Passive motion and active inference: Commentary on “Muscleless motor synergies and actions without movements: From motor neuroscience to cognitive robotics” by Vishwanathan Mohan, Ajaz Bhat and Pietro Morasso

Abstract

Mohan et al offer an exhaustive and compelling survey of different paradigms for understanding an embodied exchange with the world. They describe a new way of looking at motor control that has emerged over the past years, – a view that resolves many issues with previous (optimal motor control) formulations. Pleasingly, this new way of looking at things picks up on historical themes that date back to the 19th century. For example, notions of synergy formation and the equilibrium point hypothesis, re-emerge with a new simplicity and explanatory power, when one takes a holistic and enactive view of embodied behaviour. Indeed, one might trace the ideas explored in Mohan et al back to foundational notions enshrined in ideomotor theory and Helmholtz's notion of unconscious inference. This new way of looking at things is centred on the notion of a forward or generative model that plays the functional role of a “plastic configurable internal representation of the body (body schema) as a critical link enabling the seamless continuum between motor control and imagery.” Mohan et al.