Gray matter volumetric changes with a challenging adaptive cognitive training program based on the dual n-back task

Abstract Here we analyze changes in gray matter volumes following a challenging adaptive cognitive training program based on the n-back task. Twenty-six young healthy women completed twenty-four cognitive training sessions across twelve weeks showing substantial average improvements in cognitive performance. High-resolution MRI scans were obtained before and after training. Brain images of the training group were compared to those of a control group by applying optimized longitudinal voxel-based morphometry. We observed a significant interaction between groups (training versus control) and times (before versus after training), driven by a gray matter volume increase for the training group in clusters of voxels located in left posterior cingulate, right cerebellum, and right temporal lobe. The regions identified are known to support executive control and working memory processes (such as monitoring and updating) required by the completed training regime. Changes in the gray matter volume of these clusters were correlated with a) behavioral changes across the training program and b) changes in four psychological factors assessed before and after training (fluid and crystallized intelligence, working memory capacity, and attention control). None of these correlations were statistically significant, and therefore, psychological and biological changes were seen as independent. The sensitivity of voxel-based approaches for this kind of research is discussed.