Saturday 10th of May 11.45-13.15
Aula Magna
A complex systems perspective on aging
Later adulthood is marked prominently by declines in physical health, cognitive capacities, and shifts in social networks. Still, most aging research remains entrenched in approaches that overlook the complexity of multifaceted aging-related changes in the functioning and well-being of aging individuals across domains. In accordance with recent and urgent calls, here we propose to research aging and its dynamics from a complex systems perspective, accounting for the intricate interplay of physical, psychological, and social factors. This symposium will unite interdisciplinary experts to explore how embracing the concepts, language, and computational models of complexity science can transform our understanding of aging.
Chair |
Richard Ridderinkhof |
|
Speakers |
Almar Kok |
Adopting a complex systems approach to functional ageing: Key principles and empirical example using dynamic time warping. |
Kaisa Koivunen |
Using network analysis to examine the interplay between perceived fatigability, physical activity and intrinsic capacities in older adults. |
|
Arko Ghosh |
Functional states in healthy aging based on smartphone behavior |
|
Richard Ridderinkhof |
Complex systems modelling of age-related decline across biological, psychological, and social domains: A cascade theory of aging |
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Abstracts
Talk 1: Adopting a complex systems approach to functional ageing: Key principles and empirical example using dynamic time warping.
by Almar Kok
Authors: Almar Kok1 | Martijn Huisman1 | Erik J. Giltay2 | Gabriela Lunansky1
1 Amsterdam UMC, Department of Epidemiology & Data Science, Amsterdam, The Netherlands
2 Leiden University Medical Center, Department of Psychiatry, Leiden, The Netherlands
Related to but distinct from biological and environmental systems, we define functional ageing as the system of interacting changes in physical and mental body functions, behavioural factors and social participation that occur as individuals age. We propose that a complex systems perspective to functional ageing can illuminate how outcomes such as quality of life and longevity, and prevention and treatment success emerge from dynamic interactions among these domains, rather than from isolated causes. To support this view, we briefly explain how three principles of complex systems science – resilience, non-linearity and heterogeneity – could apply to functional ageing. Then, we show results from our analysis of the temporal ordering of fifteen aspects of functional ageing using dynamic time warping applied to empirical data. The analysis was based on 4-10 repeated observations across 10-30 years in N=1560 participants aged 55 and over in the Longitudinal Aging Study Amsterdam, the Netherlands. The results showed that in the general population, changes in cognitive and physical functioning tend to precede changes in social functioning, whereas psychological functioning tends to show no clear temporal ordering. Latent class analysis revealed various subgroups with variations on these temporal orderings.
Talk 2: Using network analysis to examine the interplay between perceived fatiguability, physical activity and intrinsic capacities in older adults.
by Kaisa Koivunen
Authors: Kaisa Koivunen1 | Lotta Palmberg1 | Gabriela Lunansky2 | Almar Kok2 | Nancy Glynn3 | Rachel Cooper4
1 University of Jyväskylä, Faculty of Sport and Health Sciences and Gerontology Research Center, Finland
2 Amsterdam UMC, Department of Epidemiology & Data Science, Amsterdam, The Netherlands
3 Department of Epidemiology, Center for Aging and Population Health, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
4 AGE Research Group, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
Background: Fatigability – an individual’s fatigue when performing standardised activities – may play an important role in the disablement process. We employed network analysis to investigate the complex associations between perceived physical and mental fatigability, physical activity (PA) and intrinsic capacities (ICs).
Methods: We ran cross-sectional analyses of data on participants from the MRC National Survey of Health and Development at age 60-64 (n=1537). Physical and mental fatigability were assessed using the Pittsburgh Fatigability Scale. PA in the last 4 weeks was self-reported. We quantified five IC domains: vitality, locomotion, cognition, psychology, and sensory, using performance-based measurements and questionnaires. Networks were estimated based on Mixed Graphical Models stratified by sex.
Results: In both sexes, physical and mental fatigability were positively associated with the IC domains of psychology (measured with mastery) and locomotion (walking speed, chair rise) and PA. The network structure showed that the locomotion and psychology domains and PA were related through physical fatigability while mental fatigability did not mediate the associations between ICs and PA.
Conclusions: Perceived physical fatigability is a potentially important pathway between lower physical and mental resources and activity behaviour in older adults. Future work is needed to study the temporality of these associations.
Talk 3: Functional states in healthy aging based on smartphone behavior
by Arko Ghosh
Author: Arko Ghosh
Cognitive Psychology Unit, Institute of Psychology, Leiden University, The Netherlands
Our daily behaviors fluctuate considerably, resembling the ups and downs we experience. Smartphone interactions provide a reliable, objective lens for observing these variations, offering insights into behavioral changes over adulthood through complex-systems approaches. First, we uncover multi-day oscillations in smartphone interactions, tracked through touchscreen logs collected over several months. These oscillations are not random; they are tied to specific behaviors and remain stable across the adult lifespan, even though major aging events like menopause and retirement. This reveals that some behavioral rhythms persist independently of biological aging milestones. Second, we find that certain age-related smartphone behaviors show stable yet distinct patterns, separated by tipping points. Observed over periods up to four years, individuals’ smartphone behaviors appear “younger” on some days and “older” on others, suggesting age-related stability interspersed with shifts. By applying concepts like critical transitions and tipping points, we demonstrate that older adults are less resilient to forces that push behavior into an “older” state, suggesting a natural yet complex ebb and flow in behavioral age. These findings suggest that aging research could benefit from a new perspective—one that recognizes and explores the intricate fluctuations in behavior across the lifespan, rather than focusing solely on linear decline.
Talk 4: Complex systems modelling of age-related decline across biological, psychological, and social domains: A cascade theory of aging
by Richard Ridderinkhof1
Authors: Richard Ridderinkhof1 | Sophie Hendrikse2 | Marcel Olde Rikkert3 | Han van der Maas1
1 Dept. of Psychology, University of Amsterdam, The Netherlands
2 Dept. of Psychology, University of Tilburg, The Netherlands
3 Dept. of Geriatrics, University Medical Center, Radboud University, Nijmegen, The Netherlands
Later adulthood is marked prominently by declines in physical health, cognitive capacities, and shifts in social networks. Surprisingly, no theory of aging exists that integrates and explains the structure and dynamics of this multifaceted process across domains. Here we aim to understand aging from a complex systems perspective, accounting for the intricate interplay of biological, psychological, and social factors. Building on the ecological concept of resilience, we propose that aging can be viewed as a progression through various distinct but variable stages, characterized by abrupt or more gradual transitions between stable, resilient states. To capture these interdependencies comprehensively, we explore the nonlinear dynamics of aging using network theory, highlighting resilience to perturbations and phase transitions as critical aspects. We present two concrete models based on cascades of catastrophe models and cascading networks to demonstrate how perturbations in one domain can cascade into large-scale decline across domains in a stepwise fashion. Emerging from a complex systems perspective, our novel Cascade Theory of Aging holds promise for unraveling the intricacies of aging and advance our understanding of this multifaceted process.