Factor scores of targeted PCA factors (i.e., those covering variance associated with episodic memory ERP effects between 300 and 800 ms) were submitted to repeated measures ANOVA with condition (old, new) and task (word, face) as a within-subjects factors, and group (controls, patients) and gender (male, female) as between-subjects factors. Although selectively choosing optimal sites for significance testing is a known issue, this problem is exacerbated by employing a dense EEG montage and by the use of CSD measures, which have sharper topographies and lack the spatial redundancies of volume-conducted surface potentials. Thus, for the crucial decision of which electrode sites to use when comparing experimental effects, overall old/new effects for a given CSD factor were first evaluated for each task by means of randomization distributions estimated from the observed data (10,000 repetitions), which, unlike parametric ANOVA F statistics, do not depend on any auxiliary assumption (Maris, 2004). Scaled multivariate (entire topography) and univariate (channel-specific) T2 statistics were computed to evaluate topographic old/new differences for paired samples (see Kayser et al., 2007, for computational details). Likewise, task-related differences of old/new
