ERP old/new effects during auditory and visual word recognition memory tasks: Findings for healthy adults and depressed patients

Jürgen Kayser, Craig E. Tenke, Regan Fong, Jonathan W. Stewart, Frederic M. Quitkin, Gerard E. Bruder

Department of Biopsychology, New York State Psychiatric Institute, New York, NY 10032, USA

Abstract

Event-related brain potentials (ERPs) recorded during serial presentations of words or pictures show enhanced positivity between 300 and 800 ms after repeated items. Few studies have characterized this recognition memory effect using auditory stimuli. Study 1 directly compared the ERP old/new effect during visual and auditory versions of a continuous word recognition memory task in 16 healthy, right-handed adults. Spatially and temporally overlapping ERP components of data recorded from 30 scalp sites were measured by covariance-based principal components analysis. The expected old/new effect was observed in both modalities, with a comparable time course peaking at 560 ms, but having a more anterior scalp topography for visual items. This suggests a common cognitive process associated with separable neural generators in each modality. Despite this temporal synchronization, the cross-modality old/new effect overlapped ERP components having distinct scalp topographies (N2) or peak latencies (P3) for each modality. Study 2 compared 13 healthy adults with 16 unmedicated outpatients (MDD or dysthymia, DSM-IV) in auditory and visual ERP recognition memory, which has rarely been studied in mood disorders. A comparable old/new effect was again observed in both modalities for healthy adults, but was markedly reduced in depressed patients, particularly for the auditory task, despite a lack of group differences in performance level. The combined use of auditory and visual tasks allowed a better description of modality-independent processes of ERP recognition memory, which may be impaired in depression.

Keywords: ERP recognition memory, auditory/visual modality, depression