Anodal cerebellar stimulation increases cortical activation: Evidence for cerebellar scaffolding of cortical processing

Abstract

While the cerebellum contributes to nonmotor task performance, the specific contributions of the structure remain unknown. One possibility is that the cerebellum allows for the offloading of cortical processing, providing support during task performance, using internal models. Here we used transcranial direct current stimulation to modulate cerebellar function and investigate the impact on cortical activation patterns. Participants ( n = 74; 22.03 ± 3.44 years) received either cathodal, anodal, or sham stimulation over the right cerebellum before a functional magnetic resonance imaging scan during which they completed a sequence learning and a working memory task. We predicted that cathodal stimulation would improve, and anodal stimulation would hinder task performance and cortical activation. Behaviorally, anodal stimulation negatively impacted behavior during late‐phase sequence learning. Functionally, we found that anodal cerebellar stimulation resulted in increased bilateral cortical activation, particularly in parietal and frontal regions known to be involved in cognitive processing. This suggests that if the cerebellum is not functioning optimally, there is a greater need for cortical resources.

Time dependent effects of cerebellar tDCS on cerebello-cortical connectivity networks in young adults

“…Resting state data was collected as part of a larger imaging study which took approximately two hours (Maldonado, Bryan Jackson, et al, 2022). In the context of this larger study, the resting state data was collected first, immediately after entering the scanner and all data were collected within 45 minutes of the stimulation.…”