Volumetric variation in subregions of the cerebellum correlates with working memory performance.

We aimed to investigate the relationship between structural variations in the cerebellum and individual differences in working memory performance as assessed by average reaction time (RT) and correction rate (CR) on a 3-back task. High-resolution T1-weighted magnetic resonance images were acquired in 311 healthy young adults. Voxel-based morphometry (VBM) was used to identify cerebellar areas with volumes correlated to working memory performance when controlling for age, gender, years of education and handedness. We found that RT was positively correlated with the grey matter volume (GMV) bilaterally in cerebellar lobules IV/V, VI and VIII, in vermis VII/VIII and in left Crus I; CR was positively correlated with the GMV in the left lobule VI and Crus I. These findings suggest that RT on a working memory task is related to structural variation in both motor and cognitive subregions of the cerebellum, while CR is mainly associated with the cognitive subregions. Our findings provide further evidence that the cerebellum contributes to working memory function.