Slow reading in dyslexia tied to disorganized brain tracts

This image, created by a specialized form of MRI called diffusion tensor imaging, shows white matter tracts (colored lines) in one corner of the brain. White matter tracts connect brain regions so they can communicate. Tracts appear in this image only if they are organized. In a normal brain (left), tracts run in an organized, uninterrupted fashion between points in the brain (tracts in white box). In patients with periventricular nodular heterotopia (right), tracts are disrupted by nodules of gray matter (red arrow), leaving areas without organized fiber tracts (lack of tracts in white box), which might lead to poor connections between brain regions. Credit: Bernard Chang, Beth Israel Deaconess Medical Center