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

Abstract

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. The rotation resulted in a comfortable final posture at the cost of a harder initial reaching action on 50% of trials. We hypothesized that grip selection would be dominated by motoric developmental status. Adults were always biased towards a comfortable end-state with their dominant hand, but occasionally ended uncomfortably with their nondominant hand. Most 9-to 14-year-olds with and without autism also showed this "end-state comfort" bias but only 50% of 5-to 8-year-olds. In contrast, children with DCD were biased towards selecting the simplest initial movement. Our results are best understood in terms of motor planning, with selection of an easier initial grip resulting from poor reach-to-grasp control rather than an executive planning deficit. The absence of differences between autism and controls may reflect the low demand this particular task places on executive planning.

Motor imagery skills of children with Attention Deficit Hyperactivity Disorder and Developmental Coordination Disorder

“…Though it is unclear whether motor imagery deficits play a causal role in motor impairment in ADHD or are in fact a symptom of such impairment, an inability to accurately represent movements internally is likely to result in problems with motor planning and the efficient use of feedforward models of motor control (Blakemore et al, 2002;Flanagan et al, 2003). In DCD, this is reflected not only in motor imagery as it is here, but also in motor planning (van Swieten et al, 2010) and online movement control (Hyde & Wilson, 2011a, 2011b. It is critical therefore that clinically, motor skill assessments are included in assessments of children with ADHD and impairments are considered seriously, with interventions provided.…”

Using the ICF Framework to Explore the Multiple Interacting Factors Associated with Developmental Coordination Disorder

“…In particular, problems with motor planning for end-state-comfort have been reported to occur more often in DCD [81,82]. Problems with sequencing and coordinating complex movement, referred to as ideomotor apraxia have also been found [80].…”

Executive Functioning, Motor Difficulties, and Developmental Coordination Disorder

“…This is in line with evidence for impairments in visuospatial processing in DCD (see Wilson & McKenzie, 1998;Wilson, Ruddock, Smits-Engelsman, Polatajko & Blank, 2013, for meta-analyses). Finally, in tests of planning in children with DCD, both Pratt et al (2014) and van Swieten et al (2010) reported significantly more errors compared to controls in a task with significant motor demands, which involved planning arm movements to end in a comfortable position. On the other hand, Several methodological and interpretational difficulties arising from previous research into EF in DCD were addressed in the current study.…”