Intraindividual variability in the present context refers to the moment-to-moment variation in attentional or executive engagement over a given time period. Typically, it is measured using the response latencies collected across the trials of a behavioral neurocognitive task. In aging research, the measure has received a lot of recent interest as it may provide important insights into age-related cognitive decline and neuropathology as well as having potential as a neurocognitive assessment tool in healthcare settings. In the present chapter, we begin by reviewing the key empirical findings relating to age and intraindividual variability. Here, research shows that intraindividual variability increases with age and predicts a range of age-related outcomes including gait impairment, falls and errors more broadly, mild cognitive impairment, dementia, and mortality. Brain imaging research suggests that greater variability is associated with age-related or neuropathological changes to a frontal–cingulate–parietal network and that white matter compromise and dopamine depletion may be key underlying mechanisms. We then consider the cognitive and neurobiological theoretical underpinnings of the construct before providing a description of the various methods and metrics that have been used to compute measures of variability – reaction time cut-offs, raw and residualized intraindividual standard deviations, coefficient of variation, ex-Gaussian curve and fast Fourier transformation. A further section considers the range of neurocognitive tasks that have been used to assess intraindividual variability. Broadly, these tasks can be classified on a continuum of cognitive demands as psychomotor, executive control or higher-order cognitive tasks (e.g., episodic memory). Finally, we provide some pointers concerning the pressing issues that future research needs to address in the area. We conclude that the existing body of theoretical and empirical work underlines the potential of intraindividual reaction time variability measures as additions to the neuropsychological test batteries that are used in the early detection of a range of age-related neurocognitive disorders in healthcare settings.
Article
Intraindividual Reaction Time Variability, Attention, and Age-Related Outcomes
David Bunce and Sarah Bauermeister
Article
Aging and Cognitive Skill Learning
Jack Kuhns and Dayna R. Touron
The study of aging and cognitive skill learning is concerned with age-related changes and differences in how we gather, store, and use information and abilities. As life expectancy continues to rise, resulting in greater numbers and proportions of older individuals in the population, understanding the development and retention of skills across the lifespan is increasingly important. Older adults’ task performance in cognitive skill learning is often equal to that of young adults, albeit not as efficient, where older adults often require more time to complete training. Investigations of age differences in fundamental cognitive processes of attention, memory, or executive functioning generally reveal declines in older adults. These are related to a slowing of cognitive processing. Slowing in cognitive processing results in longer time necessary to complete tasks which can interfere with the fidelity of older adults’ cognitive processes in time-limited scenarios. Despite this, older adults maintain comparable rates of learning with young adults, albeit with some reduced efficiency in more complex tasks. The effectiveness of older adults’ learning is also impacted by a lesser tendency to recognize and adopt efficient learning strategies, as well as less flexibility in strategy use relative to younger adults. In learning tasks that involve a transition from using a complex initial strategy to relying on memory retrieval, older adults show a volitional avoidance of memory that is related to lower memory confidence and an impoverished mental model of the task. Declines in learning are not entirely problematic from a functional perspective, however, as older adults can often rely upon their extensive knowledge to compensate for certain deficiencies, particularly in everyday tasks. Indeed, domains where older adults have maintained expertise are somewhat insulated from other age-related declines.
Article
Implicit Memory and Cognitive Aging
Emma V. Ward and David R. Shanks
It is well documented that explicit (declarative, conscious) memory declines in normal aging. Studies have shown a progressive reduction in this form of memory with age, and healthy older adults (typically aged 65+ years) usually perform worse than younger adults (typically aged 18–30 years) on laboratory tests of explicit memory such as recall and recognition. In contrast, it is less clear whether implicit (procedural, unconscious) memory declines or remains stable in normal aging. Implicit memory is evident when previous experiences affect (e.g., facilitate) performance on tasks that do not require conscious recollection of those experiences. This can manifest in rehearsed motor skills, such as playing a musical instrument, but is typically indexed in the laboratory by the greater ease with which previously studied information is processed relative to non-studied information (e.g., repetition priming). While a vast amount of research has accumulated to suggest that implicit memory remains relatively stable over the adult lifespan, and is similar in samples of young and older adults, other studies have in contrast revealed that implicit memory is subject to age-related decline. Improving methods for determining whether implicit memory declines or remains stable with age is an important goal for future research, as the issue not only has significant implications for an aging society regarding interventions likely to ameliorate the effects of age-related explicit memory decline, but can also inform our theoretical understanding of human memory systems.
