Serial dependence in auditory temporal perception is influenced by temporal proximity but not stimulus type

Serial dependence (SD) is a phenomenon where current perceptions are biased toward previous ones, promoting stability over time. While SD has been originally studied in vision, it has recently been shown to occur in other sensory modalities, like hearing. Given its relative novelty, the mechanisms underlying auditory SD are still to be explored, particularly regarding how the characteristics of a stimulus, or its position in time, may or may not affect current perception. To shed light on the theme, we designed a series of temporal discrimination tasks in which participants judged whether the first of three sounds was longer than the third, with the second one serving as an inducer to elicit SD. In separate conditions, we directly manipulated both the stimulus type, using full or empty intervals, and the inter-stimulus interval (ISI) between the inducer and the third stimulus. Overall, our results suggest that SD can also be observed in the auditory timing domain. Interestingly, we found evidence that performance did not differ due to the stimulus type. Conversely, varying the ISI revealed that SD was significant at the shortest ISI, while it was not significant at the longer ISI.