Submovements in visually-guided and memory-guided reaching tasks: Changes in Parkinson´s disease

Movements in people with Parkinson´s disease are often hypometric, although we have found that this was not the case in an experimental visually-guided reaching task. We wished to explore our hypotheses that (1) people with Parkinson´s disease produce hypometric primary submovements but (2) are able to use visual feedback to accurately reach the target in a single overall movement, and (3) this effect may be greater in memory-guided tasks in which an internal representation of the target location is used instead of a fixation-centered representation of the target.