title: Primary motor cortex neurons classified in a postural task predict muscle activation patterns in a reaching task.
abstract: Primary motor cortex (M1) activity correlates with many motor variables, making it difficult to demonstrate how it participates in motor control. We developed a two-stage process to separate the process of classifying the motor field of M1 neurons from the process of predicting the spatiotemporal patterns of its motor field during reaching. We tested our approach with a neural network model that controlled a two-joint arm to show the statistical relationship between network connectivity and neural activity across different motor tasks. In rhesus monkeys, M1 neurons classified by this method showed preferred reaching directions similar to their associated muscle groups. Importantly, the neural population signals predicted the spatiotemporal dynamics of their associated muscle groups, although a subgroup of atypical neurons reversed their directional preference, suggesting a selective role in antagonist control. These results highlight that M1 provides important details on the spatiotemporal patterns of muscle activity during motor skills such as reaching.
authors: Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada;
authors: Ethan A
authors: http://orcid.org/0000-0002-0303-3065
authors: EA
authors: Heming
authors: Google DeepMind, London, United Kingdom;
authors: Timothy P
authors: TP
authors: Lillicrap
authors: Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada;
authors: Mohsen
authors: M
authors: Omrani
authors: Department of Exercise Science, University of South Carolina, Columbia, South Carolina;
authors: Troy M
authors: http://orcid.org/0000-0001-7466-1619
authors: TM
authors: Herter
authors: Department of Physiology and Pharmacology, Western University, London, Ontario, Canada; Robarts Research Institute, Western University, London, Ontario, Canada; Brain and Mind Institute, Western University, London, Ontario, Canada;
authors: J Andrew
authors: JA
authors: Pruszynski
authors: Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada; and Department of Medicine, Queen's University, Kingston, Ontario, Canada steve.scott@queensu.ca.
authors: Stephen H
authors: SH
authors: Scott
mesh_terms: D000818:Animals; D001132:Arm / Q000294:innervation / Q000502:physiology; D008253:Macaca mulatta; D008297:Male; D009044:Motor Cortex / Q000166:cytology / Q000502:physiology*; D009046:Motor Neurons / Q000502:physiology*; D009068:Movement; D018482:Muscle, Skeletal / Q000294:innervation* / Q000502:physiology; D011187:Posture
keywords: electromyography; motor fields; neural network model; primary motor cortex