Proceedings. Biological sciences

Human circadian system shifts timing depending on light flash brightness but not duration

Circadian Biology Weekly Brief ↗PubMed ↗DOI ↗

Updated

Abstract

A dose-response relationship exists between flash intensity and circadian phase shift, with 28 participants studied at fixed duration and 31 participants at variable duration.

  • Circadian phase shifts were influenced by the intensity of light flashes, suggesting a potential threshold effect.
  • Flash duration showed a slight relationship with circadian phase shift.
  • No significant impact was found on melatonin suppression or measures of alertness and sleepiness from light exposure.
  • Responses to light flashes appear to be integrated by specialized retinal cells that process input from other photoreceptors.

Simplified

Full Text

We can’t show the full text here under this license.
View Full Text ↗

Funding

Competing interests

We declare we have no competing interests.
PubMed

Related papers

Dec '22
Human sensitivity to different light colors for adjusting body clock and melatonin changes with light exposure time
top 2% journal
cited by 51 papers
research support, n.i.h., extramural
Jul '20
Light's effects through melanopsin on body clock timing, melatonin levels, and sleepiness
cited by 35 papers
journal article
Sep '20
Problems in Light-Sensing Cells May Contribute to Sleep Issues in Parkinson’s Disease
top 10% journal
cited by 20 papers
research support, non-u.s. gov't
May '10
How the human body clock responds to light depends on its brightness and length of exposure
top 1% journal
cited by 356 papers
research support, n.i.h., extramural
Dec '19
Light-sensitive retinal cells combine rod and melanopsin signals to detect dim light
top 2% journal
cited by 42 papers
research support, n.i.h., extramural
Dec '23
How specific blue and yellow light changes affect the human internal body clock
top 1% journal
cited by 25 papers
journal article

What Lands in Your Inbox Each Week:

  • 📚7 fresh studies
  • 📝plain-language summaries
  • ✅direct links to original studies
  • 🏅top journal indicators
  • 📅weekly delivery
  • 🧘‍♂️always free

Recent issues from the circadian biology brief

issue #48
A blood test can now estimate your internal clock time using just 60 proteins
2 days ago7 studies
issue #47
Your body clock controls liver fibrosis — and scientists just found the on/off switch
1 week ago7 studies
issue #46
Night shift workers' metabolomes fall out of sync — and glucose pays the price
2 weeks ago7 studies
issue #45
80% of FDA-approved drug targets show clock-dependent activity — timing may be everything
3 weeks ago7 studies
issue #44
Sleeping late on weekends is independently linked to higher cardiovascular disease risk
4 weeks ago7 studies
issue #43
A smartphone app cut mood episode recurrence 3.4x in people with depression and bipolar disorder
5 weeks ago7 studies
issue #42
Morning cancer immunotherapy linked to 49% vs 40% disease control rate in 969 patients
6 weeks ago7 studies
issue #41
Timing cancer treatment before 3pm nearly doubled survival in lung cancer patients
7 weeks ago7 studies
issue #40
Male mice lived 12% longer when they ate only during an 8-hour window at night
8 weeks ago7 studies
issue #38
Emergency doctors had 67% higher odds of chronic pain when working evening shifts vs. morning shifts
10 weeks ago7 studies
explore the archive
See more issues from the circadian biology brief