The cerebellum's role in non-motor processes is now well accepted, but cerebellar interaction with cerebral targets is not well understood. Complex cognitive tasks activate cerebellar, parietal, and frontal regions; but the effective connectivity between these regions has never been tested. To this end, we used psycho-physiological interactions analysis (PPI) to test connectivity changes of cerebellar and parietal seed regions in complex (2-digit by 1-digit multiplication, e.g., 12 x 3) versus simple (1-digit by 1-digit multiplication, e.g., 4 x 3) task conditions ('complex - simple'). For cerebellar seed-regions (lobule VI, hemisphere and vermis), we found significantly decreased cerebellar-parietal, cerebellar-cingulate, and cerebellar-frontal connectivity in complex multiplication. For parietal seed regions (PFcm, PFop, PFm) we found significantly increased parietal-parietal and parietal-frontal connectivity in complex multiplication. These results suggest decreased cerebellar-cerebral connectivity contributes to complex task performance. Interestingly, BOLD activity contrasts revealed partially overlapping parietal areas of increased BOLD activity but decreased cerebellar-parietal PPI connectivity.
- parietal lobe
- psycho-physiological interactions (PPI)
- Copyright © 2015, Journal of Neurophysiology