This chapter considers ways that perceived time – both at the level of seconds and lifetimes – may influence adult development. Research suggests that age-related impairments in divided attention contribute to older adults’ underestimation of short-term duration judgments. A separate literature suggests that perceived constraints on future time lead to the prioritization of emotionally meaningful goals. We consider ways that these two research streams may inform one another. Findings about duration judgments may help to explain age-related time acceleration that affects perceptions of the future. Findings about motivational changes associated with perceived constraints on time may influence attention in ways that reduce accuracy of duration judgments. We urge joint consideration of these literatures in hypothesis generation about developmental trajectories of cognitive processing, motivation, and emotional well-being.

Even healthy older people undergo some cognitive decline with real-world consequences, although the neural plasticity persisting in older brains indicates substrates for interventions. Yet there is no consensus on cognitive interventions. The literature on cognitive training is equivocal regarding the factors important in far transfer of training to untrained abilities. That there have been few hypotheses on mechanisms underlying far transfer of training is an obstacle to the design of cognitive interventions. We evaluate two hypotheses: (1) updating and (2) distraction suppression. (1) The updating hypothesis argues that updating and monitoring of working memory representations is an important mechanism of far transfer of training. Two meta-analyses of n-back training tasks found small, but significant, effect sizes in favor of transfer to fluid intelligence (Gf) in young and older people. However, direct tests of the updating hypothesis supported only narrow transfer effects. (2) The distraction suppression hypothesis argues that suppression of irrelevant events has a central role in cognitive processing. Perceptual discrimination training improved distraction suppression, enhanced neural activity associated with task-relevant targets, suppressed neural activity associated with task-irrelevant distractions, improved brain-stem evoked potential firing patterns and “speech-in-noise” perception, transferred to working memory, and reduced risk of dementia in a large-scale study. The evidence supports the conclusion that the strongest far transfer of cognitive training would be achieved by combined updating and distraction suppression training. Even small effect sizes of transfer to Gf can be beneficial to older people, consistent with the growing evidence for the role of lifestyle factors, including educational attainment, in risk of Alzheimer’s disease.

Older adults often collaborate with others to recreate past events and reminisce. In the current chapter, we discuss the patterns of gains and losses associated with social memory and aging specifically as they relate to research on collaborative remembering and social contagion. Within the collaborative remembering literatures, we focus on different methods of measuring group and individual memory performance and the role of partner familiarity. Within social contagion, we focus on age differences in susceptibility to socially suggested false memories and how perceptions of age influence the effects. Across literatures, there is some disagreement on precisely how and when collaboration benefits and/or disrupts older adults’ memories. However, there is strong agreement that collaboration influences memory and that social influence is an important contextual factor on older adults’ cognition.

Much of the extant work in the cognitive neurosciences of aging has focused on identifying the neural correlates of age-related declines in episodic memory and working memory. This chapter reviews evidence from human studies that speaks to the hypothesis that age-related dysfunctions in specific neurotransmitter systems play a critical role in cognitive decline. Based in large part on results from functional neuroimaging studies including positron emission tomography (PET) and pharmacological functional magnetic resonance imaging (fMRI), we conclude that there is emerging evidence that dysfunctions in the dopamine, noradrenaline, and cholinergic systems play a critical role in age-related cognitive decline of working memory and episodic memory. These conclusions are important and encourage further study in order to tailor interventions that preserve cognitive functions in older age via augmentation of neurotransmitter functions.

The concept of cognitive reserve was proposed to account for the discrepancy between clinical outcomes and the extent of age-related brain changes, neuropathology, or brain damage. This chapter reviews the concept of cognitive reserve, the methods used to characterize it, and theoretical issues concerning its measurement and utilization. We begin with an overview of the concept of cognitive reserve, how it is distinguished from brain reserve, and how it is defined in current literature. We then explore both epidemiological and neuroimaging evidence supporting the concept of cognitive reserve and review how novel neuroimaging tools are contributing toward our understanding of the mechanisms by which cognitive reserve may operate. We conclude by addressing the future of cognitive reserve and its implications for the field of cognitive aging as a whole.

