As the infant gets used to certain behaviors, such as grasping, nursing, or cooing, the synaptic junctions that enable a successful behavior get strengthened by increased usage. The connections that are never used gradually wither away. As the infant grows, this synaptic reinforcement continues until some pathways are massively strengthened, while countless others that turned out to be useless have died out.
Neuronal connections die away when unused. Strengthened when constant stimulated.synaptic pruning
