Enhancing Cognitive Control in Mild Cognitive Impairment Via Non-invasive Brain Stimulation

Study Overview
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Brief Summary
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The overall goal of this project is to improve cognitive control abilities in adults with mild cognitive impairment (MCI) through a form of non-invasive brain stimulation, transcranial alternating current stimulation (tACS).

Detailed Description
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30 older adults aged 60-80 years with md-aMCI were randomized to 8 sessions of transcranial alternating current stimulation (tACS) with simultaneous cognitive control training (CCT). The intervention took place within the participant's home without direct researcher assistance. Half of the participants received prefrontal theta tACS during CCT and the other half received control tACS. Outcomes were assessed pre and post intervention.

Official Title
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Enhancing Cognitive Control in Mild Cognitive Impairment Via Non-invasive Brain Stimulation

Conditions
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Mild Cognitive Impairment

Intervention / Treatment
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* Device: Transcranial alternating current stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: English speaking Grade 12 or more education Normal or corrected to normal vision and hearing Ability to complete cognitive tasks Ability to cooperate and comply with all study procedures Ability to tolerate tACS Montreal Cognitive Assessment score: 17-28 -1 z-score on immediate memory, delayed memory, fluency, processing speed, or task switch Self-reported memory complaint Exclusion Criteria: Neurological or psychiatric disorders other than mild cognitive impairment Receiving investigational medications or have participated in a trial with investigational medications within last 30 days Family history of epilepsy Implanted electronic devices (e.g., pacemaker) Prior head trauma Pregnant IQ < 80 Taking cholinesterase inhibitory, memantine, or psychotropic medication Taking anti-depressants or anti-anxiety medication Color blind Substance abuse Glaucoma Macular degeneration Amblyopia (lazy eye) Strabismus (crossed eyes)

Ages Eligible for Study
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Minimum Age: 60 Years
Maximum Age: 80 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Theta Stimulation Group<br>This group will receive 6 Hz (theta) stimulation | Device: Transcranial alternating current stimulation<br>* Transcranial alternating current stimulation (tACS) will be applied across the prefrontal cortex near electrodes coordinates AF3/AF4<br>|
| Active Comparator: Delta Stimulation Group<br>This group will receive 1 Hz (delta) stimulation | Device: Transcranial alternating current stimulation<br>* Transcranial alternating current stimulation (tACS) will be applied across the prefrontal cortex near electrodes coordinates AF3/AF4<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Divided Attention Performance | Divided attention was assessed as the difficulty level achieved during perceptual discrimination performance while participants were engaged in the Akili AKL-T01 task. Higher is better. | Post-tACS (1-day follow-up), approximately 1 week after baseline | 
| Divided Attention Performance | Divided attention was assessed as the difficulty level achieved during perceptual discrimination performance while participants were engaged in the Akili AKL-T01 task. Higher is better. | Post-tACS (1-month follow-up), approximately 1 month after baseline | 
| Sustained Attention Performance | Sustained attention was assessed via response times to visual targets during the continuous performance task. Lower is better. | Post-tACS (1-day follow-up), approximately 1 week after baseline | 
| Sustained Attention Performance | Sustained attention was assessed via response times to visual targets during the continuous performance task. Lower is better. | Post-tACS (1-month follow-up), approximately 1 month after baseline | 
| Working Memory Performance | Working memory was assessed as the average maximum number correct from the ACE-X span tasks - memory for order of illuminated squares. | Post-tACS (1-day follow-up), approximately 1 week after baseline | 
| Working Memory Performance | Working memory was assessed as the average maximum number correct from the ACE-X span tasks - memory for order of illuminated squares | Post-tACS (1-month follow-up), approximately 1 month after baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Instrumental Activities of Daily Living (IADL) | Scores on the IADL will be assessed pre and post intervention. Higher scores are better (minimum = 0, maximum = 4). | Post-tACS (1-day follow-up), approximately 1 week after baseline | 
| Instrumental Activities of Daily Living (IADL) | Scores on the IADL will be assessed pre and post intervention. Higher scores are better (minimum = 0, maximum = 4). | Post-tACS (1-month follow-up), approximately 1 month after baseline |