The neuroimaging signature of cognitive automaticity and the role of the cerebellum

Abstract

Delegation of behaviours to automaticity is an evolutionary advantage, allowing for parallel processing and adaptive behaviour. In primates and humans, both motor and cognitive behaviours are automatised allowing for increasingly complex behaviours. Across these species, the cortico-cerebellar circuit has become exceedingly prominent, however the contributions of the cortico-cerebellar circuit to cognitive automaticity remains largely unknown. In this thesis, we attempt to characterise the role of the cortico-cerebellar circuit in cognitive automaticity and adaptation. Specifically, this thesis highlights distinct contributions from the cerebellum that facilitate adaptive behaviours. We reveal that the cerebellum serves unique contributions to cognitive automaticity during a mental rotation task. We demonstrate that expertise during sensorimotor adaptation is driven by increased dependence on the cerebellum and decreased dependence on the cerebral cortex. Then, we explore features of compositional cognition that facilitate adaptive behaviour. We breakdown compositional cognition into two systems: specialised components (i.e., existing behaviours) that mainly feature specialised cerebral regions, and recombination, a generalised process supported by the cortico-cerebellar circuitry. Lastly, we combine insights from complementary dimensionality reduction approaches to understand resting-state brain patterns in Parkinson’s disease patients with and without visual hallucinations. Together, this thesis illustrates the cortico-cerebellar circuitry as pivotal to cognitive automaticity, driving the development of adaptive, complex behaviours.