The output code of a visual fixation

Abstract

The present experiment investigated whether a saccadic eye shift is delayed until perceptual and postperceptual processing of the fixated signal are completed. Two signals were presented with an angular distance of 100°. Subjects inspected the left signal (SL) first and then made an eye-and-head movement to the right signal. Various task conditions were manipulated in such a way, that, although SL remained the same, the information it contained either allowed for perceptual processing only or also included postperceptual processing (classification, response selection). In addition, the signal quality of SL was manipulated in all conditions. The fixation duration of SL was affected by signal quality and not by task condition. It was concluded that a saccade is initiated upon completion of perceptual processing of a signal. © 1992, Psychonomic Society, Inc.. All rights reserved.