Oliver Huxhold

Dual-tasking postural control: Aging and the effects of cognitive demand in conjunction with focus of attention

Postural control in everyday life is generally accompanied by posture-unrelated cognitive activity. Thus, mild forms of dual-tasking postural control are the norm rather than the exception. Based on this consideration and available evidence, we propose and empirically examined, in young and old adults, a non-monotonic, U-shaped relation between the efficacy of postural control and concurrent cognitive demands that reflect opposing trends of the effects of attention focus and attentional resource competition. When instructed to perform an easy cognitive task that presumably shifted the focus of attention away from posture control, the center of body pressure (COP) excursions decreased both in young and older adults relative to a single-task baseline where the focus of attention was explicitly directed towards the postural control task itself. However, when performing more demanding cognitive tasks, older adults showed increased COP displacements, in line with the predicted U-shape function, whereas young adults did not. We outline mechanisms linking postural control to cognitive demand and suggest routes for future investigation.

Working memory plasticity in old age: practice gain, transfer, and maintenance.

Adult age differences in cognitive plasticity have been studied less often in working memory than in episodic memory. The authors investigated the effects of extensive working memory practice on performance improvement, transfer, and short-term maintenance of practice gains and transfer effects. Adults age 20-30 years and 70-80 years practiced a spatial working memory task with 2 levels of processing demands across 45 days for about 15 min per day. In both age groups and relative to age-matched, no-contact control groups, we found (a) substantial performance gains on the practiced task, (b) near transfer to a more demanding spatial n-back task and to numerical n-back tasks, and (c) 3-month maintenance of practice gains and near transfer effects, with decrements relative to postpractice performance among older but not younger adults. No evidence was found for far transfer to complex span tasks. The authors discuss neuronal mechanisms underlying adult age differences and similarities in patterns of plasticity and conclude that the potential of deliberate working memory practice as a tool for improving cognition in old age merits further exploration.

Healthy mind in healthy body? A review of sensorimotor–cognitive interdependencies in old age

We review four broad lines of research on couplings between sensorimotor and cognitive aging, with an emphasis on methodological concerns. First, correlational cross-sectional and longitudinal data indicate increasing associations between sensorimotor and cognitive aspects of behavior with advancing age. Second, older adults show greater performance decrements than young adults when sensorimotor and cognitive tasks or task components need to be performed concurrently rather than in isolation. Third, aerobic fitness interventions produce positive transfer effects on cognition that are particularly pronounced for tasks with high demands on attention and executive control. Fourth, neuroscience findings from animal models and humans have identified aging-sensitive structural and functional circuitries that support cognitive functions and are enhanced by higher levels of sensorimotor functioning. We conclude that sensorimotor and cognitive aging are causally related and functionally interdependent and that age-associated increments in cognitive resource demands of sensorimotor functioning are malleable by experience.

Aging and attenuated processing robustness : Evidence from cognitive and sensorimotor functioning

Background: Within-person, across-time variations in processes and performance are intrinsic to all aspects of human functioning. Objective: This article starts with a brief taxonomy of intraindividual dynamics. There are adaptive as well as non-adaptive types of intraindividual variations that unfold with different degrees of reversibility on different time scales and involve either single, or systems of, functions. Methods: Empirical findings regarding aging and a specific type of intraindividual variation, namely attenuated processing robustness, are then presented with respect to cognitive and sensorimotor functioning. Results: In both domains of functioning, old adults exhibit less robust functioning with a greater amount of week-to-week, day-to-day, or trial-by-trial fluctuations in their cognitive, walking, and postural control performances. Conclusion: Currently, the causes for the attenuation of processing robustness in cognitive and sensorimotor functioning are not well understood. Neurocomputational models are useful tools for exploring the tripartite relationships between the aging of neural information-processing fidelity, and cognitive, and sensorimotor processes.

The dynamic interplay of social network characteristics, subjective well-being, and health: The costs and benefits of socio-emotional selectivity.

This study investigated the interacting dynamics of different aspects of the social network, specifically network structure (size and frequency of contact), social activity engagement, and emotional support, and different aspects of health and subjective well-being in a representative sample of 2034 older adults across 6 years of development. The analysis, using latent change score models, revealed that older age at Time 1 was related to steeper declines in network structure and social engagement, but was unrelated to changes in emotional support. Furthermore, levels of social engagement and levels of emotional support predicted changes in functional health and life satisfaction with equal strength. Changes in social engagement were associated with changes in life satisfaction, positive affect, functional health, and subjective health. Changes in emotional support were only associated with changes in negative affect. Mediation analyses suggested that network structure may stimulate social engagement and emotional support, thereby exerting indirect influences on key aspects of successful aging. The results underscore the importance of considering the multifaceted nature of social relations in understanding their impact on distinct developmental goals, and across different domains of successful aging.

