The term “acquired brain injury” refers to any type of brain damage that occurs after birth. Two main types of acquired brain injury are stroke and traumatic brain injury (TBI). A stroke occurs when there is a blockage or bleed in the vascular system of the brain, while a TBI results from an external force to the head. Older adults are at a higher risk of both stroke and TBI; thus, overall incidence is increasing as the proportion of older adults in the population is growing. Stroke and TBI result in immediate and long-term cognitive changes. Impairments in the domains of language, attention, memory, executive functions, perception, and social cognition have been documented following stroke and TBI. However, strokes tend to cause focal or selective cognitive disorders, while cognitive deficits following TBI are widespread and can be generalized. Individuals who have suffered a stroke or TBI may also experience psychosocial changes; for example, symptoms of depression and anxiety are common. Functional outcomes, including independence in activities, are varied and are associated with a range of factors including age, injury severity, cognitive disorders, and psychosocial factors. To achieve optimal outcomes for individuals following stroke and TBI, and to reduce the impact of the injury on everyday functioning, a multidisciplinary rehabilitation process is recommended.
Acquired Brain Injury (Stroke and TBI) in Later Life
Megan S. Barker, Emily C. Gibson, and Gail A. Robinson
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.
Sarah Krichbaum, Adam Davila, Lucia Lazarowski, and Jeffrey S. Katz
The contemporary field of animal cognition began over 150 years ago when Charles Darwin posed questions regarding the abilities of the animal mind. Animal cognition is a science dedicated to understanding the processes and mechanisms that allow nonhumans to think and behave. The techniques that are used and the species that are studied are diverse. The historical questions originally proposed by ethologist Nikolas Tinbergen as a framework for studying animal behavior remain at the core of the field. These questions are reviewed along with the domains and methods of animal cognition with a focus on concept learning, memory, and canine cognition. Finally, ideas on how a field rich in tradition and methodological strength should proceed in the future are presented.
Attentional Processes in Sport and Performance
Aidan Moran and John Toner
We are constantly bombarded by information. Therefore, during every waking moment of our lives, we face decisions about which stimuli to prioritize and which ones to ignore. To complicate matters, the information that clamors for our attention includes not only events that occur in the world around us but also experiences that originate in the subjective domain of our own thoughts and feelings. The end result is that our minds can consciously attend to only a fraction of the rich kaleidoscope of information and experiences available to us from our senses, thoughts, memories, and imagination. Attentional processes such as “concentration,” or the ability to focus on the task at hand while ignoring distractions, are crucial for success in sport and other domains of skilled performance. To illustrate, Venus Williams, one of the greatest tennis players of all time, proclaimed that “for the players it is complete and pure focus. You don’t see anything or hear anything except the ball and what’s going on in your head.” For psychological scientists, concentration resembles a mental spotlight (like the head-mounted torch that miners and divers wear in dark environments) that illuminates targets located either in the external world around us or in the internal world of our subjective experiences. A major advantage of this spotlight metaphor is that it shows us that concentration is never “lost”—although it can be diverted to targets (whether in the external world or inside our heads) that are irrelevant to the task at hand. Research on attentional processes in sport and performance has been conducted in cognitive psychology (the study of how the mind works), cognitive sport psychology (the study of mental processes in athletes), and cognitive neuroscience (the study of how brain systems give rise to mental processes). From this research, advances have been made both in measuring attentional processes and in understanding their significance in sport and performance settings. For example, pupillometry, or the study of changes in pupil diameter as a function of cognitive processing, has been used as an objective index of attentional effort among skilled performers such as musicians and equestrian athletes. Next, research suggests that a heightened state of concentration (i.e., total absorption in the task at hand) is crucial to the genesis of “flow” states (i.e., rare and elusive moments when everything seems to come together for the performer) and optimal performance in athletes. More recently, studies have shown that brief mindfulness intervention programs, where people are trained to attend non-judgmentally to their own thoughts, feelings, and sensations, offer promise in the quest to enhance attentional skills in elite athletes. By contrast, anxiety has been shown to divert skilled performers’ attention to task-irrelevant information—sometimes triggering “choking” behavior or the sudden and significant deterioration of skilled performance. Finally, concentration strategies such as “trigger words” (i.e., the use of short, vivid, and positively phrased verbal reminders such as “this ball now”) are known to improve athletes’ ability to focus on a specific target or to execute skilled actions successfully.
