Changes in brain activity during motor learning measured with PET: Effects of hand of performance and practice

Department of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Journal of Neurophysiology (Impact Factor: 3.04). 11/1998; 80(4):2177-99.
Source: PubMed

ABSTRACT The aim of this study is to assess brain activity measured during continuous performance of design tracing tasks. Three issues were addressed: identification of brain areas involved in performing maze and square tracing tasks, investigation of differences and similarities in these areas related to dominant and nondominant hand performance, and most importantly, examination of the effects of practice in these areas. A total of 32 normal, right-handed subjects were instructed to move a pen with the dominant right hand (16 subjects) or nondominant left hand (16 subjects) continuously through cut-out maze and square patterns with their eyes closed during a 40-s positron emission tomography (PET) scan to measure regional blood flow. There were six conditions: 1) holding the pen on a writing tablet without moving it (rest condition); 2) tracing a maze without practice; 3) tracing the same maze after 10 min of practice; 4) tracing a novel maze; and tracing an easily learned square design at 5) high or 6) low speed. To identify brain areas generally related to continuous tracing, data analyses were performed on the combined data acquired during the five tracing scans minus rest conditions. Areas activated included: primary and secondary motor areas, somatosensory, parietal, and inferior frontal cortex, thalamus, and several cerebellar regions. Then comparisons were made between right- and left-hand performance. There were no significant differences in performance. As for brain activations, only primary motor cortex and anterior cerebellum showed activations that switched with hand of performance. All other areas, with the exception of the midbrain, showed activations that were common for both right- and left-hand performance. These areas were further analyzed for significant conditional effects. We found patterns of activation related to velocity in the contralateral primary motor cortex, related to unskilled performance in right premotor and parietal areas and left cerebellum, related to skilled performance in supplementary motor area (SMA), and related to the level of capacity at which subjects were performing in left premotor cortex, ipsilateral anterior cerebellum, right posterior cerebellum and right dentate nucleus. These findings demonstrate two important principles: 1) practice produces a shift in activity from one set of areas to a different area and 2) practice-related activations appeared in the same hemisphere regardless of the hand used, suggesting that some of the areas related to maze learning must code information at an abstract level that is distinct from the motor performance of the task itself.

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    • "Finally, as the infant becomes a skilled walker, he falls less, is able to balance better, and incorporates other more complex motor activities such as running [1]. Although the precise mechanism of muscle memory is unknown , it is theorized that when an individual learns a new motor activity or practices an older one, it leads to significant brain activity at that time in the anterior cingulated gyrus, prefrontal cortex, primary motor cortex and cerebellum, areas related to higher leaning , planning, coordination and execution of motor function [2] [3]. "
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    Medical Hypotheses 09/2012; 79(6). DOI:10.1016/j.mehy.2012.08.025 · 1.15 Impact Factor
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    • "Previous PET studies found that rCBF in the cerebellum had a significant positive relationship with the velocity of joystick movements about the wrist joint (Jenkins et al., 1997; Turner et al., 1998; van Mier et al., 1998; VanMeter et al., 1995). A study in humans using fMRI found that BOLD activation in bilateral lobule V, vermis VI, and vermis VIII scaled significantly with increasing frequency of bimanual, cyclical movements (Debaere et al., 2004). "
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    • "Consistent with this, we observed a correlation between BOLD signal and learning behavior in left parietal opercular cortex, part of a network for predicting sensory consequences of motor commands along with brainstem nuclei and the cerebellum [Blakemore et al., 1999]. There is also evidence for subcortical activation in the right dentate nucleus with learning [Doyon et al., 2002; van Mier et al., 1998], a region that correlates with individual behavioral variation in this study. Consistent with this, we find correlations between motor learning and FA within cerebellar WM, although, given the spatial resolution of the imaging data, it is difficult to determine precisely whether these WM locations are related to the GM regions showing structural and functional covariations. "
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