Pace alteration and estimation of time intervals.

This experiment examined the effects on participants' estimates of interval duration of altering the pace of auditory stimuli contained within "filled" intervals. Because most previous studies on the filled interval effect have utilized visual displays, auditory stimuli were used to assess whether the effect would be present. In addition, previous studies compared two intervals, one of which was filled and the other unfilled. In the present study, both intervals were filled with tones at one of three rates (or "paces"): slow, medium, or fast. 25 participants (20 women) ages 18 to 29 years (M = 20.4, SD = 2.3) were recruited from psychology courses and programs. Participants first heard a "training" interval filled with tones at one of the three paces and then attempted to reproduce the duration of that training interval in the "test" interval. The pace of stimuli in each pair of training and test intervals was varied so participants received all possible combinations of paces of auditory stimuli during the training and test trial sets. Analysis showed that, when training pace was fast and test pace was medium or slow, participants' estimates were longer than the actual test interval durations. Conversely, when training pace was slow and test pace was medium or fast, participants' estimates were shorter than actual test interval durations. In addition, when judging shorter intervals, participants estimated more time had passed than actually had, while they estimated that less time had passed than actually had for longer intervals, thus providing support for Vierordt's law.