Early language development in typically-developing infants and infants with Down Syndrome : a longitudinal study

• Main Author: Mason-Apps, Emily
• Published: University of Reading 2013
• Subjects: 155.4
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.625436

Individuals with Down syndrome typically have marked delays in language development relative to their general cognitive development, with particular difficulties in expressive compared to receptive language, and syntax compared to vocabulary. Knowledge is currently limited with regard to which factors in early infancy may predict language outcomes at age 3. The current study assessed a group of infants with Down syndrome and a group of typically-developing infants on a variety of factors that have been shown to be related to language in both typical infants and those with developmental delays. These factors included: Non-Verbal Mental Ability, Speech Segmentation, Initiating Joint Attention, Initiating Behavioural Requests, Responding to Joint Attention, and Parental Responsivity. The primary aim of this longitudinal study was to investigate which of these factors are the strongest predictors of later language in typically-developing infants and infants with Down syndrome. When infants with Down syndrome (mean age 19.5 months) were compared to typically-developing infants of approximately 10 months of age, no differences were found between groups on any of the measures, apart from Receptive Vocabulary and Initiating Behavioural Requests, for which the infants with Down syndrome outperformed the typically developing group. Longitudinal analyses of the relationships between predictor measures and language showed that Speech Segmentation and Initiating Joint Attention were the most important predictors of later language in the typically-developing group, whereas Non-Verbal Mental Ability and Responding to Joint Attention were the most important predictors of later language for the infants with Down syndrome. These results are considered in relation to findings from previous research, and the theoretical implications are discussed, with the findings largely being argued to support a neuroconstructivist view of language acquisition.