Effect of Visual Illusion on Motor Skills Learning in Boys With Developmental Coordination Disorder: A School-Based Randomized Controlled Trial

Children with Developmental Coordination Disorder (DCD) have deficits in visual perception and motor planning, which negatively impact motor learning. To address this, paradigms that manipulate visual perception during training have been proposed. This study investigated the influence of a visual illusion-based training paradigm, which alters the perceptual size of a target, on learning a beanbag throwing skill in children with DCD. A school- based randomized controlled trial was conducted in nine public schools. Seventy five males with DCD (Mean Age: 8.50 ± .63, IQ > 70) practiced a beanbag throwing task under one of three conditions: with a visual illusion inducing a perceptually smaller target (n = 25), a perceptually larger target (n = 25) and without visual illusion (n = 25). Motor learning was assessed using a retention task at 48 hours after the last practice session. The visual illusion significantly altered perceptions of target size. There were significant differences between the intervention groups in both the acquisition (F (2, 72) = 29.75, p < .001) and retention (F (2, 72) = 32.95, p < .001) phases, indicating that children with DCD demonstrated superior learning of the beanbag throwing task when the target was perceived as smaller than it actually was. These findings suggest that manipulating visual perception through illusions can be an effective clinical or educational strategy for enhancing motor skill training in children with DCD. This approach optimizes motor planning by providing a more constrained perceptual goal, offering a practical tool for motor interventions.