A comparison of 'Early' and 'Late' stage brain activation during brief practice of a simple motor task

This research study addresses the question: does the neural circuit impleme nting a motor task undergo change as a function of even limited practice.! To detect potential neural changes associated with limited practice we comp ared brain activation at the early and late stages of motor performance on a simple task over one relatively brief session. Single-finger opposition s erved as cognitive stimulation during collection of BOLD fMRI signal. We pr edicted prefrontal cortex activation would be prominent early, with basal g anglia activation becoming prominent during late stage performance. Results revealed that both early and late performance involve areas in the cerebel lum, prefrontal, mid-temporal, extrastriate, and parietal cortices, but tha t the particular regions within these broad areas differed for the two poin ts of performance. The strongest dissociation between early and late perfor mance involved the corpus striatum, thalamus, and cingulate gyrus. The find ings suggested the neural circuit implementing this simple task varied over a relatively brief window of practice. Implications for defining the neuro cognitive function of the structures involved, particularly the cerebellum, are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.