During what stage of cognitive development do children acquire the concept of object permanence?

Question

Quizplus · Accepted Answer

Object permanence is the understanding that objects continue to exist even when they cannot be seen, heard, or touched. This concept is developed during the sensorimotor stage of cognitive development, which occurs from birth to about 2 years of age. During this stage, infants learn about the world through their senses and actions and develop the ability to mentally represent objects in their environment.

During What Stage of Cognitive Development Do Children Acquire the Concept