Academic journal article Attention, Perception and Psychophysics

Stevens's Law for Time: A Direct Comparison of Prospective and Retrospective Judgments

Academic journal article Attention, Perception and Psychophysics

Stevens's Law for Time: A Direct Comparison of Prospective and Retrospective Judgments

Article excerpt

Published online: 23 April 2015

# The Psychonomic Society, Inc. 2015

Abstract Participants are aware that they have to perform a temporal task in a prospective timing condition but not in a retrospective timing condition. In the present study, a direct comparison of temporal estimates under each paradigm is proposed via a strategy where each participant is restricted to only 1 response. Participants were assigned to either a prospective or retrospective testing condition and asked to reproduce and then estimate verbally 1 of 6 intervals lasting .5 to 16 s. The analyses based on Stevens's power law were restricted to intervals lasting 2 to 16 s. With a verbal estimate method, the results indicate that the exponent is higher in retrospective than in prospective conditions (1.20 vs. 1.10 for females and 1.31 vs. 1.02 for males, respectively). For the interval reproduction task, the exponent based on Eisler's (1975) model was slightly higher for males (1.13) than for females (1.08) in prospective timing, but slightly higher for females (1.10) than for males (1.04) in retrospective timing. The results based on inferential statistics and the 6 intervals reveal that, with the verbal estimate method, females make significantly larger relative verbal estimates than males and, at 16 s, intervals were judged as longer in the retrospective than in the prospective condition; with the reproduction method, the perceived duration is about the same in each paradigm and there is no significant sex effect. Overall, the data do not confirm that temporal intervals are perceived as longer in the prospective than in the retrospective conditions.

Keywords Prospective and retrospective timing . Sex effect . Stevens'slaw. Temporal processing

One critical distinction for understanding some research findings in the field of time perception is related to the fact that a participant in an experiment might or might not know that the duration of a sensory signal, or of a given activity, has to be timed (Bisson & Grondin, 2013;Block,1992; Block & Zakay, 1997; Brown, 1985). When a participant knows that a time interval will have to be estimated-what is called a prospective timing condition-paying attention to time during the sensory signal or the activity becomes relevant. When a participant is unaware that time is a concern-a retrospective timing condition-the estimation of the duration of this signal or activity will likely require some reconstruction in memory.

There is a general report about the relative duration of time intervals judged prospectively versus retrospectively: Intervals judged prospectively are most often reported to be perceived as longer than intervals judged retrospectively (Block & Zakay, 1997; for a review, see Tobin, Bisson, & Grondin, 2010). Moreover, retrospective judgments are reported to be much more variable than prospective ones (Block & Zakay, 1997).

Beyond the fact of being aware or not that a temporal estimation will be required, the comparison of these paradigms suffers from two fundamental methodological differences. On the one hand, the interval length under investigation is usually briefer in the prospective than in the retrospective paradigm. It is easy to understand that studying the perception of long intervals in prospective conditions exposes experimenters to the possibility that a participant decides to use some internal strategies (like the explicit counting of chronometric units) for segmenting them into a series smaller subintervals. Such strategies, which are proved to be efficient (Grondin & Killeen, 2009; Grondin, Meilleur-Wells, & Lachance, 1999), are not possible in retrospective conditions. On the other hand, retrospective and prospective timing data most often differ on the basis of the number of trials completed in a given experimental condition. The study of prospective timing most often involves multiple estimations of intervals, and the variability of judgments is as important in assessing performances as the mean estimates are. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.