Distinguishable brain activation networks for short- and long-term motor skill learning
Distinguishable brain activation networks for short- and long-term motor skill learning
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DOI：
10.1152/jn.00717.2004
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发表时间：
2005-07-01
影响因子：
2.5
通讯作者：
Matthews, PM
中科院分区：
文献类型：
--
作者：
Floyer-Lea, A;Matthews, PM
新的运动技能的获得的特征首先是表现迅速提高的短期快速学习阶段，随后是额外的表现增益是递增的长期较慢的学习阶段。以前的功能成像研究表明，不同的大脑网络介导了这两个学习阶段，但没有使用相同的任务进行直接比较。在这里，我们使用了一个任务，在该任务中，受试者学习跟踪一个连续的8-S序列，要求可变的等长力量发展之间的手指和拇指的优势，右手。学习相关的变化，大脑激活的特点是使用功能磁共振成像（fMRI）在短期学习的一个新的序列，在短期学习之前，短暂暴露的序列，并在长期（3周）的任务培训。短期学习与背外侧前额叶、前扣带回、后顶叶、初级运动和小脑皮质的活动减少有关，与右侧小脑齿状核、左侧壳核和左侧丘脑的活动增加有关。前额叶，顶叶和小脑皮质的变化不明显，短期学习后，事先暴露的序列。随着长期学习，活动的增加被发现在左侧初级躯体感觉和运动皮层和右侧壳核。我们的观察扩展了以前的工作，表明可区分的网络在运动学习的不同阶段被招募。虽然短期的运动技能学习似乎主要与特定的学习动作的皮层网络中的激活，长期的学习涉及增加激活的双半球皮质-皮质下网络的模式，这表明“塑料”的发展新的代表运动输出和体感传入信息。
The acquisition of a new motor skill is characterized first by a short-term, fast learning stage in which performance improves rapidly, and subsequently by a long-term, slower learning stage in which additional performance gains are incremental. Previous functional imaging studies have suggested that distinct brain networks mediate these two stages of learning, but direct comparisons using the same task have not been performed. Here we used a task in which subjects learn to track a continuous 8-s sequence demanding variable isometric force development between the fingers and thumb of the dominant, right hand. Learning-associated changes in brain activation were characterized using functional MRI (fMRI) during short-term learning of a novel sequence, during short-term learning after prior, brief exposure to the sequence, and over long-term (3 wk) training in the task. Short-term learning was associated with decreases in activity in the dorsolateral prefrontal, anterior cingulate, posterior parietal, primary motor, and cerebellar cortex, and with increased activation in the right cerebellar dentate nucleus, the left putamen, and left thalamus. Prefrontal, parietal, and cerebellar cortical changes were not apparent with short-term learning after prior exposure to the sequence. With long-term learning, increases in activity were found in the left primary somatosensory and motor cortex and in the right putamen. Our observations extend previous work suggesting that distinguishable networks are recruited during the different phases of motor learning. While short-term motor skill learning seems associated primarily with activation in a cortical network specific for the learned movements, long-term learning involves increased activation of a bihemispheric cortical-subcortical network in a pattern suggesting "plastic" development of new representations for both motor output and somatosensory afferent information.