Author ORCID Identifier
Date of Award
5-2025
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Psychology
First Advisor
Tricia Z. King, Ph.D.
Second Advisor
Lisa C. Krishnamurthy, Ph.D.
Third Advisor
Jingyu Liu, Ph.D.
Fourth Advisor
Vince D. Calhoun, Ph.D.
Fifth Advisor
Jeffrey G. Malins, Ph.D.
Abstract
Pediatric brain tumor survivors are at heightened risk for cognitive deficits in areas of executive functioning including, but not limited to, attention and working memory (WM). To date, research examining task-based within-individual blood oxygen level-dependent (BOLD) signal variability has focused on healthy individuals and a select group of clinical populations. Survivors of pediatric brain tumor are not yet represented in this literature. The present study examines task-based within-individual BOLD signal variability patterns during attention and WM trials of a letter n-back task and examines the relationship between in-scanner within-individual BOLD signal variability and out-of-scanner neurocognitive abilities in a sample of pediatric brain tumor survivors (N = 30) and healthy controls (N = 48). Using peak coordinates of an attention/WM network, we first explored within-individual BOLD signal variability patterns during n-back task loads. We found limited significant differences in within-individual BOLD signal variability in common contrasts between n-back load types for the 20 regions of interest. There were no significant differences in within-individual BOLD signal variability patterns in each n-back task load between brain tumor survivors and healthy controls. Within-individual BOLD signal variability in each n-back task load was not significantly correlated to mean accuracy or mean reaction time. Within-individual BOLD signal variability did not have a significant influence over group in the relationship between BOLD signal variability and task accuracy. Finally, for WM n-back task loads, greater within-individual BOLD signal variability was significantly negatively associated with performance on out-of-scanner measures of attention and WM. Group differences between brain tumor survivors and healthy controls were present in latent values from neuropsychological data rather than from within-individual BOLD signal variability data. We document evidence that chemoradiation treatment significantly impacts within-individual BOLD signal variability patterns; those with chemoradiation demonstrate lesser variability. Examining task-based within-individual BOLD signal variability and how it relates to neuropsychological outcomes contributes to the literature to allow greater understanding of brain-behavior relationships in this unique clinical population with documented deficits in domains of executive functioning. Understanding within-individual BOLD signal variability patterns in this population may help explain these cognitive weaknesses and/or provide avenues for appropriate intervention in this vulnerable population.
DOI
https://doi.org/10.57709/37361033
Recommended Citation
Steinberg, Stephanie, "Within-Individual BOLD Signal Variability in an N-Back Task: Relation to Neuropsychological Assessments of Attention and Working Memory in Survivors of Pediatric Brain Tumor." Dissertation, Georgia State University, 2025.
doi: https://doi.org/10.57709/37361033
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