Motor difficulties are common in individuals with Autism Spectrum Disorder ASD), creating yet another burden for independent living in this population. Moreover, motor difficulties in ASD appear to be intertwined with core ASD features, as more severe motor difficulties have been found to be related to more severe social symptoms, repetitive behavior symptoms, and poorer daily living skills. Recent evidence suggests that the white matter microstructure a measure of circuit integrity) of the corticospinal tract predicts both motor symptoms and core ASD symptoms. The corticospinal tract is an early developing white matter tract known to be associated with motor function. Studies in typical development demonstrate that fitness levels and balance training are associated with improved corticospinal microstructure. Therefore, the current two-year study investigates an exploratory video-game-based motor intervention that trains balance and targets the corticospinal tract in ASD. Thirty individuals with ASD will be randomly assigned to either the video-game training group n=15) or the passive control group n=15). The training group will undergo intensive video-game-based training over the course of 6 weeks. The video game intervention will consist of both an in-lab developed game that uses a Kinect camera and Wii balance board to take fine-tuned measurements of postural stability and also an off-the-shelf balance game Wii fit). Participants in the control condition will come to the lab to do motor measurements, but they will not engage in the video game training. Brain scans of all participants will be taken both before and after the 6-week training. These scans will include diffusion tensor imaging DTI) and multicomponent relaxometry mcDESPOT) to examine pre- and post-training changes in white matter microstructure and myelination of the corticospinal tract. Furthermore, we will be collecting pre- and post-training data on social symptoms, repetitive behavior symptoms, and daily living skills to examine if there are training-related changes in core ASD symptomatology. We hypothesize that the training group will have greater pre-post training changes in their corticospinal white matter microstructure and myelination compared to the control group. Further, we predict that these changes in corticospinal white matter will be associated with improvements in postural stability, core ASD symptomatology, and daily living skills in the treatment group.