Сognitive factors affecting language development in children with intellectual disabilities
Language development in young children who have intellectual disabilities is often delayed. This delay has time and again been attributed to cognitive disabilities. Such cognitive disabilities include Down syndrome, Williams syndrome, specific language impairments among other disabilities.
Botting, Conti-Ramsden and Hick (2005) believe that some difficulties experienced by young children are not just language-specific, but are also related to cognitive inabilities. For example, children with language specific impairments may also have limited processing resources.
Again, children with Down syndrome may have difficulties in syntax, speech production as well as speech intelligibility (Segers, Van Balkom, Van der Schuit and Verhoeven, 2011). The question therefore remains, what influences the different levels of language development in young children?
Children require a number of cognitive functions to enable them acquire aspects of the language. Such cognitive functions include the phonological working memory which allows for short-term storage of words/concepts or rehearsal of information which in turn supports long-term memory.
Children who posses better phonological working memory skills learn acquire syntax easily, while those who have better non-word repetition learn vocabulary faster. Children with intellectual disabilities have problems with tasks which involve phonological working memory.
According to Segers et al. (2011) they have lower working memory especially in visuospatial as well as phonological storage as compared to normal developing children of their age.
However, children with intellectual disabilities perform better in visuospatial memory tasks but poorly in word span tasks. This implies that their visuospatial memory is less affected as compared to phonological working memory.
Children who have Down syndrome are the most affected by phonological memory impairment, and this is what affects their vocabulary development. Sergers et al. (2011) established that phonological working memory has a limiting influence on vocabulary development in children.
Botting, Conti-Ramsden and Hick (2005) attribute this to difficulties in their short-term memory which is mostly common in children with intellectual disabilities. It can also be associated with cognitive processing difficulties especially for children with specific language impairment.
In the study conducted by Segers, Van Balkom, Van der Schuit and Verhoeven, it was found that there is a positive correlation between phonological working memory at age four and vocabulary growth at age five. This implies that children with better phonological memory at age four could have positive vocabulary development in their later life.
Vocabulary development in children with intellectual difficulties is also influenced by nonverbal intelligence. Language development is also determined by the ability to categorize objects. During children’s cognitive development, they begin to categorise objects at age of one and half years as they begin to associate objects to specific actions or events till they reach “vocabulary burst” (Segers et al., 2011).
This is also when they begin syntactic development. It is also this stage that the development one language skill can predict the development of another, a process known as bootstrapping. Syntactic bootstrapping facilitates lexical development.
However, lower verbal intelligence in children with intellectual disabilities interferes with their ability to categorise objects. This hampers further lexical development which creates the delay in language development in children with intellectual disabilities as it prolongs the period of lexical bootstrapping effects. This normally occurs at a stage when children have begun to use about 50-100 words.
These two articles provide evidence that cognitive factors such as phonological working memory (visuospatial short-term memory), verbal and nonverbal intelligence as well as lexical bootstrapping affect language development in children with intellectual disabilities. Thus, intervention programs aimed at improving language development in this group should focus on all language domains.
Reference List
Botting, N., Conti-Ramsden, G. & Hick, R. F. (2005). Short-term memory and vocabulary development in children with Down syndrome and children with specific language impairment. Developmental Medicine & Child Neurology, 47, 532–538.
Segers, E, Van Balkom, H, Van der Schuit, M. & Verhoeven, L. (2011). How cognitive factors affect language development in children with intellectual disabilities. Research in Developmental Disabilities, 32, 1884–1894.