Discussion
hand movements, associative sensorimotor learning
Regular engagement over 12 weeks in low-volume PEBs with coordinative exercises was associated with an improvement in juggling performance and an increase in vertex-wise cortical depth in a cluster including the right inferior parietal lobe. In addition, a reduction of GM volume in a cluster primarily involving the right insula and the right operculum following the intervention was also observed. Decreases in GM volume of the right insula/operculum were correlated with improvements in juggling performance. This corroborates nicely with the fact that the volumetric decreases in this brain structure were related to the juggling training.The increase in the sulcal depth in the inferior parietal lobe following juggling training is a novel finding. Sulcal depth is a measure of cortical shape (van Essen The decrease of GM volume in response to our 12-week long juggling training was restricted to a cluster involving the right insula, the right operculum, and the right inferior frontal gyrus. The right inferior frontal gyrus is a part of the Broca’s region and represents motor functions, including complex hand movements, associative sensorimotor learning, and sensorimotor integration (Binkofski and Buccino It is evident that brain changes following physical exercise vary as a function of the practice level. For example, Sampaio-Baptista et al. (This study also has some limitations. Firstly, we did not assess changes in diffusion-weighted MRI and functional characteristics of the brain following the intervention. Recent research has indicated that the combined consideration of these different imaging modalities provides a comprehensive and more holistic view of the manifold brain changes associated with coordinative exercises (e.g., Weber et al. 