Final answer:
The process by which a person incorporates new experiences into existing mental schemes in Piaget's theory of cognitive development is called assimilation. Assimilation is accompanied by accommodation, where existing schemes are adjusted to accommodate new information.
Step-by-step explanation:
According to Jean Piaget, a renowned developmental psychologist, the process by which a person responds to new objects or events with existing schemes is known as assimilation. This is part of Piaget's theory of cognitive development. Assimilation occurs when individuals integrate new information into their preexisting mental models or schemata. For example, if a child knows the scheme for dogs and they encounter a new type of dog, they would integrate this new dog into their existing dog scheme.
Conversely, when existing schemes are altered based on new information, this is referred to as accommodation. Piaget's theory suggests that through both assimilation and accommodation, children's understanding of the world evolves as they interact with their environment.