Infant Stimulation Activity 108: simon says

Your baby is learning from you every day. He is learning your sounds, your movements, your vocabulary; baby is watching everything you do and eventually will begin doing those same things. However, as your infant grows, develops, and becomes more coordinated a fun way to change up your stimulation activity is for you to mimic baby.

Imitate his oohs, ahs, and coos; your baby will know that what he is saying is being heard and responded to. Actions are fun too. Imitate his facial expressions: when he opens his mouth, open your mouth; if he squints his eyes, squint your eyes. Or if your infant is now sitting up and can pat a drum or roll a ball, your response with the same motion will ensure him that what he is doing is good, and then he is likely to continue doing it and to continue having fun.

Providing this positive feedback to baby will help him learn about himself as well as continue to develop his social skills for interacting.