Modulation of the Parieto-frontal Communication
- Conditions
- Normal Physiology
- Interventions
- Device: Transcranial Magnetic Stimulation (TMS)Behavioral: Working Memory Task
- Registration Number
- NCT03434093
- Brief Summary
Background:
Research shows that the parietal and prefrontal areas of the brain are involved in short-term memory. Researchers want to look at the effects of transcranial magnetic stimulation (TMS) of these areas on short-term memory and brain activity. They will use functional magnetic resonance imaging (fMRI) to look at brain activity.
Objective:
To look at the effects of TMS on brain pathways involved in memory.
Eligibility:
Healthy, right-handed adults ages 18-50
Design:
Participants will have 3 or 4 visits at least 1 week apart. They cannot drink alcohol for at least 48 hours before each visit.
The screening visit lasts about 1 (Omega) hours. It can be combined with the first testing visit. Screening includes:
* Medical history
* Physical exam
* Neurological exam
* Urine tests
* Questionnaires about being left or right handed and about their ability to imagine physical activities.
The first testing visit lasts about 1 (Omega) hours and includes an MRI. For the MRI, participants lie on a table that slides into a machine. They will lie still or perform simple memory tasks on a computer screen.
The second and third testing visits last about 3 hours. Participants will have:
* 2 MRIs
* TMS: A wire coil is held to the scalp. A brief electrical current passes through the coil to create a magnetic pulse that affects brain activity. They will perform simple memory tasks.
* EMG: Small electrodes are taped to the skin to record muscle activity while they rest.
After the study, participants will complete a questionnaire about any discomfort they experienced during the study.
...
- Detailed Description
Objective: This study aims to identify whether repetitive dual-site transcranial magnetic stimulation (TMS) can modulate the functional connectivity between the parietal and dorso-lateral prefrontal cortices.
Study population: The study involves 26 healthy volunteers.
Design: This controlled study comprises 3 main visits for each subject: (1) a baseline, evaluation visit during which fMRI will be acquired during a visual short memory task along with diffusion tensor imaging and structural MRI; (2) a visit during which resting state fMRI (rsfMRI) will be acquired, followed by paired-associative stimulation (PAS) with pulses delivered over the parietal and then over the dorso-lateral prefrontal cortex, in order to induce a temporary plastic change in the interaction between the parietal and prefrontal cortices; the PAS will be followed by another rsfMRI and task fMRI; (3) a visit identical to #2 during which the PAS will be delivered with pulses in reverse order of previous visit.
Outcome measures: The effects of PAS will be quantified with rsfMRI and a short working memory task, considered as a proxy for complex motor and cognitive control.
* The primary outcome will be to investigate the resting state functional connectivity changes induced by each PAS intervention
* The secondary outcome #1 will be to evaluate the difference in visual angle error between sessions 2 and 3 in a working memory task during which the subjects will be asked to remember the position of a bar presented on the screen at different time intervals before the inquiry.
* The secondary outcome #2 will be to build an fMRI-DTI analysis pipeline for generation of TMS targets individually customized for each subject and a given task.
Recruitment & Eligibility
- Status
- WITHDRAWN
- Sex
- All
- Target Recruitment
- Not specified
Not provided
Not provided
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description PPC-DLPFC Transcranial Magnetic Stimulation (TMS) In this arm, the TMS paired-pulses will be first delivered over the posterior parietal cortex (PPC) and then over the dorsolateral prefrontal cortex (DLPFC) PPC-DLPFC Working Memory Task In this arm, the TMS paired-pulses will be first delivered over the posterior parietal cortex (PPC) and then over the dorsolateral prefrontal cortex (DLPFC) DLPFC-PPC Working Memory Task Arm Description: In this arm, the TMS paired-pulses will be first delivered over the over the dorsolateral prefrontal cortex (DLPFC) and then posterior parietal cortex (PPC) DLPFC-PPC Transcranial Magnetic Stimulation (TMS) Arm Description: In this arm, the TMS paired-pulses will be first delivered over the over the dorsolateral prefrontal cortex (DLPFC) and then posterior parietal cortex (PPC)
- Primary Outcome Measures
Name Time Method Resting state functional connectivity change induced by the paired associative stimulation Study completion
- Secondary Outcome Measures
Name Time Method Difference in the visual angle error of a working memory task between the DLPFC-PCC and PPC-DLPFC paired associative stimulation Study completion