The corresponding old/new effects overlapping the stimulus-locked CSD component structure are depicted for each group at five representative sites (Fz, Cz, POz, P3, P7) in Figure 3 for words, and in Figure 4 for faces.4 Across groups and tasks, old items resulted in more positive-going current sources than new items, starting at about 300 ms and lasting for about 1 s. Early old/new effects were most prominent at mid-frontal sites and overlapped the falling phase of the N2 sink (Fz, Cz), whereas the later old/new effects were most prominent at left parietal sites, mostly overlapping P3 source but also an ensuing post-response negativity (cf. Kayser et al., 2003, 2007; Johansson and Mecklinger, 2003). Despite the presence of these old/new effects in each group, the late episodic memory effects seemed to be restricted to medial parietal sites in patients (POz, P3) and did not include more lateral sites as seen in controls (P7).
