Latent structure and neuroanatomical localization of visuospatial impairment following focal brain damage
Visuospatial ability refers to a broad range of cognitive functions, from navigating an environment to mentally rotating objects in space, and can be impaired in various ways following brain lesions. Despite its clinical relevance, the latent factor structure of visuospatial ability and its neuroanatomical substrates remain incompletely characterized. This dissertation addressed both questions using a large cohort of patients with focal brain lesions (N=480).
Patients with focal brain lesions from the Iowa Neurological Patient Registry completed a battery of eleven neuropsychological tests sensitive to visuospatial dysfunction. Factor analysis and structural was used to identify the latent factor structure of visuospatial dysfunction in a data-driven manner. Lesion-symptom mapping (LSM) and lesion network mapping (LNM) were then applied to link latent visuospatial factors to lesion location, white matter disconnections, and lesion-associated functional networks. Predictive models were subsequently evaluated in an independent cohort to assess cross-cohort generalizability of neuroanatomical findings.
Results revealed a single domain-general visuospatial factor that accounted for shared variance across tests. Damage to the right putamen, higher-order visual cortex, and occipital white matter bilaterally as most strongly associated with domain-general visuospatial dysfunction. The right putamen and surrounding white matter emerged as particularly important regional contributors. Predictive models of chronic visuospatial impairment based on lesion location showed meaningful generalization to the independent cohort, supporting the translational value of this work.
Doctoral dissertation completed at the University of Iowa, 2023. Winner of the Neuroscience Research Day Best Poster Award, 2022.