Investigating the literacy, language and memory skills of children with Down syndrome
Angela Byrne, Sue Buckley, John MacDonald and Gillian Bird
This paper presents the first phase of a longitudinal study following 24 children with Down syndrome who are receiving their education in mainstream primary schools. The literacy, numeracy, language and memory skills of the children with Down syndrome were compared to 2 groups of children selected from their classmates. The comparison groups were a group of typically developing children who were average readers in the classes and a group of children who were matched to the children with Down syndrome for reading age. The baseline data revealed that the children with Down syndrome had uneven cognitive profiles with relatively advanced reading skills compared to their other cognitive skills. The group of ordinary children who were matched to the children with Down syndrome on reading ability, attained significantly higher scores than the children with Down syndrome on all assessments other than reading. However, the reading matched group who were generally of below average reading ability for their age, were also significantly delayed relative to the average readers on measures of language, number and memory. As a group the average readers were average or above average on all measures. A cross-sectional analysis which divided the children with Down syndrome into 3 groups according to age and school year group indicates steady progress in all skills as the children move through primary school.
Byrne A, Buckley SJ, MacDonald J, Bird G. Investigating the literacy, language and memory skills of children with Down syndrome. Down Syndrome Research and Practice. 1995;3(2);53-58.
doi:10.3104/reports.51
Introduction
Published literature concerning reading skills in children with Down syndrome
is extremely limited and consists mainly of anecdotal evidence and single
case studies (see
Buckley et al, in press). One reason for the limited amount of information
on the reading abilities of children with Down syndrome is that until recently
the majority of them have not had the opportunity to learn to read. Until
the last five years, the majority of children with Down syndrome in the
United Kingdom, were educated in special schools for children with severe
learning difficulties. Children with Down syndrome were not introduced to
literacy teaching at the usual age of 4 or 5 because it was assumed that
most of them were not able to learn to read. However, over the past five
years increasing numbers of children with Down syndrome have been included
in mainstream primary schools and educated alongside their peers. In 1994
there were approximately 40 children with Down syndrome attending their
local mainstream school in the county of Hampshire (Bird
and Buckley,1994). This number includes children in both primary and
secondary schools. Almost all the primary age children in the local district
were in integrated mainstream placements and had access to literacy teaching
from beginning of school.
Frith's developmental model of reading describes the way in which literacy
skills change as the typical child learns to read and write (Frith,
1985). Most children will at first recognise words by sight only. They
will then go on to an alphabetic stage when words can be sounded out letter
by letter and then on to an orthographic stage of morpheme recognition.
The building of a child's sight vocabulary will depend on his or her visual
discrimination and visual memory skills as the printed words are stored
visually. The alphabetic stage involves learning letter to sound rules so
that when the child is faced with an unfamiliar word he or she can sound
it out to identify the printed word from its spoken form. Seymour has proposed
a set of operational characteristics which can be used to identify whether
children are using the logographic or alphabetic strategy when reading,
(e.g. Seymour,
1993). The characteristics studied by Seymour include the types of errors
the children make when trying to read words and the times it takes to read
words in milliseconds.
Many children with Down syndrome are able to establish a sight vocabulary
even from as young as two to three years of age (Bird
and Buckley,1994). Very few studies have focused on the use of the phonological
route to reading in children with Down syndrome. However to be able to make
use of phonological recoding the child must be able to hear all of the sounds
in words. If the hearing loss and auditory short term memory difficulties
that are often associated with having Down syndrome are taken into consideration,
it would seem likely that they would find this strategy more difficult than
the direct visual route (Buckley
et al 1995).
Buckley has also suggested that children with Down syndrome may be logographic
readers after observing that the children were not translating print to
speech in order to retrieve the meaning of a word, but were going straight
from the visual form of the word to its meaning (Buckley,
1985). Buckley goes on to suggest that the reading and language skills
of children with Down syndrome may rely on right hemisphere processes in
the brain, whereas in the majority of the population these functions are
handled by the left hemisphere. The language processing abilities of the
right hemisphere are more limited than those of the left and one of its
limitations is that it is not able to use sound to print (grapheme to phoneme)
coding.
