Investigation of the Psychological Length of a 1-s Interval With a Time Production Task

Abstract

Several studies using the production of 1-s intervals report instability in the results. This suggests that there is no clear representation of the value of 1 s in long-term memory. This instability may partly be explained by the specific methodological requirements of studies using 1-s production tasks. Typically, this task requires participants to produce 1-s intervals by either using two intermittent finger taps (one at the beginning and one at the end of the interval), or by continuously pressing a key for the duration of the second. The purpose of this study was to investigate the impact of two main factors on the production of 1-s intervals, namely the effects of kinesthetic cues (continuous press vs. two intermittent presses) and auditory cues (sound vs. no sound) during the production of each interval. Participants produced 30 1-s intervals under four conditions. The results showed significant effects of both kinesthetic and auditory factors on the produced intervals. The kinesthetic effects applied to both the accuracy (staying close to the 1-s target) and precision (minimizing intertrial variability), and the auditory effects were limited to accuracy. This study highlights that the expression of what is likely a representation of the psychological second in long-term memory is prone to much distortion. Explanations of this instability of the psychological second are explored, including the simultaneous involvement of circuits related to sub- (<1 s) and supra-second (>1 s) intervals and individual differences in the internal clock.