Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106, USA.
Neuron. 2012 Jun 7;74(5):936-46. doi: 10.1016/j.neuron.2012.03.038.
Motor chunking facilitates movement production by combining motor elements into integrated units of behavior. Previous research suggests that chunking involves two processes: concatenation, aimed at the formation of motor-motor associations between elements or sets of elements, and segmentation, aimed at the parsing of multiple contiguous elements into shorter action sets. We used fMRI to measure the trial-wise recruitment of brain regions associated with these chunking processes as healthy subjects performed a cued-sequence production task. A dynamic network analysis identified chunking structure for a set of motor sequences acquired during fMRI and collected over 3 days of training. Activity in the bilateral sensorimotor putamen positively correlated with chunk concatenation, whereas a left-hemisphere frontoparietal network was correlated with chunk segmentation. Across subjects, there was an aggregate increase in chunk strength (concatenation) with training, suggesting that subcortical circuits play a direct role in the creation of fluid transitions across chunks.
运动模块化为运动元素组合成行为的整合单元提供了便利。先前的研究表明，模块化为两个过程：连接，旨在形成元素或元素集之间的运动-运动关联，以及分割，旨在将多个连续的元素解析为更短的动作集。当健康受试者执行提示序列产生任务时，我们使用 fMRI 测量与这些模块形成过程相关的大脑区域的试验招募情况。动态网络分析为在 fMRI 期间获得的一组运动序列确定了模块结构，并在 3 天的训练中进行了收集。双侧感觉运动壳核的活动与模块连接呈正相关，而左半球额顶叶网络与模块分割相关。在所有受试者中，随着训练的进行，模块强度（连接）呈总体增加趋势，这表明皮质下回路在跨模块流畅转换的创建中发挥了直接作用。
