Effect of tACS Stimulation on Stress

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Verified June 2017 by University of North Carolina, Chapel Hill



National Institutes of Health (NIH)

National Institute of Mental Health (NIMH)

Information provided by (Responsible Party):

University of North Carolina, Chapel Hill

ClinicalTrials.gov Identifier:


First received: June 2, 2017

Last updated: June 2, 2017

Last verified: June 2017

Transcranial Alternating Current Stimulation (tACS) is one method that has been demonstrated to enhance alpha oscillations in healthy participants by applying weak electrical currents to the scalp to modulate rhythmic brain activity patterns. Analysis of results from other studies involving tACS indicate that the response to stimulation is gated by stress, previously measured using heart rate variability, pupil diameter, and respiration. Therefore, this study will involve tACS-induced frontal alpha oscillations, EEG recordings, and more detailed physiological markers of stress in order to further explore this relationship.

Healthy Device: XCSITE100 Stimulator tACS
Device: XCSITE100 Stimulator Sham

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Intervention Model Description:

Each participant will receive sham stimulation or 10Hz tACS stimulation at two separate sessions. The order will be randomized (ie, half the participants will receive sham stimulation at the first session and 10Hz tACS stimulation at the second session, and the other half will receive 10Hz tACS stimulation at the first session and sham stimulation at the second session).

Masking: Participant, Investigator
Masking Description:

This study will follow a double-blind experimental design, so neither the participant nor the experimenter will know what kind of stimulation the participant is receiving at what session. A separate unblinded monitor, who will not interact with the participants, will be responsible for creating the stimulation codes for each session.

Primary Purpose: Basic Science

Official Title: Rational Optimization of tACS for Targeting Thalamo-Cortical Oscillations (Experiment 2)

Primary Outcome Measures:

Secondary Outcome Measures:

  • Heart Rate Variability [ Time Frame: Before and after 40-minute stimulation at each session. ]

    Change in the ratio between the power in low frequency band and the power in high frequency band. As this outcome variable is a ratio between two items that are measured in microvolt^2, the ratio does not have a unit of measure.

  • Galvanic Skin Response [ Time Frame: Before and after 40-minute stimulation at each session. ]

    Galvanic Skin Response (GSR) is a physiological measure of stress, measured via a weak electrical current passed along a participant’s fingertips.

  • Respiration [ Time Frame: Before and after 40-minute stimulation at each session. ]

    Respiration rate is a physiological measure of stress, measured via a belt placed around the participant’s abdomen.

  • Electroencephalogram (EEG) [ Time Frame: Before and after 40-minute stimulation at each session. ]

    The investigators will compare alpha oscillation power from resting-state EEG recordings before and after stimulation/sham at each session.

Estimated Enrollment: 20
Anticipated Study Start Date: June 2017
Estimated Study Completion Date: July 2017
Estimated Primary Completion Date: July 2017 (Final data collection date for primary outcome measure)
Sham Comparator: Sham Stimulation

Sham Stimulation mimics the physical effects of stimulation, with up to one minute of stimulation during the session. Sham stimulation is delivered using the XCSITE100 Stimulator Sham.

Device: XCSITE100 Stimulator Sham

The participant will receive up to one minute of tACS stimulation until the stimulation fades. Sham stimulation mimics the skin sensations a participant would experience during a tACS session.

Other Name: Sham tACS

Experimental: Alpha Stimulation

Participants will receive 2mA of alternating current stimulation at a frequency of 10Hz for 40 minutes. tACS stimulation is delivered using the XCSITE100 Stimulator tACS.

Device: XCSITE100 Stimulator tACS

Transcranial alternating current stimulation (tACS) is a method of noninvasive brain stimulation in which weak electrical current are applied to the scalp in a sine wave pattern to induce cortical oscillations at the frequency at which they are applied.

Other Name: tACS

Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Ages 18-65
  • Capacity to understand all relevant risks and potential benefits of the study (informed consent)
  • Negative pregnancy test for female participants

Exclusion Criteria:

  • History of major neurological or psychiatric illness, including epilepsy
  • Medication use associated with neurological or psychiatric illnesses
  • Currently undergoing counseling or psychotherapy treatment for depression, anxiety, eating disorders, PTSD or other behavioral conditions
  • First degree relative (parent, sibling, child) with major neurological or psychiatric illness
  • Prior brain surgery
  • Major head injury
  • Any brain devices/implants (including cochlear implants and aneurysm clips)
  • Braids or other hair styling that prevents direct access to the scalp (if removal not possible)
  • Skin allergies or very sensitive skin
  • Pregnant or nursing females
  • Failure to pass a urinary drug test at the first session
  • Use of hormonal birth control or supplements in the past two weeks
  • Non English speakers
  • Cardiovascular disease

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT03178344

University of North Carolina Chapel Hill
Chapel Hill, North Carolina, United States, 27514
Contact: Jhana Parikh    919-802-6873    jhana@live.unc.edu   

University of North Carolina, Chapel Hill

National Institutes of Health (NIH)

National Institute of Mental Health (NIMH)

Principal Investigator: Flavio Frohlich, PhD University of North Carolina, Chapel Hill

Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: Yes
Device Product Not Approved or Cleared by U.S. FDA: Yes
Pediatric Postmarket Surveillance of a Device Product: No
Product Manufactured in and Exported from the U.S.: No

ClinicalTrials.gov processed this record on June 06, 2017