Age-related deficits in component processes of working memory
ABSTRACT Working memory deficits in normal aging have been well documented, and studies suggest that high memory load plus the presence of distraction negatively impacts successful memory performance to a greater degree in older individuals. However, characterization of the component processes that are impaired by these task manipulations is not clear. In this behavioral study, younger and older subjects were tested with a delayed-recognition and recall task in which the encoding and delay period were both manipulated. During the encoding period, the subjects were presented with either a single letter or multiple letters at their predetermined forward letter span, and the delay period was either uninterrupted or interrupted with a visual distraction. There was an age-related impairment of working memory recognition accuracy only in the combination of high memory load and distraction. These results suggest that when working memory maintenance systems are taxed, faulty recognition processes may underlie cognitive aging deficits in healthy older individuals.
Full-textDOI: · Available from: Mark D'Esposito, Jan 07, 2015
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ABSTRACT: Objective: To compare periodontal health status in individuals with and without Alzheimer's disease (AD). Methods: A total of 58 individuals with AD and 60 cognitively normal (ND) adult individuals, ranging in age from 50 to 80 years, were assessed for periodontal health status. Individuals with AD were further divided as mild, moderate, and severe, based on degree of cognitive impairment as evaluated using Mini-Mental State Examination. Gingival index (GI), plaque index (PI), probing depth (PD), clinical attachment level (CAL), and percentage of bleeding sites (%BOP) were evaluated. Results: All the evaluated periodontal parameters were higher in individuals with AD than that in ND individuals, and the periodontal status deteriorated with the progression of AD. There were significant differences in mean GI, PI, PD, CAL, and %BOP between all the groups. Conclusion: The periodontal health status ofindividuals with AD deteriorates with disease progression and was closely related to their cognitive function.American Journal of Alzheimer s Disease and Other Dementias 09/2014; 29(6):498-502. DOI:10.1177/1533317514549650 · 1.43 Impact Factor
Dataset: Rissman Neuropsychologia 2009
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ABSTRACT: We aimed to identify brain functional correlates of working memory performance in aging, in hopes of facilitating understanding of mechanisms that promote better versus worse working memory in late-life. Among 64 healthy adults, aged 23 to 78, we examined the relationship between age, working memory performance, and brain functional response during task performance. We focused on the association between working memory load-modulated functional response and individual differences in performance and whether these function-performance relationships differed with age. As expected, older age was associated with poorer working memory performance. Older age was also associated with reduced load-modulated activation including in bilateral prefrontal and parietal regions and left caudate as well as reduced deactivation including in the medial prefrontal cortex. Contrary to findings of hyperactivation in aging, we found no evidence of increased activation with older age. Positive associations identified between brain response and performance did not differ with age. Our findings suggest that the neural mechanisms underlying better versus worse working memory performance are age-invariant across adulthood, and argue against a pattern of functional reorganization in aging. Results are discussed within the broader literature, in which significant heterogeneity in findings between studies has been common. (JINS, 2014, 20, 1-6).Journal of the International Neuropsychological Society 09/2014; 20(9):1-6. DOI:10.1017/S1355617714000824 · 3.01 Impact Factor