Ostensive Cueing Enhances Retention of Fast Mapped Words in Typically Developing 24-Month-Olds but Not Those at High-Risk for Autism Spectrum Disorders (ASDs)

Background:

Individuals on the autistic spectrum are characterised by social-communication impairments and, in some cases, language deficits. In typical development, children use various strategies to disambiguate the referent of a new word. Impairments in these mechanisms may offer a potential explanation for the subsequent language problems often seen in autism. Preissler and Carey (2005) demonstrated that under conditions of referential ambiguity children with autism are able to use their knowledge of familiar labels to constrain hypotheses about the meaning of novel words (mutual exclusivity; ME). On the contrary, autistic children benefit less from social cues when learning words (Preissler and Carey, 2005; Parish-Morris, Hennon, Hirsh-Pasek, Golinkoff and Tager-Flusberg, 2007).

Objectives:

In order to explore development of this word learning strategy in the broader autism phenotype (BAP), our study examines ME in a group of 24-month-olds at high risk for autism (due to having an older sibling with autism) and low-risk controls. We also aimed to extend these findings to include a memory component and explore performance in novel word retention to see whether memory performance is affected by ostensivelly correcting or reinforcing children’s initial choices. 

Methods:

Participants were 24-month-old children, 40 at high risk for ASD and 40 low-risk controls, recruited through the British Autism Study of Infant Siblings (BASIS).
On each of the eight trials, the child was presented with three objects, two familiar and one novel, and asked for either a familiar object (four trials) or a novel object (four trials). On all familiar object trials and two of the novel trials the experimenter responded ‘thank you’ irrespective of the child’s choice of object. On the remaining two novel trials the experimenter either corrected (if the child made an incorrect or no object selection) or reinforced (if the correct object was selected) the word-object mapping, by labelling it ostensivelly. Following a five minute delay, four memory trials were presented.

Results:

There were no group differences between high-risk and control children in the ME mapping task with both groups performing significantly above chance in both the familiar and novel objects trials. In the memory trials, the performance of both groups for the non-reinforced trials was at chance level. However, performance of the control group was improved significantly when initial choices were corrected or reinforced using ostensive cueing. In contrast, high-risk children did not benefit from the ostensive labelling. 

Conclusions:

Both typically developing 24-month-olds and those at high risk for autism are able to use the principle of mutual exclusivity. However, for the children in the high-risk group, unlike the control children, the retention of word-object mapping is not helped by ostensive naming. This suggests that the observed difficulties may reflect social characteristics, rather than word learning ability per se.

* The BASIS Team in alphabetical order: S. Baron-Cohen^a, P. Bolton^b, S. Chandler^c, M. Elsabbagh^d
aUniversity of Cambridge, ^bInstitute of Psychiatry, ^cInstitute of Education, ^dBirkbeck, University of London