Timing of saccadic eye movements during demanding visual tasks E Kowler, C Aitkin, J Wilder, C-C Wu |
|---|
Department of Psychology, Rutgers University, NJ, United States
|
| Decisions about directing gaze are, explicitly or implicitly, decisions about managing time. Given that most visual discriminations are completed within the duration of a typical fixation, the best strategy should be to aim for highest possible saccade rates in an effort to fixate as many locations as possible in the available time. To examine this possibility, we studied saccadic timing in two visual tasks, a scanning task that required localization judgments, and a visual search task that required search for multiple targets. Timing patterns of saccades depended on a host of factors including: the quality of available visual information (both foveal and extrafoveal), the functional role of the saccade (exploratory vs. targeting), expectations about the time needed to make visual decisions, and the ordinal position of the saccade in the sequence. These results show that saccadic timing is not set to uniformly high rates by default. Timing is modulated according to available visual information, momentary goals, memory, and expectations. These factors operate cooperatively to ensure efficient management of time and processing resources during the performance of visual tasks. |
| Up Home |
|---|