Memory impairments are a major cognitive change associated with aging. Functional neuroimaging studies have routinely reported age-related changes in brain activity in prefrontal cortex (PFC) during memory formation (encoding). The primary goal of the proposed experiments is to examine whether differences in self-initiated strategy use between young and older adults play a significant role in age-related changes in prefrontal activity patterns during intentional encoding. In Experiment 1, the relationship between older and younger adults'regional brain activity in PFC during intentional encoding and their self-initiated encoding strategy use will be examined. The effects that training older adults to use a semantic (meaning-based) encoding strategy have on older adults'regional activity in PFC and self-initiated strategy use will also be investigated. In Experiment 2. Regional activity in PFC will be compared for successful encoding trials on which young and older adults report using the same encoding strategy.
The specific aims of the proposed experiments are 1) to examine whether young and older adults spontaneously use different strategies to intentionally encode words. 2) to examine whether differences in the strategies that young and older adults spontaneously use to intentionally encode words play a major role in age-related changes in inferior prefrontal brain activity during intentional encoding, 3) to examine whether training older adults to use a semantic strategy to memorize words will reduce older adults'under-recruitment and non-selective recruitment of inferior PFC during intentional encoding and 4) to examine whether the differences in brain activity patterns in inferior PFC between young and older adults during intentional encoding are still present when these groups report using the same self-initiated encoding strategies. The effects of prefrontal structural lesions on older adults'self-initiated encoding strategy use will also be explored. This KOI Career Development Award will provide me with the aging research experience, mentoring, and training in the cognitive aging, cognitive rehabilitation, and structural neuroimaging research techniques that I need to accomplish my goal of becoming an independent aging researcher at the University of Missouri - St. Louis.
This research will provide important new insights into the mechanisms of age-related changes in prefrontal cortex. It will also provide valuable information concerning the ability of cognitive training techniques to treat age-related memory impairments and changes in brain activity patterns.
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