Rhythm Perception and Generation
Rhythm Perception and Generation
This study will examine how different brain areas are involved in the perception of rhythmic
 patterns and the performance of rhythmic movements. Patients with certain types of brain
 diseases, such as Parkinson's disease and some types of stroke, may have difficulty
 performing rhythmic movements, such as finger tapping.

 Healthy, right-handed volunteers between 21 and 65 years of age may be eligible for this
 study. Candidates with visual, motor or hearing problems are excluded, as are musicians and
 pregnant women.

 Participants will come to the National Institutes of Health (NIH) Clinical Center for up to
 six sessions of functional magnetic resonance imaging (fMRI) scanning. MRI uses a strong
 magnetic field and radio waves to obtain images of body organs and tissues. The scanner is a
 metal cylinder surrounded by a magnetic field. During the MRI, the subject lies still for up
 to 20 minutes at a time on a table in the cylinder and wears earplugs to muffle loud knocking
 noises that occur with the electrical switching of the magnetic fields. He or she can
 communicate with the MRI staff through a microphone at all times during the procedure.

 For fMRI, images are obtained while the subject performs a task, such as hearing sounds or
 moving a finger. The machine detects changes in brain movement that are involved in
 performing the task. The tasks are explained, and subjects can practice them before entering
 the scanner.
Objective

 Rhythmic movements, such as finger tapping, are relatively simple. However, many brain areas
 including motor, somatosensory, premotor and prefrontal cortex, supplementary motor area,
 basal ganglia, cerebellum, etc. have been reported to be activated during rhythmic movements.
 Patients with lesions located in the extrapyramidal or cerebellar system, such as patients
 with Parkinson's disease, cerebellar ataxia or stroke with a lesion in these systems, have
 difficulties in performing rhythmic movements. Timing deficits after basal ganglia or
 cerebellar damage could also be due to abnormalities in interconnecting cortical systems
 commonly associated with these processes. Few studies have examined involvement of cerebral
 cortex in time perception.

 The purpose of this study is to detect the brain areas associated with three hypothesized
 processes associated with rhythm perception and generation: (1) perception of external
 rhythmic stimulation, (2) internal rhythm generation and (3) execution of rhythmic movement.
 To investigate whether the process of rhythm perception is common across sensory modalities,
 we will use auditory and visual stimulation.

 Study population

 This research will be conducted using normal adult volunteers.

 Design

 Using functional magnetic resonance imaging, we will examine the brain activity of subjects
 while they will hear or watch rhythmic stimulation and press buttons rhythmically with their
 fingers. A series of experiments will be designed to demonstrate the hypothesized three
 processes separately.

 Outcome measures

 The brain activity correlated with experimental conditions and behavioral data (the timing
 error of button press to the corresponding rhythmic stimulation) will be collected and
 analyzed by using statistical parametric mapping (SPM).

 The findings we expect to obtain with this experiment will contribute to basic knowledge for
 better understanding of the pathophysiology of the disturbance of perception and generation
 of rhythm in patients with neurological disorders, and give theoretical background for
 repetitive, rhythmically patterned movement training in neurorehabilitation.
-  INCLUSION CRITERIA:

 Fifty healthy, right-handed adult (aged between 21 to 65 years old) 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.

 Female subjects of childbearing potential will have a pregnancy test and a specific
 interview prior to the study to ensure that pregnant subjects will not participate in the
 study.

 EXCLUSION CRITERIA:

 Subjects with implanted devices such as pacemakers, medication pumps or defibrillators,
 metal in the cranium except mouth, intracardiac lines, history of shrapnel injury or any
 other condition/device that may be contraindicated or prevent the acquisition of MRI.

 Pregnant female. A pregnancy test will be performed within 24 hours preceding each MRI and
 if the result is positive, that subject will not be studied.

 Subjects with claustrophobia

 Subjects with any visual, motor or hearing difficulties

 Musicians