Use it or lose it: Engaged lifestyle as a buffer of cognitive decline in aging?

Data from the Victoria Longitudinal Study were used to examine the hypothesis that maintaining intellectual engagement through participation in everyday activities buffers individuals against cognitive decline in later life. The sample consisted of 250 middle-aged and older adults tested 3 times over 6 years. Structural equation modeling techniques were used to examine the relationships among changes in lifestyle variables and an array of cognitive variables. There was a relationship between changes in intellectually related activities and changes in cognitive functioning. These results are consistent with the hypothesis that intellectually engaging activities serve to buffer individuals against decline. However, an alternative model suggested the findings were also consistent with the hypothesis that high-ability individuals lead intellectually active lives until cognitive decline in old age limits their activities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intraindividual variability is related to cognitive change in older adults: Evidence for within-person coupling.

In this study, the authors addressed the longitudinal nature of intraindividual variability over 3 years. A sample of 304 community-dwelling older adults, initially between the ages of 64 and 92 years, completed 4 waves of annual testing on a battery of accuracy- and latency-based tests covering a wide range of cognitive complexity. Increases in response-time inconsistency on moderately and highly complex tasks were associated with increasing age, but there were significant individual differences in change across the entire sample. The time-varying covariation between cognition and inconsistency was significant across the 1-year intervals and remained stable across both time and age. On occasions when intraindividual variability was high, participants' cognitive performance was correspondingly low. The strength of the coupling relationship was greater for more fluid cognitive domains such as memory, reasoning, and processing speed than for more crystallized domains such as verbal ability. Variability based on moderately and highly complex tasks provided the strongest prediction. These results suggest that intraindividual variability is highly sensitive to even subtle changes in cognitive ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in the inhibition of recall as a function of retrieval cues.

Asked 64 Ss from 3 age ranges (18–37, 50–64, and 65–88 yrs) to look at word lists in which the words were either categorized under headings or additionally subcategorized. Ss were then asked to recall the words when (a) the category name was given, or (b) the category name and half of the list words were given. Words recalled decreased with increasing age in all conditions. The youngest age group recalled more words when the category name only was used as a recall cue. There were no significant differences between the 2 recall conditions for the other age groups, suggesting that they were not as susceptible to recall inhibition as the younger adults. (5 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance variability is related to change in cognition: Evidence from the Victoria Longitudinal Study.

Performance variability across repeated task administrations may be an important indicator of age-related cognitive functioning. In the present investigation, the authors examined whether age differences and change in inconsistency were related to 6-year (3 occasion) cognitive change. Inconsistency scores were computed from 4 reaction time tasks performed by 446 older adults (54-89 years). Replicating previous cross-sectional results, greater inconsistency was observed for older participants even after controlling for differences in response speed. New longitudinal results demonstrated (a) associations between inconsistency at baseline measurement and 6-year change in cognitive performance; (b) longitudinal change in inconsistency; and (c) intraindividual covariation between 6-year change in inconsistency and 6-year change in level of cognitive function. These findings support the view that performance variability serves as a marker of cognitive aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for the convergent validity of two self-report metamemory questionnaires.

Examined the convergent validity of two metamemory questionnaires: the Metamemory in Adulthood questionnaire (MIA) and the Memory Functioning Questionnaire (MFQ). Confirmatory factor analysis showed that each instrument yields a higher-order factor labeled Memory Self-Efficacy (MSE) with approximately a .9 factor correlation. The analysis also showed convergence of the two questionnaires' scales measuring self-reported strategy use and perceived change in MSE. Simultaneous factor analysis in multiple cross-sectional age groups indicated that MSE has age-invariant factor loadings, although there was an age-related increase in the correlation of the MSE and Change factors. Additional models suggested (a) age differences in metamemory scales are primarily produced by age differences in MSE and (b) a minor method factor in the MFQ, producing both the less-than-perfect correlation of the two MSE factors and a reduced sensitivity of the MFQ to age differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the problem of detecting effects of lifestyle on cognitive change in adulthood: Reply to Pushkar et al. (1999).

The authors respond to issues raised about data from the Victoria Longitudinal Study and further explain concerns regarding evidence for the engagement hypothesis. Discussion focuses on the use of social stratification variables such as occupational prestige and educational attainment as measures of an engaged lifestyle. It is argued that (a) tests of the hypothesis should focus on the relationship of behaviors and activities thought to be proximal beneficial influences on adult cognitive development; (b) persuasive evidence for engagement effects from existing data require demonstration of effects of intellectual activities that are statistically independent of associations of social status with intellectual and cognitive development; and (c) currently available longitudinal data do not provide definitive evidence regarding the benefits of an engaged lifestyle on cognitive change. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intraindividual variability in reaction time predicts cognitive outcomes 5 years later.

Objective: Building on results suggesting that intraindividual variability in reaction time (inconsistency) is highly sensitive to even subtle changes in cognitive ability, this study addressed the capacity of inconsistency to predict change in cognitive status (i.e., cognitive impairment, no dementia [CIND] classification) and attrition 5 years later. Method: Two hundred twelve community-dwelling older adults, initially aged 64–92 years, remained in the study after 5 years. Inconsistency was calculated from baseline reaction time performance. Participants were assigned to groups on the basis of their fluctuations in CIND classification over time. Logistic and Cox regressions were used. Results: Baseline inconsistency significantly distinguished among those who remained or transitioned into CIND over the 5 years and those who were consistently intact (e.g., stable intact vs. stable CIND, Wald (1) = 7.91, p     

Inconsistency in Reaction Time Across the Life Span.

Inconsistency in latency across trials of 2-choice reaction time data was analyzed in 273 participants ranging in age from 6 to 81 years. A U-shaped curve defined the relationship between age and inconsistency, with increases in age associated with lower inconsistency throughout childhood and higher inconsistency throughout adulthood. Differences in inconsistency were independent of practice, fatigue, and age-related differences in mean level of performance. Evidence for general and specific variability-producing processes was found in those aged less than 21 years, whereas only a specific process, such as attentional blocks, was evident for those 21 years and older. The findings highlight the importance of considering moment-to-moment changes in performance in psychological research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personal time perspective in adulthood: A time-sequential study.

2 measures of personal time perspective were obtained from 1,247 adults using a time-sequential data collection strategy. 2 cross-sectional studies, separated by 1 yr, were conducted to test for the effects of age and time of measurement. Data analyses yielded significant main effects due to ages for both dependent measures. Main effects due to Time of Measurement, Sex, and all interactions were nonsignificant. The findings suggest that differences in personal time perspective during adulthood are related to age rather than sociocultural change during the year. (PsycINFO Database Record (c) 2010 APA, all rights reserved)