Stevens's law for time: A direct comparison of prospective and retrospective judgments

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.