Abstract
Selection is the hallmark of attention: processing improves for attended items but is relatively impaired for unattended items. It is well known that visual spatial attention changes sensory signals and perception in this selective fashion. In the research we will present, we asked whether and how attentional selection happens across time. Specifically, we investigated voluntary temporal attention, the goal-driven prioritization of visual information at specific points in time. First, our experiments revealed that voluntary temporal attention is selective, resulting in perceptual tradeoffs across time. Perceptual sensitivity increased at attended times and decreased at unattended times, relative to a neutral condition in which observers were instructed to sustain attention. Temporal attention changed the precision of orientation estimates, as opposed to an all-or-none process, and it was similarly effective at different visual field locations (fovea, horizontal meridian, vertical meridian). Second, we measured microsaccades and found that directing voluntary temporal attention increases the stability of the eyes in anticipation of a brief, attended stimulus, improving perception. Attention affected microsaccade dynamics even for perfectly predictable stimuli. Precisely timed gaze stabilization can therefore be an overt correlate of the allocation of temporal attention. Third, we developed a computational model of dynamic attention, which incorporates normalization and dynamic gain control, and accounts for the time-course of perceptual tradeoffs. Altogether, this research shows how voluntary temporal attention increases perceptual sensitivity at behaviorally relevant times, and helps manage inherent limits in visual processing across short time intervals. This research advances our understanding of attention as a dynamic process.