Date of Award


Document Type

Open Access Thesis




Clinical-Community Psychology

First Advisor

Jeffrey Schatz


Children with sickle cell disease (SCD) are at risk for neurocognitive impairment due to disease effects including stroke, sleep disordered breathing, anemia-induced hypoxia, and small vessel occlusion. In particular, problems in working memory are an area of concern due to the importance of this construct in determining intelligence and academic functioning. According to Baddely’s model, working memory is composed of verbal and spatial working memory, but it is unclear whether one aspect of working memory is more impacted than another in children with SCD. In addition, little is known about the role of two key components in SCD-related working memory deficits: the central executive and processing/rehearsal speed. Consequently, the aims of this study were to examine potential differences in verbal versus spatial working memory and the role of the central executive and processing speed in working memory among children with SCD. In addition, MRI findings were examined to understand the relationship between working memory deficits and neurocognitive sequelae. The results indicated that children with SCD perform more poorly than healthy controls on measures of working memory, central executive, and processing speed, but that there is not a difference in magnitude of deficit between spatial and verbal working memory. The central executive was found to mediate the relationship between disease status and working memory, but this relationship was not found for processing speed. Finally, midsagittal corpus callosum size, a measure of the extent of normal appearing white matter, was a better indicator of cognitive deficits than visible cerebral infarction.


© 2015, Kelsey Erin Smith