Related Experiment Video
Updated: Jul 17, 2025
08:36
Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments
Published on: August 8, 2019
12.0K
Moving time zones in a flash with light therapy during sleep
Renske Lok1, Marisol Duran2, Jamie M Zeitzer3,4
1Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, 94305, USA.
Scientific Reports
|September 2, 2023
Summary
Flash therapy, using brief light pulses during sleep, effectively delays the human circadian clock. This novel approach shows significant phase shifts with minimal sleep disruption, offering potential for shift workers and travelers.
Area of Science:
- Chronobiology
- Sleep Science
- Light Therapy
Background:
- Continuous light exposure is a known method for altering circadian clock timing in humans.
- Investigating intermittent light exposure during sleep offers a novel approach to circadian rhythm manipulation.
Purpose of the Study:
- To evaluate the efficacy of intermittent light flashes during sleep for shifting circadian timing.
- To assess the impact of this 'flash therapy' on sleep architecture and spectral power.
Main Methods:
- Healthy participants (n=10) underwent two laboratory sessions involving a placebo and a 60-minute flash therapy intervention during habitual sleep onset.
- Flash therapy consisted of 2-ms broad-spectrum light pulses every 15 seconds.
- Circadian phase shifts were measured using salivary dim light melatonin onset (DLMO); sleep was monitored via polysomnography.
Main Results:
- Flash therapy induced a significant delay in DLMO (1.13 ± 1.27 hours) compared to placebo (12 ± 20 minutes).
- Two participants showed exceptionally large phase delays of 6.4 and 3.1 hours.
- No significant changes in sleep architecture were observed, though some sleep instability was noted.
Conclusions:
- One hour of flash therapy during sleep can effectively delay the circadian clock, with potential for shifts up to 6 hours.
- This method appears to have minimal impact on sleep quality.
- Flash therapy presents a promising, practical strategy for circadian clock adjustment in individuals experiencing circadian disruption, such as shift workers and jet travelers.
Related Concept Videos
01:19Management of Insomnia
278
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...
278
01:15Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response
87
Circadian rhythms are cyclic changes that are crucial in plasma drug concentrations. Various standard circadian parameters, including core body temperature, heart rate, and other cardiovascular factors, directly impact disease states and the therapeutic response to drug therapy.
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
87
01:13Insufficient Sleep and Sleep Deprivation
167
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...
Sleep deprivation is a more severe form of sleep loss...
167
01:24Substance Use Disorders Affecting Sleep
196
Substance use disorders involve a pattern of using drugs more extensively than intended and continuing use despite harmful consequences. This includes legal substances like alcohol and nicotine, as well as illegal drugs. These disorders often involve both physical and psychological dependence, reflecting compulsive use of substances that significantly alter thoughts, feelings, and behaviors, contributing to a major public health issue.
Understanding the concepts of physical dependence,...
Understanding the concepts of physical dependence,...
196
01:22Stages of Sleep
367
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...
Before sleep begins, in wakefulness, the brain exhibits primarily beta waves, which are high in frequency and low in amplitude, indicating alertness...
367
01:11Understanding Sleep
407
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...
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...
407