Final answer:
Infants learn about the world through their senses and body movements during the sensorimotor stage, the first phase of Piaget's cognitive development theory. They develop critical skills such as object permanence, enabling them to understand that objects exist even when not in view.
Step-by-step explanation:
Infants learn about physical objects through their senses and body movements in the sensorimotor stage, the first stage in Piaget's theory of cognitive development, which lasts from birth to about 2 years old.
During the sensorimotor stage, children explore the world by seeing, touching, sucking, grasping, and manipulating objects. One significant milestone in this stage is the development of object permanence, the understanding that objects continue to exist even when they cannot be observed.
For instance, when a toy is hidden under a blanket, an infant who has developed object permanence will search for it, whereas an infant who has not developed this concept will act as if the toy has ceased to exist.
This stage is crucial for cognitive development, as it lays the groundwork for later stages, such as the preoperational stage where children start using symbols and engaging in pretend play.