Answer: synaptic pruning
Explanation: Synaptic pruning, a phase in the development of the nervous system, is the process of synapse elimination that occurs between early childhood and the onset of puberty in many mammals, including humans.
When we are born we get way more neurons and synapses than we will ever need. This forms a web, a very messy web. As you grow older the brain starts fine-tuning itself. Only certain synapses and pathways are necessary, others are never used. The one’s we never use would only get in the way, so they are cleaned up.
Think of it like driving a car with a limited amount of gas. The goal is to drive at the perfect speed. Rather than speeding up and slowing down several times to hit that sweet spot, you just hit the gas hard and then slow down until you reach the speed you want.
There’s a limited time when the brain has the ability to produce neurons and synapses, to build the web it has to use forever. So it goes overboard and makes a very dense web that it prunes down to be perfect.
When you are older the vast majority of these neurons and synapses are indeed lost, but not completely. You still produce a small amount of neurons throughout your life, and the existing neurons still make new connections (synapses).
So pruning is the process of removing synapses that aren’t used in favor of synapses that are used a lot. This makes the brain more efficient.