“…There has been a great deal of interest in factors thought to affect the functional activation associated with movements of the hand and arm, such as the spatial and temporal complexity (Roland et al, 1980b;Colebatch et al, 1991;Grafton et al, 1992;Matelli et al, 1993;Kawashima et al, 1994a,b;Shibasaki et al, 1993;Sadato et al, 1996), whether movements were stimulus triggered or internally generated (Roland et al, 1980a;Fox et al, 1985;Deiber et al, 1991Deiber et al, , 1996Rao et al, 1993Rao et al, , 1997Boecker et al, 1994;Larsson et al, 1996), and the learning and acquisition of motor skills (Seitz et al, 1990Seitz and Roland, 1992;Jenkins et al, 1994;Schlaug et al, 1994;Grafton et al, 1995;Deiber et al, 1997;Hazeltine et al, 1997;Jueptner et al, 1997a,b;Shadmehr and Holcomb, 1997). However, to our knowledge there have not been any functional imaging studies which have specifically addressed the issue of the predictability of a motor response.…”