[Alterations of time judgement with age]

Time perception can be divided into two processes: time experience and time judgement. Although there have been frequent reports of changes in these two processes with increasing age, none of these changes has been demonstrated using objective measures.

We evaluated time judgement by employing time estimation, time production, and time reproduction tasks in 33 healthy subjects of all age groups. In addition, we used the Trail-Making Test to measure attentional performance.

For both time estimation and time reproduction, we found positive correlations between length of time interval and age (overestimation). After we calculated partial correlations controlling for the results of the Trail-Making Test, the age-related changes we initially observed in the time estimation task disappeared, but the age-related changes seen in the time reproduction task remained significant.

Considering the Scalar Timing Theory and the Attentional Gate Theory, our findings indicated that age-related effects on time estimation may be due to attentional factors. In contrast, the age-related changes seen in the time reproduction task may be due to disturbances in working memory function.