Voxel Based Morphometric Study on Chinese Blind Mens Brain Structure

Many studies have shown the functional relevance of cross-modal plasticity in blind men. In order to study the changes of their brain structure, voxel-based morphometry (VBM) methods are used. The regional gray matter (GM) and white matter (WM) concentrations of magnetic resonance (MR) images from 11 blind people and 9 sighted control subjects are compared using standard VBM. Optimized VBM is also discussed to measure the absolute local volume of GM or WM. Consistent results are achieved by statistical analysis with these methods. There are distinct differences not only in visual cortex but also the sensory area, auditory area and motor area. GM concentrations in blind men significantly decreased in Brodmann 7 and 22. While in Brodmann 18 and 19, GM concentration increased. GM volumes decreased in Brodmann 3,4,6,9 and 45. On the other hand, both WM concentration and volume increased in Brodmann 7. These results suggest that early visual deprivation can lead to changes in the brain structural anatomy which is consistent with the cortical cross-modal reorganization found by functional imaging. It may help to discover the relationship between the brain structural anatomy and the brain functional data of blind men at a macroscopic level from neuroimaging perspective.