Comparing the Prediction Value of Different Measures of Subjective Memory Complaints on Structural Brain Differences in Healthy Aging
Previous work has investigated the validity of Subjective Memory (SM) complaints in predicting structural changes associated with aging with mixed results. The current dissertation aimed to further the understanding of the association between structural changes and SM and investigate the utility of SM discrepancy variables both in cross sectional and a longitudinal approach. Two SM discrepancy variables, which examined the discrepancy between perceived and actual memory failures, were calculated two ways to determine which measure would be more sensitive in predicting white matter hyperintensities and cortical thickness in a cross-sectional sample of (N = 110 participants). We found no relationship between SM or either SM discrepancy variable when predicting cross sectional CTh but did find that the standard measure of SM and the two discrepancy scores predicted higher WMH burden in the frontal and parietal lobes. Next, we examined how change in CTh across a four-year lag related to our three SM variables at baseline and at follow up using a smaller sample (N = 60) and found that SM score and SM discrepancy at baseline predicted CTh change in frontal, temporal, and parietal regions. In contrast, only the standard MFQ was predictive of CTh decline in the frontal, parietal, and temporal regions. These findings support previous research that SM complaints relate to more than just behavioral differences and may represent differences relating to early sings of structural changes associated with aging. Additionally, the sensitivity differences when comparing the standard SM score to the discrepancy scores depends on the time of assessment and structural component being examined. Further research including more impaired individuals should be investigated to determine if a pattern with cross sectional CTh differences exists. Further, how would impairment change the relationship with the three SM variables in a longitudinal setting.