Effects of Endogenous Gamma Light Stimulation on Brain Oscillations in Cognitively-normal Older Adults

Effects of Endogenous Gamma Light Stimulation on Brain Oscillations in Cognitively-normal Older Adults: a Randomized, Placebo-controlled, Double-blind Study

This study aims to evaluate the effects of endogenous gamma non-flickering light stimulation on resting-state EEG rhythms and cognitive function in cognitively healthy older adults. Specifically, it will assess the immediate and long-term effects of this stimulation on brainwave activity and cognitive performance. The study will explore the potential of gamma light stimulation as a non-pharmacological intervention for cognitive decline in aging populations.

Study Overview

• Status: Recruiting
• Conditions: Cognitively Normal Older Adults; EEG Brain Oscillations; Alzheimer's Disease (AD)
• Intervention / Treatment: Device: Gamma Wave Stimulation Table Lamp (Aleddra, Inc., USA)

Detailed Description

Some Alzheimer's disease (AD) studies have investigated the effects of gamma-frequency light stimulation on healthy older adults and AD patients; they have several limitations, including small sample sizes, short intervention durations, the use of flickering light (which may cause discomfort), and lack of rigorous randomized controlled trials. The aim of this study is to address these gaps by conducting a randomized, placebo-controlled, double-blind trial.

This study will recruit 52 cognitively healthy older adults aged 55 and above (N= 52). Participants will be randomly assigned to either the experimental group (N=26), receiving endogenous gamma non-flickering light stimulation, or the control sham group (N=26), receiving 70 Hz non-flickering light stimulation. The intervention will consist of 1 hour of daily stimulation, 7 days a week, for a total of 4 weeks (28 hours). Both participants and outcomes assessors will remain blinded to group allocation.

Resting-state EEG and cognitive assessments will be conducted at three time points: prior to the intervention (T1), post one-hour intervention (T2), and post one-month intervention (T3). Resting-state brainwave activity will be the primary outcome, with data collected at all three time points (T1, T2, and T3). As secondary outcomes, cognitive assessments will be administered at T1 and T3. Adverse events will also be recorded by participants immediately following each light stimulation session.

The primary aim of this study is to assess the immediate (T2 relative to T1) and long-term (T3 relative to T1) effects of endogenous gamma light stimulation on resting-state brainwave activity. Secondary objectives include evaluating cognitive performance and assessing the safety, user acceptance, and adherence to the intervention device. The results of this study will provide valuable insights into the potential of endogenous gamma light stimulation as a non-pharmacological intervention for cognitive decline in aging populations.

• Study Type: Interventional
• Enrollment (Estimated): 52
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Chia-Hsiung Cheng, Ph.D.; Phone Number: 3854 +886-3-211800; Email: ch.cheng@mail.cgu.edu.tw

Study Locations

• Taiwan
  • Guishan
    • Taoyuan, Guishan, Taiwan, 33302
      • Recruiting
      • Chang Gung University
      • Contact: Chia-Hsiung Cheng, Ph.D.; Phone Number: 3854 +886-3-211800; Email: ch.cheng@mail.cgu.edu.tw
      • Contact: Chia-Hsiung Cheng, Ph.D.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 1. Age over 55 years old.
• 2. The Cognitive Abilities Screening Instrument (CASI) score is within normal ranges adjusted for age and education.
• 3. Participants have no history of severe neurological or psychiatric disorders (such as stroke, epilepsy, depression, migraine, etc.) that could affect cognitive function.
• 4. Participants have not used drugs that may affect cognitive function (e.g., benzodiazepines, anticholinergic medications, etc.).
• 5. Participants with normal or corrected vision (e.g., glasses or contact lenses) to normal levels.
• 6. Voluntary to sign the Informed Consent Form.

