tACS to Enhance Language Abilities

August 21, 2026 updated by: University of Pennsylvania

Transcranial Alternating Current Stimulation (tACS) to Enhance Language Abilities

The goal of this study is to see if transcranial alternating current stimulation (tACS) can be used to enhance language abilities in people with post-stroke aphasia. Participants will receive real and sham tACS in conjunction with various language tests. Researchers will compare the post-stroke aphasia group with aged matched controls to see if brain response to tACS differs between groups.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This research will investigate whether transcranial alternating current stimulation (tACS), a form of noninvasive brain stimulation, can be used to enhance language abilities in people with aphasia (PWA) due to stroke and healthy older adults when compared to placebo (sham) tACS. The investigators hypothesize that alpha vs. sham tACS will improve language abilities. In addition, the investigators propose that alpha vs. sham tACS will increase local alpha power as well as alpha-induced functional connectivity, and the degree to which alpha tACS increases will be related to the degree of language performance improvement. Finally, the investigators hypothesize that PWA will exhibit abnormalities in alpha-related activity when compared to matched controls, and aphasia severity will be associated with the degree of PWA dysfunction in alpha power and alpha-driven functional connectivity.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
120

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria for Persons with Aphasia:

  1. Presence of aphasia
  2. Suffered a single, left hemisphere stroke
  3. Stroke ≥6 months old (chronic) at the time of enrollment

Inclusion Criteria for Healthy Controls:

  1. Right-handedness
  2. Must be able to understand the nature of the study, and give informed consent

Exclusion criteria for Persons with Aphasia:

  1. Inability to understand the nature of the study
  2. Marked naming impairment
  3. Impaired non-verbal, conceptual processing
  4. History of significant medical or neurological disorder (other than stroke)
  5. History of significant or poorly controlled psychiatric disorders
  6. Current abuse of alcohol or drugs, prescription or otherwise
  7. Nursing a child, pregnancy, or intent to become pregnant during the study
  8. Clinically significant hearing loss
  9. Contraindications to tACS
  10. Contraindications to MRI

Exclusion Criteria for Healthy Controls

  1. Diagnosis of a neurodegenerative disease or clinically significant cognitive complaint
  2. Any unrelated neurologic or physical condition that impairs communication ability
  3. History of unrelated neurological conditions including but not limited to traumatic brain injury, stroke, or small vessel disease that has resulted in a neurologic deficit
  4. Any additional neurological condition that would likely reduce the safety of study participation, including central nervous system (CNS) vasculitis, intracranial tumor, intracranial aneurysm, multiple sclerosis or arteriovenous malformations
  5. A medically unstable cardiopulmonary or metabolic disorder
  6. Terminal illness associated with survival <12 months
  7. Major active psychiatric illness that may interfere with required study procedures or treatments as determined by the enrolling physician
  8. Current abuse of alcohol or drugs, prescription or otherwise
  9. Contraindications to tACS
  10. Contraindications to MRI

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: real-tACS
The active stimulation will consist of an alternating current delivered in the alpha frequency band with a peak-to-peak intensity of 4 milliamps (mA) for 20 minutes. Participants will complete sentence completion and verb generation task during stimulation.
Device: Active transcranial alternating current stimulation (tACS)
Transcranial Alternating Current Stimulation (tACS) is a device that applies a low-intensity electrical current to the brain through electrodes on the scalp.
Other Names:
  • Sham transcranial alternating current stimulation [(ACS)
Placebo Comparator: sham-tACS
Sham stimulation involves the delivery of 60 seconds of the actual stimulation waveform ("ramp up") which is then gradually reduced to 0 milliamps (mA) ("ramp down"). Participants will complete sentence completion and verb generation task during stimulation.
Device: Active transcranial alternating current stimulation (tACS)
Transcranial Alternating Current Stimulation (tACS) is a device that applies a low-intensity electrical current to the brain through electrodes on the scalp.
Other Names:
  • Sham transcranial alternating current stimulation [(ACS)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Performance on the Blocked-Cyclic Naming (BCN) Task
Time Frame: 5-10 minutes after a single session of active (alpha tACS) and sham (fake tACS).
The BCN tasks involves naming a set of pictures repeatedly. Sets of pictures come from either the same semantic category (high competition condition; e.g., categorically related: "dog", "cat", "panda") or different semantic categories (low competition condition; e.g., unrelated: dog, eye, crib).
5-10 minutes after a single session of active (alpha tACS) and sham (fake tACS).

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Pennsylvania

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 12, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 31, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 31, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 28, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 17, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 23, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 24, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 21, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 854139

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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