Date of Award


Publication Type

Doctoral Thesis

Degree Name




First Advisor

Anne D. Baird


Cognitive Functioning, Cognitive Reserve, Neuropsychology, Occupational Complexity, Older Adults, Word Reading




There is ample evidence that higher levels of mental stimulation, greater complexity of occupation, and higher word reading ability increase levels of cognitive reserve. The purpose of the current study was to investigate the unique contribution of these two proxy measures of cognitive reserve on measures of fluid and crystallized intelligence and episodic and semantic memory. This contribution was hypothesized to exist over and above the influence of age, formal education, ethnicity, gender, and overall cognitive status. The sample consisted of 218 African American and European American older adults seen in an urban outpatient clinic for suspected memory problems and other problems in thinking. The select neuropsychological measures administered included the WASI Vocabulary (Vocab) and Matrix Reasoning (MR) subtests, the Boston Naming Test (BNT), and the Logical Memory (LM) I subtest from the WMS-R. A missing value analysis determined that the pattern of missing data on the WASI Vocab and MR subtests and the LM I subtest was not at random, and not ignorable. A series of hierarchical regressions were run, with the Heckman two-step model included to correct for the missing data. Complexity of occupation was a significant predictor of performance on measures of fluid and crystallized intelligence and a measure of episodic memory. Similarly, oral word reading ability was a significant predictor of performance on measures of fluid and crystallized intelligence and semantic memory. The contribution of these predictors was found to exist beyond the expected impact of key background variables. These findings indicate that proxy measures of cognitive reserve, including complexity of occupation and oral word reading ability, are important factors to consider when examining neuropsychological test performance in clinical settings. The importance of adequately assessing and addressing the problem of missing data is also highlighted by this study.