Exclusion Criteria:

• 1. Participants enrolled in any cognitive enhancement study within the past two months.
• 2. Participants with a history of disease that could affect cognitive function (e.g., cancer, autoimmune diseases, etc.).
• 3. Pregnant, or planning to become pregnant.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: endogenous gamma light; This device is an LED light source table lamp with a vertical surface measuring 16 cm by 22 cm. It will be positioned within arm's reach, approximately 50 cm from the participant, to ensure continuous exposure to the light stimulation. The active device delivers endogenous gamma light stimulation.	Device: Gamma Wave Stimulation Table Lamp (Aleddra, Inc., USA); Participants will receive light stimulation using the Gamma Wave Stimulation Table Lamp (Aleddra, Inc., USA) for 1 hour per day, 7 days a week, over 4 weeks, for a total of 28 hours.
Sham Comparator: Sham (70Hz) gamma light; The sham device is identical in appearance to the active device. It will be positioned within arm's reach, approximately 50 cm from the participant, to ensure continuous exposure to the light stimulation. The sham device delivers 70 Hz light stimulation.	Device: Gamma Wave Stimulation Table Lamp (Aleddra, Inc., USA); Participants will receive light stimulation using the Gamma Wave Stimulation Table Lamp (Aleddra, Inc., USA) for 1 hour per day, 7 days a week, over 4 weeks, for a total of 28 hours.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in gamma brain oscillations.	Gamma (31-100Hz) brain oscillations obtained through resting-state EEG will evaluate the changes of gamma light stimulation intervention.	baseline (T1), post one-hour intervention (T2), post one-month intervention (T3)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change score of the Cognitive Abilities Screening Instrument (CASI).	CASI will be applied to measure the participant's general cognitive ability. The range of score is 0 to 100, with a higher score indicating better performance.	baseline (T1), post one-month intervention (T3)
Change score of the Chinese version Verbal Learning Test (CVVLT).	A nine-item of CVVLT (total recall, delayed recall) will be applied to measure the participant's memory ability, with a higher score indicating better performance.	baseline (T1), post one-month intervention (T3)
Change score of the WMS-III logical memory test	WMS-III logical memory test (immediate recall, delayed recall) will be applied to measure the participant's memory ability. The maximum score is 25 for each recall trial, with a higher score indicating better performance	baseline (T1), post one-month intervention (T3)
Change score of the Taylor Complex Figure Test (TCFT).	TCFT (immediate recall, delayed recall) will be applied to measure the participant's memory ability. The maximum score is 36 for each recall trial, with a higher score indicating better performance.	baseline (T1), post one-month intervention (T3)
Performance changes of the Trail Making Test Form A/B (TMT-A/B).	TMT-A/B will be applied to measure participant's attention and executive function. The number of seconds to complete each trial and the number of errors would be recorded, with a higher value indicating greater impairment.	baseline (T1), post one-month intervention (T3)
Subjective cognition decline complaint survey.	A 14-item Subjective Memory Complaints Questionnaire measured memory impairment. The response was restricted to either "Yes" or "No".	baseline (T1), post one-month intervention (T3)
Change score of the category Verbal Fluency Test (VFT).	The category VFT will be applied to measure the participant's language and executive function, with a higher score indicates better performance.	baseline (T1), post one-month intervention (T3)
Safety/Adverse event outcome measure.	Adverse events, such as fatigue, headache, dizziness, dazzling, ocular pain, and others, will be recorded using a 6-point Likert scale ranging from 'not at all' to 'extremely uncomfortable' (0 = not at all, 1 = minimal discomfort, 2 = mild discomfort, 3 = tolerable, 4 = severe discomfort, 5 = extreme discomfort). Participants will report adverse events (such as fatigue, headache, dizziness, dazzling, ocular pain, and others) using a 6-point Likert scale ranging from 'not at all' to 'extremely uncomfortable' after each light stimulation session.	Throughout the one-month intervention

Collaborators and Investigators

• Sponsor: Chang Gung Memorial Hospital
• Collaborators: Aleddra, Inc.

Study record dates

Study Major Dates

• Study Start (Estimated): December 9, 2024
• Primary Completion (Estimated): September 30, 2025
• Study Completion (Estimated): September 30, 2025

Study Registration Dates

• First Submitted: November 28, 2024
• First Submitted That Met QC Criteria: November 28, 2024
• First Posted (Estimated): December 4, 2024

Study Record Updates

• Last Update Posted (Estimated): December 4, 2024
• Last Update Submitted That Met QC Criteria: November 28, 2024
• Last Verified: November 1, 2024

More Information

Terms related to this study

• Keywords: Cognitive function; Endogenous gamma; EEG rhythms; Resting-state EEG (rs-EEG); Alzheimer's disease (AD); non-flickering light
• Other Study ID Numbers: 202401421B0A3

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No