Research on reading development in typically developing children suggests
a reciprocal relationship between reading progress and other cognitive skills
such as working memory development and phonological awareness, (Ellis
and Large, 1988,
Gathercole and Baddeley, 1993). Tests of phonological awareness aim
to measure a persons ability to make judgements about or manipulate the
sound structure of words. Bradley and Bryant (1983) asserted that an overt
knowledge of how spoken words can be analysed into their constituent sounds
play a causal role in the development of reading ability. However recent
studies (Cossu,
Rossini and Marshall,1993,
Evans, 1994) have
shown that many children with Down syndrome have acquired reading skills
despite their inability to perform phonological awareness tasks.
Cossu, Rossini and Marshall (1993) investigated the phonological skills
of 10 Italian children with Down syndrome who ranged in age from 8 to 15
years and who could read at about the same level as ordinary 7 year old
children. However the children with Down syndrome failed the phonological
awareness tasks passed by the reading age matched children. Thus Cossu et
al suggest that phonological awareness tasks may not embody those skills
which are crucial to reading.
Evans (1994) describes a study of phonological skills in six children with
Down syndrome who were participating in a larger study of literacy development.
The results indicated that some logographic reading ability had developed,
while alphabetic and phonological skills were largely absent. The lack of
alphabetic processing was indexed by an inability to read or spell non-words,
although all the children had some knowledge of the sounds of individual
letters of the alphabet. The results supported those of Cossu et al in that
the children with Down syndrome were unable to perform competently in tasks
which required phonological skills.
Buckley et al (in press), also point out that the phonological route to
reading is only of any real use if the word that is being sounded out is
in the child's vocabulary. Children will often use phonological recoding
and the context given by other words in the sentence to help them guess
a word that will fit that sentence. However children with Down syndrome
often have less language knowledge both in terms of their vocabulary and
their knowledge of grammar and syntax than other children with the same
level of reading ability. Therefore it would seem likely that children with
Down syndrome may not be able to make as much use of context or phonological
recoding as other children.
Ellis and Large (1988) also found reciprocal interactions between reading
development and other cognitive skills in typically developing children.
By looking at the cognitive skills that were associated with reading at
several time samples, Ellis and Large were able to investigate developmental
changes in reading ability. 40 children were tested annually on 44 variables.
From the analyses the authors concluded that the nature of reading skills
changes rapidly in the first three years of acquisition. For example the
correlations between various short-term memory abilities and reading skill
indicate that in the early stages of reading acquisition it is the visual
STM tasks that predict later reading ability not the auditory ones. Thus
it seems that early reading builds on visual STM skills. Although reading
and auditory STM are associated in these early stages, they seem to be developing
in unison and with mutual benefit. From 6 to 7 years it is auditory rather
than visual STM that is more highly associated with reading skill and it
is now reading that is a better predictor of the auditory STM skills than
auditory STM is of later reading skill. Hence Ellis and Large's conclusion
that it is "the acquisition of reading skill which underpins the developmental
changes in strategies and skills used in STM tasks."
In 1993 the author embarked upon a longitudinal research project which has
only been made possible because of the recent changes in educational provision
for children with Down syndrome in the local area. The opportunity for this
research project has arisen because almost all of the primary aged children
with Down syndrome in the local district are now in mainstream placements.
For the first time it has become possible to study the literacy development
of a representative sample of children with Down syndrome who have all had
access to literacy teaching. The main aims of this study are:
- to chart the literacy, language and memory skills of 24 children with
Down syndrome comparing their progress with their mainstream classmates.
- to investigate the interrelationships between literacy, language and
memory skills.
- to look at the cognitive strategies the children are using to read.
This paper will present the results of the first phase of the longitudinal
study. It will focus on the results of a battery of standardised assessments
which were administered to three groups of children (children with Down
syndrome, average readers, and reading age matches) in order to obtain baseline
measures. The profiles of cognitive abilities in the three groups will be
discussed.
Methodology
Participants
A total of 97 children participated in the study. The children were drawn
from 18 schools in Hampshire, 5 schools in West Sussex and 1 school on the
Isle of Wight.
The research strategy used, was to identify the children with Down syndrome
first and then to select 2 control groups, (I) children matched for reading
age, and (ii) average readers from the same classes.
The sample was restricted to the primary school age range and to schools
within a seventy mile radius of Portsmouth. A letter was sent to 25 mainstream
Primary schools in Hampshire, West Sussex and the Isle of Wight that had
included a child with Down syndrome, inviting them to take part in the research
project. All of the schools that were contacted agreed to take part. A sample
of 20 schools was established in the spring of 1994. Another 4 schools joined
the research project in September 1994.
