at the range and speed of thought is greatly enhanced (Wadsworth, 1979).
In the sensorimotor stage, the child has to physically be acting or perceiving a stimulus in order to "think" about it. A child in this stage can only organize his behavior through schemas, such as sucking or biting, but cannot conceive of an action or object outside of the actual experience. This means that all though is tied to direct experiences in the here and now, and that stimuli can only be considered in a one-step-at-a-time fashion (Wadsworth, 1979).
In the preoperational stage, on the other hand, language allows the child to consider many elements at one time, and to think about objects and experiences of the past and future as well as the present. Also, because thought is no longer tied to movement or direct perception, the rate of experience is speeded up. The ability to internally represent the world (which Piaget calls "semiotic function") allows for the mental rehearsal of new actions as well as replays of old ones. Lee (1976) states that the transition from the sensorimotor stage to the preoperational stage entails the child being able to rapidly make sense of separate experiences and being aware of his own thought processes. "The child must not only be able to do something,but must be able to know that he or she can do it."(p.85).
The two main categories of preoperational speech are egocentric speech and socialized speech. Between the ages of two and four or five, the child tends to speak in the presence of others, but without the apparent intention of conveying any information to them. That is, he doesn't care if anyone else is listening or not, seeming to be merely thinking out his own actions aloud. This type of nonconversation is called a "collective monologue" by Piaget (1968). Socialized speech, evidenced by six to seven-year-olds, involves a meaningful exchange of ideas between the participants. One of the important developm...