Systematically Assessing Effects of Colored Light on Humans With a Multi-modal Approach (Substudy 3 of 7)
- Conditions
- Exposure to Man-made Visible Light
- Interventions
- Other: Visible light exposure
- Registration Number
- NCT02882542
- Lead Sponsor
- University of Bern
- Brief Summary
NOTE: This is the third of in total 7 sub-studies related to the Ethics Committee of the Canton of Bern Ref. No. KEK-BE 2016-00674. This sub-study includes 50 participants and 6 arms, in total 350 participants will be assessed in all 7 sub-studies.
General study information: This is a randomized, cross-over, quantitative study, which investigates physiological variables, mood, and affect of healthy participants in response to colored light exposure. The Participants take part in 5-8 arms and are exposed to colored light only, or are additionally asked to solve cognitive tasks during the colored light exposure. Primary aim is to measure the change in several physiological variables, mood, and affect during colored light exposure of 15 or 45 minutes. The risk for the participants is negligible and comparable to the risk during daily life.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 41
- Normal color vision
- Right handed
- Written informed consent
- Smoking
- Any kind of diagnosed sleep disorder or neurological or psychiatric disorder in the last 3 months
- Acute severe traumas
- Chronic diseases with the necessity for medication
- Use of recreational drugs
- Regular intake of medication that would affect the outcome measures
- Regular excessive alcohol use (> 18 standard units / week)
- Transmeridian travel in the last month (crossed > 1 time zone border)
- Night shift word during the last month
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description Visible light exposure Cyan 30 lux Visible light exposure The participants will be exposed to cyan LED light at a illuminance of 30 lux at eye level for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness. Visible light exposure Orange 120 lux Visible light exposure The participants will be exposed to orange LED light at a illuminance of 120 lux at eye level for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness. Visible light exposure White 30 lux Visible light exposure The participants will be exposed to white LED light at a illuminance of 30 lux at eye level for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness. Visible light exposure White 120 lux Visible light exposure The participants will be exposed to white LED light at a illuminance of 120 lux at eye level for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness. Visible light exposure Orange 30 lux Visible light exposure The participants will be exposed to orange LED light at a illuminance of 30 lux at eye level for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness. Visible light exposure Cyan 120 lux Visible light exposure The participants will be exposed to Cyan LED light at a illuminance of 120 lux at eye level for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness.
- Primary Outcome Measures
Name Time Method Change in cerebral hemoglobin concentration during colored light exposure compared with a baseline and a recovery period 43 minutes (8 min baseline, 15 min colored light exposure, 20 min recovery) 3 hemoglobin concentrations will be analyzed: of oxygenated hemoglobin, of deoxygenated hemoglobin, and of total hemoglobin.
Change in cerebral tissue oxygen saturation during colored light exposure compared with a baseline and a recovery period 43 minutes (8 min baseline, 15 min colored light exposure, 20 min recovery) Change in variables of the electro-dermal activity during colored light exposure compared with a baseline and a recovery period 43 minutes (8 min baseline, 15 min colored light exposure, 20 min recovery) The tonic and phasic parts of the electro-dermal activity will be analyzed.
Change in variables of the heart rate variability during colored light exposure compared with a baseline and a recovery period 43 minutes (8 min baseline, 15 min colored light exposure, 20 min recovery) Heart rate variability variables are: the standard deviation of the NN intervals (SDNN), the square root of the mean of the sum of the squares of differences between adjacent NN intervals (RMSSD), the power of the high-frequency component (HF, 0.15-0.4 Hz), the power of the low-frequency component (LF, 0.04-0.15 Hz), the power of the very low-frequency component (VLF, \<0.04 Hz), normalized LF and HF components, and the LF/HF ratio.
Change of the partial pressure of carbon dioxide during colored light exposure compared with a baseline and a recovery period 43 minutes (8 min baseline, 15 min colored light exposure, 20 min recovery) The partial pressure of carbon dioxide will be assessed by the end-tidal partial pressure of carbon dioxide of the exhalation air.
Change of the arterial oxygen saturation during colored light exposure compared with a baseline and a recovery period 43 minutes (8 min baseline, 15 min colored light exposure, 20 min recovery) Change of the pulse-respiratory quotient during colored light exposure compared with a baseline and a recovery period 43 minutes (8 min baseline, 15 min colored light exposure, 20 min recovery) The pulse-respiratory quotient will be calculated as heart rate divided by the respiration rate.
Change of the blood pressure during colored light exposure compared with a baseline and a recovery period 43 minutes (8 min baseline, 15 min colored light exposure, 20 min recovery) The systolic, diastolic, and mean arterial pressure will be analyzed.
Change of the respiration rate during colored light exposure compared with a baseline and a recovery period 43 minutes (8 min baseline, 15 min colored light exposure, 20 min recovery) Change of the heart rate during colored light exposure compared with a baseline and a recovery period 43 minutes (8 min baseline, 15 min colored light exposure, 20 min recovery)
- Secondary Outcome Measures
Name Time Method
Trial Locations
- Locations (1)
University of Bern, Institute of Complementary Medicine
🇨ðŸ‡Bern, Switzerland