Keywords

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3.1 Summary and Learning Goals

Gerontopsychology explores the effects of ageing on the brain and on personality. It explores how cognitive functions change with ageing and how individuals can cope with such change in order to maintain a high quality of life. An important age-related cognitive change is dementia, which is a disease that causes people to lose their memory and their capabilities. This chapter describes how common dementia is across Europe and it discusses what we can do to prevent it.

After reading this chapter, you should be able to:

  • Explain what fluid and crystallized intelligence are

  • State how fluid and crystallized intelligence change with old age

  • Name four explanations for age-related changes in fluid and crystallized intelligence

  • Explain why older people can have a good quality of life even when their cognitive health declines

  • Describe what people can do to prevent dementia

3.2 What is Gerontopsychology?

Gerontopsychology is the field of psychology which investigates stability and changes of behaviour and experience of human beings in their later life. It assumes that processes of development and change in the course of ageing are not necessarily unidirectional decline processes, but rather can be multidirectional or stable. This is in contrast to the time gerontology became established as a discipline, when declines were the defining features of ageing or senescence. In contrast, gerontopsychology focuses on the developmental potentials of ageing individuals’ personal and environmental resources. Thus, there is a shift in research from pathological to healthy ageing.

3.3 Central Theories and Concepts in Gerontopsychology

In the following, the basic concepts and theories of gerontopsychology will be discussed, concentrating primarily on aspects of cognitive ageing. Two major concepts in this area are the concepts of cognitive health and of quality of life. Both terms refer to functional concepts of competence, i.e., they describe and explain how elementary cognitive and non-cognitive processes are actively managed by individuals to achieve stability in such complex functional outcomes as cognitive health and wellbeing. Cognitive health refers to “not just the absence of disease, but rather the development and preservation of the multidimensional cognitive structure that allows the elderly to maintain social connectedness, an ongoing sense of purpose, and the abilities to function independently, to permit functional recovery from illness or injury and to cope with residual functional deficits” (Hendrie et al. 2005, p. 1). Quality of life (QOL) refers to the “… integration of multiple subjective representations of the functionality of ones’ resources. That is, QOL … is higher, the more strongly individuals represent their resources as being principally functional to perform complex activities that serve individually central life or goal domains” (Martin et al. 2012, p. 35). Thus, both concepts are situated in the individual and environmental context and imply that next to the characteristics of individual resources, influences such as the integration into social structures and the adaptation to different environments and situations have to be taken into consideration when measuring performance.

Cognition is composed of multiple abilities which demonstrate different developmental courses (multidimensionality), and the mean levels of most cognitive abilities decline differentially across adulthood (Park et al. 1996). Cognitive abilities can generally be categorized into two types of intelligence. In fact, a multitude of studies have reported age-related declines in measures of fluid intelligence such as speed of processing, working memory, cued and free recall, reasoning, or verbal fluency. In contrast, performance in tests of crystallized intelligence (Horn and Cattell 1967), i.e., experience—and culture-dependent non-speeded performances such as vocabulary normally increases quickly after mastering language and then more slowly across the lifespan well into very old age (multidirectionality). That is, despite the general tendency of a decrease in cognitive abilities, some individuals maintain or even increase their cognitive abilities in old age. More generally, cognitive ageing can be characterized by interindividual differences, generational differences, multidimensionality, and multidirectionality (Baltes and Schaie 1976).

Currently, four main theories are used to explain the differential age-related changes in measures of fluid and crystallized intelligence. Salthouse (1991, 1996) proposed the processing speed theory which assumes that the age-related differences in performance are the consequence of a general decrease in speed of performing mental operations. According to Salthouse’s theory the slowing in processing speed is related to all aspects of cognition whether they have a speed component or not (Park 1999). A similar theory is the one developed by Craik and Byrd (1982). They argue that the age-related decline in cognitive functioning is due to reduced processing resources. Processing resources describe the ability to self-initiate processes and to manipulate and process information and are best measured by working memory tasks. Although both theories explain age differences in more complex cognitive performances requiring the integration of multiple elementary cognitive processes, it is only speed that accounts for the variance in less effortful memory tasks such as spatial memory (Park et al. 1996). Hasher and Zacks (1988) see the decline in inhibitory control, i.e., the ability to suppress currently irrelevant informations or behaviours, as cause for cognitive deficits associated with age. According to this theory, older individuals have more problems to inhibit prior information from working memory, thus reducing the “work space” for new material (Glisky 2007). Another approach is to relate changes in sensory functions such as visual and auditory acuity to age-associated changes in cognitive function. Lindenberger and Baltes (1997) found that both, visual and auditory functions together can account for a large amount of the variation in intellectual functioning. These findings were the base of the their “common cause hypothesis” stating that sensory function, as a general marker of the intactness of the neurobiological architecture is fundamental for all cognitive functions and has, when it declines, a generally negative effect on all cognitive abilities (Park 1999).

