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Changes in Old Age of Neurocognitive Functions and Everyday Functions Together

Roche Chatain Virginy

 

  Note: This work is partially presented at World Conference On Neurology and Neurosurgery, Paris, France | March 27, 2019. Editorial Although neurocognitive functions are known to decline normatively with adult age, there is a common belief that everyday functions are unaffected by these changes. This hypothesis was examined by applying longitudinal growth models to data from a community-based sample of 698 adults (ages 65 to 94 years and living independently at baseline) who were repeatedly measured over 5 years on neurocognitive tests of executive reasoning, episodic memory, and perceptual speed, and on a number of tasks that adults should be reasonably expected to be able to perform in their day-to-day lives. Individual differences in changes in neurocognitive performance strongly correlated with individual differences in changes in performance on the everyday tasks. Alternatively, changes in self-reports of everyday functions were only weakly correlated with changes in performance on the neurocognitive tests and the everyday tasks. There are at least three types of evidence potentially relevant to testing the independence versus interdependence of neurocognitive functions and everyday functions. First, one could examine the correlations between individual differences in cognition and everyday functions in older adults. In community-based crosssectional samples of older adults a number of researchers have reported that such concurrent relations between performance on cognitive tests and objective tests of everyday functions range from approximately r = .30 to r = .70. However, while positive concurrent correlations could be indicative of a interdependence between cognition and everyday functions during late adulthood, they could also be reflective of a interdependence that existed earlier on in life, but no longer exists. Examination of concurrent relations between cognitive functions and everyday functions is therefore only likely to be of limited value for resolving the question of interdependence. Second, one could examine the extent to which everyday functions exhibit negative average age trends similar to those exhibited by neurocognitive functions. Using cross-sectional data, for example, reported that the correlation between age and everyday functions was −.23 in older adults ages 60 to 92 (compared to a correlation of −.26 between age and general cognitive ability in these same adults). Moreover, using seven-year longitudinal data, Willis reported that average levels of performance by healthy communitydwelling individuals on an objective measure of everyday functioning significantly declined from baseline to follow-up. However, while the finding that average levels of both cognition and everyday functions decline similarly with age could reflect a