Department of Psychology, Oxford Brookes University, Oxford OX3 0BP, United Kingdom.
Res Dev Disabil. 2013 Jan;34(1):174-82. doi: 10.1016/j.ridd.2012.07.020. Epub 2012 Aug 31.
When picking up an object, adults show a longer deceleration phase when the onward action has a greater precision requirement. Tailoring action in this way is thought to need forward modelling in order to predict the consequences of movement. Some evidence suggests that young children also tailor reaching in this way; however, how this skill develops in children with Developmental Coordination Disorder (DCD) is unknown. The current study compared the kinematics of reaching to an object when the onward intention was: to place the object on a target (either with high or low precision requirements), to throw the object or to lift the object vertically. Movements of both adults (N = 18) and children (N = 24) with DCD and their age-matched controls were recorded. The typically developing adults discriminated across all action types, the adults with DCD and the typically developing children only across the actions to place and throw and the children with DCD only between the actions to lift and throw. The results demonstrate developmental progression towards fine tuning the planning of reaching in relation to onward intentions. Both adults and children with DCD are able to plan movement using inverse models but this skill is not yet fully developed in early adulthood.
当捡起一个物体时，成年人在向前的动作需要更高精度要求时，会表现出更长的减速阶段。这种有针对性的动作被认为需要进行前向建模，以便预测运动的后果。有一些证据表明，幼儿也以这种方式调整伸手动作；然而，患有发育性协调障碍（DCD）的儿童的这种技能是如何发展的尚不清楚。本研究比较了成年人（N=18）和儿童（N=24）（包括 DCD 患者和年龄匹配的对照组）在将物体向目标放置（高或低精度要求）、投掷物体或垂直提起物体等不同向前意图时的伸手动作的运动学特征。研究结果表明，动作的规划会根据向前的意图进行精细调整，这是一种发展过程。有 DCD 的成年人和典型发展的儿童仅能区分放置和投掷这两种动作，而有 DCD 的儿童仅能区分提起和投掷这两种动作。典型发展的成年人可以使用逆模型来计划运动，但这种技能在成年早期尚未完全发展。
