Neural Organization of Hierarchical Motor Sequence Representations in the Human Neocortex
Document Type
Article
Publication Date
9-25-2019
Journal
Neuron
Volume
103
Issue
6
First Page
1178
Last Page
1190.e7
URL with Digital Object Identifier
10.1016/j.neuron.2019.06.017
Abstract
© 2019 Elsevier Inc. Although it is widely accepted that the brain represents movement sequences hierarchically, the neural implementation of this organization is still poorly understood. To address this issue, we experimentally manipulated how participants represented sequences of finger presses at the levels of individual movements, chunks, and entire sequences. Using representational fMRI analyses, we then examined how this hierarchical structure was reflected in the fine-grained brain activity patterns of the participants while they performed the 8 trained sequences. We found clear evidence of each level of the movement hierarchy at the representational level. However, anatomically, chunk and sequence representations substantially overlapped in the premotor and parietal cortices, whereas individual movements were uniquely represented in the primary motor cortex. The findings challenge the common hypothesis of an orderly anatomical separation of different levels of an action hierarchy and argue for a special status of the distinction between individual movements and sequential context.
Notes
This article is freely available from the publisher