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IC‐P3‐176: What goes up, must come down: Compensatory neural activity among the very old
Author(s) -
Daffner Kirk R.,
Riis Jenna L.,
Chong Hyemi,
McGinnis Scott M.,
Wolk David A.,
Holcomb Phillip J.,
Rentz Dorene M.
Publication year - 2008
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2008.05.120
Subject(s) - novelty , psychology , cognition , cognitive skill , audiology , oddball paradigm , population , developmental psychology , young adult , event related potential , neuroscience , medicine , social psychology , environmental health
Background: Understanding factors that contribute to successful cognitive aging has become increasingly important as a growing portion of the population lives to very old age. Our research has focused on different patterns of cognitive aging by using electrophysiologic and behavioral measures. Previously, we demonstrated (e.g., NeuroImage, 2008; 39(1)) that cognitively high-functioning younger-old (y-old) (65-79 y.o.) subjects allocate more neural resources, as measured by the P3 event-related potential, than cognitively high-functioning middle-aged and young subjects and than cognitively average-functioning y-old subjects. Interestingly, although cognitively average-functioning middle-aged subjects appropriate more resources to novel stimuli than cognitively-matched young subjects, cognitively average-functioning y-old subjects exhibit a substantial reduction in novelty P3 amplitude. These findings suggest that age-related compensatory activity may involve increased allocation of capacity-limited controlled resources that persists until capacity limits are exceeded. For cognitively average-functioning adults this may occur by y-old age. We hypothesized that in cognitively high functioning adults this would develop in old-old (o-old) age. Here we have extended our investigations to include o-old individuals (’80 y.o.), and report on preliminary results. Objective: To determine whether cognitively high functioning o-old adults continue to exhibit compensatory neural activity and a preference for attending to novelty. Methods: Electrophysiologic and behavioral responses to standard, target, and novel visual stimuli were recorded while young, middleaged, y-old, and o-old individuals performed a subject-controlled variant of the novelty oddball task. Results: Cognitively high-functioning o-old adults exhibited a large reduction in their novelty P3, but not until their mid to late 80s. Behaviorally, cognitively high-functioning individuals in their 90s continued to spend more time exploring novel than repetitive standard visual stimuli. Conclusions: Our research suggests that age-related compensatory neural activity may not be limited to high-functioning older individuals with substantial cognitive reserve, but also be observed among cognitively average-functioning adults at an earlier stage of the lifespan. Cognitively high-functioning adults appear to have the capacity to appropriate compensatory neural resources at least through their early 80s, and continue to be attracted to novelty, a hallmark of healthy human behavior, at least through their early 90s.