Abstract
Saccades are important for the visual perception of our environment and for the interaction with the objects within it. These rapid shifts of gaze from one location in the visual field to another precede our actions and are therefore modulated by our current action goals. The accuracy of saccadic eye movements required to precisely align the fovea with objects of interest is ensured by saccade adaptation. This recalibration process is understood to be based on an implicit comparison between the expected and actual post-saccadic position of the target on the retina. However, there is increasing evidence that task demands modulate eye movement behavior and that task errors also evoke gradual changes in saccade amplitude. We investigated whether human participants are able to flexibly use the different sources of information included in the post-saccadic visual image to adapt their saccade amplitude to a current task. We instructed our participants to saccade towards a target object within an object array that was either defined by its color or by its position within the array. During the saccade, the object positions and the colour of the objects were manipulated such that participants were confronted either with congruent post-saccadic information, unambiguously defining the target object, or with incongruent post-saccadic information, evoking a conflict between two possible targets. We found that participants were able to gradually modify their saccade behavior such that they achieved the goal of the task. They succeeded in decreasing saccade gain or maintaining it, depending on what was necessary to directly look at the defined target object, irrespective of whether the post-saccadic image provided congruent or incongruent information. It appears that action intentions prime task-relevant feature dimensions and thereby facilitated the selection of the relevant information source. Thus, participants use post-saccadic feedback flexibly, depending on their intentions and pending actions.