The purpose of the study is to assess the status of brain-derived neurotrophic factor brain (BDNF) and how the brain behaves in response to skill acquisition. Specifically we will investigate the relationship of the status of BDNF with cortical excitability changes and learning that occur during a motor training paradigm. We aim to 1) determine cortical excitability changes by using transcranial magnetic stimulation (TMS) before and after training; 2) to determine finger tracking accuracy before and after training; and 3) determine the presence of BDNF polymorphism in each participant. We are testing healthy adults in this study, and eventually would like to apply to persons who have neurologic disorders such as stroke or dystonia. By applying a magnetic field to the outside of the head, electrical currents are produced within the brain that can stimulate brain tissue. Using TMS, the brain can be studied to gain a greater understanding of the mechanisms associated with cortical excitability in healthy and patient populations. There is limited knowledge of what influence genetic biomarkers such as BDNF have on cortical excitability changes within the cortex following learning. Studies have indicated that people without this certain gene are less likely to show changes in brain excitability during TMS and during motor learning than people with this gene
Description: A computer quantified tracking performance measure in each test. This is a calculation of accuracy by using the equation: AI = 100(P-E)/P. Where E is the root mean square (r.m.s.) error between the target line and the response line, and P is the size of the individual's target pattern, calculated as the r.m.s. difference between the sine wave and the midline separating the upper and lower phases of the sine wave. The magnitude of P is determined by the scale of the vertical axis, which is the subject's range of finger motion. Therefore, the AI is normalized to each subject's own range of motion and takes into account any differences between subjects in the excursion of the tracking target. The maximum possible score is 100%. Negative scores occur when the response line is so distant from the target that it falls on the opposite side of the midline.
Measure: Accuracy Index Time: Day 1: posttest after trainingDescription: Cortical excitability will be measured with transcranial magnetic stimulation (TMS) single and paired pulse stimulation to measure short-interval intracortical inhibition (SICI), cortical silent period (CSP) and motor evoked potential (MEP) amplitude.
Measure: Cortical Excitability Time: Day 1: baselineDescription: Cortical excitability will be measured with transcranial magnetic stimulation (TMS) single and paired pulse stimulation to measure short-interval intracortical inhibition (SICI), cortical silent period (CSP) and motor evoked potential (MEP) amplitude.
Measure: Cortical Excitability Time: Day 1: posttestDescription: BDNF genetic variant screening will be conducted via saliva sample collected at the end of the session on day 1. We will screen for the Val66met polymorphism.
Measure: BDNF genetic status Time: Day 1Cohort
There is one SNP
We will screen for the Val66met polymorphism.. Inclusion Criteria: - 18-45 years - no past history of psychiatric or neurologic disease. --- Val66met ---