COGNITIVE NEUROSCIENCESuppression of vision by transcranial magnetic stimulation a third mechanismCorthout, Erik1,4; Uttl, Bob2; Juan, Chi-Hung1; Hallett, Mark3; Cowey, Alan1Author Information 1Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OX1 3UD, UK 2Department of Psychology, Oregon State University, OR, USA 3Human Motor Control Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA 4Corresponding Author: Erik Corthout Received 4 April 2000; accepted 11 May 2000 NeuroReport: August 3, 2000 - Volume 11 - Issue 11 - p 2345-2349 Buy Abstract We recently reported three periods when single-pulse transcranial magnetic stimulation (TMS) of the occipital pole impaired performance on a forced-choice visual letter-identification task. TMS-induced suppression during these periods is best explained by a blink-associated covering of the pupils and by a direct interference with letter-processing neural activity. We now report TMS-induced suppression at times that seem too late for the suppression to be explained by the first mechanism and too early for the suppression to be explained by the second mechanism. The most likely explanation is a blink-associated interference with letter-processing neural activity. © 2000 Lippincott Williams & Wilkins, Inc.