The Trans-Saccadic Extrafoveal Preview Effect is Modulated by Object Visibility

We used a gaze-contingent eye-tracking setup to investigate how peripheral vision before the saccade affects post-saccadic foveal processing. Studies have revealed robust changes in foveal processing when the target is available in peripheral vision (the extrafoveal preview effect). To further characterize the role of peripheral vision, we adopted a paradigm where an upright/inverted extrafoveal face stimulus was shown and changed orientation (invalid preview) on 50% of trials during the saccade. Invalid preview significantly reduced post-saccadic discrimination performance compared to valid preview (aka preview effect). In addition, the preview face varied in eccentricity and added noise which affected its visibility. Face visibility was operationalized by a lateralized face identification task, run in a separate session. A mixed model analysis suggests that visibility modulated the preview effect. Overall, these findings constrain theories of how preview effects might influence perception under natural viewing conditions.