Reference-independent ERP Old/New Effects of Auditory and Visual Word Recognition Memory: Joint Extraction of Stimulus- and Response-locked Neuronal Generator Patterns

Jürgen Kayser^1,2, Craig E. Tenke^1,2, Nathan A. Gates², Gerard E. Bruder^1,2

¹Division of Cognitive Neuroscience, New York State Psychiatric Institute, New York, NY, USA; ²Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY, USA

Received 2 March 2007; revised 9 May 2007; accepted 25 May 2007; available online 18 July 2007. 

Abstract

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 response-locked, reference-free current source densities (31-channel, N = 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 pre-response. A mid-frontal sink 45 ms post-response 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 (pre-response) and response sink (post-response) effects from motor and modality-specific ERPs.

Key Words: recognition memory; event-related potential (ERP); current source density (CSD); principal components analysis (PCA); stimulus- and response-locked; visual and auditory modality