New York University
Abstract: To prioritize the visual analysis of behaviorally relevant information, we selectively attend to the environment covertly (without eye movements) or overtly (with accompanying eye movements). I will discuss studies demonstrating perceptual consequences of these selective processes. First, I will show concurrent changes in visual performance and perceived contrast both at the covertly attended location and before saccade onset at the target location; simultaneous enhancement in both orientation discrimination performance and perceived contrast progressively as time approaches saccade onset. The temporal dynamics of pre-saccadic effects are faster than those of the voluntary deployment of covert attention. These results link the dynamics of pre-saccadic attention, visual performance, and subjective experience and show that upcoming eye movements alter visual processing by increasing the signal strength.
Second, I will show how we can keep track of moving objects, despite the frequent eye movements that interrupt their retinal motion trajectory. We found that trans-saccadic tracking relies on tradeoffs of attentional resources from a tracked object’s motion path to its remapped location. During fixation, attention shifts smoothly in anticipation of the tracked object’s displacement. However, just before a saccade, attentional resources are withdrawn from the object’s current motion path and reflexively drawn to the retinal location on which the object will land after the saccade. This finding demonstrates the predictive choice the visual system makes to maintain the tracking of moving objects across saccades. By manipulating covert attention and pre saccadic attention, these studies further our understanding of selective processing of information in static and dynamic tasks.