This study will use transcranial magnetic stimulation (TMS) to investigate functions of
brain regions that may use information from sensory organs, such as the eyes or ears, to
For TMS, a wire coil is held over the scalp. A brief electrical current is passed through
the coil, creating a magnetic pulse that stimulates the brain. This may cause a pulling
sensation on the skin under the coil and twitching in muscles of the face, arm, or leg.
During the stimulation, the participant may be asked to tense certain muscles slightly or
perform other simple actions.
Healthy normal volunteers 18 years of age and older may be eligible for this study.
Individuals with a history of neuropsychiatric disorders, brain lesions such as tumors,
stroke, or trauma, or a history of significant medical disorders, such as cancer, may not
participate. Candidates will be screened with a medical history, brief physical
examination, and questionnaire.
Participants will be presented a sequence of shapes (circles, rectangles, and triangle) and
will count the number of a specified shape. Each number is assigned to a corresponding
response button. The subject will push the appropriate button with the corresponding
finger. During these experiments, the scalp will be stimulated by TMS. Each set of TMS
measurements will take up to 3-1/2 hours.
The role of multimodal brain regions for sensory-to-motor processing is not well understood.
In our recent neuroimaging study with fMRI, we found that multimodal areas such as the
right superior temporal cortex and right dorsal premotor cortex were activated during
sensory instructed movements. These regions might contribute to extract common features or
concepts from sensory stimuli, but we do not have firm experimental evidence yet. In order
to investigate the functional roles of multimodal brain regions further, we propose to apply
a transcranial magnetic stimulation (TMS) technique. TMS can create transient brain lesions
allowing functional mapping of cortical regions. In this protocol, by stimulating the
multimodal areas using TMS, we will determine the functional role of these areas.
Forty normal volunteers will be included. Normal volunteers would be recruited from
people who are registered as HMCS Normal Volunteers. All subjects participating in this
study should have a valid Clinical Center Medical Record Number. Procedures for the
experiment will follow the Standard Operating Procedures of HMCS TMS group.
Contraindications for TMS;
Magnetic stimulation will not be performed in people who have pacemakers, implanted pumps
or stimulators, or have metal objects inside the eye or skull. If the participants find
the procedures too uncomfortable, they may discontinue the study at any time. Brain
functions at a development stage are out of scope of this particular experiment. In this
study, subjects 18 years or older will be included.
Contraindications for MRI;
Pacemakers, brain stimulators, dental implants or metallic braces, aneurysm clips (metal
clips on the wall of a large artery), metallic prostheses (including metal pins and rods,
heart valves, and cochlear implants), permanent eyeliner, insulin pump, or shrapnel
fragments. Welders and metal workers are also at risk for injury because of possible
small metal fragments in the eye which they may be unaware. Subjects will be screened for
these contraindications prior to the study.
Subjects with previous or current neuropsychiatric disorders will be excluded. Patients
with MRI findings consistent with organic brain lesions such as brain tumors, stroke, or
trauma will be excluded. Subjects not capable of giving informed consent will be
We will not scan pregnant women with MRI because safety of high magnetic field to fetus is
not established. Therefore, we will administer a urine pregnancy test for any female
subject of childbearing potential prior to MRI scan. Brain functions at a developmental
stage are out of scope of this particular experiment. In this study, subjects aged 18
years or older will be included.