It is very hard to overstimulate a child, we should offer the children a stimulus regardless the signs of refusal he or she might manifest. When a baby does not to stare at something, listen to a stimulus or do something, he/she lets us know by stepping back or crying; we should respect that and cease. If we ignore that, we are exposing the baby to a stressful event and our goal would be impossible to achieve; instead we have to wait until the baby is ready again.