Slow-wave Enhancement in Adults Aged 30-49
Condition: Sleep
Study type: Interventional

Summary: 
      A single-site, randomized study to assess the effectiveness of different types of closed-loop
      auditory stimulation on slow-wave enhancement using SmartSleep in an astronaut-like sample of
      adults between the ages of 30 and 55. Secondary analyses will be performed to determine
      whether slow-wave enhancement influences neurobehavioral performance in this population.
      Participants will be on study for 8 weeks.
    

Detailed description: 
      The investigators seek to determine the extent to which various closed-loop auditory
      stimulation protocols (continuous fixed interval, block, in-phase adjustable) differentially
      affect slow-wave sleep. Participants will run the study for eight weeks, which includes
      wearing the SmartSleep device nightly, and completing one 3-min and one 20-min cognitive
      assessment battery each day, as well as computerized post-sleep questionnaires each morning,
      sleepiness scales three times a day, and a weekly evaluation of device comfort. This study
      will employ various types of auditory stimulation in order to determine 1) which stimulation
      pattern is maximally effective at enhancing slow wave activity (SWA) and 2) to assess
      cognitive performance associated with each stimulation algorithm. The study requires a longer
      duration so that sufficient data on each distinct type of stimulation may be collected.

      Participants will be instructed to wear the SmartSleep device at home for three two-week
      periods, and will complete 10 nights per period of continuous fixed interval, block, or
      in-phase adjustable stimulation (in randomized order). Between each of these periods,
      participants will complete one week of sham condition (this condition records sleep EEG
      without any stimulation and is used to define each participant's typical sleep). During all
      eight weeks, participants will complete a 20-minute cognitive assessment in the evening, a
      five-minute cognitive assessment in the morning, and respond to the Karolinska Sleepiness
      Scale three times per day. The cognitive assessments will be accompanied by short
      questionnaires. Participants will receive text message reminders from study staff when it is
      time to perform these assessments.

      Primary objective: Determine which stimulation type (e.g., Block stimulation, Fixed ITI,
      in-phase) is most effective at enhancing slow-waves slow-wave sleep relative to baseline
      sleep in a group of astronaut-like subjects in an ecologically valid setting.

      Main secondary objective: Determine the extent to which various closed-loop auditory
      stimulation protocols (continuous fixed interval, block, inphase adjustable) differentially
      affect various aspects of neurobehavioral function using a set validated cognitive tasks as
      part of the Cognition battery.

      Other secondary objectives: Explore the relationships between improvements in SWA and
      measures of subjective sleepiness as assessed by the Karolinska Sleepiness Scale
    

Intervention name(s): Philips SmartSleep
Intervention type(s): Device
Intervention description(s): closed-loop auditory stimulation
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: sleep; cognitive performance