Health TrialsbyHealthPanel

Neural Mechanisms of Interpersonal Expectations on Negative Affect

ConditionsNegative AffectivityNon-invasive Brain StimulationPlacebo EffectExpectations
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-55
SponsorTrustees of Dartmouth College

About this trial

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 criteria

This trial accepts healthy volunteers

Qualifiers

None

Disqualifiers

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)

Trial design

Design model

Crossover

Treatments tested in this trial

  • 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.

Treatment groups

196 Participants
are divided into 6 treatment groups

6

Treatment groups

See each treatment group below.

Group A: Experiment 1 - Crossover Order: Session A-B-D-CExperimental treatment 4 interventions
Group B: Experiment 1- Crossover Order: Session B-C-A-DExperimental treatment 4 interventions
Group C: Experiment 1- Crossover Order: Session C-D-B-AExperimental treatment 4 interventions
Group D: Experiment 1- Crossover Order: Session D-A-C-BExperimental treatment 4 interventions
Group E: Experiment 2 - Crossover Order : Session E-FExperimental treatment 2 interventions
Group F: Experiment 2 - Crossover Order : Session F-EExperimental treatment 2 interventions

Trial outcomes

Primary outcomes

1

Cognitive effort ratings

Participants report cognitive effort after each trial on a Generalized Linear Magnitude scale (GLMS) with anchors of "No effort" and "Most effort imaginable". Raw units are on a 0-180 scale.

Time frame
3-10 sec post-stimulus throughout testing sessions, with all sessions complete within 1 month
2

Subjective fear ratings

Participants report subjective fear experience after each trial on a well-validated Generalized Linear Magnitude scale (GLMS) with anchors of "No fear" and "Most intense fear imaginable". Raw units are on a 0-180 scale.

Time frame
3-10 sec post-stimulus throughout testing sessions, with all sessions complete within 1 month
3

Pain ratings

Participants report subjective pain experience after each trial on a well-validated Generalized Linear Magnitude scale (GLMS) with anchors of "No pain" and "Most intense pain imaginable". Raw units are on a 0-180 scale.

Time frame
3-10 sec post-stimulus throughout testing sessions, with all sessions complete within 1 month

Secondary outcomes

1

Electrodermal autonomic responses to painful heat, fear-related images and cognitive effort

Skin conductance (EDA) is recorded continuously throughout test sessions and per-stimulus amplitude of canonical stimulus-locked EDA responses is reported in microsiemens (uS). Higher values indicate a higher EDA response.

Time frame
Peri-stimulus throughout testing sessions, with all sessions complete within 1 month

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Trustees of Dartmouth College

Lead sponsor

Source ClinicalTrials.gov
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