Effects of Different Colors of Light on Human Physiology

The recruitment status of this study is unknown because the information has not been verified recently.
Verified January 2010 by Brigham and Women's Hospital.
Recruitment status was  Active, not recruiting
Sponsor:
Collaborator:
Information provided by:
Brigham and Women's Hospital
ClinicalTrials.gov Identifier:
NCT00200863
First received: September 12, 2005
Last updated: January 12, 2010
Last verified: January 2010

September 12, 2005
January 12, 2010
January 2005
March 2008   (final data collection date for primary outcome measure)
  • Subjective alertness prior to, during and after light exposure [ Time Frame: 9.5 hours ] [ Designated as safety issue: No ]
  • Auditory psychomotor performance prior to, during and after light exposure [ Time Frame: 9.5 hours ] [ Designated as safety issue: No ]
  • EEG power frequency prior to, during and after light exposure [ Time Frame: 9.5 hours ] [ Designated as safety issue: No ]
  • Plasma melatonin and cortisol prior to, during and after light exposure [ Time Frame: 60 hours ] [ Designated as safety issue: No ]
  • Heart rate, blood pressure, respiration rate and temperature prior to, during and after light exposure [ Time Frame: 9.5 hours ] [ Designated as safety issue: No ]
  • Urinary catecholamines prior to, during and after light exposure [ Time Frame: 32 hours ] [ Designated as safety issue: No ]
  • Subjective alertness prior to, during and after light exposure
  • Auditory psychomotor performance prior to, during and after light exposure
  • EEG power frequency prior to, during and after light exposure
  • Plasma melatonin and cortisol prior to, during and after light exposure
  • Heart rate, blood pressure, respiration rate and temperature prior to, during and after light exposure
  • Urinary catecholamines prior to, during and after light exposure
Complete list of historical versions of study NCT00200863 on ClinicalTrials.gov Archive Site
Not Provided
Not Provided
Not Provided
Not Provided
 
Effects of Different Colors of Light on Human Physiology
Mechanism Underlying the Effects of Blue Light in Humans

This study will determine which color of light is most effective in stimulating a range of biological functions in humans including activation of sleep-wake regulatory system (alertness, performance, microsleeps, brain activity), activation of the nervous system (heart rate, temperature, blood pressure, breathing rate), and shifting the timing of the internal 24-hour (circadian) pacemaker.

Light has long been proposed to have a stimulatory effect on a range of biological functions in humans including increased feelings of activation, such as improved alertness or ability to perform. The mechanisms underlying how light stimulates these neurobiological systems remain to be elucidated. We propose to investigate the effects of different colors of light on human physiology, and in particular, test the claims that specific colors of light preferentially stimulate neurobiological, physiological and hormonal systems. Using classical photobiological techniques, we will construct action spectra for the effects of different colors of light on a range of non-image forming responses in humans.

We will test the hypotheses that: 1) light-induced activation of the neurobiological sleep-wake regulatory system, as indicated by increased alertness, faster reaction time, suppression of EEG alpha activity, microsleeps and slow rolling eye movements, and suppression of pineal melatonin, is most sensitive to retinal exposure to short wavelength blue light (460 nm) compared to equal photons of other colors of visible light; 2) light-induced activation of autonomic and hypothalamic-pituitary-adrenal axis measures of arousal, as indicated by increased heart rate variability, core body temperature, blood pressure, respiration rate, plasma cortisol levels and urinary catecholamines, is most sensitive to exposure to short wavelength blue light (460 nm) compared to equal photons of other colors; 3) phase shifts of the human circadian pacemaker, as assessed by changes in temperature, melatonin and cortisol rhythms, are most sensitive to exposure to short wavelength blue light (460 nm) compared to equal photons of other colors. The resultant action spectra will help to identify the photoreceptor mechanism(s) by which light activates arousal and circadian resetting, these non-image-forming physiological responses and enable us to distinguish between major candidate photoreceptive mechanisms, including potential novel photoreceptor systems, that might mediate such responses.

Interventional
Not Provided
Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
  • Healthy
  • Circadian Rhythm
Device: Monochromatic visible light exposure
Monochromatic light in the visible range from 420-620 nm up to 60uW/cm2 for 6.5 hours
  • Experimental: 1
    420 nm light
    Intervention: Device: Monochromatic visible light exposure
  • Experimental: 2
    480 nm
    Intervention: Device: Monochromatic visible light exposure
  • Experimental: 3
    507 nm
    Intervention: Device: Monochromatic visible light exposure
  • Experimental: 4
    555 nm
    Intervention: Device: Monochromatic visible light exposure
  • Experimental: 5
    620 nm
    Intervention: Device: Monochromatic visible light exposure
  • Experimental: 6
    460 nm
    Intervention: Device: Monochromatic visible light exposure
Gooley JJ, Chamberlain K, Smith KA, Khalsa SB, Rajaratnam SM, Van Reen E, Zeitzer JM, Czeisler CA, Lockley SW. Exposure to room light before bedtime suppresses melatonin onset and shortens melatonin duration in humans. J Clin Endocrinol Metab. 2011 Mar;96(3):E463-72. doi: 10.1210/jc.2010-2098. Epub 2010 Dec 30.

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Active, not recruiting
48
July 2010
March 2008   (final data collection date for primary outcome measure)

Inclusion Criteria:

  • Free from any acute, chronic or debilitating medical, psychological, or ophthalmological conditions
  • Drug-free (including caffeine, nicotine, and alcohol) for entire study duration

Exclusion Criteria:

  • History of drug or alcohol dependency
  • History of psychiatric illnesses or evidence of psychopathology according to standardized questionnaires, or in a structured clinical interview
  • Night shift work during the past 3 years
  • Transmeridian travel in the last 3 months
Both
18 Years to 30 Years
Yes
Contact information is only displayed when the study is recruiting subjects
United States
 
NCT00200863
R01 AT002129-01, R01AT002129-01
No
Steven W. Lockley, Ph.D., Brigham and Women's Hospital, Boston, MA
Brigham and Women's Hospital
National Center for Complementary and Alternative Medicine (NCCAM)
Principal Investigator: Steven W Lockley, Ph.D. Brigham and Women's Hospital, Harvard Medical School
Brigham and Women's Hospital
January 2010

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP