NIMLAB Study Information

Investigation of cerebellar involvement in cognitive sequencing

Study Description

The sections below describe the different arms of the study and the experiments associated with each. Please note that the eligibility criteria and travel reimbursements differ for each arm of the study.

For all arms of the study, interested individuals should contact the study coordinators by phone call, text, or email (see info above) to ensure that they meet all eligibility criteria.

Experiments 1 & 2

These experiments investigate the role of the cerebellum on cognitive processes related to language. Individuals with spinocerebellar ataxia (confirmed with genetic testing) and healthy controls between 18 and 85 years of age are being recruited for this arm of the study. Participants will perform two experiments while undergoing functional MRI scanning, which allows researchers to visualize brain activity. Experiment 1 assesses how the brain mentally keeps track of verbal information, like a sequence of letters or numbers. Experiment 2 assesses how the brain begins to learn a new language.

In all, participation in the study entails a five-hour visit to the Johns Hopkins University School of Medicine. This includes being in the MRI scanner for approximately 1 hour and 45 minutes. Enrolled participants will be compensated $25 an hour for their time. Travel reimbursements and hotel accommodation are available for out-of-town patients with ataxia. While the study does not provide any direct benefits to participants, the data collected from the study may reveal information about the role of the cerebellum in language and help identify targets for future interventions. Participants may receive copies of their brain images upon request.

Experiment 3

This experiment investigates the effects of transcranial magnetic stimulation (TMS), a non-invasive brain stimulation technique, on verbal working memory during functional MRI scanning. TMS uses rapidly changing magnetic fields to induce brief, temporary electric changes in the brain. We are recruiting healthy individuals between the ages of 18 and 50 for this arm of the study. Participants will perform verbal memorize-and-recall tasks while their brain is scanned and occasionally stimulated. This will allow us to study the effects of TMS on overall brain activity and task performance.

Participation in this experiment will involve a three hour visit to Johns Hopkins University School of Medicine. Subjects will be in the MRI scanner for approximately 1 hour and 15 minutes. Enrolled participants will be compensated $25 per hour for their time. Although subjects will not receive any direct benefits from their participation, the results from this study may help illuminate the subtle ways the cerebellum contributes to verbal cognition. Participants may receive copies of their brain images upon request.

Experiment 4

Only individuals who are between 18 and 85 and who have confirmed genetic testing for spinocerebellar ataxia may participate in Experiment 4, which examines whether phonemic fluency (the ability to generate words starting with a particular letter, which can impact the ability to converse) can be improved by transcranial direct current stimulation (tDCS). During tDCS, a small amount of current is passed between electrodes on the scalp, causing temporary changes in brain activity. We will explore whether different electrode configurations can alleviate phonemic fluency deficits. Subjects will undergo functional MRI scans at rest and during a verbal fluency task while simultaneous receiving tDCS.

Participation in this experiment involves one to two visits to the Johns Hopkins Medical Center and at least one MRI scanning session. Each visit will last between one hour and three hours. Enrolled participants will be compensated $25 an hour for their time. In addition, the study coordinators can arrange a complimentary one to two night stay at the Residence Inn on the medical campus as well as ground transportation for enrolled subjects. Since the tDCS effects that will be explored in this study are believed to be temporary, there will be no direct benefits to those who participate. However, data gathered from this study could potentially inform the design of tDCS protocols that have long-term benefits. Participants may receive copies of their brain images upon request.