Lexikal organisation hos en- och flerspråkiga skolbarn med språkstörning

Sammanfattning: Children with language impairment (LI) often exhibit lexical difficulties with negative consequences for school success. Lexical size and lexical organization have both been found to be affected, with problems in lexical organization exceeding those in lexical size. The research on LI has had a long-standing focus on monolingual children, resulting in assessment routines ill-suited for bilingual children. Conceptual scoring, i.e., acknowledging that the lexical ability of bilingual children is distributed across two languages by awarding points if the child knows a target concept in one of the languages, has been put forward as a way of reducing the risk of overidentification of lexical deficits in bilingual populations. The studies in this thesis investigate lexical size and lexical organization in mono- and bilingual children with LI using picture identification, picture naming, and word associations. Mono- and bilingual children, with and without LI, aged 5;11 to 9;3, completed a battery of cognitive and linguistic tests, aimed at assessing lexical size, lexical organization, and relevant background variables. The aim was to 1) compare lexical size between bilingual children with and without language impairment, 2) to investigate whether mono- and bilingual children with LI exhibit difficulties with lexical organization, as measured by word associations, and 3) to compare differences in outcome between mono- and bilingual children with LI when different scoring methods were applied, a conventional monolingual assessment, and conceptual scoring. Results revealed limitations in lexical size for bilingual children with LI, when compared to a bilingual age-matched comparison group with typical development (TD), particularly when receptive and expressive measures in both languages were combined. Regarding lexical organization, monolingual children with LI performed below monolingual children with TD as a group. Differing developmental trajectories were found for bilingual children with and without LI regarding lexical organization in both languages, with the bilingual children with LI increasing their syntagmatic associations over time whereas the TD children showed increased use of paradigmatic associations. With monolingual Swedish scoring, bilingual children performed on par with monolingual children, but showed superior performance when conceptual scoring was applied. The overall results of the thesis confirm that children with LI have difficulties within the lexical domain. The results promote the use of conceptual scoring when assessing bilingual school-aged children with LI.