Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Sleep-Wake Cycles

Sleep-Wake Cycles

Sleep is an essential physiological process vital to maintaining overall well-being. The reticular activating system (RAS), a network of neurons in the brainstem, regulates wakefulness and sleep. While it may seem passive, sleep consists of distinct cycles, each with its unique characteristics and functions. Two key sleep phases are non-rapid eye movement (NREM) and rapid eye movement (REM).
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:

Stages of Sleep

Stages of Sleep

Sleep progresses through distinct stages, each characterized by specific brain wave patterns and physiological responses ranging from wakefulness to stages of non-rapid eye movement, known as non-REM, to rapid eye movement, referred to as REM. Understanding these stages helps in recognizing how sleep supports various bodily and cognitive functions.
Before sleep begins, in wakefulness, the brain exhibits primarily beta waves, which are high in frequency and low in amplitude, indicating alertness...

Understanding Sleep

Understanding Sleep

Sleep, an essential biological state, involves significant reductions in physical activity, sensory awareness, and interaction with the environment. This complex physiological process is primarily regulated by specific brain regions, notably the hypothalamus and pons, which govern the sleep-wake cycle or circadian rhythm.
The circadian rhythm, a nearly 24-hour cycle, is deeply influenced by environmental light cues. Light exposure directly affects the hypothalamus, which in turn regulates...

Insufficient Sleep and Sleep Deprivation

Insufficient Sleep and Sleep Deprivation

Insufficient sleep refers to not getting the recommended amount of sleep for optimal functioning, even if it's just slightly less than needed. Sleep insufficiency may occur due to lifestyle choices, such as staying up late for social events or work, resulting in routinely getting less sleep than required. For example, consistently sleeping 6 hours when the body needs 7-9 hours can lead to cumulative effects on health and well-being.
Sleep deprivation is a more severe form of sleep loss...

Management of Insomnia

Management of Insomnia

The sleep cycle, an integral part of human health, consists of several stages with distinct characteristics and functions. It begins with a transition from wakefulness to sleep, known as the light sleep phase, followed by the restorative deep sleep phase, essential for physical recovery and growth. The cycle concludes with the Rapid Eye Movement (REM) phase, characterized by high brain activity and vivid dreaming. Insomnia, a prevalent sleep disorder, involves difficulty falling asleep, staying...

Narcolepsy

Narcolepsy

Narcolepsy is a chronic sleep disorder characterized by pervasive, uncontrolled sleepiness and other sleep disturbances. One of its hallmark symptoms is an abrupt transition to REM sleep upon falling asleep, which causes symptoms typically associated with this phase to occur unexpectedly during wakefulness. These include the following symptoms, which typically last from a minute or two to half an hour.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Targeted dream incubation at sleep onset can influence later dream content in REM sleep: a pilot study.

Frontiers in sleep·2026

Same author

Repeat Exposures to Spaceflight or Bed Rest and Spaceflight-Associated Neuro-Ocular Syndrome Findings.

JAMA ophthalmology·2026

Same author

Sleep and wake markers of thalamocortical functioning in early-course psychosis and first-degree relatives.

Schizophrenia (Heidelberg, Germany)·2026

Same author

Jugular venous flow dynamics during acute weightlessness and partial gravity in parabolic flight.

Journal of applied physiology (Bethesda, Md. : 1985)·2026

Same author

Recovery sleep after total sleep deprivation preserves neutral and enhances emotional declarative memory.

Sleep advances : a journal of the Sleep Research Society·2026

Same author

Prediction of Optic Disc Edema Progression During Spaceflight.

JAMA ophthalmology·2025

Search research articles

Related Experiment Video

Updated: Jun 7, 2025

Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments

Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments

Published on: August 8, 2019

Changes to human sleep architecture during long-duration spaceflight.

Oliver Piltch^1,2, Erin E Flynn-Evans³, Millennia Young⁴

¹Division of Life Sciences, Department of Neuroscience, Harvard University, Cambridge, Massachusetts, USA.

Journal of Sleep Research

|November 11, 2024

Summary

Spaceflight increases wakefulness and alters sleep architecture, initially reducing rapid eye movement (REM) sleep. Sleep patterns largely recovered upon return to Earth, suggesting spaceflight impacts sleep quality.

Keywords:

astronaut non‐rapid eye movement rapid eye movement sleep sleep architecture spaceflight

More Related Videos

Quantifying Infra-slow Dynamics of Spectral Power and Heart Rate in Sleeping Mice

Quantifying Infra-slow Dynamics of Spectral Power and Heart Rate in Sleeping Mice

Published on: August 2, 2017

A Chronic Sleep Fragmentation Model using Vibrating Orbital Rotor to Induce Cognitive Deficit and Anxiety-Like Behavior in Young Wild-Type Mice

A Chronic Sleep Fragmentation Model using Vibrating Orbital Rotor to Induce Cognitive Deficit and Anxiety-Like Behavior in Young Wild-Type Mice

Published on: September 22, 2020

Related Experiment Videos

Last Updated: Jun 7, 2025

Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments

Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments

Published on: August 8, 2019

Quantifying Infra-slow Dynamics of Spectral Power and Heart Rate in Sleeping Mice

Quantifying Infra-slow Dynamics of Spectral Power and Heart Rate in Sleeping Mice

Published on: August 2, 2017

A Chronic Sleep Fragmentation Model using Vibrating Orbital Rotor to Induce Cognitive Deficit and Anxiety-Like Behavior in Young Wild-Type Mice

A Chronic Sleep Fragmentation Model using Vibrating Orbital Rotor to Induce Cognitive Deficit and Anxiety-Like Behavior in Young Wild-Type Mice

Published on: September 22, 2020

Area of Science:

Space Medicine
Sleep Science
Human Physiology

Background:

Sleep is crucial for cognitive function and well-being.
Human sleep architecture's response to long-duration spaceflight remains under-investigated.
Previous research has not extensively studied sleep patterns during extended space missions.

Purpose of the Study:

To investigate the effects of long-duration spaceflight on human sleep architecture.
To compare sleep parameters during spaceflight with those on Earth.
To analyze longitudinal changes in sleep patterns over a ~6-month mission.

Main Methods:

Utilized the Nightcap sleep monitor to record 256 nights of sleep data.
Collected sleep data from five crew members before, during, and after space missions.
Compared sleep outcomes including total sleep time, efficiency, latency, and REM/NREM sleep.

Main Results:

Spaceflight was associated with a 1-hour increase in wakefulness compared to Earth-based sleep.
Rapid eye movement (REM) sleep was initially reduced during spaceflight, then recovered.
Non-rapid eye movement (NREM) sleep decreased as REM sleep recovered.
Sleep architecture returned to preflight levels after returning to Earth.

Conclusions:

Long-duration spaceflight significantly alters human sleep architecture.
Wakefulness increases and REM/NREM sleep patterns are modified during space missions.
Further research is warranted to understand and mitigate spaceflight-induced sleep disturbances.