Almost all neurons (nerve cells) are present at birth but are not connected in networks.  The connecting process (synapse formation) is rapid during this year, with brain activity becoming closer to adult than newborn by 12 months.  At this age, the name of the game is touch, taste, smell, sight and sound.  Babies are like little scitntists, constantly exploring the world around them.  Toys that help baby learn dexterity and cause and effect make excellent choices.