In Piaget's theory, a newborn child has reflexes like sucking, grasping, looking, etc. He labels each of these behaviors as schemata, the potential to act in a certain way. From birth on we have to adapt these reflexes to our environment using assimilation and accommodation. Assimilation and accommodation are different processes in the brain. To actually learn something new, we have to accommodate the information.
Accommodation changes our existing cognitive structures.
If we come across new information or a new stimulus, it must be placed into a new structure. Piaget labeled these two processes as functional invariants because they occur at all stages of development. The actual development of our learning capabilities, according to Piaget, lasts from birth up to around 14 or 15 years of age. This is in agreement with physiological psychologists, which claim that the human brain is fully developed at age 15. Between birth to 2 years old, children are in the sensorimotor stage and use reflexes to interact with the world.