Developing Transcranial Neuromodulation Protocols for Learning and Decision-Making

Background: People with substance use disorder (SUD) often have changes in brain function that can make it difficult to control drug-seeking behavior. These changes may heighten the urge to use drugs or lessen the desire to seek nondrug-related rewards. Researchers want to know how a technique called transcranial magnetic stimulation (TMS) may cause changes in brain activity that may help people with SUD. Objective: To test TMS in healthy volunteers. Eligibility: Healthy people aged 18 to 45 years who are right-handed. Design: Participants can volunteer for up to 5 different experiments. Each experiment requires 2 to 8 clinic visits. Each visit will last 3 to 7 hours. Some visits will include TMS. A coil will be placed on the participant s head. A brief electrical current will pass through the coil to create a magnetic field. Participants may feel a tapping or pulling sensation on the skin under the coil. They may feel a twitch in their face, neck, arm, or leg muscles. Participants may be asked to tense certain muscles during TMS. Some visits will include functional magnetic resonance imaging (fMRI) scans. Participants will lie on a bed that slides into a large tube. They will perform tasks on a computer inside the tube. The fMRI will show which parts of the brain are used during each task. Participants will perform tasks on a computer. Some tasks may be done at a desk as well as during TMS and fMRI. Participants may look at images, listen to sounds, smell odors, or taste flavored liquids. Their vital signs may be monitored and their eye movements may be tracked during tasks.

Study Description: Learning and decision-making are critical for adaptive behavior and survival. Treating maladaptive behaviors in neuropsychiatric conditions, such substance use disorder, requires knowledge about the causal neural mechanisms supporting these functions as well as ways to modulate them. The goal of the current study is to develop and validate neuromodulation protocols that target specific cognitive functions involved in learning and decision making. Objectives: The primary objective is to develop and validate non-invasive neuromodulation protocols that target specific cognitive functions related to learning and decision making and modulate activity in associated brain networks. Endpoints: The primary endpoints are to determine if the developed neuromodulation protocols reliably modulate specific cognitive functions and whether they modulate activity in the targeted brain networks.