| dc.description.abstract | The literature implicating the cerebellum and non-motor cognitive processing is quickly growing. Though there is an understanding that the cerebellum is active during non-motor task performance, little work has looked to understand why the cerebellum is active. Work in aging a disease suggest that disruptions in the cerebellum negatively impact cortical connectivity, function and processing. Critically, the cerebellum might be important for offloading cortical processing, providing support during task performance and cortical processing. The current work used transcranial direct current stimulation (tDCS) to modulate cerebellar function to better understand how changes in cerebellar output might affect cortical activation, connectivity, and behavioral performance. This work used a between-subjects design, in which participants received either anodal, cathodal, or sham stimulation over the right cerebellum before a functional and resting state magnetic resonance imaging scan where participants completed both a motor (sequence learning) and non-motor (Sternberg) task. We predicted that cathodal stimulation would improve, and anodal stimulation would hinder, task performance, connectivity, and cortical activation. Behaviorally, anodal stimulation negatively impacted behavior during late phase sequence learning. Functionally, we found that anodal stimulation resulted in increased bilateral cortical activation, particularly in parietal and frontal regions known to be involved in memory. Qualitative interpretations of the resting state data suggest anodal stimulation increases contralateral activity and decreases ipsilateral activity. This was particularly noticeable in cognitive lobules, such as Crus I and II. Additionally, we found behavioral correlates in connectivity to frontal and temporal regions in the cortex following stimulation. Assuming the change in function here parallels what occurs in aging or disease, this may provide a mechanism whereby offloading of function to the cerebellum is negatively impacted, resulting in subsequent differences in prefrontal cortical activation patterns and performance deficits. This work has a potential to update existing compensatory models to include the cerebellum as a structure use to support cognitive processes, which has implications in remediation techniques in a number of clinical populations. | en |
