This study investigated the role of sex, mean NAA/Cr and Cho/Cr, and variability in these metabolites in predicting memory and processing speed. This study utilized predictive models including sex, mean ratios of NAA/Cr and Cho/Cr, as well as the standard deviation of these ratios, within tissue type, among voxels in a supraventricular slice. In addition, models included interaction terms between each neurometabolic variable and sex. Tests of memory and processing speed were then regressed in a three-step hierarchical regression onto sex, main effects for neurometabolites, and interaction effects. The regression of memory was significant in the model including interaction terms, and showed higher mean NAA/Cr and lower standard deviation of NAA/Cr in gray matter related to better memory performance in boys, with the reverse pattern in girls. Lower standard deviation of NAA/Cr in the white matter was related to faster processing speed for both sexes. A model including sex, Cho/Cr mean and standard deviation by tissue type, and sex by Cho/Cr interactions significantly predicted memory performance. No model using Cho/Cr predicted processing speed. Posthoc analyses suggest that tests of working memory showed stronger relationships to metabolites than tests of learning. Moreover, relationships may differ by sex depending on whether digit span or spatial span is the working memory variable of interest.
|Advisor:||Yeo, Ronald A.|
|Commitee:||Erickson, Sarah J., Gangestad, Steven W., Jung, Rex E., Thoma, Robert J.|
|School:||The University of New Mexico|
|School Location:||United States -- New Mexico|
|Source:||DAI-B 71/10, Dissertation Abstracts International|
|Subjects:||Psychobiology, Neurobiology, Developmental psychology|
|Keywords:||Cognitive functioning, Memory, N-acetylaspartate, Neurometabolism, Processing speed, Sex differences, Working memory|
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