Human perception of short and long time intervals: its correlation with body temperature and the duration of wake time.

Time estimation was studied in seven human subjects during prolonged sojourn is isolation from time cues. They wore rectal temperature probes throughout the experiments, and during wakefulness recorded each time they thought one hour had passed. At the end of each of these subjective hours they produced a subjective 5 or 10 sec interval. The produced intervals on the 1-h task were not related to body temperature but were correlated with and proportional to the duration of waketime in all subjects. The produced 5 and 10 sec intervals were in all subjects negatively correlated with rectal temperature, but were not associated with wake time. Brief and long time intervals are subjectively experienced via different mechanisms.