Early concepts tend to be very concrete, but soon broaden their scope aided by the processes of Abstraction, Imagery and Generalization.
A child, for example, handles and looks at a shoe she has come across as she crawls across the floor. Immediately, a flurry of changes take place in her brain as a consequence of the experience.
The next time the child sees the shoe, there is a match between the visual and/or haptic input and the stored data from the past experience; and there is recognition and some understanding of its shape, mass, texture and possibly its use.
There may eventually even be a name attached to it, “shoe.” The name, however, may signify just that particular shoe only.
That is the child’s concept of shoe and it is very concrete in that it relates to just on one object. In time, the concept and symbol will be expanded to include any shoe. What cognitive processes are active in this expansion? We shall discuss three: Abstraction, Imagery and Generalization.