Ataxias are characterized by dysmetria, a hallmark manifestation of cerebellar dysfunction, involving impaired scaling, timing, and coordination of movement. Although dysmetria has been studied in the motor domain, recent theoretical and clinical work suggests that similar coordination deficits extend to cognition, giving rise to the concept of cognitive dysmetria. This project explores whole-brain structural alterations in a mixed sample of spino-cerebellar ataxias, as well as cerebellar functional connectivity, against neurocognitive symptoms and performance in different domains.