A Neurophysiological Deficit in Early Visual Processing in Schizophrenia Patients with Auditory Hallucinations
Jürgen Kayser1,2, Craig E. Tenke1,2, Christopher J. Kroppmann2, Daniel M. Alschuler2, Shiva Fekri2, Roberto B. Gil1,3, L. Fredrik Jarskog1,4, Jill M. Harkavy-Friedman1, Gerard E. Bruder1,2
1Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY, USA; 2Division of Cognitive Neuroscience, New York State Psychiatric Institute, New York, NY, USA; 3Clinical Psychobiology, New York State Psychiatric Institute, New York, NY, USA; 4Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
Received 25 April 2012; accepted 15 May 2012; published online 16 July 2012; published 13 August 2012.
Abstract
Existing 67-channel ERPs, obtained during recognition and working memory paradigms with words or faces, were used to examine early visual processing in schizophrenia patients prone to auditory hallucinations (AH, n = 26) or not (NH, n = 49) and healthy controls (HC, n = 46). Current source density (CSD) transforms revealed distinct, strongly left- (words) or right-lateralized (faces; N170) inferior-temporal N1 sinks (150 ms) in each group. N1 was quantified by temporal PCA of peak-adjusted CSDs. For words and faces in both paradigms, N1 was substantially reduced in AH compared with NH and HC, who did not differ from each other. The difference in N1 between AH and NH was not due to overall symptom severity or performance accuracy, with both groups showing comparable memory deficits. Our findings extend prior reports of reduced auditory N1 in AH, suggesting a broader early perceptual integration deficit that is not limited to the auditory modality.
Key Words: schizophrenia; auditory hallucination; event-related potentials (ERPs); visual N1; current source density (CSD); principal components analysis (PCA)