Department of Biomechanics, University of Nebraska at Omaha, Omaha, NE 68182.
Department of Psychology, Arizona State University, Tempe, AZ 85287.
Proc Natl Acad Sci U S A. 2024 Jul 30;121(31):e2400687121. doi: 10.1073/pnas.2400687121. Epub 2024 Jul 23.
The seemingly straightforward task of tying one's shoes requires a sophisticated interplay of joints, muscles, and neural pathways, posing a formidable challenge for researchers studying the intricacies of coordination. A widely accepted framework for measuring coordinated behavior is the Haken-Kelso-Bunz (HKB) model. However, a significant limitation of this model is its lack of accounting for the diverse variability structures inherent in the coordinated systems it frequently models. Variability is a pervasive phenomenon across various biological and physical systems, and it changes in healthy adults, older adults, and pathological populations. Here, we show, both empirically and with simulations, that manipulating the variability in coordinated movements significantly impacts the ability to change coordination patterns-a fundamental feature of the HKB model. Our results demonstrate that synchronized bimanual coordination, mirroring a state of healthy variability, instigates earlier transitions of coordinated movements compared to other variability conditions. This suggests a heightened adaptability when movements possess a healthy variability. We anticipate our study to show the necessity of adapting the HKB model to encompass variability, particularly in predictive applications such as neuroimaging, cognition, skill development, biomechanics, and beyond.
系鞋带这个看似简单的任务，需要关节、肌肉和神经通路的复杂相互作用，这对研究协调复杂性的研究人员来说是一个巨大的挑战。一个被广泛接受的衡量协调行为的框架是 Haken-Kelso-Bunz（HKB）模型。然而，该模型的一个显著局限性是，它没有考虑到其经常建模的协调系统中固有的各种可变性结构。可变性是各种生物和物理系统中普遍存在的现象，它在健康成年人、老年人和病理人群中都会发生变化。在这里，我们通过实证和模拟实验表明，操纵协调运动中的可变性会显著影响改变协调模式的能力——这是 HKB 模型的一个基本特征。我们的结果表明，模拟健康可变性的双手同步协调会引发协调运动更早的转变，而其他可变性条件则不会。这表明当运动具有健康的可变性时，适应性会增强。我们预计我们的研究将表明需要适应 HKB 模型以包含可变性，特别是在神经影像学、认知、技能发展、生物力学等领域的预测应用中。
