Aim: The objective of this study was to investigate the mechanisms underlying the deficit in visuospatial working memory (VSWM) seen in children with developmental coordination disorder (DCD) and to compare brain activity while performing a VSWM task in children with DCD and typically developing children.
Method: Behavioural performance and event-related potentials (ERPs) were recorded in 24 children (12 males, 12 females; mean age 139 mo, SD 4 mo) with DCD (as determined by a score <5th centile on the Movement Assessment Battery for Children - Second Edition) and in 30 age- and sex-matched typically developing children (15 males; 15 females; mean age 140 mo, SD 5 mo) recruited from local schools, while performing one spatial non-delay and two time-delayed spatial memory tasks.
Results: Compared with typically developing children, children with DCD exhibited longer reaction times (p = 0.022; partial η(2) =0.10) and lower accuracy rates (p < 0.001; partial η(2) = 0.35) on the two spatial memory tasks. Electrophysiological indices also showed distinct modulatory effects, with children with DCD exhibiting smaller P3 (p < 0.001; partial η(2) = 0.26) and positive slow wave (pSW; p = 0.003; partial η(2) = 0.16) amplitude and a smaller area under the curve of P3 and pSW components (p = 0.002; partial η(2) = 0.17).
Interpretation: The combined analysis of behavioural performance and ERP data suggests that children with DCD have deficits of visuospatial working memory owing to fewer resources being allocated to comparison of spatial locations, less effort allotted to the response selection, and less neural processing employed during the retrieval process phase.
© The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.