Reference‐independent ERP old/new effects of auditory and visual word recognition memory: Joint extraction of stimulus‐ and response‐locked neuronal generator patterns

To clarify polarity, topography, and time course of recognition memory ERP old/new effects during matched visual and auditory continuous word recognition tasks, unrestricted temporal PCA jointly analyzed stimulus- and responselocked, reference-free current source densities (31-channel, N 5 40). Randomization tests provided unbiased statistics for complete factor topographies. Old/new left parietal source effects were complemented by lateral frontocentral sink effects in both modalities, overlapping modality-specific P3 sources 160 ms preresponse. A mid-frontal sink 45 ms postresponse terminated the frontoparietal generator pattern, showed old/new effects consistent with bilateral activation of anterior cingulate and SMA, and preceded similar activity extending posteriorly along the longitudinal fissure. These methods separated old/new stimulus source (preresponse) and response sink (postresponse) effects from motor and modality-specific ERPs. Descriptors: Recognition memory, Event-related potential (ERP), Current source density (CSD), Principal components analysis (PCA), Stimulus- and response-locked, Visual and auditory modality