<P> In 1870 Eduard Hitzig and Gustav Fritsch demonstrated that electrical stimulation of certain parts of the dog brain resulted in muscular contraction on the opposite side of the body . </P> <P> A little later, in 1874, David Ferrier, working in the laboratory of the West Riding Lunatic Asylum at Wakefield (at the invitation of its director, James Crichton - Browne), mapped the motor cortex in the monkey brain using electrical stimulation . He found that the motor cortex contained a rough map of the body with the feet at the top (or dorsal part) of the brain and the face at the bottom (or ventral part) of the brain . He also found that when electrical stimulation was maintained for a longer time, such as for a second, instead of being discharged over a fraction of a second, then some coordinated, seemingly meaningful movements could be caused, instead of only muscle twitches . </P> <P> After Ferrier's discovery, many neuroscientists used electrical stimulation to study the map of the motor cortex in many animals including monkeys, apes, and humans . </P> <P> One of the first detailed maps of the human motor cortex was described in 1905 by Campbell . He did autopsies on the brains of amputees . A person who had lost an arm would over time apparently lose some of the neuronal mass in the part of the motor cortex that normally controls the arm . Likewise, a person who had lost a leg would show degeneration in the leg part of motor cortex . In this way the motor map could be established . In the period between 1919 and 1936 others mapped the motor cortex in detail using electrical stimulation, including the husband and wife team Vogt and Vogt, and the neurosurgeon Foerster . </P>

Where is the location of motor and sensory cortexes