DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY
ORIGINAL ARTICLE
Examining the link between working memory behaviour and academic attainment in children with ADHD TRACY PACKIAM ALLOWAY 1 | SUSAN E GATHERCOLE 2 | JULIAN ELLIOTT 3 1 Director of the Center for Memory & Learning in the Lifespan, University of Stirling, Stirling, UK. 2 Department of Psychology, University of York, York, UK. 3 School of Education, University of Durham, Durham, UK. Correspondence to Dr Tracy Packiam Alloway, Department of Psychology, University of Stirling, Stirling FK9 4LA, UK. E-mail:
[email protected]
PUBLICATION DATA
AIM The aim of the present study was to investigate whether behaviours typical of working mem-
Accepted for publication 25th November 2009. Published online 12th February 2010.
ory problems are associated with poor academic attainment in those with attention-deficit–hyperactivity disorder (ADHD), as well as a non-clinical group identified on the basis of working memory difficulties. METHOD Children clinically diagnosed with ADHD-combined (n=31; mean age 9y 7mo, SD 12mo; 27 males) were matched with 44 low working memory children (mean age 9y 4mo, SD 15mo; 32 males) and 10 healthy controls (mean age 10y, SD 12mo; 5 males). Working memory behaviour was measured using the Working Memory Rating Scale (WMRS) and academic attainment was assessed with standardized tests of literacy and numeracy. RESULTS The majority of children considered by their teachers to have problematic behaviours performed poorly in literacy and numeracy. When the whole sample were split into two groups on the basis of their working memory behaviour (on the WMRS), the ‘At Risk’ group performed significantly worse in academic attainment. INTERPRETATION As children with ADHD and a non-clinical group exhibit classroom behaviour typical of working memory problems, early screening to prevent subsequent learning difficulties is important. The use of the WMRS allows educators to draw on their expertise in the classroom for early detection of children with working memory failures.
LIST OF ABBREVIATIONS
AWMA Automated Working Memory Assessment WMRS Working Memory Rating Scale
Classroom behaviour of children with attention-deficit–hyperactivity disorder (ADHD) is characterized by overactivity, inattention, and impulsiveness.1 There are currently several standardized teacher ratings scales of classroom behaviour, such as the Behavior Rating Inventory of Executive Function (BRIEF)2 and the Conners’ Teacher Rating Scale (CTRS).3 The BRIEF is a behaviour checklist that yields scores relating to different aspects of executive function, and the CTRS is designed to identify attention failures on the basis of classroom behaviours. In addition to the characteristic hyperactivity and impulsivity, there is growing evidence that children with ADHD also exhibit classroom behaviour typical of working memory problems.4 For example, children with ADHD are usually seen as having great difficulty remaining seated when required to, and being much more active than their peers. They also find it hard to remember complex instructions, show poor attention to instructions, and find it hard not to interrupt with their comments.5 The aim of the present study was to investigate whether behaviours typical of working memory problems are associated with poor academic attainment in those with ADHD, as well as a non-clinical group identified on the basis of working memory difficulties. This issue is of value as, at present, working memory problems 632 DOI: 10.1111/j.1469-8749.2009.03603.x
often go undetected in the classroom or are mislabelled as a lack of motivation.6 The term ‘working memory’ refers to the capacity to store and manipulate information for a brief period. There is now extensive evidence that working memory is linked to key learning outcomes in literacy and numeracy.7 In a screening study of over 3000 primary-school children, 10% of those in mainstream classrooms were identified with working memory deficits. Inspection of their learning profiles indicates that two-thirds achieved standard scores below age-expected levels (90 on both tests) formed a com-
What this paper adds • Children with ADHD exhibit behaviours that are characteristic of working memory failure. • Children who exhibit classroom behaviour typical of working memory problems perform significantly worse in attainment. • Early screening using standardized behavioural checklists, such as the Working Memory Rating Scale, can prevent subsequent learning difficulties.
parison group. The low working memory (LWM) group consisted of 44 children (32 males, 12 females; mean age 9y 4mo, SD 15mo) identified via screening with standard scores below 86 on both the listening recall and backwards digit recall tests from the AWMA. The average working memory (AWM) group consisted of 10 children (five males, five females; mean age 10y, SD 12mo) identified via screening with standard scores below 86 on both the listening recall and backwards digit recall tests from the AWMA. The uneven sample sizes of the LWM and AWM groups reflect those with completed behaviour questionnaires, as well as cognitive assessments. None of the children in the LWM or the AWM groups had a clinical diagnosis of ADHD, as confirmed by parent reports and school records. Both groups were also administered with the CTRS and group means for the T scores were within the average range for the ADHD Index (LWM=56; AWM=48).
Tasks and procedure Each child was tested individually in a quiet area of the school for two sessions lasting up to 40 minutes. Measures of memory and learning were administered in a fixed sequence designed to vary task demands across successive tests. Behaviour rating scale The Working Memory Rating Scale (WMRS)13 consists of 20 descriptions of behaviours characteristic of children with working memory deficits. These include: ‘Does not volunteer answers in group situations’ or ‘To move on to the next step in an activity, needs frequent prompts by teaching staff’. Teachers rate how typical each behaviour was of a particular child, using a four-point scale ranging from (0) not typical at all to (1) occasionally to (2) fairly typical to (3) very typical. Cronbach’s alpha across the normative sample was 0.978, establishing internal reliability of the scale.14 The responses were summed and converted into age-appropriate T scores (mean 50, SD 10). Working memory All 12 tests from the AWMA,19 a computer-based standardized battery, were administered. Test reliability and validity are reported in Alloway et al.20 and Alloway et al.8 respectively. The three verbal working memory measures were listening recall, backward digit recall, and counting recall. In the listening recall task, the child is presented with a series of spoken sentences, has to verify the sentence by stating ‘true’ or ‘false’ and recalls the final word for each sentence in sequence. In the backwards digit recall task, the child is required to recall a sequence of spoken digits in the reverse order. In the counting recall task, the child is required to count the number of Working Memory and Academic Attainment in ADHD Tracy Packiam Alloway et al. 633
IQ The Block Design test from the Wechsler Abbreviated Scale of Intelligence (WASI)21 was also administered. The raw scores were converted into scaled scores, with a mean of 10 and a SD of 3. Corrected coefficients for test–retest reliability is 0.87. Attainment Two measures of academic attainment were administered. The Wechsler Objective Reading Dimensions (WORD)22 consists of tests of basic reading, reading comprehension, and spelling for children. Test–retest reliabilities are 0.95, 0.92, and 0.91 for basic reading, reading comprehension, and spelling respectively. The Wechsler Objective Numerical Dimensions (WOND)21 assesses mathematical reasoning and number operations. Test–retest reliabilities are 0.89 and 0.85 respectively.
cally control for the contribution of IQ. All data were analysed using a statistical software package program called SPSS (SPSS Inc., Chicago, IL, USA).
RESULTS Figure 1 is a scatterplot that represents the performance of all three groups (ADHD-C, LWM, and controls) on the WMRS (behaviour rating scale) and the cognitive assessments of working memory. As a guide, scores of 55 or below on the WMRS do not represent a cause for concern, while scores above 60 can be viewed in terms of increasing risk of impairment.14 Table I provides descriptive statistics as a function of groups for the WMRS T score (mean 50, SD 10) and standard scores for the IQ and academic attainment (mean 100; SD 15). A univariate ANOVA was performed on the WMRS scores as a function of group. There was a significant difference in the rating scale scores across groups, F(2,82)=11.75, p