C. Philip Beaman
The modern world is noisy. Streets are cacophonies of traffic noise; homes and workplaces are replete with bleeping timers, announcements, and alarms. Everywhere there is the sound of human speech—from the casual chatter of strangers and the unwanted intrusion from electronic devices through to the conversations with friends and loved ones one may actually wish to hear. Unlike vision, it is not possible simply to “close our ears” and shut out the auditory world and nor, in many cases, is it desirable. On the one hand, soft background music or environmental sounds, such as birdsong or the noise of waves against the beach, is often comfortingly pleasurable or reassuring. On the other, alarms are usually auditory for a reason. Nevertheless, people somehow have to identify, from among the babble that surrounds them, the sounds and speech of interest and importance and to follow the thread of a chosen speaker in a crowded auditory environment. Additionally, irrelevant or unwanted chatter or other background noise should not hinder concentration on matters of greater interest or importance—students should ideally be able to study effectively despite noisy classrooms or university halls while still being open to the possibility of important interruptions from elsewhere. The scientific study of auditory attention has been driven by such practical problems: how people somehow manage to select the most interesting or most relevant speaker from the competing auditory demands made by the speech of others or isolate the music of the band from the chatter of the nightclub. In parallel, the causes of auditory distraction—and how to try to avoid it where necessary—have also been subject to scrutiny. A complete theory of auditory attention must account for the mechanisms by which selective attention is achieved, the causes of auditory distraction, and the reasons why individuals might differ in their ability in both cases.
Autism Spectrum Disorders in Later Life
Ye In (Jane) Hwang, Kitty-Rose Foley, Samuel Arnold, and Julian Trollor
Autism spectrum disorder (ASD), or autism, is a neurodevelopmental disorder that is typically recognized and diagnosed in childhood. There is no established biological marker for autism; rather, the diagnosis is made based on observation of behavioral traits, including (a) persistent deficits in social interaction and communication, and (b) restricted, repetitive patterns of behavior, interests, or activities. Because autism is a spectrum disorder, autistic individuals are a highly heterogeneous group and differ widely in the presentation and severity of their symptoms. The established prevalence of ASD is approximately 1% of the population. Information about autism in adulthood is limited; most of the literature examines childhood and adolescence. While the term “later life” has traditionally been associated with those over the age of 65, a dire lack of understanding exists for those on the autism spectrum beyond early adulthood. Individuals remain on the spectrum into later life, though some mild improvements in symptoms are observed over time. Autistic adults experience high levels of physical and mental health comorbidities. Rates of participation in employment and education are also lower than that of the general population. Quality of life is reportedly poorer for autistic adults than for nonautistic peers, though this is not affected by age. More robust studies of the health, well-being, and needs of autistic adults are needed, especially qualitative investigations of adulthood and aging and longitudinal studies of development over the lifespan.
Awareness of Aging Processes
Anne Josephine Dutt, Hans-Werner Wahl, and Manfred Diehl
The term Awareness of Aging (AoA) incorporates all aspects of individuals’ perceptions, behavioral experiences, and subjective interpretations related to their process of growing older. In this regard, AoA goes beyond objective descriptions of the aging process, such as calendar age or biological age. Commonly used AoA constructs referring to the ongoing experience of the aging process encompass concepts such as subjective age, attitudes toward one’s own aging, self-perceptions of aging, and awareness of age-related change. AoA also incorporates elements that are more pre-conscious in nature, such as age stereotypes and culturally held notions about the aging process. Despite their theoretically broad common foundation, AoA constructs differ according to their specific frames of reference, such as whether and how they take into account the multidimensionality and multi-directionality of development. Examining the existing body of empirical work identifies several antecedents of AoA, such as sociodemographic “background” variables, physical health and physical functioning, cognition, psychological well-being and mental health, psychological variables (e.g., personality, anxiety), and life events. In general, more positive manifestations on these variables are accompanied by a more positive perception and evaluation of the aging process. Moreover, AoA is longitudinally linked to important developmental outcomes, such as health, cognition, subjective well-being, and mortality. Overall, the study of AoA has developed as a promising area of psychological aging research that has grown in its conceptual and empirical rigor during recent years.
