title: Sleep inertia, sleep homeostatic and circadian influences on higher-order cognitive functions.
abstract: Sleep inertia, sleep homeostatic and circadian processes modulate cognition, including reaction time, memory, mood and alertness. How these processes influence higher-order cognitive functions is not well known. Six participants completed a 73-day-long study that included two 14-day-long 28-h forced desynchrony protocols to examine separate and interacting influences of sleep inertia, sleep homeostasis and circadian phase on higher-order cognitive functions of inhibitory control and selective visual attention. Cognitive performance for most measures was impaired immediately after scheduled awakening and improved during the first ~2-4 h of wakefulness (decreasing sleep inertia); worsened thereafter until scheduled bedtime (increasing sleep homeostasis); and was worst at ~60° and best at ~240° (circadian modulation, with worst and best phases corresponding to ~09:00 and ~21:00 hours, respectively, in individuals with a habitual wake time of 07:00 hours). The relative influences of sleep inertia, sleep homeostasis and circadian phase depended on the specific higher-order cognitive function task examined. Inhibitory control appeared to be modulated most strongly by circadian phase, whereas selective visual attention for a spatial-configuration search task was modulated most strongly by sleep inertia. These findings demonstrate that some higher-order cognitive processes are differentially sensitive to different sleep-wake regulatory processes. Differential modulation of cognitive functions by different sleep-wake regulatory processes has important implications for understanding mechanisms contributing to performance impairments during adverse circadian phases, sleep deprivation and/or upon awakening from sleep.
authors.affiliation: Sleep and Chronobiology Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder CO, USA.
authors.forename: Tina M
authors.initials: TM
authors.lastname: Burke
authors.affiliation: Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital and Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA.
authors.forename: Frank A J L
authors.initials: FAJL
authors.lastname: Scheer
authors.affiliation: Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital and Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Ronda
authors.affiliation: Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital and Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Czeisler
authors.affiliation: Sleep and Chronobiology Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder CO, USA.|Division of Sleep and Circadian Disorders, Department of Medicine, Brigham and Women's Hospital and Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA.
authors.forename: Kenneth P
authors.initials: KP
authors.lastname: Wright
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D005260:Female; D006706:Homeostasis; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D020178:Sleep Disorders, Circadian Rhythm / Q000503:physiopathology; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology; D014851:Wakefulness / Q000502:physiology
keywords: circadian rhythms; cognitive speed; cognitive throughput; executive function; neurobehavioural; stroop colour word task; visual search