Abstract
Recent experimental evidence suggests that the perception of temporal intervals is influenced by the temporal context in which they are presented (Jazayeri & Shadlen, 2010). A longstanding example is the time-order-error (TOE), wherein the perception of two intervals relative to one another is influenced by the order in which they are presented. Here, we test whether the perception of temporal intervals in an absolute judgment task is influenced by the preceding temporal context. Human subjects (n=70) participated in a temporal bisection task with no anchor durations (partition method). Intervals were demarcated by a Gaussian blob (visual condition) or burst of white noise (auditory condition) that persisted for one of seven logarithmically spaced intervals between 300 and 900ms. Crucially, the order in which stimuli were presented was determined by a De Bruijn sequence (Aguirre, et al. 2011), such that all consecutive interval orders were counterbalanced. The results demonstrated a number of distinct findings. First, the perception of each interval was biased by the prior response, such that each interval was judged similarly to the previous choice. Second, the perception of each interval was influenced by the prior interval, such that perception was shifted away from the preceding duration. Third, the effect of prior interval was linear, such that more extreme intervals had a larger influence. Fourth, influence of the prior interval was negatively correlated with influence of the prior response, such that subjects with a large decision bias showed a smaller perceptual effect. Fifth, the effect of decision bias was larger for visual than auditory intervals. These effects extend TOE findings to absolute judgments, and demonstrate that temporal bisection is influenced by the immediate temporal context. Furthermore, our findings demonstrate that a single exposure to an interval can shift perception of a subsequent interval in a manner consistent with Bayesian and adaptation-level theory.
Meeting abstract presented at VSS 2013