Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4321394 | Neuron | 2012 | 11 Pages |
SummaryMotor 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.
► Chunk concatenation is correlated with activity of the putamen ► Chunk segmentation is correlated with activity of a left frontoparietal network ► Multitrial community detection is a reliable estimator of chunk structure ►Multitrial community detection is sensitive to both subject and sequence variability