Event-related potential (ERP) asymmetries to emotional stimuli in a visual half-field paradigm


  • This research was financially supported in part by a scholarship from the G. A. Lienert-Foundation to J. Kayser and in part by grants from the Norwegran Research Council (NAVF) to K. Hugdahl. Raw data were collected during J. Kayser's work at the Psychophysiology Laboratory of the University of Bergen, Norway.

  • We thank Hans-Jürgen Trosiener and Arild Vaksdal for their technical assistance during data collection, and Charles I. Brown for additional software support. We greatly appreciate helpful suggestions and comments from Gerard Bruder. David Friedman, and Douglas Potter on earlier versions of this manuscript.

Address reprint requests to Jürgen Kayser. New York State Psychiatric Institute. Department of Biopsychology. Box 50. 722 West 168th Street. New York, NY 10032, USA. E-mail: kayserj@nypimail.cpmc.columbia.edu.


To investigate the hypothesis of a right hemispheric superiority in negative emotional processing, event-related potentials (ERPs) were recorded from 17 sites (Fz, Cz, Pz, F3/4, F7/8, C3/4, T7/8, P3/4, P7/8, O1/2) in a visual half-field paradigm. While maintaining fixation, right-handed women viewed pictures of patients with dermatological diseases before (negative) and after (neutral) cosmetic surgery. A principal components analysis with Varimax rotation performed on ERPs revealed factors identified as N1, N2, early P3, late P3, late P3, and slow wave. Repeated measures analyses of variance performed on factor scores revealed a significant effect of emotional content for all factors except for N1. However, asymmetries in emotional processing were restricted to N2 and early P3, with maximal effects over the right parietal region. N2–P3 amplitude was augmented for negative and reduced for neutral stimuli over right hemisphere regions. Visual field presentation interacted with these asymmetries in enhancing amplitudes contralaterally for early but ipsilaterally for late ERP components. Overall, findings for N2 and P3 support theories of an asymmetry in emotional processing.