Psychophysiology, 38:S54, 2001.

Event-related potentials (ERPs) in depressed patients and healthy adults during hemifield presentations of emotional stimuli: A replication

Jürgen Kayser, Craig Tenke, Nilabja Bhattacharya, Jonathan Stewart, Frederic Quitkin, Gerard Bruder

Department of Biopsychology, New York State Psychiatric Institute, 1051 Riverside Drive, New York, NY 10032-2695, USA

Abstract

Behavioral and electrophysiologic evidence suggests that depression involves right parietotemporal dysfunction, a region also known to be activated during perception of affective stimuli. When ERPs were measured to emotional stimuli (pictures of cosmetic surgery patients showing disordered [negative] or healed [neutral] facial areas before or after treatment) using a visual half-field paradigm, healthy adults showed larger P3 to negative than neutral stimuli, particularly over the right parietal region (Kayser et al., 1997, 2000). In contrast, 30 depressed patients failed to show an increase in late P3 for negative compared to neutral stimuli over either hemisphere and had smaller late P3 than controls. Using new right-handed samples of 28 unmedicated depressed patients and 30 healthy adults with 30-channel EEG montage, spatially and temporally overlapping ERP components were measured by covariance-based principal components analysis, which extracted the distinctive, previously identified ERP factors (N150, N235, P310, P415, P600, slow wave) for both groups. Controls showed emotional content effects, i.e. enhanced amplitudes to negative stimuli, for P310 and P415 (inferior- or mid-parietal topography), with both factors revealing distinct hemispheric asymmetries of emotional processing, i.e. greater over right parietal region. For these two P3 subcomponents, depressed patients again had smaller amplitudes and showed no emotional content effects or related hemispheric asymmetries. However, both groups showed symmetric enhancements of central-parietal P600 for negative compared to neutral stimuli. Results further corroborate abnormalities in the evaluation of affective content in depression, presumably arising from a disengagement of right parietal regions essential for perceiving and processing emotional stimuli.

Keywords: ERP, Emotion, Depression