RecruitingNot ApplicableNCT06980090

Neural Mechanisms of Interpersonal Expectations on Negative Affect

Sponsor

Trustees of Dartmouth College

Enrollment

196 participants

Start Date

Sep 1, 2025

Study Type

INTERVENTIONAL

Conditions

Placebo effect Negative Affectivity Non-invasive Brain Stimulation Expectations

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.

Eligibility

Min Age: 18 YearsMax Age: 55 Years

Plain Language Summary

Simplified for easier understanding

This clinical trial is studying a behavioral approach called Session A: Positive Placebo + Active tTIS, a behavioral approach called Session B: Positive Placebo + Sham tTIS, and others for people with expectations, negative affectivity, and other related conditions. The study is currently recruiting participants at 1 location.

This summary was AI-generated to explain the trial in plain language. It is not medical advice. Always discuss eligibility with your doctor before enrolling in a clinical trial.

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Interventions

BEHAVIORALSession 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.

BEHAVIORALSession 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.

BEHAVIORALSession 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.

BEHAVIORALSession 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.

BEHAVIORALSession 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.

BEHAVIORALSession 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.