A Psycholinguistic Study of a Sample of Down Syndrome Individuals Compared to Typically Developing Children of the Same Mental Age in the Light of Chomsky’s Minimalist Approach

Abstract

Down Syndrome (DS) is one of the most common causes of intellectual disabilities that occurs owing to a chromosomal abnormality in the twenty-first chromosome. Poor cognitive and linguistic abilities are characteristic of the syndrome. Ongoing research on the linguistic deviations in the DS population reported underlying linguistic deficiencies in diverse language areas in all their developmental stages. However, most of the literature in this area primarily focused on English speaking individuals. Thus, the current study endeavored to investigate the syntactic and phonological defects in the language of five Egyptian DS individuals by deploying the Minimalist Approach and compare them to the patterns reported in the literature of typical language acquisition. The study hypothesized that the phonological deviations can be accounted for by the phonological processes reported in typical language acquisition. The phonological processes revealed from the analysis of the current study, i.e. elision, assimilation, substitutions, and metathesis; coincide with those reported in the studies on typical language acquisition and Down Syndrome. The study also hypothesized that the syntactic deviations are constrained by the rules of Universal Grammar. The syntactic analysis revealed that despite the syntactic deviations on the surface structure, the underlying structure of these utterances operates on functional heads which are phonetically null yet syntactically operant on the deep structure.