The role of segmentation in prospective and retrospective time estimation processes.

In five experiments, we investigated the effects of the segmentation level of an interval on its perceived duration. A prospective paradigm and an absolute time estimation method were used in two experiments, and in two others we used a retrospective paradigm and a comparative estimation method. A positive relationship was obtained between segmentation level of the estimated interval and its perceived duration under retrospective-comparative conditions for both auditory and tactual stimuli, but no relationship was found under prospective-absolute conditions. The paradigm, estimation method, and segmentation level were jointly manipulated in the fifth experiment. The impact of segmentation was significant under retrospective (both absolute and comparative) and close to significant under prospective-comparative conditions. These findings suggest that high-priority events are perceived and coded as contextual changes and that the impact of segmentation on time estimation is mediated by memory processes.