Aging, Sleep, Cognitive Process (SOMVIE)

Social evolutions (nocturnal activity, shift work) have consequently reduced average sleep duration average. In addition, aging leads to a physiological reduction of nocturnal sleep duration.

Many studies have shown that extended wakefulness impairs nocturnal performances measured with a simple reaction time test (SRTT) and that this decrement is also age-related. In deed, young subjects (20-30 years) are more affected than old subjects (50-60 years) during an extended wakefulness period.

The results obtained in confinement constant conditions, associated to a high or low sleep pressure, show that this difference observed between young and old subjects should be essentially related to a reduced circadian regulation (ex : reduced melatonin secretion) with age rather than to a reduced sleep pressure (homeostatic regulation) as previously suggested. However, studies on confinement have shown that sleep pressure (identified during the sleep period with the EEG delta band) could be reduced with aging specifically on the anterior brain regions (frontal regions).

It is well-known that executive performances (related to frontal lobes functioning) are affected by extended wakefulness, but respective effects of age, circadian system and sleep pressure in this decrement remain unknown.

The aim of this study is to determine the evolution of the executive functions during a 40-hour extended wakefulness period ("high sleep pressure protocol") or during a multiple nap protocol ("low sleep pressure protocol") according to the subjects' age, in constant experimental conditions of confinement.

It's a repeated measurements study with protocol (sleep deprivation and multiple naps) and time of day as within factors and age group (young versus older subjects) as between factor