Article
Episodic Future Thinking and Cognitive Aging
Daniel L. Schacter, Aleea L. Devitt, and Donna Rose Addis
Episodic future thinking refers to the ability to imagine or simulate experiences that might occur in an individual’s personal future. It has been known for decades that cognitive aging is associated with declines in episodic memory, and recent research has documented correlated age-related declines in episodic future thinking. Previous research has considered both cognitive and neural mechanisms that are responsible for age-related changes in episodic future thinking, as well as effects of aging on the functions served by episodic future thinking. Studies concerned with mechanism indicate that multiple cognitive mechanisms contribute to changes in episodic future thinking during aging, including episodic memory retrieval, narrative style, and executive processes. Recent studies using an episodic specificity induction—brief training in recollecting episodic details of a recent experience—have proven useful in separating the contributions of episodic retrieval from other non-episodic processes during future thinking tasks in both old and young adults. Neuroimaging studies provide preliminary evidence of a role for age-related changes in default and executive brain networks in episodic future thinking and autobiographical planning. Studies concerned with function have examined age-related effects on the link between episodic future thinking and a variety of processes, including everyday problem-solving, prospective memory, prosocial intentions, and intertemporal choice/delay discounting. The general finding in these studies is for age-related reductions, consistent with the work on mechanisms that consistently reveals reduced episodic detail in older adults when they imagine future events. However, several studies have revealed that episodic simulation nonetheless confers some benefits for tasks tapping adaptive functions in older adults, such as problem-solving, prospective memory, and prosocial intentions, even though age-related deficits on these tasks are not eliminated or reduced by episodic future thinking.
Article
New Directions in Theories of Emotion and Aging
Joseph A. Mikels and Nathaniel A. Young
The adult life span is characterized as a time of divergent trajectories. It is a time of compounding losses (such as physical, sensory, and cognitive declines) and is also a time of surprising growth (such as improvements in well-being and emotion regulation). These divergent trajectories present theorists with the paradox of aging: in the face of accumulating losses, how is it that as people age, they generally feel good and experience greater well-being? Theorists have grappled with this paradox and have focused on how motivational, cognitive, control, and social factors impact emotional development across the adult life span. These foundational theories have paved the way to a deeper understanding of adult life-span development, but they do not draw as deeply from theories in affective science. Some of the latest perspectives on emotion and aging offer integrative views, such as how older adults may experience different discrete emotion (i.e., anger versus sadness) from an evolutionary functional perspective. Other perspectives consider how an array of appraisal processes may change across adulthood (such as shifts in evaluations of self-control versus other-control for younger versus older adults). These newer approaches dig deeper into mechanistic explanations and underscore the need for greater theoretical integration. Later life is clearly a time of increased well-being, but the field is only on the cusp of understanding the mysteries of emotional experience in later life.
Article
Prospective Memory and Cognitive Aging
Simon J. Haines, Jill Talley Shelton, Julie D. Henry, Gill Terrett, Thomas Vorwerk, and Peter G. Rendell
Tasks that involve remembering to carry out future intentions (such as remembering to attend an appointment), and the cognitive processes that enable the completion of such tasks (such as planning), are referred to as prospective memory (PM). PM is important for promoting quality of life across many domains. For instance, failures in remembering to meet social commitments are linked to social isolation, whereas failures in remembering to fulfill occupational goals are linked to poorer vocational outcomes. Declines in PM functioning are of particular concern for older adults because of the strong links between PM and functional capacity. The relationship between age and PM appears to be complex, dependent on many factors. While some aspects of PM appear to hold up relatively well in late adulthood, others appear to show consistent age-related decline. Variability in age differences appears to partially reflect the fact that there are diverse types of PM tasks, which impose demands on a range of cognitive processes that are differentially affected by aging. Specifically, the level and type of environmental support associated with different PM task types appears to be a meaningful determinant of age-related effects. Given the worldwide changing age demographics, the interest in age-related effects on PM will likely intensify, and a primary focus will be how to optimize and maintain PM capacity for this population. This is already reflected in the increasing research on interventions focused on enhancing PM capacity in late adulthood, and points to important future directions in this area of study.
Article
Cultural Variance and Invariance of Age Differences in Social Cognition
Li Chu, Yang Fang, Vivian Hiu-Ling Tsang, and Helene H. Fung
Cognitive processing of social and nonsocial information changes with age. These processes range from the ones that serve “mere” cognitive functions, such as recall strategies and reasoning, to those that serve functions that pertain to self-regulation and relating to others. However, aging and the development of social cognition unfold in different cultural contexts, which may assume distinct social norms and values. Thus, the resulting age-related differences in cognitive and social cognitive processes may differ across cultures. On the one hand, biological aging could render age-related differences in social cognition universal; on the other hand, culture may play a role in shaping some age-related differences. Indeed, many aspects of cognition and social cognition showed different age and culture interactions, and this makes the study of these phenomena more complex. Future aging research on social cognition should take cultural influences into consideration.