The Preparation of Reach-To-Grasp Movements in Adults, Children, and Children with Movement Problems

Abstract

This study explored the use of advance information in the control of reach-to-grasp movements. The paradigm required participants to reach and grasp illuminated blocks with their right hand. Four target blocks were positioned on a table surface, two each side of the mid-saggital plane. In the complete precue condition, advance information precisely specified target location. In the partial precue condition, advance information indicated target location relative to the midsaggital plane (left or right). In the null condition, the advance information was entirely ambiguous. Participants produced fastest responses in the complete precue condition, intermediate response times in the partial condition, and the slowest responses in the null condition. This result was observed in adults and four groups of children including a group aged 4-6 years. In contrast, children with Developmental Coordination Disorder (DCD, n=11, aged 7--13 years) showed no advantage of partial precueing. Movement duration was determined by target location but was unaffected by precue condition. Movement duration was a clear function of age apart from children in the DCD group who showed equivalent movement times to those of the youngest children. These findings provide important insights into the control of reach-to-grasp movements and highlight that partial cues are exploited by children as young as 4 years but are not used in situations of abnormal development.

European Academy for Childhood Disability (EACD): Recommendations on the definition, diagnosis and intervention of developmental coordination disorder (long version)*

“…Other authors find mainly immature movements in children with DCD (SDDMF) underlining the aspect of development. Thus Mon‐Williams et al 48 . found mainly prolonged duration of movements as in much younger children, whereas Missiuna et al 49 .…”

A test of motor (not executive) planning in developmental coordination disorder and autism.

“…We found a clear developmental trend in line with this hypothesis where younger children (aged 5-8 years) showed a greater bias towards selecting an MR grip than older children (aged 9-14 years). We had also hypothesised that a group of children with DCD would be biased towards MR at all ages due to their known prehension difficulties (Smyth, Anderson & Churchill 2001;Mon-Williams et al, 2005). The children with DCD showed the predicted bias towards MR, and the proportion of children with DCD who showed the MR bias was higher than even the youngest group of typically developing children.…”

“…Adults reaching with their preferred hand would always be biased by ESC, but might occasionally be biased by MR with their non-preferred hand. Young children are likely to select an easier initial movement (because they have less well developed prehension skills; Kuhtz-Buschbeck, Stolze, Johnk, Boczek-Funcke & Illert, 1998;Mon-Williams, Tresilian, Bell, Coppard, Nixdorf & Carson, 2005;) and so we predicted that young Motor planning -7 -children would primarily show the MR bias. Children with DCD would be even more strongly biased by MR because of their fundamental difficulty with prehension.…”

Is auditory perceptual timing a core deficit of developmental coordination disorder?

“…For example, children with DCD were poorer than TD children at visually predicting the trajectory of and intercepting moving objects, and less accurate in temporally synchronizing their eye tracking to moving objects, suggesting difficulties in sensory predictive timing and online motor error correction. Furthermore, they were poorer at making use of sensory priming cues when required to reach to grasp, whether the cues were static or dynamic …”