Explanation : Sensori Motor is the first stage of Piaget's theory of cognitive development. It extends from birth to
approximately 2 years. The main development during this stage is the understanding that objects exist and
events occur in the world independently of one's own actions (object permanence). Object permanence means knowing that an object still exists, even if it is hidden. It requires the ability to form a menal representation (i.e. a schema) of the object.