Rossi Cristina, Roemmich Ryan T, Bastian Amy J
Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
Center for Movement Studies, Kennedy Krieger Institute, Baltimore, MD, 21205, USA.
NPJ Sci Learn. 2024 Jul 23;9(1):48. doi: 10.1038/s41539-024-00258-2.
Our nervous system has the remarkable ability to adapt our gait to accommodate changes in our body or surroundings. However, our adapted walking patterns often generalize only partially (or not at all) between different contexts. Here, we sought to understand how the nervous system generalizes adapted gait patterns from one context to another. Through a series of split-belt treadmill walking experiments, we evaluated different mechanistic hypotheses to explain the partial generalization of adapted gait patterns from split-belt treadmill to overground walking. In support of the credit assignment hypothesis, our experiments revealed the central finding that adaptation involves recalibration of two distinct forward models. Recalibration of the first model generalizes to overground walking, suggesting that the model represents the general movement dynamics of our body. On the other hand, recalibration of the second model does not generalize to overground walking, suggesting the model represents dynamics specific to treadmill walking. These findings reveal that there is a predefined portion of forward model recalibration that generalizes across context, leading to overall partial generalization of walking adaptation.
我们的神经系统具有非凡的能力，能够调整我们的步态以适应身体或周围环境的变化。然而，我们适应后的行走模式在不同情境之间往往只能部分（或根本不能）泛化。在此，我们试图了解神经系统如何将适应后的步态模式从一种情境泛化到另一种情境。通过一系列分带跑步机行走实验，我们评估了不同的机制假设，以解释适应后的步态模式从分带跑步机到地面行走的部分泛化现象。支持信用分配假设的是，我们的实验揭示了核心发现，即适应涉及对两个不同前向模型的重新校准。第一个模型的重新校准可以泛化到地面行走，这表明该模型代表了我们身体的一般运动动力学。另一方面，第二个模型的重新校准不能泛化到地面行走，这表明该模型代表了跑步机行走特有的动力学。这些发现表明，前向模型重新校准中有一个预定义的部分可以跨情境泛化，从而导致行走适应的整体部分泛化。
