Explaining human motor coordination via the synergy expansion hypothesis

• 成果类型: Article
• 署名作者: Tessari, Federico; West Jr, A. Michael; Hogan, Neville
• 署名单位: Massachusetts Institute of Technology (MIT); Johns Hopkins University; Massachusetts Institute of Technology (MIT)
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-11749
• DOI: 10.1073/pnas.2501705122
• 发表日期: 2025-04-08
• 关键词: muscle synergies; hand synergies; basal ganglia; movements; posture; stroke; prehension; REPRESENTATION; primitives; direction

摘要

The search for an answer to Bernstein's degrees of freedom problem has propelled a large portion of research studies in human motor control over the past six decades. Different theories have been developed to explain how humans might use their incredibly complex neuro-musculo-skeletal system with astonishing ease. Among these theories, motor synergies appeared as one possible explanation. In this work, the authors investigate the nature and role of synergies and propose a theoretical framework, namely the expansion hypothesis, to answer Bernstein's problem. The expansion hypothesis is articulated in three propositions: mechanical, developmental, and behavioral. Each proposition addresses a different question on the nature of synergies: i) How many synergies can humans have? ii) How do we learn and develop synergies? iii) How do we use synergies? An example numerical simulation is presented and analyzed to clarify the hypothesis propositions. The expansion hypothesis is contextualized with respect to the existing literature on motor synergies both in healthy and impaired individuals, as well as other prominent theories in human motor control and development. The expansion hypothesis provides a framework to better comprehend and explain the nature, use, and evolution of human motor skills.