Body representation plasticity is altered in Developmental Coordination Disorder

Developmental Coordination Disorder (DCD) is a pathological condition characterized by impaired motor skills. Current theories advance that a deficit of the internal models is mainly responsible for DCD children’s altered behavior. Yet, accurate movement execution requires not only correct movement planning, but also integration of sensory feedback into body representation for action to update the state of the body. Here we advance and test the hypothesis that the plasticity of body representations is altered in DCD. To probe Body Representations (BR) plasticity, we submitted a well-established tool-use paradigm to seventeen DCD children, required to reach for an object with their hand before and after tool use, and compared their movement kinematics to that of a control group of Typically Developing (TD) peers. We also asked both groups to provide explicit estimates of their arm length. Results revealed that DCD children explicitly judged their arm shorter after tool use, similarly to their TD peers. Unlike them, though, DCD did not update their implicit BR estimate: kinematics showed that tool-use affected their peak amplitudes, but not their latencies. Remarkably, the kinematics of tool-use showed that the motor control of the tool was comparable between groups, both improving with practice, confirming that motor learning abilities are preserved in DCD. These findings indicate that the update of the BR for action is impaired in DCD, suggesting a novel deficit may contribute to this pathology. Further studies are needed to tease apart the possible role played by motor and body representations deficits in DCD.