Understanding Sensorimotor Feedback through Optimal Control

Excerpt

The general problem of “control” may be divided into two main categories, often designated open-loop and closed-loop (see Fig. 1). We adopt here the convention of using “controller” to designate a device that formulates a set of commands intended to change the state of a system, which commands are executed openloop, i.e., without modification during the task. (We emphasize that this is a shorthand terminology, not to be confused with the standard usage in control theory denoting both open- and closed-loop components.) We use the term “regulator” to designate a device that attempts to stabilize the state of a system, generating only closed-loop commands, i.e., responses to deviations from the state detected by sensors in the system (Bryson and Ho 1975). Obviously, most complex systems require a mixture of the two types of control.

In sensorimotor neurophysiology, it is common to depict these kinds of controls schematically as if they...