Mark Hallett (neurologist)

Mark Hallett is an American neurologist who researched the physiology of human movement and movement disorders including functional motor disorders at the NIH, and currently serves as Distinguished NIH Investigator Emeritus. Hallett worked at NIH for 40 years in the federal government, with several decades at the Human Motor Control Section and was previously chief of the Clinical Neurophysiology Laboratory at Brigham Women's Hospital.

Research
Hallett has contributed work "to the principles of normal human voluntary movement, understanding the motor system and movement disorders including dystonia, parkinsonism and myoclonus, and the use of transcranial magnetic stimulation (TMS) and botulinum toxin to treat movement disorders." He is noted for his prolific research output throughout his career and is the 96th most cited scientist in the United States, according to Research.com, by h-index. Hallett has suggested that education, awareness, and availability of the latest treatment programs remains a key challenge for motor diseases. His work is considered to be pioneering in the field of functional motor disorders.

Hallett is also considered a pioneer of the field of TMS and helped create the first conferences on TMS safety guidelines, as well as providing additional foundational research around principles of brain stimulation; he was awarded the 2019 International Brain Stimulation Award as a result.

Career
Hallett graduated from Harvard with an AB and MD and trained at Peter Bent Brigham hospital and Massachusetts General Hospital. Hallett also founded the Functional Neurological Disorder Society in 2003 and served as an editor in chief of Clinical Neurophysiology. He has also served as President of the International Parkinson and Movement Disorder Society and Vice-President of the American Academy of Neurology. He retired from NIH and serves as professor emeritus as of 2023 after 40 years of federal service. Hallett pioneered experimental botulinum injections to treat Leon Fleisher's hand dystonia. In the wake of diplomats suffering Havana Syndrome, Hallett was among the physicians asked to examine the diplomats.

Neurophysiology of free will
Hallett has worked on topics of volition and free will through a neurophysiological lens, including reformulations of the Libet clock experiment.