NCT05923606 · Massachusetts General Hospital
Modulation of Brain Oscillations Underlying Working Memory
What this study is about
This study will use novel transcranial alternating current stimulation (tACS) protocols and electroencephalography (EEG) to modulate and measure brain oscillations that underlie working memory. tACS is a noninvasive method used to modulate the timing and patterns of brain rhythms via weak electric currents passed through electrodes on the scalp.
View original scientific description
This study will use novel transcranial alternating current stimulation (tACS) protocols and electroencephalography (EEG) to modulate and measure brain oscillations that underlie working memory. tACS is a noninvasive method used to modulate the timing and patterns of brain rhythms via weak electric currents passed through electrodes on the scalp.
Interventions
DEVICE
Active tACS
Active tACS will be administered over the left dorsolateral prefrontal cortex for approximately 25 minutes.
DEVICE
Placebo tACS
Placebo tACS will be administered over the left dorsolateral prefrontal cortex for approximately 25 minutes.
Primary outcome measures
Working memory accuracy
Time frame: 2 hours
Accuracy of working memory retrieval during a Delayed Match-to-Sample task will be assessed before and during tACS interventions
Working memory accuracy under interference
Time frame: 2 hours
Accuracy of working memory retrieval during interference conditions of a Delayed Match-to-Sample task will be assessed before and during tACS interventions.
Theta-gamma cross-frequency coupling
Time frame: 2 hours
Cross-frequency coupling between theta band phase and gamma band amplitude will be calculated using the EEG data collected while subjects perform the Delayed Match-to-Sample task before and after tACS interventions.
Fronto-parietal theta phase synchronization
Time frame: 2 hours
Phase synchronization in the theta band between frontal and parietal brain regions will be calculated using the EEG data collected while subjects perform the Delayed Match-to-Sample task before and after the tACS interventions.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Able to provide informed consent
- Fluent in English.
Exclusion criteria
- History of a neurological/psychiatric disorder
- Current use of psychotropic medications
- Current use of substances and drugs that were shown to affect tES (transcranial electrical stimulation) efficacy (dopamine altering drugs, nicotine, NMDA (N-methyl-D-aspartate) antagonists/agonists, sodium/calcium channel blockers, norepinephrine reuptake inhibitors, GABAergic modulators and selective serotonin reuptake inhibitors)
- Contraindications for tACS (e.g., history of seizures, metallic implants in the head or neck, implanted brain stimulators, vagus nerve stimulators, pacemakers, pregnancy)
Where
- Charlestown, Massachusetts
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Feb 9, 2026 · Source of record for eligibility and locations