Protocol Number: 00-M-0177

Title:

Transcranial Magnetic Stimulation Studies of Visual Attention

Number:

00-M-0177

Summary:

The purpose of this study is to learn more about how the brain allows people to focus on important objects and filter out unimportant ones when looking at visual images.

Our senses provide us with a vast amount of information at any given moment in time. For example, visual scenes contain many different objects that cannot be processed simultaneously because of the limited processing capacity of the brain's visual system. Evidence suggests that a a network of brain regions selects relevant information and filters out irrelevant information when people view cluttered visual scenes. This study will use transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) to determine how the different brain regions involved in attentional control and filtering interact.

Participants in this study will undergo computer tests, an MRI scan, and TMS. During the MRI, participants will look at pictures and count objects appearing on a screen. During the TMS, participants will perform a computer test. Participants' ability to pay attention will be tested with and without TMS. Participants may be asked to return for additional tests in the future.

Sponsoring Institute:

National Institute of Mental Health (NIMH)

Recruitment Detail

Type: Active Accrual Of New Subjects

Gender: Male & Female

Referral Letter Required: No

Population Exclusion(s): None

Eligibility Criteria:

INCLUSION CRITERIA:

All subjects will be healthy, right-handed and between the ages of 20 and 40.

Subjects must have normal or corrected-to-normal vision.

EXCLUSION CRITERIA

Pregnant women will be excluded.

Subjects with a personal or family history of seizures will be excluded.

Subjects with a history of neurologic disease, ocular foreign body, increased intracranial pressure, open head injury or significant closed head injurywill be excluded.

Subjects with cochlear implants, implanted brain stimulators, aneurysm clips or other metal in the head (except mouth) will be excluded.

Subjects taking tricyclic anti-depressants, neuroleptic agents or other drugs that lower the seizure threshold will be excluded.

Subjects with a history of illicit drug use or who are abusing or withdrawing from alcohol abuse will be excluded.

Subjects with a history of a major psychiatric disorder will be excluded.

Subjects with implanted medication pumps, pacemakers, intracardiac lines or significant heart disease will be excluded.

Special Instructions: Currently Not Provided

Keywords:

Transcranial Magnetic Stimulation

Parietal Lobe

fMRI

Cognition

Perception

Cortical Stimulation

Spatial Attention

Recruitment Keywords:

None

Conditions:

Healthy

Investigational Drug(s):

None

Investigational Device(s):

Magstim SuperRapid Magnetic Stimulator

Contacts:

Patient Recruitment and Public Liaison Office
Building 61
10 Cloister Court
Bethesda, Maryland 20892-4754
Toll Free: 1-800-411-1222
TTY: 301-594-9774 (local),1-866-411-1010 (toll free)
Fax: 301-480-9793

Electronic Mail:prpl@mail.cc.nih.gov

Citations:

Temporal aspects of visual search studied by transcranial magnetic stimulation

Transcranial magnetic stimulation in study of the visual pathway

Safety at different inter-train intervals for repetitive transcranial magnetic stimulation and recommendations for safe ranges of stimulation parameters

• Questions about participating in a study, please contact the Patient Recruitment and Public Liaison Office, CC.
• Technical questions regarding the Clinical Center web site, please contact the Department of Networks and Applications, CC.

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Warren Grant Magnuson Clinical Center (CC)
National Institutes of Health (NIH)
Bethesda, Maryland 20892. Last update: 10/23/2004