Concept maps have their origin in the Parallel Distributed Processing (PDP) model, also called the Connectionist Model, of memory (McClelland & Rumelhart, 1981). The PDP model is based on the premise that our memory system consists of an interconnected series of nodes, or concepts. Our understanding of an individual concept depends on the connections made between that node and other nodes. For instance, child development is a node in the concept maps above. Each individual's understanding of child development depends on the nodes that are connected to the child development node. If the child development node was not connected to other nodes, the individual would not know anything about child development.
According to the PDP model, our memory system functions through the activation of nodes. When a node is activated, turned on, it becomes accessible to your conscious thought. A node can be activated by an external stimulus, such as a test question on child development, or by another node. When a node is turned on it activates the nodes connected to it. The node causing the activation is called a prime and its activation of other nodes is called the priming effect. The activation of nodes acts in a cascading way, with each activated node activating the nodes connected to it. For instance, in concept map “a” above the activation of child development would result in the activation of theorists, learning, growth, and social problems. Each of these nodes would activate the nodes connected to them. For instance, theorists would activate Freud, Erickson, and Piaget. This cascading series of activations is called spreading activation. The parallel part of the Parallel Distributed Processing model represents the fact that all this activation occurs at the same time (i.e., in parallel).
In the classroom, the PDP model is used when teachers introduce new topics by asking students to recall related information that they already know. For instance, a teacher might start a lecture on Piaget by asking students to recall the definition of child development. Recalling the definition of child development will activate a student’s nodes related to child development, allowing them to make connections between Piaget and other concepts they know related to child development.