Assessment of linguistic and cognitive abilities in the learning disabled deaf population

[摘要] This study set out to determine methods of identifying a specific subgroup of learningdisabled deaf individuals - those with a language impairment. A South African SignLanguage (SASL) test battery was developed for assessing sign language skills in thelearning disabled deaf population, Linguistic and cognitive profiles for three learningdisabled profoundly deaf adults and three nondisabled profoundly deaf adult controls wasdescribed.The battery of diagnostic tests consisted of a standard battery of language tests adaptedfor SASL, formal sign language tests, a signed narrative discourse task and a cognitivetest battery translated into SASL. The inclusion of a signed narrative task and its analysismethod enabled an examination of higher order linguistic and cognitive skins and specificaspects of sign language which have not been previously investigated. The perception andproduction of facial expressions used for linguistic purposes in sign, the breakdown ofthis perception and production and the role of these facial expressions in themacrostructure of signed discourse were examined ill this study. Although much researchon the production of facial expressions and other nonmanual behaviours in sign languagehas been undertaken previously. to the writer's best knowledge no research concerningthe perception of facial expressions in sign language, the breakdown in the perception anduse of facial expressions in sign language and its role in the form of evaluative elementsin the macrostructure of signed discourse have been previously undertaken. Furthermorethe function of facial expressions as grammatical markers in sign language and otherfunctions of facial processing not particular to signed languages were studied from aneuropsychological perspective. Studying the breakdown of sign language from apsycholinguistic perspective allowed for the identification of some of the underlyingprocesses essential to sign language competence. A fundamental component of this studywas the involvement of adult deaf native signers at all levels of the research.The particular combination of tests used in this study revealed linguistic and cognitivedeficits in the three learning disabled deaf (LDD) subjects which were not evident in thecontrol subjects. It highlighted the similarities as well as the heterogeneity of the threeLDD subjects' linguistic and cognitive profiles in terms of both the nature and degreeof severity of the deficits. In addition it revealed deficits in some of the underlyingprocesses in sign language, such as spatial and facial processing, as well as theirmanifestations in various forms. The numerous theoretical and clinical implicationsarising from the results of this study are discussed in detail.

[发布机构] University of the Witwatersrand