Bilingualism: A Cognitive and Neural View of Dual Language Experience
Judith F. Kroll and Guadalupe A. Mendoza
There has been an upsurge of research on the bilingual mind and brain. In an increasingly multilingual world, cognitive and language scientists have come to see that the use of two or more languages provides a unique lens to examine the neural plasticity engaged by language experience. But how? It is now uncontroversial to claim that the bilingual’s two languages are continually active, creating a dynamic interplay across the two languages. But there continues to be controversy about the consequences of that cross-language exchange for how cognitive and neural resources are recruited when a second language is learned and used actively and whether native speakers of a language retain privilege in their first acquired language. In the earliest months of life, minds and brains are tuned differently when exposed to more than one language from birth. That tuning has been hypothesized to open the speech system to new learning. But when initial exposure is to a home language that is not the majority language of the community—the experience common to heritage speakers—the value of bilingualism has been challenged, in part because there is not an adequate account of the variation in language experience. Research on the minds and brains of bilinguals reveals inherently complex and social accommodations to the use of multiple languages. The variation in the contexts in which the two languages are learned and used come to shape the dynamics of cross-language exchange across the lifespan.
Suzanne McKee and Preeti Verghese
This article describes human binocular vision. While it is focused primarily on human stereopsis, it also briefly tells about other binocular functions, including binocular summation, rivalry, and vergence, the eye movement that is driven by stereopsis. Stereopsis refers to the depth perception generated by small differences in the locations of visual features in the two retinal images; these differences in retinal location are called disparities. Disparities are detected by special binocularly driven cortical neurons whose properties are outlined here; the article also describes studies that have used fMRI imaging to show that many areas of human cortex respond to depth based on disparity. The development of stereopsis in human infants, as well as clinical abnormalities in stereopsis, is also documented.
Brain Basis of Blindsight
The sensation of vision arises from the detection of photons of light at the eye, but in order to produce the percept of the world, extensive regions of the brain are required to process the visual information. The majority of information entering the brain via the optic nerve from the eye projects via the lateral geniculate nucleus (LGN) of the thalamus to the primary visual cortex, the largest visual area, having been reorganized such that one side of the brain represents one side of the world. Damage to the primary visual cortex in one hemisphere therefore leads to a loss of conscious vision on the opposite side of the world, known as hemianopia. Despite this cortical blindness, many patients are still able to detect visual stimuli that are presented in the blind region if forced to guess whether a stimulus is present or absent. This is known as “blindsight.” For patients to gain any information (conscious or unconscious) about the visual world, the input from the eye must be processed by the brain. Indeed, there is considerable evidence from functional brain imaging that several visual areas continue to respond to visual stimuli presented within the blind region, even when the patient is unaware of the stimulus. Furthermore, the use of diffusion imaging allows the microstructure of white matter pathways within the visual system to be examined to see whether they are damaged or intact. By comparing patients who have hemianopia with and without blindsight it is possible to determine the pathways that are linked to blindsight function. Through understanding the brain areas and pathways that underlie blindsight in humans and non-human primates, the aim is to use modern neuroscience to guide rehabilitation programs for use after stroke.
Ian Q. Whishaw and Megan Sholomiski
A brain lesion is an area of damage, injury, or abnormal change to a part of the brain. Brain lesions may be caused by head injury, disease, surgery, or congenital disorders, and they are classified by the cause, extent, and locus of injury. Lesions cause many behavioral symptoms. Symptom severity generally corresponds to the region and extent of damaged brain. Thus, behavior is often a reliable indicator of the type and extent of a lesion. Observations of patients suffering brain lesions were first recorded in detail in the 18th century, and lesion studies continue to shape modern neuroscience and to give insight into the functions of brain regions. Recovery, defined as any return of lost behavioral or cognitive function, depends on the age, sex, genetics, and lifestyle of patients, and recovery may be predicted by the cause of injury. Most recovery occurs within the first 6 to 9 months after injury and likely involves a combination of compensatory behaviors and physiological changes in the brain. Children often recover some function after brain lesions better than adults, though both children and adults experience residual deficits. Brain lesion survival rates are improved by better diagnostic tools and treatments. Therapeutic interventions and treatments for brain lesions include surgery, pharmaceuticals, transplants, and temperature regulation, each with varying degrees of success. Research in treating brain lesions is progressing, but in principle a cure will only be complete when brain lesions are replaced with healthy tissue.
