Neural Mechanisms of Interpersonal Expectations on Negative Affect

Conditions

• Expectations
• Negative Affectivity
• Non-invasive Brain Stimulation
• Placebo Effect

Eligibility Criteria

Sex

ALL

Age

18 Years - 55 Years

Healthy Volunteers

Accepted

Interventions

• Session A: Positive Placebo + Active tTIS — BEHAVIORAL
  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 — BEHAVIORAL
  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 — BEHAVIORAL
  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 — BEHAVIORAL
  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 — BEHAVIORAL
  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 — BEHAVIORAL
  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.

Study Details

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.

Key Dates

Start date

Sep 1, 2025

Status verified

Jun 2026

Primary completion

Aug 31, 2027

Completion

Mar 3, 2028

Study Design

Enrollment

196 participants (estimated)

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

BASIC_SCIENCE

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

Primary Outcome Measure

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

Central Contacts

• Zhaoxing Wei, Ph.D.
  6033220577
  [email protected]

Locations (1)

Find similar trials in Hanover, NH

Related Studies

• Context Interventions: Social Modeling and Initial Treatment Experience
  Not Yet Recruiting · Trustees of Dartmouth College · Hanover, New Hampshire
• The Role of the Opioid System in Placebo Effects on Pain and Social Rejection
  EARLY_PHASE1 · Not Yet Recruiting · Trustees of Dartmouth College · Hanover, New Hampshire
• Interactions Between Placebo Effects and Mindful Awareness State
  Not Yet Recruiting · Trustees of Dartmouth College · Hanover, New Hampshire