During the first six months or so of life... the infant brain is unable to clearly distinguish the source of sensory inputs; vision, hearing, and touch meld into a unitary perceptual representation.... inputs from the various sensory receptors may connect to many different parts of the brain, pending pruning that will occur later in life. As Simon Baron-Cohen has described it, with all this sensory cross talk, the infant lives in a state of complete psychodelic splendor (without the aid of drugs).

This is Your Brain on Music (2006)