UNIVERSITY GRADUATE SCHOOL BULLETIN ANNOUNCEMENT  

Florida International University  

University Graduate School  

Doctoral Dissertation Defense  

Abstract  

Space and the Developing Brain: Structural and Connective Properties Supporting Children’s Spatial Abilities  

by  

Nick Mattox 

Spatial reorientation, the capacity to regain one’s sense of direction when lost, is an essential ability to understand and interact with our environment. This dissertation sought to extend work in animal models and adults, suggesting that an extensive neurobiological substrate centered on the hippocampus, retrosplenial cortex, and parahippocampal gyrus is associated with individual differences in spatial reorientation. In this study, 122 typically developing children aged 48 to 95 months completed a multimodal structural neuroimaging protocol and an age-appropriate spatial reorientation task.  

After controlling for age, sex, parental education, and motion during image acquisition, ordinal regression models suggested that increased right parahippocampal gyrus volume predicted greater geometry use during reorientation. In a separate model, right retrosplenial cortex volumes were negatively correlated with landmark use after controlling for the same covariates. Building on those findings, performance was assessed at the microstructural level using restriction spectrum imaging to quantify the diffusive properties of these regions of interest. Across separate models, microstructural differences in all three regions of interest were associated with geometry use, while the left posterior hippocampus was uniquely related to landmark usage. Lastly, in a whole-brain analysis, diffusive properties in the retrosplenial cortex as well as regions and tracts supporting visual processing and attention predicted spatial reorientation accuracy.  

These findings represent the first steps toward integrating developmental and neurobiological accounts of spatial abilities. Results highlight the need for future studies to bridge cognitive, neurobiological, and environmental levels of analysis in characterizing spatial development.  

Date: June 22, 2026,                               Department: Psychology  

Time: 10:00 a.m.          Major Professor: Dr. Shannon Pruden 

Place: Zoom: https://fiu.zoom.us/j/89192130000?pwd=fR5acjiBnYI1vj8FgBnkdIPcCjLgYF.1  

Passcode: Ldu0EC