In the past few decades, there has been a surge of research on cognitive interventions to increase cognitive abilities in older adults, many of whom experience age-related cognitive and functional declines. It has become increasingly clear that although cognitive interventions with older adults can increase cognitive abilities that are directly targeted in the training program, increasing untrained cognitive abilities and abilities related to daily life activities has not been as effective as originally anticipated. Instead of taking a pessimistic view that it is impossible to substantially increase cognitive and functional abilities across a variety of domains in older adults, we propose that cognitive interventions could benefit from developing theory-driven research programs, especially by incorporating findings from earlier in the life span and models of behavior change, to optimize intervention gains in later adulthood. Moreover, intervention gains can also be increased by taking into consideration participant characteristics, situations, and preferences when designing interventions. Instead of considering these factors as “noise,” they provide meaningful information about differences in individual experiences in the past, present, and future. This chapter focuses mostly on cognitive engagement interventions, which are holistic interventions employing real-world skills and tasks. After briefly reviewing the current state of the literature, we discuss ways in which researchers have begun to investigate how to maximize the impact of engagement interventions on cognitive abilities and functional independence (i.e., the ability to perform daily activities independently). In addition, we consider unique cognitive, social, and environmental aspects of the older adult that can be leveraged for maximizing the impact of cognitive engagement interventions.

Without brain systems that modulate arousal, we would not be able to have daily sleep-wake cycles, focus attention when needed, experience emotional responses, or even maintain consciousness. Thus, it is not surprising that there are multiple overlapping neurotransmitter systems that control arousal. In aging, most of these systems show decline in basic features such as number of receptors and transporters, and sometimes even in neuron count. These declines have the potential to disrupt basic arousal functions. Compensatory increases in activity in some of these systems allow for maintained levels of circulating neurotransmitters in those systems – but at the cost of reduced dynamic range in arousal responses.

This chapter reviews major theories of cognitive aging. Theories such as the sensory deficit hypothesis, speed of processing, and inhibitory deficit hypothesis are based largely on behavioral findings and focus on a single process that is purported to account for a number of cognitive changes with age. Specific to memory, theories focus on age deficits in recollection and binding. Over the past twenty-five years, brain-based models have begun to pervade the literature. These have focused on concepts such as compensation, dedifferentiation, and suppression of the default mode network. The scaffolding theory of aging and cognition integrates many of these concepts into a single comprehensive model, including consideration of enrichment and depletion factors that operate over the life span. We conclude the chapter with some debates, critiques, and consideration of future directions, particularly considering the contributions of cognitive neuroscience methods.

Cognitive functions are highly heritable and polygenic, determined by many different genes. This chapter summarizes current knowledge regarding the genetic basis of cognitive abilities based on evidence from twin studies and behavioral genetic studies, focusing on single genes or polygenic scores. Given the focus of this book on aging, we also highlight differences of genetic influences on cognition across the adult life span, which contribute to the large interindividual differences in the decline of cognition in old age. In addition, we discuss the complex interplay between genetic and environmental factors in influencing cognition in adulthood and aging. Here, we focus on gene-environment interactions, gene-environment correlations, and epigenetic mechanisms, which likely account for some of the differential patterns in cognitive aging trajectories.

We examine evidence for whether brain volume reductions and neurotransmitter decline can account for older adults’ emotion recognition difficulties relative to young adults. We also consider whether emotion recognition decline is related to general cognitive decline or the positivity bias. Despite recent claims, older adults’ emotion recognition difficulties are not consistent with the positivity bias. Links to general cognitive decline are not strong, although future research could shed further light on this issue by examining links to speed of processing. We conclude that there is some evidence for the idea that neurotransmitter decline might relate to older men’s emotion recognition declines (though not older women’s), but with only two studies, more research is needed. There are more studies examining brain volume reductions, with links between emotion recognition and decline in the frontal and temporal lobes clearest.

Because of age-related cognitive declines, people sometimes expect older adults to be incompetent, senile, or extremely forgetful. Research on stereotype threat suggests that these negative expectations can interfere with older adults’ performance on cognitive tests and can cause them to underperform compared to their potential. However, research also shows that not all cognitive domains, and not all older adults, are equally affected by stereotype threat. Stereotype threat effects seem to occur most reliably on cognitive tasks where there are larger deficit expectations and for people who have concerns or negative expectations about aging and cognition. In addition to outlining these task and individual differences, in this chapter we also review potential mechanisms underlying these effects and discuss the applied implications of stereotype threat for how older adults’ memory is assessed in clinical and eyewitness settings.

