Apraxia and the neurophysiology of motor control.

Liepmann's description of apraxia still serves as a point of reference for neurological thinking about higher motor function. The extent to which this model is accessible to interpretation in the light of current neurophysiological knowledge has been examined. Planning and programming processes have been distinguished, and the separate roles of striopallidal and cerebellar loops in the generation of those processes have been considered in relation to the contribution of parietal and frontal association areas. It is emphasized that a new taxonomy of action is imperative in order that neurophysiological and psychological approaches can be correlated in the study of higher motor function and its pathological disorders.