Recruiting

tTIS

Sponsor:

Trustees of Dartmouth College

Code:

NCT06980090

Conditions

Negative Affectivity

Non-invasive Brain Stimulation

Placebo Effect

Expectations

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Accepted

Interventions

Session A: Positive Placebo + Active tTIS

Session B: Positive Placebo + Sham tTIS

Session C: Negative Placebo + Active tTIS

Session D: Negative Placebo + Sham tTIS

Session E: On-Placebo + Sham tTIS

Study Details

Brief summary:

The goal of this clinical trial is to learn whether non-invasive brain stimulation, called transcranial temporal interference stimulation (tTIS), can reduce negative affect, and how expectations shaped by care providers influence these effects.

The main questions this study aims to answer are: (1)Does active tTIS reduce negative affect more effectively than sham (inactive) tTIS? (2)Do positive treatment expectations enhance the effects compared to negative expectations?

Participants will: (1) Receive either active or sham tTIS. (2) Be provided with positive or negative messaging regarding treatment effectiveness. (3) Interact with care providers and complete assessments measuring negative affect and physiological responses.

Conditions

Negative Affectivity

Non-invasive Brain Stimulation

Placebo Effect

Expectations

Study ID

NCT06980090

Start date

Sep 1, 2025

Status verified date

Jun, 2026

Completion date

Mar 3, 2028

Anticipated

Primary completion date

Aug 31, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Accepted

Inclusion Criteria:

'Doctors' are recruited from medical students at the Geisel School of Medicine and resident physicians at Dartmouth Hitchcock Medical Center (DHMC).

Exclusion Criteria:

  • No self-reported current or history of depression, bipolar disorder, or other psychiatric diagnosis
  • No self-reported current seizure disorder (i.e., seizure within past 10 years), or history of stroke or other major neurological diagnosis that can cause cognitive impairment
  • No self-reported current chronic pain, or acute pain within three months of the study period
  • No current migraine disorder (i.e., 15 headache days or more in 1 month)
  • No use of central nervous system-effective medication or other medication for neurological/psychiatric treatment
  • No self-reported substance abuse within the last six months
  • No contraindication to MRI or tTIS (e.g., pregnancy, claustrophobia, pacemakers, ear/cochlear implants, shrapnel injuries, clips, or other ferromagnetic/electrical objects/devices, diagnosed brain abnormality such as tumor, or skin lesions on the scalp.)
  • No contraindications for induced pain (e.g., no heart disease, high blood pressure, heart surgery, heart problems of any kind, severe asthma, respiratory problems of any kind, fibromyalgia, Raynaud's Syndrome or Disease, chronic pain, diabetes)
  • Participants must be capable of performing experimental tasks (e.g., are able to read), are fluent or native speakers of English
  • Participants must be able to tolerate the maximum level of thermal pain stimuli (for thermal stimuli)

Study Design

Enrollment

196 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Experiment 1 - Crossover Order: Session A-B-D-C

Participants complete all four experimental sessions in the following sequence: 1. Session A; 2. Session B; 3. Session D; 4. Session C

experimental: Experiment 1- Crossover Order: Session B-C-A-D

Participants complete all four experimental sessions in the following sequence: 1. Session B; 2. Session C; 3. Session A; 4. Session D

experimental: Experiment 1- Crossover Order: Session C-D-B-A

Participants complete all four experimental sessions in the following sequence: 1. Session C; 2.Session D; 3. Session B; 4. Session A

experimental: Experiment 1- Crossover Order: Session D-A-C-B

Participants complete all four experimental sessions in the following sequence: 1. Session D; 2. Session A; 3. Session C; 4. Session B

experimental: Experiment 2 - Crossover Order : Session E-F

Participants complete all two experimental sessions in the following sequence: 1. Session E; 2. Session F

experimental: Experiment 2 - Crossover Order : Session F-E

Participants complete all two experimental sessions in the following sequence: 1. Session F; 2. Session E

Interventions

Session A: Positive Placebo + Active tTIS

Participants receive active tTIS with two channels set at 2000 Hz and 2010 Hz, creating a 10 Hz interference beat targeting the anterior/mid-cingulate cortex (aMCC). Stimulation is delivered at 2 mA per channel for 20 minutes. The stimulation is combined with a positive social placebo intervention delivered by the care provider. Participants complete three multimodal negative affect tasks (MNAT) before and after the stimulation.

Session B: Positive Placebo + Sham tTIS

Participants receive sham tTIS (brief 80-second stimulation followed by no current) paired with a positive social placebo intervention. The device mimics active parameters (2 mA per channel, 20 minutes) without delivering effective stimulation. The sham stimulation is paired with a positive social placebo intervention. Participants complete three MNAT tasks before and after the session.

Session C: Negative Placebo + Active tTIS

Participants receive active tTIS (2000 Hz and 2010 Hz signals, 2 mA per channel, 20 minutes) combined with a negative social placebo intervention (neutral or skeptical messaging about treatment efficacy). Participants complete three MNAT tasks before and after the stimulation.

Session D: Negative Placebo + Sham tTIS

Participants receive sham tTIS (brief 80-second stimulation followed by no current) combined with a negative social placebo intervention. Participants complete three MNAT tasks before and after the session.

Session E: On-Placebo + Sham tTIS

Participants receive sham tTIS (brief 15-second stimulation followed by no current) paired with a positive social placebo intervention. Participants complete three MNAT tasks before and after the session.

Session F: Off-Placebo + Sham tTIS

Participants receive sham tTIS (brief 15-second stimulation, then no current) without any placebo intervention. Participants complete three MNAT tasks before and after the session.

Primary outcome measure

  • Cognitive effort ratings [ Time Frame: 3-10 sec post-stimulus throughout testing sessions, with all sessions complete within 1 month ]
  • Subjective fear ratings [ Time Frame: 3-10 sec post-stimulus throughout testing sessions, with all sessions complete within 1 month ]
  • Pain ratings [ Time Frame: 3-10 sec post-stimulus throughout testing sessions, with all sessions complete within 1 month ]

Central Contacts and Locations

Central contacts

Zhaoxing Wei, Ph.D.

6033220577zhaoxing.wei@dartmouth.edu

Locations

Dartmouth College, Department of Psychological and Brain Sciences

Recruiting

Hanover, New Hampshire, United States, 03755

Contacts

Tor D. Wager, Ph.D.

603-646-2196tor.d.wager@dartmouth.edu

More Information

Sponsor

Trustees of Dartmouth College

Last update posted

Jun 11, 2026

Last verified

Jun, 2026

Keywords

  • Transcranial temporal interference stimulation
  • Pain
  • Fear
  • Cognitive effort

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Trustees of Dartmouth College on 2026-06-11.