Modulation of the Parieto-frontal Communication

Modulation of the Parieto-frontal Communication


Patrocinador principal: National Institute of Neurological Disorders and Stroke (NINDS)

Fuente National Institutes of Health Clinical Center (CC)
Resumen breve


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.


To look at the effects of TMS on brain pathways involved in memory.


Healthy, right-handed adults ages 18-50


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.


Descripción detallada

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.

Estado general Withdrawn
Fecha de inicio February 3, 2019
Fecha de Terminación February 25, 2019
Fecha de finalización primaria February 25, 2019
Fase N/A
Tipo de estudio Interventional
Resultado primario
Medida Periodo de tiempo
Resting state functional connectivity change induced by the paired associative stimulation Study completion
Resultado secundario
Medida Periodo de tiempo
Difference in the visual angle error of a working memory task between the DLPFC-PCC and PPC-DLPFC paired associative stimulation Study completion

Tipo de intervención: Device

Nombre de intervención: Transcranial Magnetic Stimulation (TMS)

Descripción: Description: This will comprise single and repeated paired-pulses delivered over motor and non-motor areas.

Tipo de intervención: Behavioral

Nombre de intervención: Working Memory Task

Descripción: This will consist in remembering an item presented 1 to 5 steps before the inquiry. This task will span the whole duration of the functional MRI acquisition.




- Age between 18-50 years.

- Right-handed (handedness questionnaire will be part of the initial evaluation)

- Able to give informed consent.

- Have a normal neurological exam within the last year and MoCA>27

- Willing and able to abstain from alcohol for at least 48 hours prior to the study.

- Willing to not participate in other rTMS studies in the week preceding visits for the current protocol.


-All participants must be able to undergo MRI and TMS, for which the MRI- and TMS-safety checklists will be part of the initial evaluation, and reconfirmed at the beginning of every visit. It will constitute as exclusion criteria if the participant:

- has metal in his/her body which would make having an MRI scan unsafe, such as pacemakers, stimulators, pumps, aneurysm clips, metallic prostheses, artificial heart valves, cochlear implants or shrapnel fragments, or if he/she was a welder or metal worker, since small metal fragments may be found in the eyes.

- is uncomfortable in small closed spaces (claustrophobia) so that he/she would feel uncomfortable in the MRI machine.

- is not able to lie comfortably on the back for up to 2 hours

has hearing loss.

--is pregnant.

- Self-reported consumption of >14 alcoholic drinks/week for a man and >7 alcoholic drinks/week for a woman.

- History of or current brain tumor, stroke, head trauma with loss of consciousness, epilepsy or seizures.

- Taking medications that act directly on the central nervous system such as anti-epileptics, anti-histamines, anti-parkinsonian medication, medication for insomnia, anti-depressants, anti-anxiety medication.

Género: All

Edad mínima: 18 Years

Edad máxima: 50 Years

Voluntarios Saludables: Accepts Healthy Volunteers

Oficial general
Apellido Papel Afiliación
Mark Hallett, M.D. Principal Investigator National Institute of Neurological Disorders and Stroke (NINDS)
Fecha de verificación

February 2019

Fiesta responsable

Tipo: Sponsor

Palabras clave
Tiene acceso ampliado No
Número de brazos 2
Grupo de brazo

Etiqueta: PPC-DLPFC

Tipo: Active Comparator

Descripción: 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)

Etiqueta: DLPFC-PPC

Tipo: Active Comparator

Descripción: 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)

Información de diseño del estudio

Asignación: Randomized

Modelo de intervención: Crossover Assignment

Propósito primario: Basic Science

Enmascaramiento: Single (Participant)