Parallel attentional allocation in antisaccades
56.529, Tuesday, May 14, 2:45 - 6:45 pm, Vista Ballroom
Anna Klapetek1, Heiner Deubel1; 1Department of Psychology, Ludwig-Maximilians-Universitaet, Munich, Germany
We investigated the allocation of spatial attention during the programming of antisaccades. The visual display consisted of a central fixation dot and two symmetrically arranged peripheral squares, one in each visual hemifield. In each trial one of the targets was briefly highlighted and participants were either instructed to shift their gaze to the cued square (prosaccade task) or to the square in the opposite hemifield (antisaccade task). After the trial they reported the orientation of a visual probe that had appeared at one of the two target locations. By probing discrimination performance at variable SOAs relative to saccade cue onset, we were able to measure the time course of attentional deployment to both target locations. An analysis of the eye movements revealed a similar pattern of results as reported in previous studies, namely longer antisaccade than prosaccade latencies and a substantial proportion of direction errors in antisaccade trials. Discrimination performance during the cue-saccade interval was analyzed both for correct antisaccades and erroneous prosaccades. The results revealed that in both cases attention was allocated in parallel to the cued location and to the correct antisaccade goal. Even before correct antisaccades, discrimination was generally better at the cued location, although this attentional bias was balanced by a rise of attention at the planned saccade endpoint immediately before the eye began to move. While the amount of attentional resources allocated to the cue location was predictive of the occurrence of erroneous prosaccades, attention at the antisaccade goal was not related to the likelihood of prosaccade errors. In conclusion, our results demonstrate parallel attentional allocation in antisaccades and support the hypothesis that the process of antisaccade programming involves the suppression of attention at the cue location.