Emotions and physical health in the second half of life: interindividual differences in age-related trajectories and dynamic associations according to socioeconomic status.

The importance of socioeconomic status (SES) for psychological functioning over the life span is increasingly acknowledged in psychological research. The Reserve Capacity Model by Gallo and Matthews (2003) suggests that SES is not only linked to physical health but also to the experience of positive and negative emotions. Moreover, due to differential amounts of psychosocial resources, cross-domain associations between emotions and health might differ according to SES. The present study examined age-related developments in positive affect (PA), negative affect (NA), and physical health, as well as dynamic associations between health and emotions in the second half of life. We looked at differences in these trajectories and their interrelationships according to education as one aspect of SES. We used data of up to three waves spanning 12 years from the nationally representative German Ageing Survey (N = 3,847, AgeT1 = 40-85 years). Applying multiple-group dual change score models, we found differential age-related change in PA and physical health, but not in NA, in two groups differing in level of education. NA did only predict change in physical health in low-educated individuals, whereas physical health was equally strongly related to change in PA in both education groups. These results indicate that SES not only affects changes in physical health and emotional functioning but also their interrelationships.

Changing predictors of self-rated health: Disentangling age and cohort effects.

Previous studies have shown that some predictors of self-rated health (SRH) become more important with age, while others become less important. Although based on cross-sectional data, these findings are often interpreted as age-related changes in evaluation criteria. However, results could be due to cohort effects as well. We attempted to disentangle age and cohort effects by combining and comparing cross-sectional and longitudinal data from a large-scale longitudinal survey. The sample consisted of 2,982 community-dwelling participants from 2 measurement occasions of the German Ageing Survey ages 40-81 years at baseline. Multigroup latent regression models were used to examine whether associations between various predictors and SRH differed between age groups and whether they changed over time. Comparisons of cross-sectional age differences in SRH-predictor associations and longitudinal age changes in the same associations allow the identification of cohort effects. Number of chronic conditions showed a constant negative association with SRH independently of age and cohort. In contrast, the association between SRH and all other predictors (physical functioning, exercise, life satisfaction, depressive symptoms, and positive affect) changed longitudinally, pointing to an age effect. Prediction of SRH by depressive symptoms and positive affect showed an additional cohort effect: The negative associations between depressive symptoms and SRH and the positive associations between positive affect and SRH were stronger among younger cohorts. The findings provide not only longitudinal support for previous cross-sectional studies, but also show the impact of historical change: Emotional facets of psychological well-being increase in relevance for SRH across cohorts.

Sozialer Wandel und individuelle Entwicklung von Altersbildern

Altersbilder umfassen sowohl gesellschaftliche als auch individuelle Sichtweisen auf die Lebensphase Alter und auf den Prozess des Alterwerdens.

Perceived Control and Social Activity in Midlife and Older Age: A Reciprocal Association? Findings From the German Ageing Survey

Objectives Perceived control may promote social activity in older adults because individuals with greater perceived control have greater confidence in their ability to achieve outcomes and are more likely to choose difficult activities, show persistence, and employ strategies to overcome challenges. Cross-sectional research has linked perceived control with social activity in life span and older adult samples but provides little insight into the direction of influence. We examined reciprocal associations between perceived control and social activity in order to establish temporal sequencing, which is one prerequisite for determining potential causation. Method Participants were 14,126 midlife and older adults from the German Ageing Survey. Using cross-lagged autoregressive modeling with age as the time metric (40-87 years), we examined reciprocal 3-year lagged associations between perceived control and social activity, while controlling for concurrent associations. Results Perceived control significantly predicted social activity 3 years later. Reciprocally, social activity significantly predicted perceived control 3 years later. The influence of perceived control on social activity was greater than the influence of social activity on perceived control. Discussion The finding that perceived control significantly predicts future social activity has potential implications for developing interventions aimed at promoting social activity in midlife and older adults.

Age Differences in Processing Fluctuations in Postural Control Across Trials and Across Days

Postural control performances of 18 younger and 18 older adults were repeatedly measured on 45 weekdays with five trials per day. This design made it possible to dissociate between long-term trends and processing fluctuations in the sensorimotor domain at moment-to-moment, trial-to-trial, and day-to-day levels. Older adults fluctuated more than younger adults at all timescales. Age differences in trial-to-trial and day-to-day processing fluctuations were reduced but remained statistically significant when controlling for fluctuations on faster timescales. We concluded that age differences in intraindividual fluctuations at the longer timescales are in part related to age differences in low-level system robustness, suggesting a cascade of effects across multiple timescales.