Gamma tACS to Improve Cognitive Function in Mild Cognitive Impairment

NCT07752316 | Completed DMC

• 1 other identifier: MAU
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

Mild cognitive impairment (MCI) is a decline in memory and thinking that exceeds normal aging but does not substantially disrupt daily life, and it raises the risk of developing dementia. Effective treatments for its cognitive difficulties are few. This study tests whether transcranial alternating current stimulation (tACS), a non-invasive method that delivers a weak oscillating electrical current through scalp electrodes, can improve thinking and memory in older women with MCI. The current oscillates at 80 Hz, a frequency in the gamma range, because gamma brain rhythms support memory and attention and are disrupted in MCI. Thirty older women with MCI are randomly assigned to receive either active 80 Hz tACS or sham (placebo) stimulation. Participants and the person delivering the stimulation do not know the group assignment. Both groups complete the same cognitive tests before and after the sessions, measuring overall cognitive status, planning, visuospatial working memory, and reaction speed. The aim is to determine whether active 80 Hz tACS improves cognitive performance more than sham stimulation.

Conditions

Mild Cognitive Impairment (MCI)

Outcome Measures

Primary Outcomes (1)

• Overall cognitive status

  The Montreal Cognitive Assessment (MoCA) is a validated screening measure of global cognitive status, scored from 0 to 30, with higher scores indicating better cognition. Change from baseline to the post-intervention assessment is compared between the active 80 Hz tACS and sham groups.

  Baseline (pre-intervention), week 2 (immediately after the intervention)

Secondary Outcomes (3)

• Planning and problem-solving - Performance accuracy and reaction time

  Baseline (pre-intervention), week 2 (immediately after the intervention)

• Spatial working memory - Performance accuracy and reaction time

  Baseline (pre-intervention), week 2 (immediately after the intervention)

• Cognitive Reaction time

  Baseline (pre-intervention), week 2 (immediately after the intervention)

Study Arms (2)

active tACS group

ACTIVE COMPARATOR

This group receives active 80 Hz transcranial alternating current stimulation (tACS). tACS delivers a weak, low-intensity sinusoidal current that oscillates at a set frequency through electrodes placed on the scalp; here, the current oscillates at 80 Hz, in the gamma range. Participants receive 10 sessions of 30-minute stimulation up to 2 mA delivered to the prefrontal and temporoparietal brain regions

Device: transcranial electrical stimulation

sham tACS group

SHAM COMPARATOR

This group receives sham stimulation using the same device, electrode montage, and setup as the active arm. The current is ramped up over 30 seconds and then ramped down over 30 seconds, so that participants feel the same initial tingling sensation as in the active condition, but no sustained stimulation is delivered for the remainder of the session. This method allows participants to remain blind to their group assignment.

Device: transcranial electrical stimulation

Interventions

transcranial electrical stimulation DEVICE

Transcranial electrical stimulation (tES) is a non-invasive neuromodulation technique that applies low-intensity electrical currents to the scalp to modulate brain activity. It targets specific brain regions to influence neuronal excitability, connectivity, and plasticity, offering potential therapeutic benefits for neurological and psychiatric conditions. tES is portable, cost-effective, and generally well-tolerated, with minimal side effects such as mild tingling or itching at the stimulation site.

active tACS group; sham tACS group

Eligibility Criteria

• Age: 60 Years - 75 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Female, aged 60 to 75 years
• Diagnosis of mild cognitive impairment (MCI) established by a psychiatrist and documented in the patient's medical record
• Montreal Cognitive Assessment (MoCA) score between 16 and 22
• Written informed consent to participate in the study
• No history of Parkinson's disease, stroke, epilepsy, schizophrenia, or congenital olfactory and gustatory disorders

You may not qualify if:

• Inability to tolerate the adverse effects of the stimulation
• Unwillingness to continue the sessions
• Absence from more than three intervention sessions

Sponsors & Collaborators

• The National Brain Mapping Laboratory (NBML): lead
• Mohaghegh Ardabili University: collaborator
• University Hospital, Aachen: collaborator

Study Sites (1)

Department of Psychology, University of Mohaghegh Ardabili

Ardabil, Iran

Location

MeSH Terms

Conditions

Cognitive Dysfunction

Interventions

Transcranial Direct Current Stimulation

Condition Hierarchy (Ancestors)

Cognition Disorders; Neurocognitive Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Electric Stimulation Therapy; Therapeutics; Convulsive Therapy; Psychiatric Somatic Therapies; Behavioral Disciplines and Activities; Electroshock; Psychological Techniques

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal collaborator

Study Record Dates

• First Submitted: August 3, 2026
• First Posted: August 7, 2026
• Study Start: March 2, 2024
• Primary Completion: April 1, 2025
• Study Completion: October 15, 2025
• Last Updated: August 7, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

IR (1)