Plasticity refers to the brain's capacity for modification, as evident in brain reorganization following damage. As the infant's muscles and nervous system matures, more complicated skills emerge. With minor exceptions, the sequence of physical development is universal. He observed that children understand concepts and reasons differently at different stages. Piaget's Cognitive Stages.
Adaptation takes two forms, assimilation and accommodation.
A process that involves modifying an existing schema when presented with undeniable new information. One of the major accomplishments at this stage is Object Permanence, which is the understanding that something continues to exist even if you can't see it or touch it. Object permanence represents the beginning of representational thoughts, the capacity for using mental imagery and other symbolic systems. The use of symbols and language accelerates in play and in imitation of adult behavior. Piaget described this stage largely in terms of what the child cannot do.