Association between Motor Planning and the Frontoparietal Network in Children: An Exploratory Multimodal Study.

OBJECTIVE: Evidence from adult literature shows the involvement of cortical grey matter areas of the frontoparietal lobe and the white matter bundle, the superior longitudinal fasciculus (SLF) in motor planning. This is yet to be confirmed in children. METHOD: A multimodal study was designed to probe the neurostructural basis of childhood motor planning. Behavioural (motor planning), magnetic resonance imaging (MRI) and diffusion weighted imaging (DWI) data were acquired from 19 boys aged 8-11 years. Motor planning was assessed using the one and two colour sequences of the octagon task. The MRI data were preprocessed and analysed using FreeSurfer 6.0. Cortical thickness and cortical surface area were extracted from the caudal middle frontal gyrus (MFG), superior frontal gyrus (SFG), precentral gyrus (PcG), supramarginal gyrus (SMG), superior parietal lobe (SPL) and the inferior parietal lobe (IPL) using the Desikan-Killiany atlas. The DWI data were preprocessed and analysed using ExploreDTI 4.8.6 and the white matter tract, the SLF was reconstructed. RESULTS: Motor planning of the two colour sequence was associated with cortical thickness of the bilateral MFG and left SFG, PcG, IPL and SPL. The right SLF was related to motor planning for the two colour sequence as well as with the left cortical thickness of the SFG. CONCLUSION: Altogether, morphology within frontodorsal circuity, and the white matter bundles that support communication between them, may be associated with individual differences in childhood motor planning.

Motor planning with and without motor imagery in children with Developmental Coordination Disorder.

Children with Developmental Coordination Disorder (DCD) demonstrate inefficient motor planning ability with a tendency to opt for non-optimal planning strategies. Motor imagery can provide an insight to this planning inefficiency, as it may be a strategy for improving motor planning and thereby motor performance for those with DCD. In this study, we investigated the prevalence of end-state-comfort (ESC) and the minimal rotation strategy using a grip selection task in children with DCD with and without motor imagery instructions. Boys with (n = 14) and without DCD (n = 18) aged 7-12 years completed one, two and three colour sequences of a grip selection (octagon) task. Two conditions were examined; a Motor Planning (MP) condition requiring only the performance of the task and a Motor Imagery and Planning (MIP) condition, which included an instruction to imagine performing the movement before execution. For the MP condition, children with DCD ended fewer trials in ESC for the one (p = 0.001) and two colour (p = 0.002) sequences and used a minimal rotation strategy more often than those without DCD. For the MIP condition, the DCD group significantly increased their use of the ESC strategy for the one colour sequences (p = 0.014) while those without DCD improved for the two colour (p = 0.008) sequences. ESC level of the DCD group on the MIP condition was similar to those without DCD at baseline for all colour sequences. Motor imagery shows potential as a strategy for improving motor planning in children with DCD. Implications and limitations are discussed.

Investigating motor planning in children with DCD: Evidence from simple and complex grip-selection tasks.

Several studies suggest that children with Developmental Coordination Disorder (DCD) may be able to plan simple movements as well as their peers, but experience increasing difficulties as the movements become complex. The present study aimed to clarify the nature of motor planning in DCD, including a putative deficit, by being the first to investigate motor planning using converging measures of simple and complex motor planning in a single sample of children with DCD. Boys aged between 8 and 12 years with (n = 10) and without DCD (n = 17) completed three commonly used 'simple' (bar grasping, sword, and bar transport tasks) measures and one 'complex' (octagon task) measure of end-state-comfort (ESC), a classic measurement of motor planning ability. To achieve ESC when manipulating an object, a person may choose to start with an uncomfortable grip in order to end the movement in a comfortable position. Results indicate that the participants with DCD planned for ESC as efficiently as their peers when performing the 'simple' measures of ESC but were significantly less likely to end their performances in ESC than those without DCD for the more 'complex' octagon task. Taken together, our data suggest that school-aged children with DCD may be able to plan simple movements as efficiently as their peers, but have more difficulty doing so for multi-movement or complex sequences. Based on the assumption that the efficiency of such motor planning is dependent on the integrity of internal modelling systems, we argue that our study provides indirect support for the internal modelling deficit hypothesis.