Age-related changes in memory are a common but worrisome occurrence in many people’s lives. However, these changes are not ubiquitous. Healthy aging appears to impact memory for associative/relational details, i.e., the ability to recollect, more so than memory for item information. We propose that alterations in the recruitment of prefrontally mediated cognitive control processes, such as strategy use and inhibitory control, underlie these age-related memory deficits in healthy adults. These processes are particularly critical for remembering specific relational details and for being able to resolve interference between competing memories. Critically, evidence suggests that while there are large individual differences in the impact of aging on memory, various methods of support/intervention can improve memory performance in healthy older adults. We discuss how recent developments in neuroscience analysis methods have enhanced our understanding of how aging affects the control processes that support episodic learning and retrieval. We further suggest that future studies should test more diverse samples of adults and assess the role of lifestyle factors on individual differences in patterns of episodic memory performance and supporting brain activity and structure.

Participation in activities that provide opportunities for mental, physical, or social engagement have been supported as cognitively protective in later life. Theories propose how mentally stimulating activities might improve or maintain specific cognitive abilities across the life course or reduce age-related cognitive changes, for example, while physical activities might promote brain health via a reduction in cardiovascular risk profiles. Given that such lifestyles and behaviors are potentially modifiable, positive associations between activity participation and maintained cognitive abilities in old age highlight leisure-time pursuits as targets for intervention. However, associations between activity participation and cognitive aging may be prone to reverse causation: those with higher engagement across the life course might have always had higher levels of cognitive ability. Life course approaches are therefore needed to correctly identify the potentially beneficial effects of activity participation. In addition, given the growth and development of cognitive abilities across the life span, there may be specific types of activity or engagement that are beneficial at different points. Understanding the associations between mental, physical, and social activity participation and cognitive aging supports the development of interventions against age-related cognitive decline, ranging from targeted cognitive training programs to broader engagement-based approaches. An ultimate goal of research exploring activity participation and cognitive aging is to provide clear and accurate information to individuals regarding the steps they might take to promote brain health in later life.

Although preserving social relationships plays a critical role in successful aging, a large body of work has shown that the size of older adults’ social networks declines with age. This decline could reflect older adults’ increased desire to preserve their emotional well-being (having greater positive than negative affect). However, because emotional well-being is associated with longer lifespans whereas having smaller social networks is not, other factors may contribute to older adults’ declining network. This chapter reviews one such possibility: age-related declines in social cognition. Core social cognitive functions that play an integral role in developing and maintaining social relationships – understanding the mental states of others, emotion recognition, inhibiting socially inappropriate responses, and prejudice reduction – are impaired in aging populations. This chapter reviews each of these, and considers how they might influence older adults’ ability to develop and maintain high-quality social networks.

Successful aging can be generally defined as minimizing disabilities, maintaining functional capacity, and supporting an engaged lifestyle. Given world population changes, this concept is of increasing importance. Technologies have become an integral part of daily life across a range of domains and have potential to support older adults. However, for that potential to be met, the technology must be designed with consideration for older adults’ capabilities, limitations, motivations to use technological support, and opinions regarding the role of technology in their lives. In this context, we review the theoretical background relevant to successful aging and technology support. Moreover, the technology should not impose cognitive demands but should augment or enhance cognitive function. We present older adult personas to highlight how current and emerging technologies can assist aging individuals in meeting their diverse needs and reaching their goals. We provide considerations and future research directions to guide technology design and promote successful aging.

Changes in sensory systems are common as we get older and become more likely with increasing age. In the auditory system, age-related changes are seen in domains such as auditory sensitivity, temporal processing, and spatial localization, which have significant effects on speech understanding. In vision, age-related changes are seen in contrast sensitivity, scotopic processing, and visual processing speed, which have consequences for activities such as reading and driving. Aging is also associated with changes in smell, taste, and balance. Beyond simple perceptual processing, age-related sensory changes can increase cognitive demands, requiring greater involvement of domain-general cognitive processes during perception that reduce resources available for other operations. Capturing individual variability in sensory changes and their consequences is an important part of understanding normal and pathological aging.