Aging, Sleep, Cognitive Process
Condition: BIOLOGICAL CLOCKS
Study type: Interventional

Summary: 
      The aim of the study is to determine the impact of aging, circadian rhythms and sleep
      deprivation on executive performances. Volunteers will complete a 40-hour extended
      wakefulness period in constant condition (semi-recumbent posture in bed, constant dim light
      levels < 10 lux, food and liquid intake at regular intervals) in order to control the
      circadian system. The volunteers will not be allowed to sleep in the sleep deprivation
      protocol ("high sleep pressure protocol") and will adopt a short wakefulness/sleep cycle
      (150/75 minutes) in the multiple nap protocol ("low sleep pressure protocol"). Tests and
      scales will be repeated every 3H45
    

Detailed description: 
      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
    

Intervention name(s): Sleep deprivation and multiple rest; Sleep deprivation and multiple rest; Sleep deprivation and multiple rest; Sleep deprivation and multiple rest
Intervention type(s): Other; Other; Other; Other
Intervention description(s): To determine the evolution of the executive functions during a 40-hour extended wakefulness period or during a 40-hour multiple nap protocol in constant experimental conditions of confinement; To determine the evolution of the executive functions during a 40-hour extended wakefulness period or during a 40-hour multiple nap protocol in constant experimental conditions of confinement; To determine the evolution of the executive functions during a 40-hour extended wakefulness period or during a 40-hour multiple nap protocol in constant experimental conditions of confinement; To determine the evolution of the executive functions during a 40-hour extended wakefulness period or during a 40-hour multiple nap protocol in constant experimental conditions of confinement
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Sleep; aging; cognitives processes; constant routine