=Types of Movement.=--Closely associated with the problem of voluntary attention is that of voluntary movement, or control of action. It is an evident fact that the infant can at first exercise no conscious control over his bodily movements. He has, it is true, certain reflex and instinctive tendencies which enable him to react in a definite way to certain special stimuli. In such cases, however, there is no conscious control of the movements, the bodily organs merely responding in a definite way whenever the proper stimulus is present. The eye, for instance, must wink when any foreign matter affects it; wry movements of the face must accompany the bitter taste; and the body must start at a sudden noise. At other times, bodily movements may be produced in a more spontaneous way. Here the physical energy stored within the system gives rise to bodily activity and causes those random impulsive movements so evident during infancy and early childhood. When these movements, which are the only ones possible to very early childhood, are compared with the movements of a workman placing the brick in the wall or of an artist executing a delicate piece of carving, there is found in the latter movements the conscious idea of a definite end, or object, to be reached. To gain control of one's movements is, therefore, to acquire an ability to direct bodily actions toward the attainment of a given end. Thus a question arises as to the process by which a child attains to this bodily control.
=Ideas of Movements Acquired.=--Although, as pointed out above, a child's early instinctive and impulsive movements are not under conscious control, they nevertheless become conscious acts, in the sense that the movements are soon realized in idea. The movements, in other words, give rise to conscious states, and these in turn are retained as portions of past experience. For instance, although the child at first grasps the object only impulsively, he nevertheless soon obtains an idea, or experience, of what it means to grasp with the hand. So, also, although he may first stretch the limb impulsively or make a wry face reflexively, he secures, in a short time, ideas representative of these movements. As the child thus obtains ideas representative of different bodily movements, he is able ultimately, by fixing his attention upon any movement, to produce it in a voluntary way.