Working memory impairments in children with attention-deficit hyperactivity disorder.
Published: 2005
Language: eng
Number of pages: 129
Description: Objectives. To examine: (a) whether children with attention-deficit/hyperactivity disorder (ADHD) exhibit impairments in working memory (WM) independent of comorbidity with language learning disorders, (b) whether WM deficits are more strongly associated with symptoms of inattention than with symptoms of hyperactivity-impulsivity, and (c) whether WM capacity is related to performance on tasks that require controlled attention (i.e., response inhibition tasks). Method. Study 1 used meta-analytic techniques to investigate existing data on WM in children with ADHD. Study 2 examined multiple components of WM (verbal and spatial storage and central executive (C.E.)) in children diagnosed with ADHD with and without comorbid language learning problems. Study 3 examined the relations between WM, controlled attention, and behavior in a non-referred sample of school children.  Results. The results of the meta-analysis indicated that children with ADHD relative to normal controls exhibit moderate weaknesses in verbal storage and verbal C.E. components of WM and large deficits in spatial storage and spatial C.E. components of WM independent of comorbidity with language learning disorders. The findings from Study 2 were mainly consistent with the meta-analysis; except that verbal storage deficits were associated with language learning problems rather than with ADHD per se. Dimensional analyses (Studies 2, 3) indicated that WM was more strongly associated with symptoms of inattention than with symptoms of hyperactivity-impulsivity. Moreover, in Study 3, WM was significantly associated with performance on a task indexing controlled attention (i.e., response inhibition), but was not associated with performance on tasks that require more automatic processing. Conclusions . The findings contribute to our understanding of the nature and severity of WM deficits in children with ADHD and support neuropsychological theories of ADHD. Evidence of working memory deficits in children with ADHD has important clinical implications given that working memory limitations are also strongly associated with academic underachievement. Longitudinal research is needed to address the causal relations between working memory, inattention symptoms, and academic achievement.
Notes: Thesis (Ph.D.)--University of Toronto, 2005.

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Source: Dissertation Abstracts International, Volume: 66-06, Section: B, page: 3436.