Prospective time estimation over a night without sleep

The aim of the present study was to investigate the time of night effect on prospective time estimation efficiency. Fifty-four participants took part in six consecutive experimental sessions from 10:00 p.m. to 8:00 a.m. at intervals of 2 h, during which they had to carry out two kinds of tasks (simple reaction time and prospective time estimation), give an evaluation of their subjective alertness, and record body temperature. In agreement with previous data on body temperature, subjective alertness and performance in simple reaction time showed a significant decrease during the night, while performance in prospective time estimation did not change over the night. Taking into account circadian typology we found that morning-types tended to produce significantly shorter time intervals and less time estimation accuracy than evening-types. With reference to recent cognitive timing models and data derived from free-running conditions, it is hypothesised that internal pace-makers pulse at different rates between the extreme chronotypes