The Impact of Artificial Sunlight on Human Sleep and Circadian Rhythms

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT03636360

Enrollment

Registered

2018-08-17

Start date

2019-07-01

Completion date

2021-03-01

Last updated

2021-03-30

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Circadian Dysregulation, Mood, Sleep

Brief summary

The purpose of this study is to examine, in healthy controls, whether LED lighting that has a color spectrum similar to that of sunlight is able to differentially impact mood, circadian rhythms, sleep, and behavior, as compared to standard fluorescent lighting.

Interventions

DEVICELight

15 hours of light exposure

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

BASIC_SCIENCE

Masking

SINGLE (Subject)

Masking description

Participants will be aware that the lighting conditions will vary during their visits, but will not be aware of the nature of the difference in the lights.

Eligibility

Sex/Gender

ALL

Age

18 Years to 35 Years

Healthy volunteers

Yes

Inclusion criteria

* Good self-reported health * Normal color vision

Exclusion criteria

* No sleep disorders * No extreme chronotype * Regular smoker * Significant hearing loss * Depression * Alcohol use disorder * Use of illegal drugs * Pregnant

Design outcomes

Primary

Measure	Time frame	Description
Alertness	15 hours	Change in median reaction time score on the auditory psychomotor vigilance test
Melatonin suppression	3 hours	Amount of reduction in the concentration of salivary melatonin concentrations during an experimental light stimulus

Secondary

Measure	Time frame	Description
Mood	15 hours	Change in total positive and negative affect scores on the Positive and Negative Affect Schedule (PANAS)

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026