Cerebral Palsy From a Developmental Psychology Perspective
Cerebral palsy (CP) is defined as non-progressive damage to the brain at or around birth, which leads to varying symptoms depending on the extent and location of damage. The leading symptom is sensory-motor impairment of varying expression, but additional perceptual, cognitive, and socio-emotional symptoms are common. CP can be divided into four types, with bilateral spastic being by far the most frequent, followed by the unilateral spastic, the dyskinetic, and the ataxic variants. The intellectual, linguistic, and cognitive profile of CP is extremely variant, but all qualities correlate more or less with CP type and motor impairment. Early diagnosis is important since early intervention may promote all developmental dimensions. Generally, individuals with unilateral spastic CP have the best (almost normal) intellectual, linguistic, and cognitive outcomes, while those with bilateral spastic CP fare the worst. Language perception is often an individual strength, while language expression, and particularly speech, may be heavily impaired. Attention and executive functions are often impaired as compared to typically developing controls, even in those children with normal intellectual functioning. The same holds true for visual perceptual functions, which are impaired in almost half of all children and adolescents with CP. The potential neuropsychological dysfunctions are a risk factor for arithmetic functions and literacy. Obstacles to participate in society are high for individuals with CP and heavily dependent on their motor, language, intellectual, and cognitive functions. However, quality of life is good for most children and adolescents, and they develop a sound self-concept. On the other side, bully experience is more common than amongst typically developing children and is associated with behavior problems and executive dysfunction. The development of children and adolescents with CP is determined by a complex interplay between physical, intellectual, and neuropsychological functions.
Cognition and Mobility With Aging
Karen Z. H. Li, Halina Bruce, and Rachel Downey
Research on the interplay of cognition and mobility in old age is inherently multidisciplinary, informed by findings from life span developmental psychology, kinesiology, cognitive neuroscience, and rehabilitation sciences. Early observational work revealed strong connections between sensory and sensorimotor performance with measures of intellectual functioning. Subsequent work has revealed more specific links between measures of cognitive control and gait quality. Convergent evidence for the interdependence of cognition and mobility is seen in patient studies, wherein cognitive impairment is associated with increased frequency and risk of falling. Even in cross-sectional studies involving healthy young and older adults, the effects of aging on postural control and gait are commonly exacerbated when participants perform a motor task with a concurrent cognitive load. This motor-cognitive dual-task method assumes that cognitive and motor domains compete for common capacity, and that older adults recruit more cognitive capacity than young adults to support gait and posture. Neuroimaging techniques such as magnetic resonance imaging (MRI) have revealed associations between measures of mobility (e.g., gait velocity and postural control) and measures of brain health (e.g., gray matter volumes, cortical thickness, white matter integrity, and functional connectivity). The brain regions most often associated with aging and mobility also appear to subserve high-level cognitive functions such as executive control, attention, and working memory (e.g., dorsolateral prefrontal cortex, anterior cingulate). Portable functional neuroimaging has allowed for the examination of neural functioning during real-time walking, often in conjunction with detailed spatiotemporal measures of gait. A more recent strategy that addresses the interdependence of cognitive and motor processes in old age is cognitive remediation. Cognitive training has yielded promising improvements in balance, walking, and overall mobility status in healthy older adults, and those with age-related neurodegenerative conditions such as Parkinson’s Disease.
Cognitive Behavior Therapy for Psychosis (CBTp)
Anthony P. Morrison and Lisa J. Wood
Cognitive behavior therapy (CBT) is an evidence-based psychological therapy that has been shown to have small to medium effects in improving outcomes for people experiencing psychosis. CBT’s theoretical model, drawing together cognitive and behavioral theories, outlines that it is the appraisal and response to an event which maintains distress rather than the event itself. CBT for psychosis (CBTp) specifically aims to modify appraisals and responses to psychotic experiences in order to reduce distress. CBTp has a substantial evidence base and is the most frequently offered psychological treatment for psychosis. There have been significant advancements in the field, with process-oriented therapies and digital interventions showing promise; however, more large-scale trials are required. Moreover, service users report positive experiences with CBTp and value the normalizing therapeutic relationship, improved personal understanding, and acquisition of new coping strategies. Improving dissemination and adapting CBTp so that it is appropriate for all populations is an ongoing priority for future research. Moreover, the evidence base requires more user-centered research to ensure CBTp is meeting the needs of service users.
