DOUBLE TAP TO ZOOM WITH PHONE OR TABLET Toddlers and Projects: Some Definitions  defensive—flow from his sensory profile. Both cognitive and physical develop- ment flow from the wiring of the nervous system. Because of these connections between body and mind, art plays a key role in helping children explore not just their sensory experience but all their actions and expressions. Ayres’s view of early childhood development clearly overlaps with Piaget’s idea of moving from a sensorimotor mode of exploration to abstract reasoning. It also parallels attachment theory’s focus on regulation. Infants and toddlers learn primarily through sensorimotor exploration. Sensory integration perspec- tives, however, remind us that infants and toddlers are still early in their sensory development. Everyone has a complex system of integrating multiple sensory inputs, and each of us has a range of reactions to stimuli. Toddler Brain Development Freud (1949), Piaget (1971b), and Vygotsky (1978) all theorized about the phys- ical structure and functioning of the human brain. Freud saw a three-part model consisting of the id, the ego, and the superego. The id is the instinctive part of the brain we share with animals. The ego is the self-conscious, reasoning mind. The superego is the rational governor of the id. Piaget argued that, as children encounter contradictions to their emerging ideas of things, their mental process of reconciling contradictions causes the pathways in the brain to physically mature and become more complex. Vygotsky refined Piaget’s ideas by suggesting that the brain is an innately interpersonal organ that develops by observing models of more expert behavior—that is, the behavior of older children and adults. As their ability to observe the brain in action has increased, researchers have developed a three-part model of the brain that confirms these thinkers’ ideas (MacLean 1990): •• •• •• The reptilian brain, or brain stem, governs instinctive behavior and survival instincts. The middle brain, or limbic system, governs emotions and how we make cognitive sense of them. The neocortex, which develops last, is where we do our abstract thinking and reasoning. Recent imaging of brain activity has shown that it is the limbic system—where feelings, senses, and early sense-making intersect—that undergoes the most intense development during early childhood. This phenomenon implies that our work with toddlers should focus on the systems that are most at play: emotions, emotional processing, and sensorimotor COPYRIGHTED MATERIAL 11