The study by Scholz et al. investigates the effects of training on white matter structure in healthy adults using diffusion imaging. They found that after six weeks of training on a complex visuo-motor skill (juggling), there was a localized increase in fractional anisotropy (FA), a measure of microstructure, in the white matter underlying the right posterior intraparietal sulcus (IPS). This is the first evidence of training-related changes in white matter structure in the human brain. Additionally, gray matter density increased in the medial occipital and parietal lobes, regions that specialize in functions related to the IPS. These changes were specific to the trained group and persisted after a four-week period without juggling. The study suggests that experience-dependent changes in white matter microstructure can occur independently from gray matter changes, highlighting the complex dynamics of brain plasticity. Future research using cellular and biochemical techniques is needed to fully understand the biological basis of these changes.The study by Scholz et al. investigates the effects of training on white matter structure in healthy adults using diffusion imaging. They found that after six weeks of training on a complex visuo-motor skill (juggling), there was a localized increase in fractional anisotropy (FA), a measure of microstructure, in the white matter underlying the right posterior intraparietal sulcus (IPS). This is the first evidence of training-related changes in white matter structure in the human brain. Additionally, gray matter density increased in the medial occipital and parietal lobes, regions that specialize in functions related to the IPS. These changes were specific to the trained group and persisted after a four-week period without juggling. The study suggests that experience-dependent changes in white matter microstructure can occur independently from gray matter changes, highlighting the complex dynamics of brain plasticity. Future research using cellular and biochemical techniques is needed to fully understand the biological basis of these changes.