Related Experiment Video
Updated: Jul 29, 2026

Polygraphic Recording Procedure for Measuring Sleep in Mice
Published on: January 25, 2016
Caffeine eliminates psychomotor vigilance deficits from sleep inertia
H P Van Dongen1, N J Price, J M Mullington
1Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia 19104-6021, USA. vdongen@mail.med.upenn.edu
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.
Related Concept Videos
Sleep-Wake Cycles
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
Management of Insomnia
Sedatives and Hypnotics Drugs: Miscellaneous Agents
Melatonin congeners like ramelteon (Rozerem) and tasimelteon (Hetlioz) selectively bind to melatonin receptors (MT1 and MT2) and thus mimic the actions of melatonin, a hormone that regulates sleep-wake cycles. Tasimelteon is primarily used for non-24-hour sleep-wake disorder, common in blind patients. They are also used to treat conditions like insomnia...
Insufficient Sleep and Sleep Deprivation
Sleep deprivation is a more severe form of sleep loss...
Narcolepsy
Substance Use Disorders Affecting Sleep
Understanding the concepts of physical dependence,...

