Neurology of volition.

Neurological disorders of volition may be characterized by deficits in willing and/or agency. When we move our bodies through space, it is the sense that we intended to move (willing) and that our actions were a consequence of this intention (self-agency) that gives us the sense of voluntariness and a general feeling of being "in control." While it is possible to have movements that share executive machinery ordinarily used for voluntary movement but lack a sense of voluntariness, such as psychogenic movement disorders, it is also possible to claim volition for presumed involuntary movements (early chorea) or even when no movement is produced (anosognosia). The study of such patients should enlighten traditional models of how the percepts of volition are generated in the brain with regard to movement. We discuss volition and its components as multi-leveled processes with feedforward and feedback information flow, and dependence on prior expectations as well as external and internal cues.