The appearance of orientation repulsion changes with developing temporal expectation

Anticipating when future events will happen improves our performance by facilitating visuomotor processing at various stages, from perception to action. We investigated whether such temporal expectation also influences the appearance of orientation repulsion, wherein a vertical target subjectively appears as tilted against a surrounding inducer. As the inducer, eight circularly arranged Gabor patches were continuously presented on both sides of the fixation point. As the target, another Gabor patch was flashed at the center of either one of the inducers. Participants reported whether the target appeared as tilted clockwise or counterclockwise from the vertical. In Experiment 1, prior to the target onset, auditory temporal cues were provided five times at constant intervals of 400 ms. Participants were instructed to attend to the fifth cue moment, as the target most often (with 69% probability) appeared at this moment. The target otherwise appeared 200 ms earlier or later than the anticipated moment. Repulsion significantly decreased when the target appeared earlier than anticipated. In Experiment 2, to isolate the effect of automatic entrainment to the cue rhythm, the cue was repeated every 450 ms throughout a session, and the target was presented either in-phase or out-of-phase with the rhythm with equal probability. Anticipating the target onset was virtually impossible in this setup, and indeed, no change in repulsion was observed. In Experiment 3, to focus on the effect of hazard rates, a single cue was provided, and the target was presented after one of three intervals (200, 400, or 600 ms) with equal probability. Although the cue was uninformative about the target onset, repulsion significantly decreased as the cue-target interval increased. These findings suggest that developing temporal expectation, especially the expectation associated with hazard rates, promotes premature decisions on the perceptual content that has not fully undergone contextual modulation during low-level visual processing.