The links between language, literacy and memory skills in children with Down syndrome
Sue Buckley and Angela Byrne
Abstract - In the past ten years there has been a great deal of research into the development of speaking, reading and memory skills in typically developing children. One clear finding is that they are inter-linked and progress in one area influences progress in another. This work has significance for children with Down syndrome as it has practical implications for teaching them. In this article, we briefly outline some of the key points from this research and then discuss the relevance for helping children with Down syndrome.
Keywords - Down Syndrome, Reading, Language, Memory
New understandingIn the past ten years there has been a great deal of research into the development of speaking, reading and memory skills in typically developing children. One clear finding is that they are inter-linked and progress in one area influences progress in another (1). This work has significance for children with Down syndrome as it has practical implications for teaching them.
In this article, we briefly outline some of the key points from this research and then discuss the relevance for helping children with Down syndrome.
Learning to readMost researchers agree that children progress through three main stages called logographic, alphabetic and orthographic stages.
When children begin to read, they establish a sight vocabulary. These are words that they recognise from their visual pattern, using cues such as overall shape, length of the word or first letter. This is the logographic stage and this strategy predominates for the first year or so of learning to read. Progress in this year is associated with good visual discrimination skills (2).
As children become more familiar with the letter-sound relationships, they move into the alphabetic stage. They are now able to sound out unfamiliar words as they read. The demands of writing and spelling develop children’s letter-sound awareness - as they can read by visual recognition - but writing words draws attention to individual letters and their sounds. At the start of this stage, children can usually read many more words than they can spell.
As they become really familiar with text, children move into the orthographic stage. Now they recognise the sight and sound of parts of words that correspond to units of meaning (morphemes) very rapidly.
Skilled adult readers read "visually" with the brain recognising the meaning of the text directly from the visual pattern. The brain only needs to draw on its knowledge of the sounds corresponding to the letters in the words, when confronted by an unfamiliar word in a text.
The links between speaking and readingAs children begin to learn to read and read words and sentences in books, their spoken language knowledge will help them a great deal. If they know the name of an object in a picture they can guess the printed word below it. If they come to an unfamiliar word in a written sentence, they can often guess which word would fit and make sense, from their spoken language knowledge. So - the child with a large vocabulary and wide knowledge of sentence construction will have an advantage when beginning to learn to read.
Soon, however, the child will come across completely new words in print, learn what they mean and then be able to use them in speech. Becoming literate has a huge impact on most children’s language knowledge and this is highlighted in recent books on learning to read (3). So, reading and speaking are closely linked activities developing together.
As children learn letter-sound relationships, this progress in a skill being taught to aid reading, leads to increased skill in listening to and identifying all the sounds in words. Most children are around seven years old before they can reliably play games which require them to identify single sounds in words. It is thought that this is because by seven years, reading has been established (1). So, the activity of learning to read increases all children’s vocabulary, language knowledge and sound discrimination skills.
The importance of memoryWorking memory is the name given to a vitally important system in the brain which handles and processes incoming information. It is also essential to the performance of mental functions such as reasoning, mental arithmetic, language comprehension and long term learning. The working memory system is made up of a central executive processor, supported by two short term stores which hold information long enough for it to be processed. These are called a phonological store (for holding spoken/auditory input) and a visual/spatial scratch pad (for visual and spatial input information).
The phonological store in this system has been widely studied and the amount of information it can hold increases dramatically during childhood. It uses a speech based rehearsal strategy to maintain information in store, so has been described as an "echo" system. The capacity of this store increases throughout childhood. One way of measuring the capacity is to record a digit span - the number of digits the person can recall when they are presented in random order at the rate of one per second. A three year old would be expected to have a span of 2 or3 digits, and a teenager a span of 7 or 8 digits by 15 years.
The development of this working memory system has been shown to be important for speech, language and reading development (1). For example, the effectiveness of working memory has been shown to influence the rate of learning to understand new words, language processing and comprehension and reading progress.
Conversely, the phonological store is influenced by a child’s language and speech skills. It is a speech based system and likely to be impaired in those with limited language skills.
Relevance for children with Down syndromeMost children with Down syndrome have a significant delay in learning to talk and many never achieve really fluent and grammatically correct speech.
