Children with specific language impairment: the role of prosodic processes in explaining difficulties in processing...

Children with specific language impairment (SLI) experience great difficulties in language comprehension and/or production whereby the majority of these children have particular problems in acquiring syntactic rules. In the speech stream boundaries of major syntactic constituents are reliably marked by prosodic cues. Therefore, prosodic information provides an important cue for discovering the syntactic structure of a language [Jusczyk, P.W., 2002. How infants adapt speech-processing capacities to native language structure. Curr. Dir. Psychol. Sci. 11, 15-18.]. Following this, the question is, whether children with SLI differ in the processing of syntactic information from normally developing children and to what extent this is related to the processing of the inherent prosodic information. Children heard either correct sentences or sentences with a word category violation (syntactic level) and a joined prosodic incongruity (prosodic level) while event-related brain potentials (ERPs) were recorded. Judging the sentence's correctness, control children performed better than children with SLI for all types of sentences. With respect to the ERPs, control children showed a bilateral early starting anterior negativity sustaining into a late anterior negativity and a P600 in posterior regions in response to incorrect sentences. Children with SLI showed a comparable P600 but unlike the control children there was only a late, clearly left lateralized anterior negativity. The complete absence of a right anterior negativity in children with SLI suggests that they may not access prosodic information in the same way normal children do. The differences in prosodic processing may in turn hamper the development of syntactic processing skills as indicated by the absence of the syntax-related early left anterior negativity.