Final answer:
The structure described in the question is a semantic network, and the process of activating one part leading to easier access to related concepts is called spreading activation. This model is vital for understanding how memory retrieval works by connecting related information efficiently.
Step-by-step explanation:
The structure consisting of nodes representing concepts, joined together by pathways that link related concepts is known as a semantic network. The process by which activating one part of the network can make it easier to access linked concepts is called spreading activation. This is because when you remember or recall something, you activate a concept, and the related concepts are more easily remembered due to their partial activation.
In essence, semantic networks and the spreading activation model play crucial roles in how our memory works, as they enable us to connect and retrieve related information efficiently. For instance, when you hear the word 'peanut butter,' you might immediately think of 'jelly,' due to the strong association between these two concepts in your semantic network.