The Role of Language in Nonlinguistic Stimuli: Comparing Inhibition in Children With Language Impairment.

Purpose: There is conflicting evidence regarding if and how a deficit in executive function may be associated with developmental language impairment (LI). Nonlinguistic stimuli are now frequently used when testing executive function to avoid a language confound. However, it is possible that increased stimulus processing demands for nonlinguistic stimuli may also compound the complexity of the relationship between executive function and LI. The current study examined whether variability across nonlinguistic auditory stimuli might differentially affect inhibition and whether performance differs between children with and without language difficulties.

Method: Sixty children, aged 8-14 years, took part in the study: 20 typically developing children, 20 children with autism spectrum disorder, and 20 children with specific LI. For the purposes of assessing the role of language, children were further categorized based on language ability: 33 children with normal-language (NL) ability and 27 children with LI. Children completed a go/no-go task with 2 conditions comparing nonlinguistic auditory stimuli: 2 abstract sounds and 2 familiar sounds (duck quack and dog bark).

Results: There was no significant difference for diagnostic category. However, there was a significant interaction between language ability and condition. There was no significant difference in the NL group performance in the abstract and familiar sound conditions. In contrast, the group with LI made significantly more errors in the abstract condition compared with the familiar condition. There was no significant difference in inhibition between the NL group and the group with LI in the familiar condition; however, the group with LI made significantly more errors than the NL group in the abstract condition.

Conclusions: Caution is needed in stimuli selection when examining executive function skills because, although stimuli may be selected on the basis of being "nonlinguistic and auditory," the type of stimuli chosen can differentially affect performance. The findings have implications for the interpretation of deficits in executive function as well as the selection of stimuli in future studies.