Mobility, cognitive function, and exercise : neuroimaging studies in older adults

As the world’s population ages, mobility and cognitive impairments are major health-care priorities. Given the particular relevance of the brain in the manifestation of both conditions, the aims of my dissertation are two-fold: 1) to advance our knowledge of the intrinsic relationship between mobility and cognitive impairments; and 2) to characterize the underlying functional neural mechanisms by which exercise promotes cognitive and mobility outcomes in older adults with mild cognitive impairment. Using magnetic resonance imaging, I focused on characterizing brain structures and brain function – as measured by functional neural activity as well as regional and network connectivity – associated with falls and slow gait. Additionally, I investigated how aerobic exercise may exert influence on mobility and cognitive function via pathways indicated by magnetic resonance imaging derived neural correlates. My research showed that while falls are associated with lower total and regional gray and white matter volume, slow gait, in conjunction with mild cognitive impairment, is reflected by disrupted neural network connectivity. Moreover, my work aligns with emerging concept of neural efficiency by generating evidence that suggests aerobic exercise training may promote mobility and cognitive function by maintaining or improving neural efficiency. Overall, these results contribute to a better understanding of the neural underpinnings of mobility and cognitive impairments, as well as provide new insight into the neural mechanisms by which exercise promotes mobility and cognitive function.Medicine, Faculty ofGraduat