Cognitive Consistency in Social Cognition
Skylar M. Brannon and Bertram Gawronski
The desire to maintain consistency between cognitions has been recognized by many psychologists as an important human motive. Research on this topic has been highly influential in a variety of areas of social cognition, including attitudes, person perception, prejudice and stereotyping, and self-evaluation. In his seminal work on cognitive dissonance, Leon Festinger noted that inconsistencies between cognitions result in negative affect. Further, he argued that the motivation to maintain consistency is a basic motive that is intrinsically important. Subsequent theorists posed revisions to Festinger’s original theory, suggesting that consistency is only important to the extent that it allows one to maintain a desired self-view or to communicate traits to others. According to these theorists, the motivation to maintain consistency serves as a means toward a superordinate motive, not as an end in itself. Building on this argument, more recent perspectives suggest that consistency is important for the execution of context-appropriate action and the acquisition and validation of knowledge. Several important lines of research grew out of the idea that cognitive consistency plays a central role in social information processing. One dominant line of research has aimed toward understanding how people deal with inconsistencies between their attitudes and their behaviors. Other research has investigated how individuals maintain their beliefs either by (1) avoiding exposure to contradictory information or (2) engaging in cognitive processes aimed toward reconciling an inconsistency after being exposed to contradictory information. Cognitive consistency perspectives have also been leveraged to understand (1) the conditions under which explicit and implicit evaluations correlate with one another, (2) when change in one type of evaluation corresponds with change in the other, and (3) the roles of distinct types of consistency principles underlying explicit and implicit evaluations. Expanding on these works, newer lines of research have provided important revisions and extensions to early research on cognitive consistency, focusing on (1) the identification of inconsistency, (2) the elicitation of negative affect in response to inconsistency, and (3) behavioral responses aimed to restore inconsistency or mitigate the negative feelings arising from inconsistency. For example, some research has suggested that, instead of following the rules of formal logic, perceptions of (in)consistency are driven by “psycho-logic” in that individuals may perceive inconsistency when there is logical consistency, and vice versa. Further, reconciling conflicting research on the affective responses to inconsistency, recent work suggests that all inconsistencies first elicit negative affect, but immediate affective reactions may change in line with the hedonic experience of the event when an individual has time to make sense of the inconsistency. Finally, new frameworks have been proposed to unite a broad range of phenomena under one unifying umbrella, using the concept of cognitive consistency as a common denominator.
Cognitive Development in Chimpanzees
Cognitive development in chimpanzees has been illuminated through fieldwork and laboratory studies. Their life history reveals the importance of the mother–infant relationship. Females give birth at 5-year intervals on average, and the infants cling to their mothers in the first 3 months. Each chimpanzee community has its own unique cultural traditions, for example in tool use. How tools are used is passed across generations through social learning, in a process called education by master-apprenticeship. Laboratory studies in the early 21st century examined chimpanzees’ learning abilities even at the fetal stage. Chimpanzee and human cognition appear similar in both physical and social domains, and they follow the same developmental stages. However, there is a fundamental difference in the levels of complexity of hierarchical structure. Chimpanzees do not show the recursive and infinite levels that characterize human cognition. Chimpanzees are good at memorizing things at a glance but less skilled at representing things through imagination. The cognitive trade-off between working memory and language may explain the essential difference in cognitive development in the two species.
Cognitive Implications of Bilingualism
There has been an enormous expansion during the early 21st century in psychological research on topics relating to bilingualism, paralleling developments in other fields of psychology that investigate the interface between experience and the mind. These issues reflect the view that brains and minds remain plastic and can be modified by experience throughout life. In the case of bilingualism, a central question is whether bilingual experience modifies cognitive systems in general, and more specifically, if it improves cognitive ability and executive functioning. The research has produced contradictory results, in some cases supporting a beneficial effect on cognition and in some cases indicating no effect. Crucially, there is essentially no research that indicates that bilingualism is associated with poorer cognitive outcomes than found for those who are monolingual. Studies showing a positive role for bilingualism on cognitive outcomes have been reported across the life span. Early research with children in the first half of the 20th century concluded that bilingualism was detrimental to children’s intelligence, a claim that has been thoroughly refuted and replaced with evidence identifying specific cognitive processes that are more advanced in bilingual than in monolingual children. A few studies have even reported better attentional control, the foundation of executive functioning, for infants in the first year of life being raised in bilingual homes than for those in monolingual environments. Young adults frequently show no behavioral differences between language groups when performing executive function tasks, but neuroimaging (electrophysiology or brain imaging) consistently indicates that monolinguals and bilinguals use different brain regions and different degrees of effort to perform these tasks. The clearest language group differences, however, occur in older age where evidence for cognitive reserve from bilingualism is found most clearly in the postponement of symptoms of dementia. Therefore, it is necessary to analyze the factors that mediate these effects, notably, the nature of bilingual experience and the details of the cognitive task being used. The conclusion is that bilingualism is complex but there is evidence for a consistent and systematic impact on cognitive systems.