Three groups of children were assessed:
Children with Down syndrome: This group consisted of 24 children with Down
syndrome, 10 girls and 14 boys, mean age 8 years 2 months, range 4 years,
11 months to 12 years, 7 months.
Average readers: The second group of children were described as average
readers in their class. The teacher of each child with Down syndrome was
asked to select 2 children who she considered to be average readers in the
class. The group of average readers comprised 42 children, 21 girls and
21 boys. Their mean age was 7 years, 3 months, range 4 years, 7 months to
10 years, 5 months.
Reading age matched: The third group of readers were children without Down
syndrome who were matched to the children with Down syndrome on reading
ability, using the British Ability Scales Word Reading subtest (Elliot,
1993). This group comprised 31 children, 12 girls and 19 boys. Their
mean age was 7 years, 1 month, range 4 years, 8 months to 9 years, 10 months.
If it was not possible to find a reading match from within the same class
as the child with Down syndrome, a match was found from another class within
the same school.
Materials and procedure
The children were assessed on standardised measures of reading, spelling,
short term memory and number, using subtests of the British Ability Scales
(BAS) and Kaufman Assessment Battery for Children (K-ABC) and on language
measures, the Test for the Reception Of Grammar (TROG) and the British Picture
Vocabulary Scale (BPVS). The children were assessed individually at school
during the summer term, 1993. The assessments were typically completed in
2 sessions lasting 30 - 40 minutes each.
Results
A series of one-way analyses of variance (ANOVA) were performed on the assessment
data raw scores, followed by the Student Newman-Keuls post hoc test. Table
1 shows the mean raw scores attained by the three groups of children.
Table 1 - Mean Raw Scores Attained by the Three Reading Groups.
|
MEAN RAW SCORES |
| ASSESSMENT |
DOWN SYNDROME |
AVERAGE READERS |
READING MATCH |
|
MEAN |
STD DEV |
N |
MEAN |
STD DEV |
N |
MEAN |
STD DEV |
N |
| AGE |
|
97.75 |
19.84 |
24 |
87.43 |
16.89 |
42 |
85.00 |
18.58 |
31 |
| BAS |
immediate visual recall |
3.77 |
2.20 |
22 |
7.98 |
2.57 |
42 |
6.59 |
2.99 |
29 |
| BAS |
delayed visual recall |
1.52 |
1.97 |
21 |
5.77 |
3.05 |
35 |
4.04 |
1.99 |
28 |
| BAS |
recall of digits |
6.70 |
3.28 |
23 |
17.90 |
4.18 |
42 |
15.41 |
5.04 |
29 |
| BAS |
number skills |
9.74 |
5.66 |
23 |
36.02 |
10.10 |
41 |
27.25 |
10.00 |
28 |
| BAS |
word reading |
16.91 |
18.35 |
23 |
41.26 |
26.25 |
42 |
17.29 |
16.86 |
31 |
| BAS |
spelling |
1.91 |
3.01 |
22 |
7.76 |
4.55 |
38 |
4.31 |
3.54 |
26 |
| K-ABC |
reading -decoding |
11.96 |
8.41 |
23 |
21.68 |
7.27 |
41 |
13.81 |
7.04 |
31 |
| K-ABC |
reading -understanding |
1.08 |
2.36 |
24 |
7.32 |
6.56 |
38 |
1.97 |
3.61 |
30 |
| TROG |
understanding of grammar |
5.63 |
2.53 |
24 |
15.07 |
2.81 |
41 |
11.90 |
4.11 |
29 |
| BPVS |
understanding vocabulary |
9.74 |
2.85 |
23 |
17.00 |
4.21 |
39 |
14.04 |
4.16 |
26 |
Memory
Significant differences were found between all 3 reading groups on the British
Ability Scales immediate visual recall task, (F(2,90)= 18.40, p< .00), and
on the delayed visual memory task, (F(2,81)= 19.20, p<.00). Similarly all
three groups differed significantly in terms of auditory short term memory
as measured by the British Ability Scales recall of digits test, (F(2,91)=
52.27, p<.00). Thus on all 3 memory assessments the average readers achieved
significantly higher scores than the group of reading matched children,
who in turn achieved significantly higher scores than the children with
Down syndrome.