Research has also identified that their auditory memory span is not developing at the rate it should. The digit span of teenagers with Down syndrome is likely to be only 3 when it should be 7. This is a serious impairment, limiting their ability to remember spoken information, to process language, to reason and to do mental arithmetic. The poor development of auditory short term memory and of speech and language may be related in children with Down syndrome. We certainly know that both need working at and that gains in one will lead to gains in another, from our own research at the Centre.
Our three year study of the effects of memory training shows that teaching children with Down syndrome to actively rehearse, a strategy children learn between 5-7 years, improved their memory span. Teaching the children to organise information into classes, a strategy also dependant on language knowledge, also improves their memory span. The results also suggest the memory gain leads to a language gain, understanding more complex grammar and sentences.
Our work on reading has identified that learning to read leads to improved speech and language for children with Down syndrome, as it does for all children, but the effect is more significant for children with Down syndrome, as they are not able to learn language easily from simply listening to it.
Being able to read gives them access to vocabulary and more importantly, to sentence structure - the grammar and syntax that they usually find difficult to learn and understand and to use in their speech.
So many studies have reported that people with Down syndrome have only keyword ‘telegraphic’ speech that authors have suggested they are unable to do better. Our reading work has shown this view to be wrong, as we have a number of children with mastery of grammar way beyond that thought to be the limit children with Down syndrome could achieve.
Being able to read also gives the child a powerful support for improving their speech production. Clear speech and production of long sentences are usually difficult to achieve - but being able to read helps the child to practise - both practise for sounds in words as letters are a clue to correct pronunciation, and practise for multi-word sentences.
In summaryFor all children, spoken language, reading and memory skills develop together. Progress in one will accelerate progress in another. Delay in any of them will delay cognitive development - children’s "mental ability" which reflects their knowledge of the world and their ability to reason, remember and use that knowledge.
Children with Down syndrome are significantly disadvantaged from the first months of life as they usually find learning to talk difficult - mainly due to hearing loss, auditory discrimination difficulties and speech production delays. If any child has language delay, they will have cognitive delay as language is the main tool for learning about the world - for accessing information - and for thinking and remembering.
In the first three years, language teaching activities using pictures, play and most importantly, signing, have been shown to accelerate the progress in language and speech for children with Down syndrome.
From three onwards, learning to read and learning active strategies to remember from around four years will help the children quite dramatically.
Our research and development work with children at the Sarah Duffen Centre has already demonstrated these effects.
However, the educational opportunities for our children have only just reached a point where we can really research the effects of reading and memory work adequately. Reading has to be taught over time and most children with Down syndrome have not had the same opportunity to learn to read and write as other children, as the focus of the curriculum in special schools is different to that in mainstream schools.
For the first time, we now have enough children in mainstream schools near us, in Hampshire and West Sussex, to establish a proper research project. We are just setting this up with 25-30 children in the primary age range, to monitor their progress with reading, speaking and memory skills closely over a two year period.
We will also be working closely with the teachers to identify the most effective ways of teaching the children in order to develop these skills.
Meanwhile, it is really important to follow up the implications of research to date and use every opportunity to teach reading, to improve speech and to help children develop their memory skills, using the methods we have already tried.
References1. Gathercole, S. & Baddeley, A. (1993) Working memory and language Hove: LEA.
2. Ellis, N. & Large, B. (1988) The early stages of reading: A longitudinal study Applied Cognitive Psycholgy 2 47-76.
3. Garton, A. & Pratt, C. (1989) Learning to be literate: the development of written and spoken language Oxford: Blackwell
4. Broadley, I. & MacDonald, J. (1993) Teaching short term memory skills to children with Down syndrome Down Syndrome: Research and Practice 1(2) 56-62. Available Online: http://www.down-syndrome.net/library/periodicals/dsrp/01/2/056/
5. Buckley, S. (1993) Language development in children with Down syndrome-Reasons for optimism Down Syndrome: Research and Practice 1(1) 3-9. Available Online: http://www.down-syndrome.net/library/periodicals/dsrp/01/1/003/
6. Buckley, S. & Bird, G. (1993) Teaching children with Down syndrome to read Down syndrome Research and Practice 1(1) 34-39. Available Online: http://www.down-syndrome.net/library/periodicals/dsrp/01/1/034/