Task-dependent Effects of TMS on the Neural Biomarkers of Episodic Memory
- Conditions
- Normal Physiology
- Registration Number
- NCT04694131
- Brief Summary
Background:
Transcranial magnetic stimulation (TMS) of the brain has been used to change the activity and connections in the brain to improve memory. Researchers are interested in how these brain changes cause memory improvements and how activity at the time of stimulation may change the effects of TMS.
Objective:
To learn how brain stimulation can be used to improve memory.
Eligibility:
Healthy adults ages 18-40
Design:
Participants will be screened with a medical record review.
Participants will have 3 study visits.
At visit 1, participants will have a physical exam and will talk about their health. They will have magnetic resonance imaging (MRI). The MRI scanner is a metal cylinder surrounded by a strong magnetic field. During the MRI, participants will lie on a table that can slide in and out of the scanner. A coil will be placed over the head. Participants will be asked to keep their eyes focused on a small cross on a computer screen inside the scanner. The scanner makes loud noises. Participants will get earplugs.
At visits 2 and 3, participants will have TMS and perform tasks. For TMS, a wire coil encased in plastic is held on the scalp. When the coil is triggered, a brief electrical current passes through the coil and creates a magnetic pulse that stimulates the brain. During TMS, an electroencephalogram (EEG) will record brain activity. For the EEG, a cloth cap with electrodes is fitted on the participant s head. Participants will complete a memory task and a spatial processing task. They will also complete surveys about their mental state.
Participation will last 2-3 weeks.
- Detailed Description
Study Description:
The Behavioral Neurology Unit studies the human brain systems underlying learning and adaptation with the goal of finding interventions to make these processes more efficient. In this study, we are interested in examining how the task state of the episodic memory network influences the effect of faciliatory TMS on memory and its EEG neural correlates. It is hypothesized that Network-targeted parietal-TMS will improve memory performance and enhance EEG biomarkers of successful memory performance, but that these changes will be modulated by the ongoing task activity during stimulation.
Objectives:
Primary Objectives:
Investigate how TMS modulates EEG neural measures of successful memory and the association of this modulation with behavioral performance
Examine how memory task state influences susceptibility to plasticity via TMS and determine the optimal neural state for improving memory
Exploratory Objectives:
Search for MRI predictors of the effects of TMS
Endpoints:
Primary Endpoints: Memory performance, Late Positive Posterior ERP, evoked theta/alpha power (secondary), EEG functional connectivity (secondary)
Exploratory Endpoints: fMRI resting state functional connectivity, fractional anisotropy
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 43
Not provided
Not provided
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- SINGLE_GROUP
- Primary Outcome Measures
Name Time Method Memory Performance 1 hour Participants completed a memory task with simultaneous EEG acquisition and transcranial magnetic stimulation (TMS) delivered to either a memory-relevant parietal lobe target or a vertex control site. Participants were shown a series of objects in one of four quadrants on the screen, with TMS delivered either prior to or concurrent with the trial onset. They were instructed to remember the object and the location. This outcome measure examines the accuracy of memory for the item and the location (context), presented as the percentage of successful trials. Accuracy is shown for each stimulation condition (parietal or vertex location, before or during the trial)
Late Positive Posterior (ERP) Event Related Potential During encoding (with TMS) and during retrieval (after TMS) Participants completed a memory task with simultaneous EEG acquisition and transcranial magnetic stimulation (TMS) delivered to either a memory-relevant parietal lobe target or a vertex control site. Participants were shown a series of objects in one of four quadrants on the screen, with TMS delivered either prior to or concurrent with the trial onset. They were instructed to remember the object and the location. This outcome measure examines the neural response to trials which were later remembered relative to trials which were later forgotten. Values represent the difference in average EEG amplitude, in uV, between remembered and forgotten trials and compared across each stimulation condition (parietal or vertex location, before or during the trial)
- Secondary Outcome Measures
Name Time Method Theta/Alpha Power During encoding (with TMS) and during retrieval (after TMS) Participants completed a memory task with simultaneous EEG acquisition and transcranial magnetic stimulation (TMS) delivered to either a memory-relevant parietal lobe target or a vertex control site. Participants were shown a series of objects in one of four quadrants on the screen, with TMS delivered either prior to or concurrent with the trial onset. They were instructed to remember the object and the location. This outcome measure examines the neural response to trials which were later remembered relative to trials which were later forgotten. Values represent the difference in average task-evoked power in the theta/alpha range (4-13Hz), in uV, between remembered and forgotten trials and compared across each stimulation condition (parietal or vertex location, before or during the trial)
Trial Locations
- Locations (1)
National Institutes of Health Clinical Center
🇺🇸Bethesda, Maryland, United States
National Institutes of Health Clinical Center🇺🇸Bethesda, Maryland, United States