Alzheimer DiseaseNCT06740864
40 Hz Transcranial Alternating Current Stimulation for Inducing Gamma Oscillations
A study testing Transcranial alternating current stimulation in people with Alzheimer Disease and Cognitive Decline, run by The National Brain Mapping Laboratory (NBML) at 1 site in Iran.
Trial summary
This study aims to compare the efficacy of different 40 Hz tACS protocols in entraining gamma oscillations, which are linked to various cognitive functions and play a significant role in cognitive impairments like Alzheimer's disease. Read more about this study
- Who is it for?
- Ages 50 to 85 yearsHealthy volunteers can take part
- Conditions the study is for
- Alzheimer Disease, Cognitive Decline
- What is being tested?
- Transcranial alternating current stimulation
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 30 participants
- Where
- 1 siteIran
- Study dates
- 1 Jun 2024to 1 Jun 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 50 to 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- healthy elderly between 50-80 years of age
- normal or corrected to normal eye vision
- right-handed
- non-smokers
- at least 70 % accuracy in working memory training task
Who cannot join
- history of neurological or psychiatric disorders including seizures or epilepsy,
- Taking CNS, blood pressure and other medications
- having metal implants in the head and neck
- significant cognitive decline meassured by The Montreal Cognitive Assessment (MoCA)
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Induction and Stabilization of Gamma Oscillations With 40 Hz Transcranial Alternating Current Stimulation in Healthy Elderly
This study aims to compare the efficacy of different 40 Hz tACS protocols in entraining gamma oscillations, which are linked to various cognitive functions and play a significant role in cognitive impairments like Alzheimer's disease. Specifically, it examines the effects of 40 Hz tACS applied to frontal brain regions versus fronto-temporal regions on gamma oscillations and working memory in healthy elderly individuals.
- Conditions
- Alzheimer Disease, Cognitive Decline
- Being tested
- Transcranial alternating current stimulation, Sham Transcranial alternating current stimulation
- Medical subject headings
- Alzheimer Disease, Cognitive Dysfunction
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Transcranial alternating current stimulationDevice
Transcranial alternating current will be delivered utilizing a Starstim 8-channel constant current, battery-powered electric stimulator (Neuroelectrics, Barcelona, Spain). Circular carbon rubber electrodes (2cm radius, 12,57 cm2) are used throughout the stimulation.
Transcranial alternating current stimulationDevice
Transcranial alternating current will be delivered utilizing a Starstim 8-channel constant current, battery-powered electric stimulator (Neuroelectrics, Barcelona, Spain). Circular carbon rubber electrodes (2cm radius, 12,57 cm2) are used throughout the stimulation.
Sham Transcranial alternating current stimulationDevice
Sham tACS will be applied by only ramping the current for 15 seconds up and 15 seconds down at the beginning and end of the stimulation respectively.
| Study group | Role | What they receive |
|---|---|---|
| 40 Hz prefrontal Transcranial alternating current stimulation | Active comparator | During prefrontal tACS, an alternating electrical current with a 1 milliamp peak-to-peak amplitude will be delivered, featuring a 15-second ramp-up at the start and a 15-second ramp-down at the end. The stimulation duration is 20 minutes and four channels are used for delivering sinusoidal alternating currents to the head. The alternating current was delivered to the prefrontal cortex bilaterally with the electrodes at F3 and F4 and the return electrodes were placed at the ipsilateral mastoids at TP9 and TP10 (international 10-20 EEG electrode placement system). Receives: Device: Transcranial alternating current stimulation |
| 40 Hz frontal-temporal Transcranial alternating current stimulation | Active comparator | During frontal-temporal tACS, an alternating electrical current with a personalized peak-to-peak stimulation intensity will be delivered, featuring a 15-second ramp-up at the start and a 15-second ramp-down at the end. The stimulation duration is 20 minutes and four channels are used for delivering sinusoidal alternating currents to the head. The alternating current was delivered to the prefrontal and temporal cortices with the active electrodes at AF3-T7 and the return electrodes over AF4-T8 (according international 10-20 EEG electrode placement system). Receives: Device: Transcranial alternating current stimulation |
| sham Transcranial alternating current stimulation | Sham comparator | During sham tACS, an alternating artificial electrical current will be delivered, only ramping the current for 15 seconds up and 15 seconds down at the beginning and end of the stimulation respectively. Receives: Device: Sham Transcranial alternating current stimulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Working Memory behavioral performance
Participants view a continuous sequence of alphabet letters, presented as stimuli in Arial font, size 120pt, on a tube screen positioned at 60cm eye distance. The stimuli are shown with a time interval of two seconds between them. The task consisted of six blocks with 70 stimuli, including 12 possible hit trials. Participants were instructed to press the left key on a response box if the presented stimulus matched either the one presented one trial prior (1-Back) or three trials prior (3-Back). In all other cases, participants press the right key. The left button is pressed with the index finger, while the right button is pressed with the middle finger of the right hand, with buttons aligned horizontally. The response condition varied by block, with three blocks for 3-Back and three for 1-Back, and the order was counterbalanced across participants and sessions.
