title: ERPs reveal the temporal dynamics of auditory word recognition in specific language impairment.
abstract: We used event-related potentials (ERPs) to compare auditory word recognition in children with specific language impairment (SLI group; N=14) to a group of typically developing children (TD group; N=14). Subjects were presented with pictures of items and heard auditory words that either matched or mismatched the pictures. Mismatches overlapped expected words in word-onset (cohort mismatches; see: DOLL, hear: dog), rhyme (CONE -bone), or were unrelated (SHELL -mug). In match trials, the SLI group showed a different pattern of N100 responses to auditory stimuli compared to the TD group, indicative of early auditory processing differences in SLI. However, the phonological mapping negativity (PMN) response to mismatching items was comparable across groups, suggesting that just like TD children, children with SLI are capable of establishing phonological expectations and detecting violations of these expectations in an online fashion. Perhaps most importantly, we observed a lack of attenuation of the N400 for rhyming words in the SLI group, which suggests that either these children were not as sensitive to rhyme similarity as their typically developing peers, or did not suppress lexical alternatives to the same extent. These findings help shed light on the underlying deficits responsible for SLI.
authors.affiliation: The University of Western Ontario, Department of Psychology and Program in Neuroscience, 1151 Richmond Street, London, Ontario, Canada N6A 5B7. jmalins@uwo.ca
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Malins
authors.forename: Amy S
authors.initials: AS
authors.lastname: Desroches
authors.forename: Erin K
authors.initials: EK
authors.lastname: Robertson
authors.forename: Randy Lynn
authors.initials: RL
authors.lastname: Newman
authors.forename: Lisa M D
authors.initials: LM
authors.lastname: Archibald
authors.forename: Marc F
authors.initials: MF
authors.lastname: Joanisse
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D002648:Child; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D007805:Language Development Disorders / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology*; D013997:Time Factors