This experiment examined how multiple planning constraints affect grasp posture planning in 6- to 10-year-old children (n = 16 in each group) by manipulating the intended object end-orientation (left end-down, right end-down) and initial precision demands (standard, initial precision) of a bar transport task. Results indicated that grasp posture…

Tool making evidences intelligent, flexible thinking. In Experiment 1, we confirmed that 4- to 7-year-olds chose a hook tool to retrieve a bucket from a tube. In Experiment 2, 3- to 5-year-olds consistently failed to innovate a simple hook tool. Eight-year-olds performed at mature levels. In contrast, making a tool following demonstration was easy…

Few studies have explored the development of response selection processes in children in the case of object manipulation. In the current research, we studied the "end-state comfort effect," the tendency to ensure a comfortable position at the end rather than at the beginning of simple object manipulation tasks. We used two versions of the…

Grip selection tasks have been used to test "planning" in both autism and developmental coordination disorder (DCD). We differentiate between "motor" and "executive" planning and present a modified motor planning task. Participants grasped a cylinder in 1 of 2 orientations before turning it clockwise or anticlockwise.…

Two experiments examined the flexibility and stability with which children and adults organize locations into categories on the basis of object relatedness. Seven-, 9-, and 11-year-olds and adults learned the locations of 20 objects belonging to 4 categories. Displacement patterns revealed that children and adults used object cues to organize the…

This study examines object construction and the ages at which children developing under various environmental conditions achieve five of the landmarks in the Uzgiris-Hunt (1974) scale of object permanence. (Author)