Measured: During procedure (20 minutes)
electroencephalogram (EEG) oscillatory power
Change in the EEG power in the gamma band
Measured: up to 2 hours after the intervention
electroencephalogram (EEG) functional connectivity
Change in EEG functional connectivity, specifically global efficiency, coherence, and phase-locking value at gamma frequency
Measured: up to 2 hours after the intervention
Secondary outcomes (1)
electroencephalogram (EEG) oscillatory power
Change in the EEG power in alpha, delta, theta and beta bands
Measured: up to 2 hours after the intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Dec 2024
- Study start1 Jun 2024
- Primary completion1 Feb 2025
- Study completion1 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Alzheimer DiseaseStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- The National Brain Mapping Laboratory (NBML)
- Sponsor type
- University, hospital or other
- Collaborators
- Technical University of Dortmund, Leibniz Research Centre for Working Environment and Human Factors, Institute for Research in Fundamental Sciences (IPM)
- Responsible party
- Principal investigator, Mohammad Ali Salehinejad, Technical University of Dortmund
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06740864
- Sponsor's protocol ID
- IfADo_196_P3
- Status last verified
- Mar 2026
- First submitted
- 14 Dec 2024
- Last updated
- 18 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Induction and Stabilization of Gamma Oscillations With 40 Hz Transcranial Alternating Current Stimulation in Healthy Elderly
- ClinicalTrials.gov ID
- NCT06740864
- Acronym / sponsor ID
- IfADo_196_P3
- Conditions
- Alzheimer Disease, Cognitive Decline
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- The National Brain Mapping Laboratory (NBML)University, hospital or other
- Collaborators
- Technical University of Dortmund, Leibniz Research Centre for Working Environment and Human Factors, Institute for Research in Fundamental Sciences (IPM)
- Study start
- 1 Jun 2024 (actual)
- Primary completion
- 1 Feb 2025 (actual)
- Study completion
- 1 Jun 2025 (actual)
- First posted
- 18 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study aims to compare the efficacy of different 40 Hz tACS protocols in entraining gamma oscillations, which are linked to various cognitive functions and play a significant role in cognitive impairments like Alzheimer's disease. Specifically, it examines the effects of 40 Hz tACS applied to frontal brain regions versus fronto-temporal regions on gamma oscillations and working memory in healthy elderly individuals.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| 40 Hz prefrontal Transcranial alternating current stimulation | Active comparator | Device: Transcranial alternating current stimulationDuring prefrontal tACS, an alternating electrical current with a 1 milliamp peak-to-peak amplitude will be delivered, featuring a 15-second ramp-up at the start and a 15-second ramp-down at the end. The stimulation duration is 20 minutes and four channels are used for delivering sinusoidal alternating currents to the head. The alternating current was delivered to the prefrontal cortex bilaterally with the electrodes at F3 and F4 and the return electrodes were placed at the ipsilateral mastoids at TP9 and TP10 (international 10-20 EEG electrode placement system). |
| 40 Hz frontal-temporal Transcranial alternating current stimulation | Active comparator | Device: Transcranial alternating current stimulationDuring frontal-temporal tACS, an alternating electrical current with a personalized peak-to-peak stimulation intensity will be delivered, featuring a 15-second ramp-up at the start and a 15-second ramp-down at the end. The stimulation duration is 20 minutes and four channels are used for delivering sinusoidal alternating currents to the head. The alternating current was delivered to the prefrontal and temporal cortices with the active electrodes at AF3-T7 and the return electrodes over AF4-T8 (according international 10-20 EEG electrode placement system). |
| sham Transcranial alternating current stimulation | Sham comparator | Device: Sham Transcranial alternating current stimulationDuring sham tACS, an alternating artificial electrical current will be delivered, only ramping the current for 15 seconds up and 15 seconds down at the beginning and end of the stimulation respectively. |
Who may qualify
- Ages
