Final Answer:
In the tertiary circular reactions stage, infants engage in intentional, goal-directed actions, exhibit increased awareness of object permanence, and display the beginning of representational thought.
Step-by-step explanation:
The tertiary circular reactions stage is a key phase in Jean Piaget's theory of cognitive development, occurring between 12 and 18 months of age. During this stage, infants move beyond repetitive actions and explore intentional, goal-directed activities. They actively experiment with objects to achieve specific outcomes, demonstrating an understanding of cause and effect. Additionally, there is an increased awareness of object permanence, meaning infants recognize that objects continue to exist even when out of sight.
Moreover, the tertiary circular reactions stage marks the beginning of representational thought. Infants start to form mental representations of objects and events, allowing them to anticipate future actions and plan activities mentally. This developmental shift signifies a progression in cognitive abilities and sets the stage for further advancements in symbolic thinking and problem-solving.