The impact of brain imaging technology on our understanding of motor function and dysfunction

Brain imaging techniques have demonstrated functional specialisation of mul tiple areas within the motor system. They have also defined the patterns of interactions between these regions during normal motor function and in mot or disorders. Functional imaging makes visible the changes in cortical acti vity that take place over time during motor functions, from the activations a fraction of a second before voluntary action to cortical neuronal plasti city several weeks after injury. Recently, the functional abnormalities und erlying various acquired and developmental motor disorders have been descri bed, as well as the effects of therapeutic intervention.