Determining How Indoor Lighting Affects the Brain Health of Older Adults

Study Overview
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Brief Summary
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The goal of this randomized, cross-over, single-site trial followed by an exploratory third intervention is to understand how indoor lighting affects different measures of brain health in older adults living in independent living residences. This is a community based study occurring in a local senior living facility. The main question this study aims to answer is: - How does the quality of ambient indoor lighting an older adult is exposed to affect measures of brain health, such as sleep quality, physical activity, cognitive function, and social engagement? Participants will be exposed to three different indoor lighting conditions for 4 weeks each while performing the following tasks: Wear a smartwatch throughout the study to measure sleep quality and physical activity Wear a small, wearable light sensor to measure light exposure during waking hours Perform cognitive assessments throughout the study to detect any changes between each of the lighting conditions Complete self-report of surveys to assess independence, social engagement, sleep quality, and mood Results from these tasks will be compared within and between subjects to assess whether the different lighting conditions affect these different measures of brain health.

Official Title
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Determining How Indoor Lighting Affects the Brain Health of Older Adults

Conditions
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Sleep, Physical Activity, Cognitive Function, Social Isolation

Intervention / Treatment
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* Behavioral: Static Lighting Condition (L1)
* Behavioral: Dynamic Lighting Condition (L2)
* Behavioral: Dynamic Lighting Condition (L3)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: At least age 60; Able to wear wearable devices throughout the study; Willing to have their lighting in their kitchen and dining areas changed and controlled for the study; Willing to have environmental sensors placed in their residence; Willing to provide contact information about their primary care provider (PCP); and Able and has capacity to provide informed consent (score > 14.5 based on UBACC consent capacity form). Exclusion Criteria: Is legally blind Previously renovated their living units and no longer have the standard lighting installation offered by the Senior Living Facility; Currently spend or plan to spend most of their day outside of their residence during the study (i.e., would not experience the indoor lighting intervention for the majority of the study); Plan to travel to a different time zone during the study; or Plan to be away from their residence for more than a week during the study.

Ages Eligible for Study
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Minimum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: L1 then L2 followed by L3 lighting condition<br>Participants will first experience a static lighting condition (L1) then a dynamic lighting condition (L2). After, participants will experience another dynamic lighting condition (L3) with increased morning brightness compared to L2. | Behavioral: Static Lighting Condition (L1)<br>* This indoor lighting condition keeps a constant brightness and correlated color temperature.<br>Behavioral: Dynamic Lighting Condition (L2)<br>* This indoor lighting condition has increased brightness and more blue correlated color temperature in the morning hours followed by decreased brightness and less blue correlated color temperature in the afternoon and evening hours.<br>Behavioral: Dynamic Lighting Condition (L3)<br>* This exploratory indoor lighting condition matches the same pattern as L2 except the brightness in the morning hours is increased.<br>|
| Active Comparator: L2 then L1 followed by L3 lighting condition<br>Participants will first experience a dynamic lighting condition (L2) then a static lighting condition (L1). After, participants will experience another dynamic lighting condition (L3) with increased morning brightness compared to L2. | Behavioral: Static Lighting Condition (L1)<br>* This indoor lighting condition keeps a constant brightness and correlated color temperature.<br>Behavioral: Dynamic Lighting Condition (L2)<br>* This indoor lighting condition has increased brightness and more blue correlated color temperature in the morning hours followed by decreased brightness and less blue correlated color temperature in the afternoon and evening hours.<br>Behavioral: Dynamic Lighting Condition (L3)<br>* This exploratory indoor lighting condition matches the same pattern as L2 except the brightness in the morning hours is increased.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total Sleep Time | Total sleep time per night in minutes as measured daily by a wearable device. | Change in total sleep time per night over the course of each condition of the 16-week study. | 
| Wake After Sleep Onset | Wake after sleep onset per night in minutes as measured daily by a wearable device. | Change in wake after sleep onset per night over the course of each condition of the 16-week study. | 
| Sleep State Duration | Sleep state duration per night in minutes as measured daily by a wearable device. | Change in sleep state duration per night over the course of each condition of the 16-week study. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sleep Quality | Self-report measurement of perceived sleep quality made daily via the Groningen Sleep Quality Survey. | Change in self-reported sleep quality over the course of each condition of the 16-week study. | 
| Steps Taken | Physical activity in steps per day as measured daily by a wearable device. | Change in physical activity in steps per day over the course of each condition of the 16-week study. | 
| Physical Activity | Physical activity in minutes per day as measured daily by a wearable device. | Change in physical activity in minutes per day over the course of each condition of the 16-week study. | 
| Working Memory | Task performance on a working memory assessment taken twice weekly. | Change in working memory performance over the course of each condition of the 16-week study. | 
| Task Switching | Task performance on a task switching assessment taken twice weekly. | Change in task switching performance over the course of each condition of the 16-week study. | 
| Response Inhibition | Task performance on a response inhibition assessment taken twice weekly. | Change in response inhibition performance over the course of each condition of the 16-week study. | 
| Sustained-Attention Reaction Time | Task performance on a sustained-attention reaction time assessment taken twice weekly. | Change in sustain-attention reaction time performance over the course of each condition of the 16-week study. | 
| Self-Reported Loneliness | Self-report measurement of loneliness assessed weekly via the UCLA Loneliness Scale. | Change in self-reported loneliness over the course of each condition of the 16-week study. | 
| Self-Reported Depression | Self-report measurement of depression assessed weekly via the Positive and Negative Affect Scale. | Change in self-reported depression over the course of each condition of the 16-week study. | 
| Self-Reported Mood | Self-report measurement of mood assessed weekly via the Depression, Anxiety, and Stress Scale. | Change in self-reported mood over the course of each condition of the 16-week study. |