Background: Deferred imitation (DI) is a non-verbal measure of recall memory, which has been extensively used in studies of typically developing infants. The role of DI in children with autism has been less investigated but research indicates that DI is less frequent in this group. The aim of the study was to compare DI performance in children with autism to other groups of children (Down syndrome and typical). The study also investigated the relationship between DI and other forms of imitation.
Method: 20 children with autism spectrum disorder (ASD) (CA = 66.8 months, LA = 29.7, MA = 45.2), 18 children with Down syndrome (DS) (CA = 63.7 months, LA = 25.44, MA = 29.5) and 23 children with no known disability (typical) (CA = 35.0 months, LA = 35.6, MA = 37.5) participated in the study. Five DI tasks were administered to all children, with a two-day delay. All children were also tested for spontaneous and elicited imitation in a play situation with an adult.
Result: A one-way ANOVA revealed a group difference (F = 10.77, p < .001) for the performance on DI. Post-hoc test (Scheffe) showed significant differences between ASD and typical (p < .01) and DS and typical (p < .001). Deferred imitation was not related to spontaneous or elicited imitation for any group.
Conclusions: Children with autism do not show DI difficulties when compared to DS children (matched on language age). However, both groups showed reduced performance when compared to children with typical development. The finding that performance on DI had no relation to other forms of imitation might indicate that DI relies more on memory capacity than imitation skills.