Date Published: January 1, 2010
Publisher: Public Library of Science
Author(s): Takahiro Soshi, Kenichi Kuriyama, Sayaka Aritake, Minori Enomoto, Akiko Hida, Miyuki Tamura, Yoshiharu Kim, Kazuo Mishima, Alex O. Holcombe. http://doi.org/10.1371/journal.pone.0008395
Abstract: Human short-time perception shows diurnal variation. In general, short-time perception fluctuates in parallel with circadian clock parameters, while diurnal variation seems to be modulated by sleep deprivation per se. Functional imaging studies have reported that short-time perception recruits a neural network that includes subcortical structures, as well as cortical areas involving the prefrontal cortex (PFC). It has also been reported that the PFC is vulnerable to sleep deprivation, which has an influence on various cognitive functions. The present study is aimed at elucidating the influence of PFC vulnerability to sleep deprivation on short-time perception, using the optical imaging technique of functional near-infrared spectroscopy. Eighteen participants performed 10-s time production tasks before (at 21:00) and after (at 09:00) experimental nights both in sleep-controlled and sleep-deprived conditions in a 4-day laboratory-based crossover study. Compared to the sleep-controlled condition, one-night sleep deprivation induced a significant reduction in the produced time simultaneous with an increased hemodynamic response in the left PFC at 09:00. These results suggest that activation of the left PFC, which possibly reflects functional compensation under a sleep-deprived condition, is associated with alteration of short-time perception.
Partial Text: Temporal perception is fundamental to environmental adaptation. Developing time management skills enables us not only to avoid life-threatening situations, but also to gain rewards and establish motor and cognitive skills. Higher organisms have at least two endogenous clock systems , . One of these is a circadian pacemaker located in the suprachiasmatic nucleus of the hypothalamus ,  which is driven by a self-sustaining oscillator with a period of about 24 h and provides the time of day as the hour hand of the clock . Another is a stopwatch-like system which perceives brief temporal intervals as the minute hand of the clock , .
Sleep is believed to be a neural state during which both consolidation of memories and homeostatic preservations are taking place –. Sleep deprivation, even for the course of an extended active period of the day, eliminates these effects, and possibly results in a deterioration in cognitive activity , , .