Selective attention: Noise suppression or signal enhancement?

Abstract

RTs were obtained to single letter displays when an indicator, designating in which of four possible positions the letter would appear, preceded the display by intervals of 0-150 msec. Prior information, even by as little as 50 msec as to the letter’s position, resulted in reduction in RT. Controls ruled out the possibility that the effect was attributable to changes in fixation, masking, or facilitating effects of a first signal. Instead, the effect appears to reflect characteristics of a central selective attentional mechanism. © 1974, The Psychonomic Society, Inc.. All rights reserved.