Research tells us that it is not only helpful if you do, but that a child is robbed of optimal brain development, if you do not. The development of the brain cells is human physiology, but development of many of the synapses is influenced by experiences. The brain cells form the framework, but the connections made in childhood determine what happens to that framework. These first years are the period when the brain has the greatest hope for growth and construction. The synapses are strengthened by exposure to experiences.
Experience provides stimulation that kick starts development of the synapses.
Expanding from that base then develops more complex connections. Research tells us that synapses that are not stimulated are eliminated. They are pruned. They are no longer there for use by the child. When children are stimulated, neurotransmitters fire in the brain, creating synapses.