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Visuospatial working memory in ADHD: Characterizing mechanisms of impairment

Arrington, Elaine F.
Meta-analytic reviews provide evidence of moderate to large magnitude deficits in the visuospatial working memory (WM) of children with attention-deficit/hyperactivity disorder (ADHD), relative to typically-developing children (Kasper et al., 2012; Martinussen, Hayden, Hogg-Johnson, & Tannock, 2005; Willcutt, Doyle, Nigg, Faraone, & Pennington, 2005). The majority of studies that have researched serial visuospatial WM in ADHD have examined general performance characteristics such as span length, number of correct trials, and average stimuli correct (Kasper et al., 2012). However, relatively few studies have examined potential cognitive processes that may underlie visuospatial WM deficits (e.g., Cornoldi et al., 2001; Re, De Franchis, & Cornoldi, 2010), despite evidence from cognitive-experimental studies (Kemps, 1999; Pearson & Sahraie, 2003; Smyth, Pearson, & Pendleton, 1988) indicating that variation in visuospatial WM performance may vary as a function of how information is presented and rehearsed. More recent studies of potential determinants of WM performance have employed spatial span tasks and focused on the mentally-imaged (Kosslyn, 1994) representation of the path formed by task stimuli connected in sequence (Guérard & Tremblay, 2012; Imbo, Szmalec, & Vandierendonck, 2009; Kemps, 2001; Parmentier, Elford, & Mayberry, 2005; Parmentier & Andrés, 2006; Parmentier, Andrés, Elford, & Jones, 2006). The current study is the first to examine the effect of such path characteristics on performance in children with ADHD and typically-developing children. Both groups of children exhibited decreased performance with longer path length, consistent with hypotheses. Disproportionate effects of path crossings on performance for children in the ADHD group were observed. The findings from this study provide first-step evidence that path characteristics inform processes underlying ADHD-related WM impairment and emphasizes the need for additional research.