Last Saturday, another “Classico” saw Messi and Ronaldo display their other-worldly skills and ball control. At the heart of their performance stands the amazing ability to control their bodies in anticipation of the movements of their team members, opponents – and especially the football.
These anticipatory motor actions are essential for sport, but also underlie our everyday behavior, from walking or grasping to riding a bicycle or typing on a keyboard. But how exactly are these actions controlled?
A recent study by the SPECS group at IBEC, directed by Prof. Paul Verschure, challenges the dominant view in neuroscience that the brain produces anticipatory actions as a sensory-motor process driven by errors in motor performance – in other words, an error in behavior triggers corrective motor commands that are executed before the less optimal action is realized. In contrast, the new study proposes that adaptive fast and skilled motor actions result from the surprising ability of the brain to simulate the future.
Using a theoretical model, and in collaboration with Karl Friston’s Theoretical Neurobiology group at University College London – recently named the most influential scientist in neuroscience – the SPECS group hypothesizes that animals seamlessly and unconsciously control their bodies based on an internal simulation of what the world will be like just after motor actions are realized. Through learning, this internal simulation will get more and more precise in predicting the future, and the motor systems that respond to it will be better tuned to how the body interacts with the real world.
“Our model incorporates insights from the cerebellum, the brain structure that is linked to action, and which makes up about 70% of all our neurons,” says Paul. “The cerebellum provides the rest of the brain with an estimate of the future that precedes the real world by hundreds of milliseconds. Primitive motor centers react to these predicted states as if they were already occurring. For example, if Messi is anticipating receiving the football just as an opponent pushes him, he usually won’t fall, because of rapid corrective action.”
Understanding biological anticipatory control has important implications in several areas. It can help develop more adaptive robot control systems; the next generation of ‘soft’ robots, which include artificial muscles and prosthetics, will rely on anticipatory control for their compliance, physical flexibility and robustness. The study also sheds new light on how we can approach the restoration of motor function after stroke and brain injury, giving further credibility to the simulation-oriented perspective that the SPECS group has been pioneering with its Rehabilitation Gaming System, used by over 1000 stroke patients so far. It could even be used to help the stars of the “Classico” hone their skills even further.
Article citation: Giovanni Maffei, Ivan Herreros, Marti Sanchez-Fibla, Karl J. Friston, Paul F. M. J. Verschure (2017). The perceptual shaping of anticipatory actions. Proc. R. Soc. B, 284, 20171780