Stimulus-locked ERP waveforms were averaged from correct, artifact-free trials using the entire 2-s epoch. The manipulation of recognition difficulty stemming from the use of short and long repetition lags was not the primary objective of the study, and our previous research using words had failed to reveal systematic performance effects associated with lag (Kayser et al., 1999, 2003, 2007, 2009). For these reasons, ERP lag effects were not considered for this report in order to maximize ERP waveform stability (i.e., maintaining a sufficient number of trials for most subjects in all conditions) and to keep the experimental design as simple as possible. The mean number of trials used to compute new and old ERP averages after pooling across lag (M ± SD, min-max range, controls vs. patients) were 114.5 ±12.5 (78 – 134) and 101.5 ±18.6 (57 – 128) vs. 113.1 ± 12.6 (83 – 135) and 79.5 ±24.2 (15 – 133) for words, and 110.7 ±12.4 (83 – 133) and 99.0 ±19.0 (52 – 127) vs. 109.1 ± 13.9 (58 – 130) and 77.2 ±22.4 (32 – 113) for
