Journal article
How is a motor skill learned? Change and invariance at the levels of task success and trajectory control
Journal of Neurophysiology, Vol.108(2), pp.578-594
Jul/2012
Abstract
Shmuelof L, Krakauer JW, Mazzoni P. How is a motor skill learned? Change and invariance at the levels of task success and trajectory control. J Neurophysiol 108: 578-594, 2012. First published April 18, 2012; doi:10.1152/jn.00856.2011.-The public pays large sums of money to watch skilled motor performance. Notably, however, in recent decades motor skill learning (performance improvement beyond baseline levels) has received less experimental attention than motor adaptation (return to baseline performance in the setting of an external perturbation). Motor skill can be assessed at the levels of task success and movement quality, but the link between these levels remains poorly understood. We devised a motor skill task that required visually guided curved movements of the wrist without a perturbation, and we defined skill learning at the task level as a change in the speed-accuracy trade-off function (SAF). Practice in restricted speed ranges led to a global shift of the SAF. We asked how the SAF shift maps onto changes in trajectory kinematics, to establish a link between task-level performance and fine motor control. Although there were small changes in mean trajectory, improved performance largely consisted of reduction in trial-to-trial variability and increase in movement smoothness. We found evidence for improved feedback control, which could explain the reduction in variability but does not preclude other explanations such as an increased signal-to-noise ratio in cortical representations. Interestingly, submovement structure remained learning invariant. The global generalization of the SAF across a wide range of difficulty suggests that skill for this task is represented in a temporally scalable network. We propose that motor skill acquisition can be characterized as a slow reduction in movement variability, which is distinct from faster model-based learning that reduces systematic error in adaptation paradigms.
Details
- Title
- How is a motor skill learned? Change and invariance at the levels of task success and trajectory control
- Creators
- Lior Shmuelof (null) - 972WIS_INST___83John W. Krakauer (null)Pietro Mazzoni (null)
- Resource Type
- Journal article
- Publication Details
- Journal of Neurophysiology, Vol.108(2), pp.578-594; Jul/2012
- Number of pages
- 17
- Language
- English
- DOI
- https://doi.org/10.1152/jn.00856.2011
- Grant note
- National Institute of Neurological Disorders and Stroke [R01-NS-052804]; Machiah Foundation/Jewish Community Federation; Parkinson's Disease FoundationThis research was supported by National Institute of Neurological Disorders and Stroke Grant R01-NS-052804 (to J.W.K., P.M.), Machiah Foundation/Jewish Community Federation (to L.S.), and the Parkinson's Disease Foundation (to P.M.)._ALMAME_DELIMITER_
- Record Identifier
- 993267602503596
Metrics
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