Systematically Assessing Effects of Colored Light on Humans With a Multi-modal Approach (Substudy 4 of 7)
Not Applicable
Completed
- Conditions
- Exposure to Man-made Visible Light
- Interventions
- Other: Visible light exposure
- Registration Number
- NCT02919228
- Lead Sponsor
- University of Bern
- Brief Summary
NOTE: This is the fourth 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 8 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
- 50
Inclusion Criteria
- Normal color vision
- Right handed
- Written informed consent
Exclusion Criteria
- 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 cognitive Red Visible light exposure The participants will be tested for cognitive performance (verbal fluency task, arithmetic task, word repetition task) during exposure to red LED light at a fixed illuminance for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness. The participants will additionally perform hyperventilation and hypoventilation tasks. Visible light exposure cognitive Orange Visible light exposure The participants will be tested for cognitive performance (verbal fluency task, arithmetic task, word repetition task) during exposure to orange LED light at a fixed illuminance for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness. The participants will additionally perform hyperventilation and hypoventilation tasks. Visible light exposure cognitive Green Visible light exposure The participants will be tested for cognitive performance (verbal fluency task, arithmetic task, word repetition task) during exposure to green LED light at a fixed illuminance for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness. The participants will additionally perform hyperventilation and hypoventilation tasks. Visible light exposure cognitive Yellow Visible light exposure The participants will be tested for cognitive performance (verbal fluency task, arithmetic task, word repetition task) during exposure to yellow LED light at a fixed illuminance for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness. The participants will additionally perform hyperventilation and hypoventilation tasks. Visible light exposure cognitive Cyan Visible light exposure The participants will be tested for cognitive performance (verbal fluency task, arithmetic task, word repetition task) during exposure to cyan LED light at a fixed illuminance for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness. The participants will additionally perform hyperventilation and hypoventilation tasks. Visible light exposure cognitive Blue Visible light exposure The participants will be tested for cognitive performance (verbal fluency task, arithmetic task, word repetition task) during exposure to blue LED light at a fixed illuminance for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness. The participants will additionally perform hyperventilation and hypoventilation tasks. Visible light exposure cognitive Violet Visible light exposure The participants will be tested for cognitive performance (verbal fluency task, arithmetic task, word repetition task) during exposure to violet LED light at a fixed illuminance for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness. The participants will additionally perform hyperventilation and hypoventilation tasks. Visible light exposure cognitive White Visible light exposure The participants will be tested for cognitive performance (verbal fluency task, arithmetic task, word repetition task) during exposure to white LED light at a fixed illuminance for 15 minutes. The colored light exposure will be preceded by sitting 8 minutes in darkness and followed by sitting 20 minutes in darkness. The participants will additionally perform hyperventilation and hypoventilation tasks.
- Primary Outcome Measures
Name Time Method 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 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) 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) 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) Change in cerebral hemoglobin concentrations 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 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) 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 Change in verbal fluency task performance during exposure to different colors. 1-4 weeks A word repetition task will serve as control condition.
Difference in brain activity evoked from the arithmetic task for the different colored light conditions. 1-4 weeks A word repetition task will serve as control condition.
Difference in brain activity evoked from the verbal fluency task for the different colored light conditions. 1-4 weeks A word repetition task will serve as control condition.
Change in arithmetic task performance during exposure to different colors. 1-4 weeks A word repetition task will serve as control condition.
Trial Locations
- Locations (1)
University of Bern, Institute of Complementary Medicine
🇨ðŸ‡Bern, Switzerland