Referential Word Learning in Toddlers at Genetic Risk for Autism

Background: Most theories of autism acknowledge the existence of a deficit in social cognition abilities, in individuals with autism or ASD. Nonetheless, the nature and the developmental origin of this deficit are still unclear. For example, the difficulties encountered by some young children with autism when acquiring language could stem from a specific impairment in social interaction (e.g. orienting to people for information and knowing how to make use of referential cues, like gaze direction) or from a more general attentional problem (e.g. being able to disengage attention from other salient environmental events and orient towards the referent of a word).

Objectives: The aim of the study was to examine referential word-learning abilities in a group of siblings of children diagnosed with ASD (Sibs-ASD) and in a control group of 3-year-olds who have no family history of autism (Controls).

Methods: 30 children (15 Sibs-ASD and 15 Controls) were presented with video scenes containing an actress and two novel objects. The actress repeatedly labelled the least “interesting” of the objects. We used en eye-tracker to measure children's ability to disengage from the “interesting” object and follow the gaze of the experimenter towards the “boring” one. Children's success in the word-learning task was measured using a word-object matching test, in which they were asked to point to the referent of the newly learned word.

Results: Preliminary results show that both groups succeed in attaching the new word to its referent, despite the concurrent presence of another salient object. However, eye-tracking data revealed a number of individual differences in the distribution of eye gaze throughout the task, possibly suggesting differences in how success is achieved. These differences were observed, for example, in the amount of looking towards the "interesting" and "boring" objects. Sibs-ASD spent more time looking at the "interesting" but non-labeled object than at the labeled "boring" object. At the same time, Sibs-ASD looked longer at the actress when she was labelling the objects.

Conclusions: As a group, siblings of children with autism and controls show no difference in terms of their success in a word learning task, despite the high attentional load. Nonetheless, individual differences revealed different strategies employed to succeed in this task.