Feedback in Movement
As adults, our ability to walk from one place to another, maintaining our balance even if the terrain is somewhat uneven, avoiding obstacles along the way, and deviating from our path if we change our mind about where we want to go, all occur so effortlessly and without conscious thought that we take this all for granted - I suspect most of us think of these as being "reflexive" behaviours just because they are unconscious actions!
However, sophisticated movements require increasing levels of control both in terms of the components that make up that movement and in terms of the brain areas involved. Think for example of playing tennis and having to run to make a return - the coordination of legs to produce rhythmic movement propelling us towards the ball, the planning that starts us moving our upper body and the arm holding the tennis racket in a fluid motion to bring the racket from behind us smoothly forward to make contact with the ball at the right, the "automatic" adjustments of our other arm and the shift in body weight so that we maintain our balance through this entire process.....
So, voluntary movement involves a number of levels of control, from reflexes through to highly planned and controlled motions that use feedback adjustments to continuously refine the motions (e.g., running to catch a ball that's been thrown to one side). Accurate and successful performance of voluntary movements is a complex and highly integrated process involving fine control of muscle activity, with guidance from sensory feedback to the central nervous system.
In the simulations here, we will examine the role of feedback in the control of movements, especially the role of sensory input in control of movement.