Working memory, processing speed, and set‐shifting in children with developmental coordination disorder and attention‐deficit–hyperactivity disorder

Griffith University, Brisbane, Queensland, Australia
Developmental Medicine & Child Neurology (Impact Factor: 3.51). 08/2007; 49(9):678 - 683. DOI: 10.1111/j.1469-8749.2007.00678.x
Source: PubMed


It has been suggested that the high levels of comorbidity between attention-deficit-hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) may be attributed to a common underlying neurocognitive mechanism. This study assessed whether children with DCD and ADHD share deficits on tasks measuring working memory, set-shifting, and processing speed. A total of 195 children aged between 6 years 6 months and 14 years 1 month (mean 10y 4mo [SD 2y 2mo]) were included in this study. A control group (59 males, 79 females), a DCD group (12 males, six females), an ADHD-predominantly inattentive group (16 males, four females), and an ADHD-combined group (15 males, four females), were tested on three executive functioning tasks. Children with DCD were significantly slower on all tasks, supporting past evidence of a timing deficit in these children. With few exceptions, children with ADHD did not perform more poorly than control children. These findings demonstrate the importance of identifying children with motor deficits when examining tasks involving a timing component.

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Available from: Jan Piek, Jul 28, 2015
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    • "This interpretation is supported by Alloway and colleagues (Alloway, 2007, 2011; Alloway & Archibald, 2008): weaknesses were found in visuospatial but not verbal ELWM in those with DCD. A second issue concerns the EF tasks: individual measures often assess multiple EFs (e.g., Piek et al., 2007), and this lack of task purity could affect results (e.g., Miyake et al., 2000). A final issue concerns the recruitment of individuals with a clinical diagnosis of DCD, who may have diagnoses/subclinical symptoms of other co-occurring conditions such as ADHD, SLI, or ASD (Bishop, 2002; Kadesjo & Gillberg, 1999; Wilmut, 2010). "
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    ABSTRACT: The current study assessed a comprehensive range of executive functions (EFs) in children with poor motor skills, comparing profiles of children with a diagnosis of developmental coordination disorder (DCD) and those identified with motor difficulties (MD). Children in both groups performed more poorly than typically developing controls on nonverbal measures of working memory, inhibition, planning, and fluency, but not on tests of switching. The similar patterns of strengths and weaknesses in children with MD and DCD have important implications for parents, teachers, and clinicians, as children with MD may struggle with EF tasks even though their motor difficulties are not identified.
    Full-text · Article · May 2015 · Developmental Neuropsychology
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    • "rable visuospatial demands , and children with DCD may be slower at completing the task because of difficulties in processing visuospatial informa - tion ; such problems are often observed in this group ( Wilson & McKenzie , 1998 ) . The result is also consistent with previous research reporting slower visual inspection time in children with DCD ( Piek et al . , 2007 ) . It remains possible , therefore , that group differ"
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    ABSTRACT: A previous study reported that children with poor motor skills, classified as having motor difficulties (MD) or Developmental Coordination Disorder (DCD), produced more errors in a motor response inhibition task compared to typically developing (TD) children but did not differ in verbal inhibition errors. The present study investigated whether these groups differed in the length of time they took to respond in order to achieve these levels of accuracy, and whether any differences in response speed could be explained by generally slow information processing in children with poor motor skills. Timing data from the Verbal Inhibition Motor Inhibition test were analyzed to identify differences in performance between the groups on verbal and motor inhibition, as well as on processing speed measures from standardized batteries. Although children with MD and DCD produced more errors in the motor inhibition task than TD children, the current analyses found that they did not take longer to complete the task. Children with DCD were slower at inhibiting verbal responses than TD children, while the MD group seemed to perform at an intermediate level between the other groups in terms of verbal inhibition speed. Slow processing speed did not account for these group differences. Results extended previous research into response inhibition in children with poor motor skills by explicitly comparing motor and verbal responses, and suggesting that slow performance, even when accurate, may be attributable to an inefficient way of inhibiting responses, rather than slow information processing speed per se.
    Full-text · Article · Mar 2015 · Child Neuropsychology
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    • "This indicates that children with DCD may need specific instruction more than what was given during this study, on how to move their body to perform a certain skill level over time. Repeated prompting to maintain this focus might be important to compensate executive control issues that are commonly observed in this population (Piek, Dyck, Francis, & Conwell, 2007). With practice, the task may become more automatic and natural over time, resulting in better performance (Wilson et al., 2012). "
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    ABSTRACT: Children with developmental coordination disorder (DCD) struggle to learn new motor skills. It is unknown whether children with DCD learn motor skills more effectively with an external focus of attention (focusing on impact of movement on the environment) or an internal focus of attention (focusing on one's body movements) during implicit (unconscious) and explicit (conscious) motor learning. This paper aims to determine the trends of implicit motor learning in children with DCD, and how focus of attention influences motor learning in children with DCD in comparison with typically developing children. 25 children, aged 8-12, with (n=12) and without (n=13) DCD were randomly assigned to receive instructions that focused attention externally or internally while completing a computer tracking task during acquisition, retention, and transfer phases. The motor task involved tracking both repeated and random patterns, with the repeated pattern indicative of implicit learning. Children with DCD scored lower on the motor task in all three phases of the study, demonstrating poorer implicit learning. Furthermore, graphical data showed that for the children with DCD, there was no apparent difference between internal and external focus of attention during retention and transfer, while there was an advantage to the external focus of attention group for typically developing children. Children with DCD demonstrate less accuracy than typically developing children in learning a motor task. Also, the effect of focus of attention on motor performance is different in children with DCD versus their typically developing counterparts during the three phases of motor learning. Results may inform clinicians how to facilitate motor learning in children with DCD by incorporating explicit learning with either internal or external focus of attention within interventions. Copyright © 2014 Elsevier Ltd. All rights reserved.
    Full-text · Article · Dec 2014 · Research in Developmental Disabilities
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