For PCA factors of interest (i.e., those covering variance associated with target detection ERP effects), factor scores for target stimuli were submitted to repeated measures ANOVA with task (tonal, phonetic) and response mode (left press, right press, silent count) as a within-subjects factors, and group (controls, patients) as a between-subjects factor. Guided by our previous findings,10,33,48 repeated measures ANOVA were conducted for subsets of recording sites at which PCA factor scores were largest and most representative of the associated CSD components. These subsets consisted of either midline or lateral, homologous recording sites over both hemispheres, thus adding either site, or site and hemisphere as within-subjects factors to the design. The rationale for selecting a “subset” of recording sites as a “representative” measure for a factor is given below with the factor descriptions. For this reason, and to avoid needless complexity, site effects are only reported if they are of critical relevance to the study objectives.
