Everybody knows, our speech, walk, a series of activities such as thinking are to suffer pallium place to control, but also a few low reflection activities do not get cerebrum control. For example severs the connection between animal cerebra and spinal cord, the animal appears instantly limb unbend, rachis hind is held out, the phenomenon such as head end cock. Pull at this moment pull tendon, still can cause muscle to reflex sexual systole.

The cerebrum development that the baby gives birth to first is returned very not perfect, but the nerve center that the movement is in charge of under pallium and spinal cord already reached the level that perfects quite relatively however on the function, because of this new student some movements are to suffer cerebral cortex to issue centre to control, and the control that does not get pallium, often can appear so not own, of aimless sex shake, this is a kind of normal phenomenon, won't affect intellectual growth more. Later the growth as the age, cerebrum development is ceaseless and perfect, this kind not own shake will decrease naturally, down to disappears finally, and by conscious, own action is replaced.