Final answer:
"Neuroconstructivism" is the theory that focuses on the maturing CNS as the primary agent of change in development, differing from Piaget's cognitive development stages by emphasizing neural and cognitive network interactions.
Step-by-step explanation:
The specific theory of development based on the assumption that the central nervous system (CNS) maturing is the primary agent of change in development is known as the neuroconstructivism theory. This theory suggests that neural brain development influences cognitive development, with experiences shaping how neural pathways develop. Unlike Piaget's cognitive theory of development, which emphasizes the stages that children go through to develop their cognitive abilities, neuroconstructivism focuses on the interaction between neural and cognitive networks and how these are affected by the environment.