Reading
Analysis of variance revealed a significant effect of reading group on the
British Ability Scales reading test, (F(2,93)= 14.48, p<.00). As the reading
matches for the children with Down syndrome were selected using the British
Ability Scales word reading test it was expected that the mean raw scores
of these two groups would not be significantly different and this was the
case. Post hoc comparisons using the Student Newman-Keuls test revealed
that the mean scores for both the children with Down syndrome and the reading
matches were significantly lower than the mean raw score attained by the
average readers at the 0.05 level. The mean scores attained by the children
with Down syndrome and the reading matches were not significantly different.
Likewise there was a significant effect of reading group on both the Kaufman
single word reading (F(2,92)= 16.01, p <.00) and on the reading comprehension,
(F(2,89)= 15.82, p < .00). Post hoc comparisons revealed that children with
Down syndrome and the reading matches did not differ significantly on the
two measures of reading taken from the Kaufman Assessment Battery for Children.
However, the mean scores for both the children with Down syndrome and the
reading matches were significantly lower than the mean scores attained by
the average readers in both tests.
Spelling
There was a significant effect of reading group on spelling, (F(2,83)=16.62,
p<.00). Post hoc comparisons revealed that all three groups differed significantly
on the British Ability Scales spelling test with the average readers achieving
the highest scores followed by the reading matches and then the children
with Down syndrome.
Number
There was a significant effect of reading group on number, (F(2,89)= 60.53,
p< .000). Post hoc comparisons revealed that all 3 groups differed significantly
on the British Ability scales basic number test with the average readers
achieving the highest scores followed by the reading matches and then the
children with Down syndrome.
Language
There was a significant effect of reading group on both the TROG (F(2,91)=
65.85, p < .00) and BPVS (F(2,85)= 25.26, p <.00). Post hoc comparisons
revealed that all 3 groups differed significantly in their understanding
of grammar as measured by Test for Reception Of Grammar, and in their knowledge
of vocabulary as measured by the British Picture Vocabulary Scale. Thus
on both language assessments the average readers achieved significantly
higher scores than the group of reading matched children, who in turn achieved
significantly higher scores than the children with Down syndrome.
In summary, on each of the subtests measuring reading ability, the children
with Down syndrome did not differ significantly from the reading match children.
However both of these groups differed from the average readers who were
scoring significantly higher. The pattern was different but equally consistent
for skills other than reading. On measures of memory, language, and number,
the average readers scored significantly higher than the matched readers
who in turn scored significantly higher than the children with Down syndrome.
This highlights the fact that although the ordinary children in group 3
were matched to the children with Down syndrome on reading ability, they
were not matched on any of the other abilities that were assessed.
Table 2. The cognitive profiles of children with Down syndrome
compared to other children selected from their mainstream classmates.
|
|
|
British Ability Scales |
Raw score |
BPVS |
TROG |
| Group |
N |
mean CA |
reading age |
spelling age |
number age |
digit recall |
vocabulary age |
grammar age |
Down
syndrome |
24 |
8y 2m |
6y 3m |
6y 4m |
4y 1m |
6.7 |
4y 5m |
4y 3m |
Average
readers |
42 |
7y 3m |
7y 3m |
7y 6m |
7y 3m |
17.9 |
7y 9m |
8y 0m |
Reading
matched |
31 |
7y 1m |
6y 4m |
6y 9m |
6y 4m |
15.4 |
6y 3m |
5y 9m |
In Table 2 the mean raw scores have been converted into age equivalent scores.
The children with Down syndrome were often in classes with children one
year younger than themselves. As a result the children with Down syndrome
are significantly older than both the average readers who were selected
from the same class and the reading matches (F(2,94)= 3.68, p < .029). Post
hoc comparisons revealed that the average readers and the reading matches
did not differ significantly in age.
All of the children with Down syndrome were learning to read but there was
a wide range of abilities with reading ages ranging from 5 years to 8 years
5 months. Although the children with Down syndrome are matched to slower
readers on reading measures, they fall significantly behind the slower readers
on the measures of language, memory and number.
The children with Down syndrome were divided into 3 groups on the basis
of their school year. Group 1 were 8 of the youngest children who were either
in reception or year 1 classes. The next group consisted of 9 children who
were in year 2 and year 3 classes of infant schools. The oldest age group
consisted of 5 junior school children who were in year 3 to year 5 classes.
