Explaining lexical-semantic deficits in specific language impairment: the role of phonological similarity, phonological working memory, and lexical competition.
OBJECTIVE
In this study, the authors investigated potential explanations for sparse lexical-semantic representations in children with specific language impairment (SLI) and typically developing peers. The role of auditory perception, phonological working memory, and lexical competition were investigated.


METHODS
Participants included 32 children (ages 8;5-12;3 [years;months]): Sixteen children with SLI and 16 typically developing age- and nonverbal IQ-matched peers (CA). Children's word definitions were investigated. The words to be defined were manipulated for phonological neighborhood density. Nonword repetition and two lexical competition measures were tested as predictors of word definition abilities.


RESULTS
Children with SLI gave word definitions with fewer content details than children in the CA group. Compared with the CA group, the definitions of children in the SLI group were not disproportionately impacted by phonological neighborhood density. Lexical competition was a significant unique predictor of children's word definitions, but nonword repetition was not.


CONCLUSIONS
Individual differences in richness of lexical semantic representations as well as differences between children with SLI and typically developing peers may-at least, in part-be explained by processes of competition. However, difficulty with auditory perception or phonological working memory does not fully explain difficulties in lexical semantics.
Mainela-Arnold
Elina
E
Department of Communication Sciences and Disorders, Pennsylvania State University, 308 Ford Building, University Park, PA 16802-3100, USA. ezm3@psu.edu
Evans
Julia L
JL
Coady
Jeffry A
JA
D002648:Child; D006801:Humans; D007805:Language Development Disorders / Q000175:diagnosis / Q000503:physiopathology*; D007807:Language Tests; D008570:Memory, Short-Term / Q000502:physiology*; D010699:Phonation / Q000502:physiology*; D010700:Phonetics; D011237:Predictive Value of Tests; D012044:Regression Analysis; D012660:Semantics; D013067:Speech Perception / Q000502:physiology; D014825:Vocabulary