The effect of spatial attention on saccadic adaptation.

Eye movements and spatial attention are both crucial to visual perception. Orienting gaze to objects of interest is achieved by voluntary saccades (VSs) driven by internal goals or reactive saccades (RSs) triggered automatically by sudden environmental changes. Both VSs and RSs are known to undergo plastic adjustments to maintain their accuracy throughout life, driven by saccadic adaptation processes. Spatial attention enhances visual processing within a restricted zone, and it can be shifted voluntarily following our internal goals (endogenous) or automatically in response to unexpected changes in sensory stimulation (exogenous). Despite the widely accepted notion that saccadic and attention shifts are governed by distinct but highly interconnected systems, the relationship between saccadic adaptation and spatial attention is still unclear. To address this relationship, we conducted two experiments combining modified versions of the double-step adaptation paradigm and the attention-orienting paradigm. Experiment 1 tested the effect of shifting exogenous attention by a tactile cue near or away from the saccade's target on RS adaptation. Experiment 2 also used tactile cueing but now to investigate the effect of shifting endogenous attention on VS adaptation. Although we were unable to obtain direct evidence for an effect of spatial attention on saccadic adaptation, correlation analyses indicated that both the rate and magnitude of saccadic adaptation were positively correlated with the allocation of attention toward the saccade target and negatively correlated with attention directed away from the target.