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

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.
    Developmental Neuropsychology 05/2015; 40(4):201-15. DOI:10.1080/87565641.2014.997933 · 2.24 Impact Factor
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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.
    Child Neuropsychology 03/2015; DOI:10.1080/09297049.2015.1014898 · 2.42 Impact Factor
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    • "Wilson et al. (2013) identified very large effect sizes across core domains of EF, including working memory (WM) (d = 1.07, averaged over visuospatial and verbal), inhibitory control (1.03), and executive attention, which includes deficits in set-shifting and planning (1.46). Most striking was degree of generalized executive dysfunction (operationalized by performance deficits on different EF tasks), in excess of that reported in children with ADHD (Piek, Dyck, et al., 2007). "
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    ABSTRACT: Deficits of cool executive function (EF) have been shown in children with motor problems (or Developmental Coordination Disorder – DCD), but little is known of hot EF in this group. Given some evidence of poor self-regulation in DCD, we predicted poorer performance on a measure of hot EF, the Hungry Donkey Task (HDT), relative to typically developing (TD) children. Participants were 14 children with DCD and 22 TD children aged between 6.5 and 12 years. The DCD group performed significantly worse than the TD group on a 100-trial version of the HDT, making more selections from disadvantageous options and less from advantageous ones. Within-group analyses showed that children with DCD had faster responses to disadvantageous options than to advantageous. These results suggest high sensitivity to immediate reward in DCD. This sensitivity may reflect a more generalized deficit in the ability to resist the rewarding aspects of emotionally significant stimuli.
    Cognitive Development 10/2014; 32:23–37. DOI:10.1016/j.cogdev.2014.06.002 · 1.73 Impact Factor
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