Nevertheless, patients and controls showed comparable condition-dependencies of these N2 sinks (i.e., inverted old/new effects), which fits well with the idea that N2 indexes stimulus classification (e.g., Simson et al., 1976). There appears also to be a striking analogy between the sequence of the current N2 sinks and P3 sources and the N2/P3 complex typically observed for target stimuli during oddball tasks, with both components showing condition sensitivity but with opposite polarity. However, exceeding caution is warranted when likening the present N2 generator patterns, which were derived by means of CSD-PCA in the context of a specific recognition memory task, to previous discourses on the meaning of N2 derived from surface ERPs using various reference schemes and other paradigms (e.g., Fabiani et al., 2000; Folstein and Van Petten, 2008). These data suggest that several functional processes can be associated with negative ERP deflections in the 200–400 ms time range after stimulus onset, with some processes, such as attention, tied in with modality-specific N2 topographies and generators. It is also plausible to conjecture that these vertex N2 sinks belong in the
