Time estimation and expectancies.

The purpose of this research was to examine the influence of different types of expectancies on time estimation behavior. In Experiment 1, subjects were led to expect that a given number of trials would occur in a music perception task. In Experiment 2, expectancies concerning the duration of a given waiting period were varied. Results of both experiments indicated that the confirmation/violation of expectancies exerted a significant impact on duration judgments. When subjects received more/fewer trials than expected or waited for a duration that was longer/shorter than expected, the total duration of these time spans was over- and underestimated, respectively. Conversely, time estimates were relatively accurate when subjects' expectancies were confirmed. The results of Experiment 1 further revealed that reaction time responses within the music perception task were also systematically influenced by the expected amount of activity. Results are discussed in terms of a framework that emphasizes the role of anticipatory attending on time estimation behavior.