Interactions Between Placebo Effects and Mindful Awareness State
Trustees of Dartmouth College
Summary
In this experiment,the investigators study the effects of interpersonally induced placebo effects and a mindful awareness induction on negative affect. Specifically, it will be examining the effects of interpersonally induced placebo effects (sham tDCS vs. control) and a mindful awareness induction (mindful state vs. control), as well as their interaction. Each group will undergo fMRI scanning and physiological recording will performing the Multimodal Negative Affect Task (MNAT).
Description
This study aims to investigate the effects of interpersonally induced placebo effects and a mindful awareness induction on negative affect. The study will involve 120 participants recruited from the Dartmouth College community, aged between 18 and 55, with an equal distribution of 60 males and 60 females. Participants will be assigned to the role of "patient" and will undergo fMRI scanning and physiological recording while performing the Multimodal Negative Affect Task (MNAT). The study design follows a 2 x 2 factorial design, examining the effects of interpersonally induced placebo effects (…
Eligibility
- Age range
- 18–55 years
- Sex
- All
- Healthy volunteers
- Yes
* 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 w…
Interventions
- BehavioraltDCS stimulation (sham)
Participants will receive sham tDCS stimulation in a 20 minute long task. Targets will be fitted with the tDCS stimulation electrode cap and instructed that they will receive 20 minutes of tDCS stimulation for the task. Sham tDCS will target the motor cortex at 2mA for 15 sec at the beginning of the session, and then the stimulator will turn off. The participant will then sit for the remaining time of the session with the electrode cap on their heads but turned off and not delivering stimulation. All participants will receive sham tDCS stimulation (n=120).
- BehavioraltDCS stimulation (real)
In their second session, participants will receive real tDCS stimulation in a 20 minute long task. Targets will be fitted with the tDCS stimulation electrode cap and instructed that they will receive 20 minutes of tDCS stimulation for the task. Real tDCS stimulation will target the motor cortex at 2mA for 20 minutes (full duration of task). All participants will receive real tDCS stimulation (n=120).
- BehavioralMindful state induction
Experimenters trained in high-competence and high-warmth will train Group 1 participants on mindful state induction (n=60). Participants will undergo two stages for this training: 1) pain education to increase beliefs in endogenous brain regulatory capacities; and 2) the Stanford Hypnotic Induction Profile (HIP) test of hypnotizability and hypnotic induction of a relaxed state receptive to suggestion. In Stage 1, participants will receive education that pain and affect are processes designed to protect the body from danger, which are transmitted rapidly and automatically to the brain. In Stage 2, participants are (a) seated in an upright, alert posture; and (b) receive suggestions that the ability to attend to and discriminate affective perceptions is achievable and that suppressing attention to the body and focusing on the task will allow them to perform optimally under pressure. Mindful state induction will only be explicitly instructed during session 1 for Group 1 participants.
Location
- Dartmouth CollegeHanover, New Hampshire