Jerome Bruner divided the process of knowledge representation into three stages. This is quite similar to Jean Piaget's stages of Cognitive Development:
Enactive Stage = Sensorimotor Stage:
Age: Birth to approximately 1–2 years.
Characteristics: Children understand things through their own body movements and physical actions/motor responses (for example: touching, putting toys in their mouth, moving them).
Comparison of Other Stages:
Iconic Stage: Understanding things through pictures, images, and visuals (similar to Piaget's Pre-operational stage).
Symbolic Stage: Thinking through language, symbols, and abstract concepts (similar to Piaget's Concrete & Formal Operational stages)."