Structural Brain Alterations Following Speed-Reading Training in Sinhala-Speaking Adults: A Voxel-Based Morphometry and Tract-Based Spatial Statistics Study.

Neuroplastic changes in brain structure have been reported following reading-related training, such as speed-reading, though these effects remain under investigation, particularly in non-alphabetic writing systems. This study examined training-related structural changes in eighteen right-handed adult native Sinhala readers following one month of speed-reading training. Voxel-based morphometry (VBM) assessed grey matter mean intensity changes, with significant clusters identified and mean values extracted for correlation with reading speed. White matter microstructural alterations were examined using diffusion MRI by generating maps of fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD) for all subjects. Tract-based spatial statistics (TBSS) were applied to these diffusion maps to identify significant white matter clusters between pre- and post-training sessions, and mean values were extracted from these clusters for correlation analysis with reading speed. Multiple comparison corrections were applied using the false discovery rate (FDR), with p < 0.05. The paired t-test of reading speeds showed significant improvements (t(17) = 11.775, p < 0.001). VBM identified the left inferior frontal gyrus, superior frontal gyrus, middle occipital gyrus, cerebellum, and bilateral thalamus as regions significantly correlated with reading speed. TBSS revealed white matter tracts associated with AD, MD, and RD that showed positive correlations with reading speed, including the superior longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, forceps major, cingulum bundle, and anterior thalamic radiation. These findings provide initial evidence that speed-reading training might be associated with structural variations in brain regions and white matter pathways involved in reading, extending current understanding to a linguistically understudied writing system.