Establishing the separable contributions of spatial attention and saccade preparation across tasks with varying acuity demands

One common way to investigate the relationship between eye movements and attention is to pair the cueing paradigm with a saccadic dual-task. Here eye movements are directed to one location in the visual field, while a spatial cue simultaneously directs attention to the same or a different location. The magnitude of the cueing effect is then compared between trials where gaze is maintained at fixation and trials where eye movements are prepared. As these comparisons typically occur across blocked single and dual-task conditions, it is difficult to address possible confounds due to changes in response caution. 

In this paper we use evidence accumulation modeling to remove this confound and extract a measure of orienting that can be used to quantify and compare the influence of spatial attention across four different manipulations of eye movements: 2 that require fixation and 2 that require saccade preparation. The results demonstrate that the magnitude of the cueing effect is similar regardless of eye movement condition or perceptual task. The perceptual benefit associated with preparing a saccade, in contrast, was found to vary by perceptual task. Taken together these results establish that spatial attention and saccade preparation are separable and, we suggest, mediated by distinct underlying mechanisms.