Functional Brain Network Changes in Patients Undergoing Deep Brain Stimulation for Essential Tremor

Inclusion Criteria: * Between 30 and 80 years of age; * Ability to provide informed consent; * Clinical diagnosis of ET by a movement disorders neurologist with a disease duration of at least 3 years and being treated with a DBS; OR * Clinical diagnosis of ET by a movement disorders neurologist with a disease duration of at least 3 years and not being treated with a DBS; OR * No known neurological disease or disorder. Exclusion Criteria: * The individual has a condition that, in the opinion of the investigator, would significantly increase the risk for interference with study compliance, safety, or outcome; * Presence of active psychiatric symptoms meeting Diagnostic and Statistical Manual of Mental Disorders-4th Edition (DSM-IV) criteria for Axis-I disorder on formal psychiatric evaluation other than depression or anxiety; * History of cognitive impairment meeting Diagnostic and Statistical Manual of Mental Disorders-4th Edition (DSM-IV) criteria for dementia on formal neuropsychological evaluation, as documented in chart; * Lack of English-language fluency which would interfere with the ability to understand the study consenting process and potential study risks; * Hearing or visual impairment precluding testing; * Motor impairment impacting test responses (i.e., orthopedic injury or disease); * Anyone currently taking medications with Antabuse-like effects (e.g. Flagyl, Bactrim, Tindamax) will be excluded from any alcohol administration.