The purpose of this protocol is to learn about movement intention and volition. To improve such knowledge, investigators will conduct sub-studies using multiple non-invasive methodologies. These results could provide preliminary data for subsequent studies evaluating local and global efficacy of plasticity-inducing treatments for PMD symptoms.

This study will:

• Explore effects of TMS and tDCS on movement intention.
• Discern the neural activity underlying modulation of movement intention with neuroimaging recording.
• Identify brain stimulation's effect in patients with psychogenic tremor and non-epileptic seizures.
• Technical development of new experimental paradigms and data analysis methods.
• Data collection for hypotheses development.

Inclusion Criteria:

(Healthy Controls)

• Fluent in English

(Patients with PMD or PNES):

• Diagnosis of PMD/PNES confirmed by a neurologist with expertise in movement disorders.
• Per the treating neurologist, subject is unlikely to require treatment and/or dosage changes for 3-6 months following screening

Exclusion Criteria:

• Any history of a significant neurological disorder, which may interfere with the interpretation of study data, as determined by the PI
• Chronic or progressive medical condition
• Any history of traumatic brain injury or significant head trauma
• Currently meets criteria for substance abuse or dependence
• History of any psychotic disorder or other psychiatric condition which may interfere with data interpretation
• Pregnancy
• Metal or devices in the head, including neurostimulators or metal foreign bodies
• Any other implanted metal device, including pacemaker, spinal cord stimulator, VNS.
• Any other ferromagnetic substance in the body that may increase study risk (including dental prosthetics, etc.).
• Taking tricyclic antidepressant or antiepileptic medications or CNS active drugs under "strong potential hazard" list in Rossi et al., 2009
• Current diagnosis of any inflammatory or autoimmune disorder within last 6 months

PMD and PNES Patients

• Any history of traumatic brain injury or significant head trauma
• Diagnosis of organic seizure disorder, including febrile seizures and tonic-clonic seizures;
• Neurological disorder other than PMD and PNES including stroke, fainting spells or syncope of unknown cause(s);
• Major or unstable medical illness, especially any current diagnosis of inflammatory or autoimmune disorders within last 6 months
• Metal or devices in the head, including neurostimulators or metal foreign bodies
• Taking tricyclic antidepressant medications or CNS active drugs under "strong potential hazard" list in Rossi et al., 2009;
• Diagnosis of dementia, or Montreal Cognitive Assessment (MoCA) ≤24;
• Recurrent visual hallucinations, within the past 6 months;
• History of significant uncontrollable movements of the head;
• Any clinically significant abnormality on vital signs