Exposure to Man-made Visible Light
Conditions
Keywords
cerebral oxygen metabolism, functional near-infrared spectroscopy, partial pressure of carbon dioxide, heart rate variability, blood pressure, affect, mood, respiration, systematic randomized cross-over study, systemic physiology, electro-dermal activity, pulse-respiratory quotient
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.
Interventions
Subjects will be exposed to visible colored light for 15 minutes. The visible light will be generated by red-green-blue light emitting diodes light cans.
Sponsors
University of Bern
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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 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 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) | — |
| 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 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 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 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 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) | — |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in arithmetic 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 verbal fluency 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 arithmetic task for the different colored light conditions. | 1-4 weeks | A word repetition task will serve as control condition. |
| Change in verbal fluency task performance during exposure to different colors. | 1-4 weeks | A word repetition task will serve as control condition. |
Countries
Switzerland
Outcome results
None listed