This study will use magnetic resonance imaging (MRI) to investigate how the brain controls
voluntary movements triggered by an external stimulus or self-initiated.
Registered HCMS healthy normal volunteers may participate. They will complete a
questionnaire and will have a medical history and brief physical examination.
The study consists of two parts: 1) body movement training and 2) magnetic resonance
imaging, as follows:
Part 1 - Body movement training
Participants will train to do three different body movements involving the hands and feet.
The movements will either be self-initiated or in response to a stimulus, such as a visual
or auditory trigger.
Part 2 - Magnetic resonance imaging
Participants will do one or more of the trained movements, with or without a triggering
stimulus, during MRI scanning. MRI is a diagnostic procedure that uses a magnetic field and
radio waves to produce images of brain structure and activity. For the procedure, the
subject lies on a stretcher that is moved into the scanner-a cylinder containing a strong
magnet. Earplugs are worn to protect the ears from loud thumping noises that occur with
electrical switching of radio frequency circuits. Scanning time varies from 20 minutes to 2
hours, with most examinations lasting 1 to 1-1/2 hours. The subject can communicate with the
staff person conducting the test at all times during the scan. A device compatible with
magnetic resonance will be used to record the participant's body movements. The participant
may be asked to push buttons of the device during the tasks.
Voluntary movements are divided into two categories, one is externally triggered movement
and the other is self-initiated movement. The underlying neural mechanisms in each movement
have been investigated, but they are not fully understood. The present study is aimed to
understand the neural mechanisms, especially aimed to find out the commonly devoted brain
area for the categorized movements. By obtaining functional magnetic resonance imaging
(fMRI) signals during triggered movement tasks designed from 3 input triggers of different
modalities (visual, auditory, and somatosensory) and 3 output movements of different body
parts (right hand, left hand, and right foot), we will determine the brain regions specially
devoted for each input or output, and commonly devoted for triggered movements. By
obtaining fMRI signals during spontaneous voluntary movement tasks designed from 3 output
movements of the same body parts, we will determine the brain regions specially devoted for
specific execution and commonly devoted for the voluntarily chosen movements.
Normal volunteers will be included. Normal volunteers will be recruited from people who
are registered as HMCS Normal Volunteers. All subjects participating in MR studies should
have a valid Clinical Center Medical Record Number.
We will not scan pregnant women because safety of high magnetic field to fetus is not
established. Therefore, we will administer a urine pregnancy test for any female subjects
of childbearing potential prior to functional MRI scan. If the result from a urine
pregnancy test is not available for some reason, a medical doctor will judge based on the
proper information prior to the scanning.