Table 3 shows the assessment data for each of these 3 groups. This cross-sectional
data indicates steady progress in these skills as the children move through
the infant and junior classes.
Table 3. The cognitive profiles of the children with Down syndrome
divided into 3 groups on the basis of age and school year.
| Children with Down syndrome |
Group 1
N=8 |
Group 2
N=9 |
Group 3
N=5 |
| Mean Chron. age |
6yrs 8m |
8yrs 3m |
9yrs 7m |
BRITISH
ABILITY
SCALES |
Number |
6.00 (3y 8m) |
8.78 (3y 11m) |
16.20 (4y 11m) |
| Reading |
5.25 (5y 5m) |
14.44 (6y 2m) |
38.60 (7y 2m) |
| Spelling |
0.75 (6y 1m) |
1.00 (6y 1m) |
5.50 (7y 2m) |
| Recall of digits |
5.13 |
5.89 |
10.60 |
| Immediate visual recall |
2.63 |
4.13 |
4.8 |
| Delayed visual recall |
0.38 |
2.5 |
1.75 |
LANGUAGE
ASSESSMENTS |
BPVS - vocabulary |
8.25 (3y 7m) |
9.75 (4y 5m) |
12.00 (5y 4m) |
| TROG - grammar |
3.75 (<4y0m) |
6.33 (4y 3m) |
7.80 (5y 0m) |
KAUFMAN
ASSESSMENT
BATTERY |
Reading/decoding |
6.00 (5y 3m) |
12.00 (6y 3m) |
20.60 (7y 6m) |
| Understanding |
0.00 (6y 3m) |
0.56 (6y 6m) |
4.20 (7y 0m) |
Discussion
The present study has established three groups of children who will be assessed
longitudinally. The children can be described as 1) children with Down syndrome,
2) average readers and 3) slower readers.
It is interesting to note that although the children with Down syndrome
were matched to the slower readers in terms of reading ability, they fall
significantly behind them on measures of language, memory and number skill.
In other words, the children with Down syndrome appear to have advanced
reading ability compared to their other cognitive abilities. The typically
developing children who were selected by their teachers as being average
readers in their class, showed even and age appropriate cognitive profiles
across all measures. The children who were selected by their teachers as
being "slower readers" and who were reading at approximately the same level
as the child with Down syndrome, showed more even cognitive profiles than
the children with Down syndrome. However the slower readers were significantly
delayed relative to the average readers on all measures, with mean age equivalent
scores approximately one year behind the mean chronological age of the group.
Within the group of children with Down syndrome there was a wide range of
ability in reading with some children yet to score on the standardised measures
and others who have attained significant reading ability and reading ages
of 8 years 5 months. It is expected that the individual rates of progress
made in reading over the next 2 years will vary dramatically. A cross-sectional
analysis which divided the group of 24 children into 3 groups according
to age and school year group, indicates steady progress in all the assessment
measures as the children move up through the primary school years. Longitudinal
data is needed to confirm this indication and this data will be available
in due course.
Future research
The assessment data that has been described will form the baseline data
for a longitudinal study which will monitor the children's reading progress
in relation to other cognitive abilities. The research design will be similar
to other longitudinal studies which select samples of children who are tested
and re-tested at further intervals, and then explore the changing predictors
and beneficiaries of reading as reading abilities develop, (Ellis
and Large, 1988; Gathercole and Baddeley, in press, cited in
Gathercole and Baddeley, 1993).
As well as exploring whether learning to read improves other cognitive abilities
such as the working memory and language skills of children with Down syndrome,
this research project will look at the strategies the children are using
to read. The main enquiry is whether the children with Down syndrome are
using the same strategies to read as the typically developing children as
well as the manner in which these strategies develop or fail to develop.
The study will investigate the extent to which the children have established,
a) a logographic process which recognises words on a visual basis, and,
b) an alphabetic process which applies letter to sound knowledge in the
decoding on unfamiliar items. A main focus of interest will be the stages
of reading development and the ages of the children when the transition
form logographic to alphabetic strategy use begins. An experimental investigative
technique will be used to compare the strategies used by children with Down
syndrome and the 2 control groups which were established for the longitudinal
study.
Acknowledgements
The authors would like to thank the children, parents and schools who participated
in the research.
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