Cerebral and cerebellar sensorimotor plasticity following motor imagery-based mental practice of a sequential movement

Michael G. Lacourse, PhD; Jessica A. Turner, PhD; Elizabeth Randolph-Orr, BFA; Steven L. Schandler, PhD; Michael J. Cohen, PhD

Neuromotor Rehabilitation Research Laboratory and Neuroimaging Research Laboratory, Department of Veterans Affairs Long Beach Healthcare System, Long Beach, CA; Department of Kinesiology and Physical Education, California State University, Long Beach, CA; Department of Psychiatry and Human Behavior, University of California, Irvine, CA; Chapman University, Orange, CA

Abstract - Motor behavior and sensorimotor activation of the cerebrum and cerebellum were measured before and after motor imagery-based mental practice (MP) and physical practice (PP) of a sequential motor task. Two-button-press sequences (A, B) were performed outside a magnetic resonance imaging scanner and at 2 Hz inside the scanner during a pretest. Participants (n = 39) completed PP, MP, or no practice (NP) of Sequence A for 1 week and were posttested. Sequence A performance improved 121%, 86%, and 4% for the PP, MP, and NP groups respectively (p < 0.05), while Sequence B improved 56%, 40%, and 38% (p > 0.05). PP improvements were accompanied by increased striatal and decreased cerebellar activation, while MP improvements were accompanied by increased cerebellar, premotor, and striatal activation. The efficacy of MP for activating cerebral and cerebellar sensorimotor networks suggests that MP might be an effective substitute or complement to PP to activate compensatory networks for motor rehabilitation.

Key words: basal ganglia, cerebellum, fMRI, mental practice, motor imagery, motor learning, neurorehabilitation, sensorimotor, supplementary motor area, thalamus.