Parallels between Sensory and Motor Information Processing
Emanuel Todorov · The Cognitive Neurosciences · 2009
The computational problems solved by the sensory and motor systems appear very different: one has to do with inferring the state of the world given sensory data, the other with generating motor commands appropriate for given task goals. However recent mathematical developments summarized in this chapter show that these two problems are in many ways related. Therefore information processing in the sensory and motor systems may be more similar than previously thought – not only in terms of computations but also in terms of algorithms and neural representations. Here we explore these similarities as well as clarify some differences between the two systems. Similarity between inference and control: an intuitive introduction Consider a control problem where we want to achieve a certain goal at some point in time in the future – say, grasp a coffee cup within 1 sec. To achieve this goal, the motor system has to generate a sequence of muscle activations which result in joint torques which act on the musculo-skeletal plant in such a way that the fingers end up curled around the cup. Actually the motor system does not have to compute the entire