Many people have a habit of gesticulating when talking. Some people do it too much while others are more subtle. To a viewer, constant hand waving while talking may seem distracting. To the speaker, however, they may never notice. We learned that the hand waving is an output that triggers in input of the person seeing their hands move. When people are habituated to moving their hands, their vision may change but they are still unaware of the motions. Does the eye habituate to the hand motions? A series of hand motions are never the same so the eye does constantly receive a change in output. Maybe, the brain is used to not the physical movements but the pattern of activity necessary to move the arms. I’m not sure. How does the brain habituate itself to a habit?