Children with Autism Spectrum Disorder Can Demonstrate Consistent Word Learning: Expressive Language Measures of Fast- and Slow-Mapping

Background:  How children with autism spectrum disorder (ASD) learn new words is often examined using a fast-mapping paradigm. In fast-mapping, children are taught a new word by associating a label they’ve never heard before (e.g., pagoune) with an object they’ve never seen before. Oftentimes, assessing learning is limited to receptive language measures, such as asking children to physically indicate the correct object from an array of objects (e.g., where is the pagoune?). More recent studies have begun to include measures of slow-mapping, or children’s extended learning of what the word represents beyond an initial association (Norbury et al. 2010). However, prior work has not tracked the consistency of individual children’s learning across multiple measures of expressive word learning, which would allow us to understand more subtle but important differences that may exist in word learning in ASD.

Objectives: We examined the consistency of word learning across expressive language measures of fast- and slow-mapping in children with ASD and typically-developing (TD) children.

Methods: Children (ASD n = 24, TD n = 24) were matched on age, gender, and nonverbal IQ. Children watched a video that taught the label of a novel object and then participated in three different measures of expressive knowledge of the word. In word association, children provided the first word they could think of when they heard the newly taught word. In word description, children described the word, and in word production children provided the name of the object when shown an image.

Children’s performance on each measure was converted into a binary score: 1 for correct target identifications and 0 for all other responses. Trials with learning across two or three measures were considered as consistent learning of the word. Trials with learning on only one measure were considered as inconsistent learning. A trial was deemed as no learning when children did not identify the word on any measure. Children were assessed immediately after teaching and one week later.

Results: Immediately after teaching, 14 children with ASD and 18 TD children had at least one consistent learning trial across all three measures. Eight children with ASD and 5 TD children did not demonstrate any consistent learning, although they did have a minimum of one inconsistent learning trial. Two children with ASD and 1 TD child demonstrated only trials of no learning. One week later, the number of children with at least one consistent learning trial decreased (9 ASD, 11 TD), whereas more children demonstrated only inconsistent learning (10 ASD, 9 TD), or no learning (5 ASD, 4 TD).

Conclusions: These results reveal that many children with ASD, who have IQ in the normal range, can demonstrate consistent learning across all three expressive language measures, although fewer children in both diagnostic groups are consistent one week later. Future analyses will compare characteristics between children who demonstrated consistent learning versus those who demonstrated inconsistent or no learning. This work provides an important look at how children represent new words and the stability of their word learning.