Effects of Photobiomodularion on Brain Connectivity and Cognitive Function in Cognitive Impairment

Condition(s) studied

Investigational drug(s) / intervention(s)

Active transcranial Photobiomodulation: The active intervention consists of transcranial photobiomodulation (t-PBM) delivered while the device is placed on the participant's head and operating at gamma-frequency. The device provides active near-infrared light output throughout the 20-minute session. Active intervention is administered for a total of 8 sessions.

sham transcranial Photobiomodulation: The sham intervention uses the same transcranial photobiomodulation (t-PBM) device and head placement as the active intervention; however, no therapeutic near-infrared light output is delivered. The device's external indicators remain active to mimic real stimulation and maintain participant blinding. Each session lasts 20 minutes. The sham intervention is administered for a total of 8 sessions.

Cognitive Rehabilitation: The cognitive rehabilitation program consists of 8 sessions, each lasting 20 minutes, delivered simultaneously with either active or sham transcranial photobiomodulation (t-PBM). The program is a pen-and-paper-based cognitive exercise protocol targeting attention, memory, executive functions, and language. Each session includes structured tasks with predefined difficulty levels. Task difficulty increases progressively by 0.5 points from Session 1 onward, ensuring gradual cognitive challenge and adaptation across all eight sessions. The rehabilitation protocol is identical for both study arms.

Study summary

The goal of this clinical trial is to learn if transcranial photobiomodulation (t-PBM), a light-based brain therapy, can help improve memory and cognitive skills in older adults with amnestic mild cognitive impairment (aMCI). This condition involves memory problems that are greater than normal aging and may increase the chance of developing Alzheimer's disease.

The main questions this study aims to answer are:

1. Does t-PBM, when used together with cognitive training, improve memory and cognitive skills?
2. Does t-PBM change how certain brain areas communicate with each other, especially in the default mode network (DMN)?

Researchers will compare:

t-PBM plus cognitive training to sham (inactive) t-PBM plus the same cognitive training to see if the active light treatment leads to better cognitive improvement and healthier brain activity.

Participants will:

* Provide a blood sample so the research team can create a genetic profile;
* Complete cognitive tests before and after the 4-week program;
* Meet with a dietitian before and after the program so the research team can make sure diet stays consistent and does not influence brain results;
* Have a brain fMRI scan before and after treatment to measure brain connectivity changes;
* Take part in eight sessions of cognitive training;
* Receive either active t-PBM or sham t-PBM during these sessions.

Eligibility

Primary outcome measure(s)

• Change in Default Mode Network (DMN) Functional Connectivity Measured by Resting-State fMRI — Baseline and after completion of the 8-session intervention (approximately 4 weeks)
• Change in Montreal Cognitive Assessment (MoCA) Total Score — From baseline to post-intervention assessment following 8 sessions
  Baseline and post-intervention cognitive performance will be compared using the Montreal Cognitive Assessment (MoCA), a standardized cognitive screening instrument. Score range: 0 to 30 points (higher scores indicate better cognitive performance).

Trial sites (2)

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