Transcranial Direct Current Stimulation and Modulation of Affect and Pain
Trustees of Dartmouth College
50 participants
Sep 9, 2023
INTERVENTIONAL
Conditions
Summary
This double-blind randomized crossover study aims to examine the effects of left primary motor cortex (M1) tDCS on evoked thermal pain perception, pain-related decision making, and placebo effects by manipulated pain and monetary offers accepted by others. The investigators plan to collect data for up to 50 participants who undergo four separate sessions: an initial pain calibration session and three experimental sessions with either anodal, cathodal, or sham tDCS. Each session includes pain testing before and after a single tDCS protocol (either anodal, cathodal, or sham), a pain-monetary decision-making task, and social placebo pain tests. All tasks following tDCS will take place inside the MR scanner. The investigators hypothesize that anodal M1 tDCS will decrease pain ratings, and that cathodal tDCS will increase them, both relative to the sham condition. The investigators will also examine the effects of M1 tDCS on social decision-making to examine whether it affects participants' valuation of pain and their altruistic behavior, as well as how these same factors impact pain sensation in the placebo task. The investigators hypothesize that participants will behave hyperaltruistically during the decision-making task, and that the same factors that influence choice will also impact pain perception in the same context.
Eligibility
Inclusion Criteria3
- ages 18-55
- Participants must be capable of performing experimental tasks (e.g., are able to read)
- Fluent or native speakers of English
Exclusion Criteria8
- 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)
- No history of stroke or other major neurological diagnosis.
- 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 tDCS (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).
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Interventions
Transcranial direct current stimulation (tDCS) is an experimental manipulation of brain circuitry using electrical current applied to the scalp. The equipment is commercially available (StarStim8, Neuroelectrics, Spain) and marketed for experimental research on brain function. Current is applied at 2 mA for 20 minutes. Electrodes are placed on the C3 and FP2 regions. There is a 30-second ramp-up and 30-second ramp-down of stimulation for each tDCS condition to minimize any discomfort during stimulation. In the anodal condition, real tDCS stimulation enters from the C3 electrode, and exits at the FP2 electrode.
Transcranial direct current stimulation (tDCS) is an experimental manipulation of brain circuitry using electrical current applied to the scalp. The equipment is commercially available (StarStim8, Neuroelectrics, Spain) and marketed for experimental research on brain function. Current is applied at 2 mA for 20 minutes. Electrodes are placed on the C3 and FP2 regions. There is a 30-second ramp-up and 30-second ramp-down of stimulation for each tDCS condition to minimize any discomfort during stimulation. In the cathodal condition, real tDCS stimulation enters from the FP2 electrode, and exits at the C3 electrode.
This is the sham (or placebo) tDCS intervention. The tDCS device is applied for one minute, for a 30-second ramp-up and 30-second ramp-down of stimulation.
Locations(1)
View Full Details on ClinicalTrials.gov
For the most up-to-date information, visit the official listing.
NCT06989749