Auditory and visual nose-referenced, grand mean surface potentials locked to stimulus onset (averaged across condition) are shown in Figure 1 for patients and controls at nine selected sites, along with the bipolar eye activity traces. Whereas horizontal and vertical eye movements differed across modalities, these eye movements were largely comparable across groups. Furthermore, blink activity was effectively removed by the spatial blink filter applied to the continuous data and did not differentially affect the ERPs of either group. The overall ERP deflections were highly comparable to our prior studies (Kayser et al., 1999, 2003). For the auditory task, distinct ERP deflections were identified as N1, P2, and N2, particularly over central sites (e.g., see Cz in Figure 1A), and as P3 and a late negativity (LN) over posterior sites (e.g., see site P3 in Figure 1A). For the visual task, distinct ERP deflections were identified as P1, N1, and N2, particularly over inferior-parietal sites (e.g., see P9 in Figure 1B), and as P3 and LN over posterior sites (e.g., see Pz in Figure 1B). As can be seen, peak latencies
