ERP Investigations of Novelty Processing in Different Patterns of Cognitive Aging

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DESCRIPTION (provided by applicant): As increasing numbers of Americans are living to advanced ages, understanding what allows individuals to maintain meaningful levels of intellectual functioning and independence has become a major public health concern. The primary goal of the proposed research is to investigate the ways in which information processing of cognitively `successful' older adults differs from that of cognitively less successful ones. Event-related potential (ERP) indices of sensory-perceptual encoding, selective attention, and capacity- limited controlled processing will be measured. This will provide an opportunity to evaluate competing theories about cognitive aging that differ in terms of which information processing operations are hypothesized to be most important to age-related changes in cognition. Our proposal emphasizes novelty processing because increased responsiveness to novelty may not only be a reflection of successful cognitive aging, but also help to promote it. In the proposed study, individuals from 18 to over 90 years old will be divided into cognitively high and cognitively average performers based on age-appropriate neuropsychological test norms. A carefully planned set of ERP experiments will examine the extent to which groups varying in cognitive status differ in age-related changes in novelty processing under conditions that manipulate demands on 1) capacity-limited controlled processing (Aim 1), 2) context-appropriate resource allocation (Aim 2), and 3) selective attention to task-relevant events (Aim 3). Aim 1 will be addressed by comparing responses to novel stimuli under single vs. dual-task conditions. Aim 2 will be addressed by comparing responses to novelty under conditions that vary whether novel stimuli serve as distracters or potentially meaningful events. Aim 3 will be addressed by comparing responses to salient stimuli under attend vs. ignore conditions. Our work will provide important insights into 1) the extent to which age-related differences between cognitively high and average performing adults are due to a decline in information processing capacity that begins earlier in the lifespan for average performers; 2) the extent to which the magnitude of age-related differences between cognitively high and average performing adults differ across various stages of information processing; 3) the extent to which members of different age and cognitive groups are able to vary their response to novel events depending on the context in which they occur; and 4) the extent to which ERP indices of sensory-perceptual encoding, selective attention, and capacity-limited controlled processing can differentially account for the variance in age-related changes in neuropsychological performance. In summary, the proposed research will provide an opportunity to elucidate factors that are fundamental to successful cognitive aging, an endeavor that is critical to this important field of study. PUBLIC HEALTH RELEVANCE: The proposed research will investigate factors that contribute to successful cognitive aging, a topic of major importance to public health as an increasing number of Americans are living to advanced ages. We will study age-related changes in brain wave activity in individuals from 18 to over 90 years old who vary in their level of intellectual functioning. We aim to identify underlying mechanisms that allow people to remain active and high functioning throughout adulthood.