Investigating the relationship between fast mapping, retention, and generalisation of words in children with autism spectrum disorder and typical development

While many studies have investigated how autism spectrum disorder (ASD) impacts how children identify the meanings of new words, this task alone does not constitute learning. Here we investigate fast (referent selection) and slow (retention, generalisation) word learning processes as an integrated system and explore relationships between these mechanisms in ASD and typical development. In Study 1, children with ASD and typically developing (TD) children matched on receptive vocabulary utilised mutual exclusivity to identify referents of unfamiliar words, but showed substantially reduced accuracy on delayed retention and generalisation trials. Thus, Study 2 investigated whether re-directing children’s attention to target objects following referent selection would enhance delayed retention. Participants received either social feedback (target objects were labelled and highlighted via social cues) or non-social feedback (target objects were labelled and highlighted via a flashing light). In both conditions, children with ASD were less accurate in their use of mutual exclusivity to fast-map novel words than TD children. However, children with ASD who received social feedback responded more accurately on delayed retention and generalisation trials than TD controls, and children with ASD who received non-social feedback or no feedback (in Study 1). Our findings imply that fundamental word learning mechanisms, and the relationships between them, are not qualitatively different in ASD. We argue that ASD may affect the efficiency of these mechanisms by disrupting children’s intake of linguistic input in natural environments, but difficulties may be mitigated by presenting visual and auditory stimuli in a way that appeals to the population’s strengths.