Let's watch a parent-child interaction with a mother who is responding positively to her infant. Watch how the mother notices her child's interest in the piano. When the child begins vocalizing, she promptly replies, showing that she is paying attention to her child’s comments. The mother talks to her child about the piano, expanding on her child’s vocalizations. She helps her up so she can play the piano, extending her experience. She also plays with her, matching her child’s interest and enthusiasm.