs derived from blink-corrected continuous EEG data.
