Effects of attention and external stimuli on duration estimation under a prospective paradigm

The study examined whether there are two independent cognitive factors affe cting duration estimation. In two experiments, we manipulated simultaneousl y and independently two variables, namely, the level of attention to the la pse of time and the quantity of perceived changes, and examined their effec ts on duration estimation under a prospective paradigm. The duration was es timated to be longer when subjects attended to the lapse of rime than when they attended to tasks during the target interval (Experiments 1 and 2). Th e characteristics of external stimuli irrelevant to the tasks, namely, the rate of presentation of sounds (Experiment 1) and the velocity of moving do ts (Experiment 2), affected duration estimation, even though the attention level was little changed by these stimuli. These findings suggest that ther e are at least two independent cognitive factors that affect duration estim ation.