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document
Caffeine eliminates psychomotor vigilance deficits from sleep inertia . STUDY OBJECTIVES This study sought to establish the effects of caffeine on sleep inertia , which is the ubiquitous phenomenon of cognitive performance impairment , grogginess and tendency to return to sleep immediately after awakening . DESIGN 28 normal adult volunteers were administered sustained low-dose caffeine or placebo ( randomized double-blind ) during the last 66 hours of an 88-hour period of extended wakefulness that included seven 2-hour naps during which polysomnographical recordings were made . Every 2 hours of wakefulness , and immediately after abrupt awakening from the naps , psychomotor vigilance performance was tested . SETTING N/A . PARTICIPANTS N/A . INTERVENTIONS N/A . MEASUREMENTS AND RESULTS In the placebo condition , sleep inertia was manifested as significantly impaired psychomotor vigilance upon awakening from the naps . This impairment was absent in the caffeine condition . Caffeine had only modest effects on nap sleep . CONCLUSIONS Caffeine was efficacious in overcoming sleep inertia . This suggests a reason for the popularity of caffeine-containing beverages after awakening . Caffeine 's main mechanism of action on the central nervous system is antagonism of adenosine receptors . Thus , increased adenosine in the brain upon awakening may be the cause of sleep inertia .
7307
Intervention_Pharmacological
Caffeine
7308
Intervention_Pharmacological
caffeine
7309
Intervention_Pharmacological
low-dose caffeine
7310
Intervention_Control
placebo
7311
Intervention_Control
placebo
7312
Intervention_Pharmacological
Caffeine
7313
Outcome_Mental
psychomotor vigilance deficits
7314
Outcome_Mental
sleep inertia
7315
Outcome_Mental
psychomotor vigilance performance
7316
Outcome_Mental
sleep inertia
7317
Outcome_Mental
psychomotor vigilance
7318
Outcome_Mental
nap sleep
7319
Outcome_Mental
sleep inertia
7320
Outcome_Mental
sleep inertia
7321
Participant_Condition
sleep inertia