- 50 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- healthy elderly between 50-80 years of age
- normal or corrected to normal eye vision
- right-handed
- non-smokers
- at least 70 % accuracy in working memory training task
Key exclusion criteria (4 listed)
- history of neurological or psychiatric disorders including seizures or epilepsy,
- Taking CNS, blood pressure and other medications
- having metal implants in the head and neck
- significant cognitive decline meassured by The Montreal Cognitive Assessment (MoCA)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Transcranial alternating current stimulationTranscranial alternating current will be delivered utilizing a Starstim 8-channel constant current, battery-powered electric stimulator (Neuroelectrics, Barcelona, Spain). Circular carbon rubber electrodes (2cm radius, 12,57 cm2) are used throughout the stimulation. | Device | 40 Hz prefrontal Transcranial alternating current stimulation |
| Transcranial alternating current stimulationTranscranial alternating current will be delivered utilizing a Starstim 8-channel constant current, battery-powered electric stimulator (Neuroelectrics, Barcelona, Spain). Circular carbon rubber electrodes (2cm radius, 12,57 cm2) are used throughout the stimulation. | Device | 40 Hz frontal-temporal Transcranial alternating current stimulation |
| Sham Transcranial alternating current stimulationSham tACS will be applied by only ramping the current for 15 seconds up and 15 seconds down at the beginning and end of the stimulation respectively. | Device | sham Transcranial alternating current stimulation |
Primary outcome
Working Memory behavioral performance
Time frame: During procedure (20 minutes)
Participants view a continuous sequence of alphabet letters, presented as stimuli in Arial font, size 120pt, on a tube screen positioned at 60cm eye distance. The stimuli are shown with a time interval of two seconds between them. The task consisted of six blocks with 70 stimuli, including 12 possible hit trials. Participants were instructed to press the left key on a response box if the presented stimulus matched either the one presented one trial prior (1-Back) or three trials prior (3-Back). In all other cases, participants press the right key. The left button is pressed with the index finger, while the right button is pressed with the middle finger of the right hand, with buttons aligned horizontally. The response condition varied by block, with three blocks for 3-Back and three for 1-Back, and the order was counterbalanced across participants and sessions.
electroencephalogram (EEG) oscillatory power
Time frame: up to 2 hours after the intervention
Change in the EEG power in the gamma band
electroencephalogram (EEG) functional connectivity
Time frame: up to 2 hours after the intervention
Change in EEG functional connectivity, specifically global efficiency, coherence, and phase-locking value at gamma frequency
1 secondary outcome
electroencephalogram (EEG) oscillatory power
Time frame: up to 2 hours after the intervention
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Mar 2026.
Related trials for Alzheimer Disease
RecruitingPhase 2
Neuroplasticity Enhancement From Cognitive Training Reinforced by Psilocybin
Alzheimer's Disease
Not yet recruiting
Acupressure as Long-term Intervention to Slow the Progression of Early/Mild Alzheimer's Disease
Alzheimer's Disease
RecruitingObservational study
Effectiveness and Safety of Disease-Modifying Therapy for Alzheimer's Disease: A Multicenter Retrospective Study
Alzheimer's Disease (AD)
RecruitingPhase 3
A Phase 3 Study to Evaluate the Safety and Efficacy of KarXT + KarX-EC for the Treatment of Agitation Associated With Alzheimer's Disease (ADAGIO-1)
Alzheimer Disease
RecruitingPhase 3
A Study of Trontinemab in Cognitively Unimpaired Individuals at Risk for Progression to Symptomatic Alzheimer's Disease
Alzheimer's Disease
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Transcranial alternating current stimulation in people with Alzheimer Disease and Cognitive Decline, run by The National Brain Mapping Laboratory (NBML) at 1 site in Iran.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 18 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Iran. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Working Memory behavioral performance (time frame: During procedure (20 minutes)). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Mar 2026.