Download New insights into human M1 function: Mapping hand

New insights into human M1 function: Mapping hand
representation and visuomotor adaptation
Eugene Tunik
Physical Therapy, Movement Science, and Rehabilitation, Northeastern University
Unit and population recordings in motor cortical neurons of animals have been systematically
used since about the 1960’s to understand the basic features of movement that are represented in
the motor cortex (M1). This body of work has highlighted the potentially multifaceted role that
M1 may play in encoding basic elements of movement, such as movement direction and force, as
well as more complex features such as muscle groupings (e.g., synergies) and even learning
novel sensorimotor mappings (e.g. adaptation). Analogous approaches to study the physiology of
M1 in humans have progressed more slowly. The focus of this talk will be to describe two
ongoing tracks of research in my lab that use non-invasive brain stimulation (TMS) as a means
of filling this gap in the literature. The first will center on using TMS-based mapping to study the
structural synergy representations in M1, and compare these maps to functional synergies that
are formed during natural voluntary hand movements. The second will center on using
longitudinal assays of motor evoked potentials (elicited by TMS) to determine if changes in M1
excitability track with motor learning, un-learning, and re-learning in two instantiations: gain
adaptation and mirror feedback adaptation. Efforts will be made to weave in data describing how
some of these explorations have been translated to clinical research.