Systematically Assessing Effects of Colored Light on Humans With a Multi-modal Approach (Substudy 3 of 7)

Sponsor

University of Bern (Other)

Overall Status

Completed

CT.gov ID

NCT02882542

Collaborator

(none)

Enrollment

Location

Arms

Actual Duration (Months)

Patients Per Site Per Month

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Exposure to Man-made Visible Light	Other: Visible light exposure	N/A

Study Design

Study Type:

Interventional

Actual Enrollment :

41 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Masking:

Single (Outcomes Assessor)

Primary Purpose:

Basic Science

Official Title:

Systematically Assessing Effects of Colored Light on Humans With a Multi-modal Approach

Actual Study Start Date :

Mar 1, 2018

Actual Primary Completion Date :

Aug 20, 2018

Actual Study Completion Date :

Aug 30, 2021

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Visible light exposure Orange 30 lux 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.	Other: Visible light exposure 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.
Experimental: Visible light exposure Orange 120 lux 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.	Other: Visible light exposure 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.
Experimental: Visible light exposure Cyan 30 lux 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.	Other: Visible light exposure 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.
Experimental: Visible light exposure Cyan 120 lux 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.	Other: Visible light exposure 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.
Experimental: Visible light exposure White 30 lux 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.	Other: Visible light exposure 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.
Experimental: Visible light exposure White 120 lux 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.	Other: Visible light exposure 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.

Outcome Measures

Primary Outcome Measures

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 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 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 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 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 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 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 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)]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 50 Years

Sexes Eligible for Study:

All

Accepts 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