Differential Behavioral and Neural Effects of Regional Cerebellar tDCS

•Different cerebellar subregions support motor and cognitive task performance.•We tested behavioral and neural effects of transcranial direct current stimulation (tDCS) targeting cerebellar subregions.•Posterolateral cerebellar tDCS improved language task performance and increased activation in left cortical regions.•Sensorimotor cerebellar tDCS had no impact on task performance and disrupted task-relevant activation increases. The human cerebellum contributes to both motor and non-motor processes. Within the cerebellum, different subregions support sensorimotor and broader cognitive functions, due to regional patterns in anatomical connectivity with the cerebral cortex and spinal and vestibular systems. We evaluated the effects of transcranial direct current stimulation (tDCS) targeting different cerebellar regions on language task performance and whole-brain functional activation patterns. Functional MRI data were acquired while 43 healthy young adults (15 males, 28 females; 23.3 ± 3.0 years) performed a sentence completion task before and after 20 min of 1.5 mA anodal tDCS. Participants received tDCS targeting either the anterior sensorimotor cerebellum (n = 11; 3 cm right of inion, over lobule V); the right posterolateral cerebellum (n = 18; 1 cm down and 4 cm right of inion, over lobule VII); or sham tDCS (n = 14). TDCS targeting the right posterolateral cerebellum improved task accuracy relative to the sham condition (p = 0.04) and increased activation in left frontal and temporal cortices relevant to task performance (post-tDCS > pre-tDCS; T 3.17, FDR p