The production of semantic representations in children with specific language impairment, autism spectrum disorder, and typical language development

Although differences in processing are well established in children with specific language impairment (SLI) and autism spectrum disorder (ASD), little is known about how these differences impact the type of information they ultimately acquire when learning new words. The purpose of this study was to analyze novel word definitions from children with SLI, ASD, and typical language development (TLD) to determine if the semantic information they learned was influenced by these processing differences. Thirty-six children (12 in each group), matched on expressive vocabulary, participated in a novel word learning study across three sessions. The semantic features of 432 definitions were coded and analyzed based on three processing dimensions: (1) visual vs. verbal vs. both visual and verbal, (2) local vs. global descriptors, and (3) inferred vs. explicit. The results indicate that: (1) children with SLI and ASD relied more on visual information to build their semantic representations than their peers with TLD, and children with SLI and ASD used verbal and a combination of visual and verbal semantic features similarly to their peers with TLD; (2) the groups with SLI and ASD produced more global descriptors than the group with TLD, and the group with SLI produced significantly fewer local descriptors than the group with TLD; and (3) all groups made inferences and used explicit information similarly. This study reveals that processing differences in children with SLI and ASD impact the formation and later production of semantic information when using newly acquired words. These results also demonstrate the wide-ranging overlap of expressive language abilities in children with SLI and ASD, highlighting why differential diagnosis of these disorders may be challenging when language alone is observed.