Cognitive Intervention in Older Adults With Mild Cognitive Impairment
Benjamin Boller and Sylvie Belleville
Individuals with mild cognitive impairment (MCI) experience cognitive difficulties and many find themselves in a transitional stage between aging and dementia, making this population a suitable target for cognitive intervention. In MCI, not all cognitive functions are impaired and preserved functions can thus be recruited to compensate for the impact of cognitive impairment. Improving cognition may have a tremendous impact on quality of life and help delay the loss of autonomy that comes with dementia. Several studies have reported evidence of cognitive benefits following cognitive intervention in individuals with MCI. Studies that relied on training memory and attentional control have provided the most consistent evidence for cognitive gains. A few studies have investigated the neurophysiological processes by which these training effects occur. More research is needed to draw clear conclusions on the type of brain processes that are engaged in cognitive training and there are insufficient findings regarding transfer to activities of daily life. Results from recent studies using new technologies such as virtual reality provide encouraging evidence of transfer effects to real-life situations.
Cognitive Rehabilitation in Mild and Moderate Dementia
Aleksandra Kudlicka and Linda Clare
The number of people living with dementia is growing, and with limited pharmacological treatment options the importance of psychosocial interventions is increasingly recognized. Cognitive rehabilitation is particularly well placed to address the needs of people living with mild and moderate dementia and their family supporters, as it offers a range of tools to tackle the complexity of the condition. It utilizes powerful approaches of problem solving and goal setting combined with evidence-based rehabilitative techniques for managing cognitive impairments. It also incorporates strategies to address emotional and motivational aspects of dementia that may affect a person’s well-being. It is provided on an individual basis, usually in people’s homes, making it directly applicable to everyday life. It is also genuinely person-centered and flexible as the therapy goals are agreed in a collaborative process between the therapist, person with dementia, and family members. Cognitive rehabilitation does not claim to address underlying pathology, but instead focuses on a person’s functional ability and enjoyment of life. Evidence for effectiveness of cognitive rehabilitation in the context of mild and moderate dementia, mostly Alzheimer’s disease (AD), is gradually accumulating with a number of randomized control trials demonstrating that people with mild and moderate dementia can significantly improve their functioning in targeted areas. For example, the GREAT trial with 475 people with mild to moderate Alzheimer’s, vascular, and mixed dementia completed in 2017 in the United Kingdom demonstrated that cognitive rehabilitation improves everyday functioning in relation to individual therapy goals. There is a growing interest in cognitive rehabilitation and the focus shifts to extending evidence to less-common forms of dementia, particularly in people with non-amnestic presentation. Future efforts need to concentrate on promoting the approach and optimizing application in real-life settings with the aim of maximizing benefits for people living with dementia and their families.
Cognitive Reserve in the Aging Brain
Michael J. Valenzuela
Cognitive reserve refers to the many ways that neural, cognitive, and psychosocial processes can adapt and change in response to brain aging, damage, or disease, with the overarching effect of preserving cognitive function. Cognitive reserve therefore helps to explain why cognitive abilities in late life vary as dramatically as they do, and why some individuals are brittle to degenerative pathology and others exceptionally resilient. Historically, the term has evolved and at times suffered from vague, circular, and even competing notions. Fortunately, a recent broad consensus process has developed working definitions that resolve many of these issues, and here the evidence is presented in the form of a suggested Framework: Contributors to cognitive reserve, which include environmental exposures that demand new learning and intellectual challenge, genetic factors that remain largely unknown, and putative G × E interactions; mechanisms of cognitive reserve that can be studied at the biological, cognitive, or psychosocial level, with a common theme of plasticity, flexibility, and compensability; and the clinical outcome of (enriched) cognitive reserve that can be summarized as a compression of cognitive morbidity, a relative protection from incident dementia but increased rate of progression and mortality after diagnosis. Cognitive reserve therefore has great potential to address the global challenge of aging societies, yet for this potential to be realized a renewed scientific, clinical, and societal focus will be required.