Emelie Nordqvist

Early declarative memory predicts productive language: A longitudinal study of deferred imitation and communication at 9 and 16months.

Deferred imitation (DI) may be regarded as an early declarative-like memory ability shaping the infants ability to learn about novelties and regularities of the surrounding world. In the current longitudinal study, infants were assessed at 9 and 16months. DI was assessed using five novel objects. Each infants communicative development was measured by parental questionnaires. The results indicate stability in DI performance and early communicative development between 9 and 16months. The early achievers at 9months were still advanced at 16months. Results also identified a predictive relationship between the infants gestural development at 9months and the infants productive and receptive language at 16months. Moreover, the results show that declarative memory, measured with DI, and gestural communication at 9months independently predict productive language at 16months. These findings suggest a connection between the ability to form non-linguistic and linguistic mental representations. These results indicate that the childs DI ability when predominantly preverbal might be regarded as an early domain-general declarative memory ability underlying early productive language development.

The relationship between deferred imitation, associative memory, and communication in 14-months-old children. Behavioral and electrophysiological indices

The present study combines behavioral observations of memory (deferred imitation, DI, after a brief delay of 30 min and after a long delay of 2–3 weeks) and electrophysiological (event-related potentials, ERPs) measures of associative memory, as well as parental reports of non-verbal and verbal communication in sixteen 14-months-old children. Results show that for DI, the children remembered the stimulus after the brief but not after the long delay. There was a clear electrophysiological response indicating associative memory. Furthermore, a correlation between DI and ERP suggests that both measures of memory (DI and associative memory) tap into similar mechanisms in 14-months-old children. There was also a statistically significant relation between parental report of receptive (verbal) language and the ERP, showing an association between receptive language skills and associative memory.

Children with Autism Respond Differently to Spontaneous, Elicited and Deferred Imitation.

BACKGROUND Imitation, a key vehicle for both cognitive and social development, is often regarded as more difficult for children with autism spectrum disorders (ASD) than for children with Down syndrome (DS) or typically developing (TD) children. The current study investigates similarities and differences in observed elicited, spontaneous and deferred imitation using both actions with objects and gestures as imitation tasks in these groups. METHODS Imitation among 19 children with autism was compared with 20 children with DS and 23 TD children matched for mental and language age. RESULTS Elicited imitation resulted in significantly lower scores for the ASD group compared with the other two groups, an effect mainly carried by a low level of gesture imitation among ASD children. We observed no differences among the groups for spontaneous imitation. However, children with ASD or DS displayed less deferred imitation than the TD group. Proneness to imitate also differed among groups: only 10 (53%) of the children with autism responded in the elicited imitation condition compared with all children with DS and almost all TD children (87%). CONCLUSIONS These findings add to our understanding of the kind of imitation difficulties children with ASD might have. They also point to the necessity of not equating various imitation measures because these may capture different processes and be differently motivating for children with autism.