Mechanism of the compression effect on visual duration perception caused by temporally sandwiching sounds.

When task-irrelevant nontarget sound temporally sandwiches brief target visual stimuli, its perceived duration is compressed (time compression). Since little is known about the mechanisms of time compression, this study examined its causal factors. Experiment 1 measured the effects of preceding, trailing, and sandwiching sounds on visual duration perception and examined whether adding the first two effects predicts the empirical effect of the third. The time compression occurred only when the target visual stimulus was 300 ms, but not for a target duration ≥500 ms. However, the predicted additive effect did not match the time compression. Experiment 2 examined the weighted integration of unisensory estimates (visual filled interval and auditory empty interval) by measuring the perceived duration of unimodal and multimodal stimuli. The predicted duration by weighted integration fitted the time compression occurring at the target duration of 300 ms. However, when the target was 500 ms or longer, no time compression occurred and the predicted durations were longer than the empirical durations. These results suggest that the visual system with weak temporal resolution integrated more accurate and reliable temporal information, rather than additive effect, resulting in time compression only when the target duration was too short. (PsycInfo Database Record (c) 2023 APA, all rights reserved).