Inhibition in preschool children at risk of Developmental Language Disorder

While the precise nature of the deficits in Developmental Language Disorder (DLD) remains poorly defined, it has been hypothesized that executive function deficits may play a central role in the disorder. Research interest has focussed on inhibition as being an important executive function deficit which may contribute to the language difficulties faced by children with DLD. The presented study compared the inhibition abilities of typically developing preschool children, with monolingual preschool children and bilingual preschool children who had already been referred to specialist language units and therefore classed as “at risk” of developing DLD . Three inhibition tasks were used (motor inhibition, verbal inhibition and self-control) along with a prospective memory task and a nonword repetition test. The results indicated that children deemed at risk of DLD performed significantly worse than typically developing children on all tasks. Correlational analysis revealed significant relationships between the nonword repetition test and inhibition in the typically developing group but different relationships were seen in the at risk groups. For the monolingual at risk group the association was with nonword repetition and verbal inhibition but in the bilingual group nonword repetition was associated with motor inhibition. These findings suggest that inhibition deficits can be observed in children who are at risk of DLD but the nature of the deficit may differ in monolingual children compared to bilingual children. The results are discussed in terms of theory and implications for therapeutic practice.