closely-matched auditory and visual continuous word recognition memory tasks in healthy adults in a within-subjects paradigm (Kayser et al., 2003, 2007). These studies revealed highly comparable old/new effects for both modalities despite prominent differences in scalp topography and peak latency of auditory and visual N2 and P3 amplitudes, supporting the view that word retrieval is a common, high-level cognitive process associated with old/new effects (cf. Johansson and Mecklinger, 2003) that are largely independent from, but superimposed on, the modality-specific ERP component structure. Taking full advantage of the CSD-PCA approach, we described left parietal old/new source effects accompanied by lateral frontocentral old/new sink effects in both modalities, which overlapped modality-specific P3 sources at about 160 ms before the response (Kayser et al., 2007).
