Children with Down syndrome have specific impairment in the phonological loop component of working memory relative to their non-verbal abilities, and this is now thought to be a major cause of their speech and language difficulties.
Language is vital for mental and social development
Speech and Language Therapy for Down Syndrome
It can be argued that speech and language therapy is the most important part of intervention services for children with Down syndrome if we wish to promote their cognitive (mental) and social development.
Cognitive development
Speech and language development are absolutely central to the cognitive development of all children. First, words equal knowledge and the faster a child learns vocabulary, the faster he or she is acquiring knowledge about the world. Therefore vocabulary development is very important – the number of words that a child knows when he or she enters school at five years will have a very significant influence on progress. Secondly, language supports thinking and reasoning. The human brain has evolved a remarkable ability to learn spoken language with amazing ease and then to use that spoken language for mental activities. Thinking, reasoning and remembering, for example, are usually carried out in mind as ‘silent speech’. It follows, therefore, that any child with significant delay in acquiring language will be delayed in the ability to use these cognitive processes. Although delayed, almost all children with Down syndrome will use spoken language as their main means of communication. The use of signs in early years will help them to progress but for most children signs are used as a bridge to talking, not to teach a sign language.
Social development
Language is equally important for children’s social development as it enables them to negotiate their social world and to control their behavior. For example, as children acquire language, they can ask for what they want, explain how they feel, describe what they have been doing and share thoughts and worries with friends. Children are able to begin to control their behavior by using silent speech to instruct themselves and to plan their actions. The more we can do to help children with Down syndrome to learn to talk, the faster they will progress in all areas of cognitive and social development
The speech and language profile associated with Down Syndrome
Specific speech and language difficulties
Children with Down syndrome usually have an uneven profile of social, cognitive and language development – they do not have a profile of equal delay in all areas, they have a profile of strengths and weaknesses. For example, social development and social understanding is typically a strength, while spoken language development is a weakness. There is now consistent evidence that these children have a profile of specific speech and language delay relative to their non-verbal mental age. There are considerable individual differences in rates of progress but the overall specific profile is usually evident for all children with Down syndrome.
An uneven profile within the language domains
While the speech and language skills of children with Down syndrome are delayed relative to non-verbal mental abilities, different aspects of speech, language and communication skills are not equally delayed. Receptive language better than expressive .Communication skills are a relative strength with good understanding and use of non-verbal communication skills and good use of gesture.
In language, the children show delayed development of vocabulary in infancy, with comprehension ahead of production, but by the teenage years, vocabulary is a relative strength with vocabulary ‘ages’ ahead of grammar ‘ages’. In grammar, there is evidence of specific difficulties in both comprehension and production. In speech, there is considerable difficulty at all levels from planning to articulation and phonology. Most teenagers still have significant intelligibility problems.
An uneven profile within the language domains
While the speech and language skills of children with Down syndrome are delayed relative to non-verbal mental abilities, different aspects of speech, language and communication skills are not equally delayed. Receptive language better than expressive .Communication skills are a relative strength with good understanding and use of non-verbal communication skills and good use of gesture.
Individual differences are seen within the typical profile, with some children having more speech difficulties than others, relative to language comprehension and some children having larger differences between comprehension and production than others, for example. Therefore, each child with Down syndrome should receive an individualized therapy program but the principles for effective practice upon which this should be based is the same for all children with Down syndrome.
Possible primary causes
Research is beginning to provide some useful information on the underlying causes of the speech and language profile associated with Down syndrome.
Working memory
Hearing
Most children with Down syndrome (at least 80-90%) suffer from conductive hearing loss and auditory discrimination difficulties which will compound the phonological loop difficulties.
Speech-motor difficulties
Speech sound and word production difficulties also have physical causes. These are linked to the motor skill difficulties associated with Down.
Practical Activities Resources
Three age specific guides to practical activities to encourage speech and language development are available from Down Syndrome Education International. They should be helpful to parents and classroom assistants: