The effects of aging are largely assumed to be universal across different cultures. Few studies test this assumption of universality, with some revealing cross-cultural differences in cognition with age. The proposed research will assess how culture (American/Taiwan) and cultural values (collectivism/independence) affect cognitive aging by comparing younger and older adults across cultures using behavioral and neuroimaging (fMRI) measures. The research program will employ longitudinal measures, assessing behavior and brain changes in the same individuals after a 3 year follow-up. Longitudinal approaches are important to establish that differences between extreme age groups (e.g., 20 vs. 70 year olds) reflect effects of aging rather than other potential cohort differences. Even longitudinal follow-up periods as short as a few years are sufficient to identify declines in performance or the volume of some brain regions, though less work has investigated effects of aging on functional brain activity longitudinally. Moreover, longitudinal measures may have sensitivity to identify exaggerated declines in aging, which could indicate pathological processes associated with aging, such as mild cognitive impairment (MCI) or Alzheimer?s disease (AD). That is, older adults who show poorer levels of performance on neuropsychological, decision making, or memory tasks at time 1 may show more pronounced decline at time 2, compared to those older adults performing at higher levels. Pronounced decline over time may serve as a marker of pathological aging (e.g., MCI or AD). The tasks selected for this research have shown promise in detecting dysfunctional patterns of aging; we will further test whether the markers are equally sensitive across cultures. Although both decision making and memory abilities can be affected by aging, the selected tasks engage largely complementary systems, with value-based decision making relying on frontostriatal systems and memory processes engaging medial temporal regions. One framework suggests that these systems differ in their vulnerability to pathological aging processes (e.g., AD) such that the frontostriatal systems largely reflect typical aging processes whereas AD disproportionately impacts temporo- parietal regions. We can test this model in the proposed research by studying decision making and memory processes across younger and older adults longitudinally, extending the model across cultures. The proposed research will address three major questions: 1) how do culture and cultural values contribute to value-based decision-making with age, 2) does aging consistently impact explicit memory across cultures, and 3) to what extent do cultural differences in decision making and memory generalize from cross-sectional to longitudinal (within-participant) measures of aging. This research will be led by two researchers with a history of collaboration who have established lines of aging research in the US (Gutchess) and Taiwan (Goh). Furthermore, the PIs areas of research expertise are complementary, with Dr. Goh?s lab investigating effects of age and culture and decision making and Dr. Gutchess? lab focused on effects of age and culture on memory.
The proposed research contributes to public health by investigating the ways in which the effects of cognitive aging on decision making and memory are modified by cultural factors. Cross-cultural comparisons will broaden our understanding of the universality of aging processes, potentially identifying differences relevant to ethnic minority groups in the US. Furthermore, the proposed research is relevant to the NIA?s mission to extend healthy, active years of life by investigating trajectories of age-related decline longitudinally, in hopes of identifying differential decline or markers of pathological aging processes, such as Alzheimer?s disease.
