Memory, attention and interaction in early development : exploring individual differences among typical children and children with autism

This thesis aimed to study differences in early memory ability, social attention and interaction and how these different areas affect language and cognitive development. This was done using a longitudinal approach where a group of children were followed from infancy to childhood and also in a comparative study where a group of children diagnosed with autism spectrum disorder was compared to a group of typically developing children, matched on language age. Study I investigated typically developing infants and showed that recall memory (measured with deferred imitation), visual recognition memory and social communicative ability could explain a large part of the differences in early language acquisition, and also that recall memory made the strongest contribution to this explanation. Study II was a follow-up of the same children as in study I, and showed that a combined low performance on tests of both recall memory and social communication in infancy was related to poorer cognitive outcome beyond infancy, when the children had reached 4 years of age. In study III, deferred imitation and different aspects of social communication were investigated in children with autism and in comparison with typically developing children. The results revealed that children with autism and low language level showed reduced performance in all areas of social communication as well as on deferred imitation. Children with autism and a higher language level, however, performed on a similar level as the typically developing children on all but one measure of social communication, but they still showed reduced performance on deferred imitation. Study IV included the same children as study III, and their performance on pretend play as well as child-parents interaction during play was investigated in relation to language level, joint attention and deferred imitation. Pretend play was related to the child’s language level, joint attention and deferred imitation. The way parents interacted verbally with their child differed between parents of children with autism compared to parents of typically developing children, but also on the child’s language level. The present thesis suggests that it is beneficial to investigate social and cognitive areas in combination if the aim is to understand how early abilities affect later development. The results contribute to the understanding of language development in autism and also point to the importance of considering the child’s developmental level. Children with autism showed large individual differences in many different areas, and the results suggest that this was partly due to the child’s language level