# The illusion of orientation repulsion is weakened in a temporally more predictable visual target

## TL;DR

The study shows that when people expect an event to happen, their perception of visual illusions like orientation repulsion changes.

## Contribution

The paper reveals that temporal expectation reduces the strength of the orientation repulsion illusion.

## Key findings

- Orientation repulsion decreases when targets appear at predicted times.
- Rhythmic cues without awareness do not affect the illusion.
- Higher hazard rates correlate with reduced repulsion.

## Abstract

Anticipating the occurrence of future events enables our adaptive behavior by facilitating processing at various stages from perception to action. While the functional benefits of temporal expectation are well acknowledged, its phenomenological effects remain unknown. Focusing on the phenomenon of orientation repulsion, wherein a vertical target is perceived as tilted against surrounding stimuli, we examined how the size of the illusion varies with developing temporal expectation. In Experiment 1, a multimodal cue predicted impending target onset through its validity and rhythmicity. We found that repulsion decreased when the target appeared at or later than the moment predicted by the cue. In Experiment 2, rhythmic cues did not significantly influence repulsion without explicit instruction or subjective awareness of the cue–target contingency. In Experiment 3, a single cue was provided, and the target appeared after one of three foreperiods. The occurrence probability of the target was equalized across foreperiods to isolate the effect of the conditional probability given that the target had not yet occurred (hazard rate). Repulsion decreased as the hazard rate increased with the foreperiod. Heightened temporal expectations inevitably produce a phenomenological change in orientation repulsion by reducing perceptual latency, whereby a premature target representation that has not completely undergone contextual modulation is brought upon one’s perception.