Investigating Preferred Nap Schedules for Adolescents
Condition: Sleep
Study type: Interventional

Summary: 
      The aim of this study is to examine the neurobehavioural responses to two successive cycles
      of sleep manipulation nights and recovery nights in adolescents, and to determine the
      benefits of napping on cognitive performance, alertness and mood. Using a split-sleep design,
      60 participants, aged 15 to 19 years old, are divided into a nap and a no-nap group. Both
      groups undergo two cycles of sleep manipulation nights and recovery nights over a period of
      15 days. The no-nap group receives an 8-hour sleep opportunity on sleep restriction nights,
      with no daytime nap opportunity. The nap group receives a 6.5-hour sleep opportunity on sleep
      restriction nights, and has a 1.5-hour nap opportunity the following afternoon.
    

Detailed description: 
      The present study investigates whether a continuous stretch of night time sleep (8 hours)
      will lead to better neurobehavioural outcomes relative to nocturnal sleep restriction (6.5
      hours) and daytime nap (1.5 hours) of the same total duration. The 15-day protocol is
      conducted in a dormitory on 60 high school students, aged 15 to 19 years old. Participants
      are assigned to a nap or no-nap group. Both groups start with two 9-hour adaptation and
      baseline nights, followed by two successive cycles of sleep restriction (6.5-h time in bed
      (TIB); 00:15-06:45 or 8-h TIB; 23:30-07:30) and recovery (9-h TIB; 23:00-08:00). Following
      each sleep-restricted night, the nap group receives a 1.5-h nap opportunity, while
      participants in the no-nap group watch a documentary. Throughout the protocol, sleep-wake
      patterns are assessed with actigraphy and polysomnography. Sleepiness levels, mood,
      vigilance, working memory / executive functions, and speed of processing are assessed 3 times
      daily (10:00, 16:15, and 20:00).

      All participants stay in air-conditioned, twin-share bedrooms with en-suite bathrooms.
      Bedroom windows are fitted with blackout panels to ensure participants are not woken up
      prematurely by sunlight. Earplugs are provided, and participants are allowed to adjust the
      temperature of their bedrooms to their personal comfort. Three main meals are served each
      day, with snacks being provided for upon request. Caffeinated drinks, unscheduled sleep, and
      strenuous physical activities are prohibited.

      Outside of scheduled sleep, meal, and cognitive testing times, participants spend the
      majority of their free time in a common room that is illuminated by natural and artificial
      lighting. They are allowed to read, play non-physically exerting games, watch videos, and
      interact with research staff and other participants. Participants are under constant
      supervision by the research staff.
    

Intervention name(s): Nap
Intervention type(s): Behavioral
Intervention description(s): Looking at the difference between continuous sleep opportunities and split-sleep opportunities.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Nap; Recovery sleep; Cognitive functions; Neurobehavioural functions; Mood; Subjective sleepiness