Why do temporal generalization gradients change when people make decisions as quickly as possible?
A study containing four experiments provided evidence in favour of assimilation effects in retrospective duration judgments due to temporal expectations. In this study, the participants did not know in advance that they would have to reproduce the duration of a target interval. Temporal expectations were induced prior to the target interval by the repeated presentation of a visually filled interval (the expectancy interval). Both the duration of the expectancy interval and the number of presentations of that interval were varied between subjects. The experiments showed a clear assimilation effect of temporal expectations on reproduced duration, indicated by judged durations strongly resembling the duration of the expectancy interval. This effect increased with the magnitude of the difference between the expectancy interval and the target interval, and with the number of repetitions of the expectancy interval. Results were discussed with reference to Helson’s adaptation-level theory.