The source of stimulation is referred to as the stimulus. For the newborn all stimuli are unique in that they have not yet been meaningfully associated with a personal response mode.
With the passage of time the child begins to associate specific stimuli with specific personal reactions. By way of example a child may relieve personal discomfort by moving the head away from an intensely bright light. Conversely the child may associate auditory sound patterns made by an adult with the satisfaction of his need for food.
Through continual exposure to stimulation, the child begins to accumulate a pool of stimulus bound information. In this way he is ultimately able to predict his personal reaction to any stimulus which he has previously experienced in some meaningful way.
A stimulus is not sufficient unto itself. A stimulus must be sensed or received if it is to have instructional value. Some sensory organ on the body must be able to detect the stimulus. Having a stimulus and the process of receiving it cannot complete a learning sequence. The received stimulus must be processed by the brain to cause some form of expression. The final part of the learning model which must be considered is what actually happens as a result of having detected a stimulus, or the terminal behavior. By combining all of these elements the basic learning model, in its simplest form, looks like this:
Stimulus —» Reception —| Processing |—» Terminal Behavior (Expression)
The learning model graphically represents a chain type of reaction commencing with receptive skills, proceeding to process skills and concluding with some form of expressive activity.