Capture of the eyes by relevant and irrelevant onsets.
During early visual processing the eyes can be captured by salient visual information in the environment. Whether a salient stimulus captures the eyes in a purely automatic, bottom-up fashion or whether capture is contingent on task demands is still under debate. In the first experiment, we manipulated the relevance of a salient onset distractor. The onset distractor could either be similar or dissimilar to the target. Error saccade latency distributions showed that early in time, oculomotor capture was driven purely bottom-up irrespective of distractor similarity. Later in time, top-down information became available resulting in contingent capture. In the second experiment, we manipulated the saliency information at the target location. A salient onset stimulus could be presented either at the target or at a non-target location. The latency distributions of error and correct saccades had a similar time-course as those observed in the first experiment. Initially, the distributions overlapped but later in time task-relevant information decelerated the oculomotor system. The present findings reveal the interaction between bottom-up and top-down processes in oculomotor behavior. We conclude that the task relevance of a salient event is not crucial for capture of the eyes to occur. Moreover, task-relevant information may integrate with saliency information to initiate saccades, but only later in time.
Cognitive Psychology, Vrije Universiteit, Van der Boechorststraat 1, 1081 BT, Amsterdam, The Netherlands. M.Mulckhuyse@psy.vu.nl
Manon
M
Mulckhuyse
Wieske
W
van Zoest
Jan
J
Theeuwes
D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology; D005133:Eye Movements / Q000502:physiology*; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D009801:Oculomotor Muscles / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods*; D011930:Reaction Time / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*