All cognitive ageing theories can account for age differences in cognitive abilities. However, they differ in focusing on basic mechanisms such as processing speed or sensory functions that are closely linked to age-related changes in neuronal structures or in focusing on complex performances such as inhibitory control that allow the use of task-specific compensatory strategies and processes. Whereas the former can be influenced by large amounts of practice, but show hardly any transfer to untrained tasks (e.g., Willis et al. 2006), the latter can be improved through strategy trainings and adaptive interventions needing relatively small amounts of practice and promising a transfer to untrained tasks (e.g., Borella et al. 2010).

3.3.1 Multidimensionality, Multidirectionality, Individual Differences and Generational Differences

Schaie (1974) proposed that most of the age differences in the performance of cognitive abilities result from cohort differences rather than age differences and that “… presumed universal decline in adult intelligence is at best a methodological artifact” (Schaie 1974, p. 802). This suggests that factors other than age and practice in specific cognitive skills such as generational differences in schooling or use of technology should also be considered when looking at the development of cognitive abilities across the lifespan (Schaie 2005).

3.3.2 Cognitive Health

A concept which gained more and more interest in gerontopsychological research in the last few years is the concept of cognitive health. The term refers to individuals’ ability to adapt their cognitive performance to changes in the environment and focuses on the ability to stabilize cognitive functioning. Whereas most existing cognitive ageing research focuses on the prediction of cognitive decline or on interventions aiming at improving impaired cognitive performance, cognitive health research examines which factors may support stable levels of cognitive functioning.

An important term in conjunction with cognitive health is plasticity. As healthy cognitive development is characterized by successful adaption to an individual’s environment, successful adaption of a person in turn leads to behavioural as well as neuronal plasticity. Hence, the concept of cognitive health and cognitive plasticity are closely interconnected. Willis et al. (2009) define cognitive plasticity as individuals’ latent cognitive potential or individuals’ cognitive capacity under certain specified conditions. Since there is a close relationship between neuronal activation and cognition for specific cognitive abilities, cognitive plasticity should be observable in both neuronal as well as behavioural data. However, the exact relationship between them is still unclear. Some researchers have demonstrated that in older people there are only small or even negative effects between cognitive performance and the reductions in cortical volume (Rodrigue and Raz 2004). According to Stern (2002), for instance, cognitive plasticity can exist despite the fact that neuronal plasticity has been compromised (cognitive reserve).

In contrast to the passive models of brain reserve which see reserve as the result of brain size and synapses, the theory of active cognitive reserve states that the brain actively copes with or compensates for pathology. Concerning plasticity this means that the brain is able to utilize brain networks more efficiently or acquire new compensatory brain networks. This phenomenon has been observed in individuals with higher levels of intelligence and educational and occupational achievement. Whereas people with lower intelligence demonstrate functional deficits after brain damage, people in the same situation with a higher level of intelligence can maintain their performance level. This concept of cognitive reserve can be transferred to non-pathological ageing. Since the brain is subject to various age-associated decomposition processes, an active lifestyle can build up cognitive reserve, which allows long-term plasticity even in old age (Stern 2002).

3.3.3 Quality of Life

Quality of life (QOL) is increasingly suggested as the central outcome variable in research on health-improving or preventive interventions in old age (e.g. Garratt et al. 2002). This is based on the observation that objective improvements in resources, performances, and functioning often do not lead to similarly large improvements in levels of self-reported life satisfaction, wellbeing or QOL (e.g., Clark et al. 2012), and that low levels of resources alone do not necessarily motivate individuals to use available and affordable interventions and respite services (e.g., Martin et al. 2009).

Although by now a large number of instruments measuring QOL or contributing factors have been developed (see Ettema et al. 2005), there is still no firm consensus on the exact definition of QOL. The WHO attempt (The WHOQOL Group 1995) to define QOL as a broad, metadisciplinary construct encompassing medical, psychological, and sociological aspects is helpful in that it gathers different conceptual strands into a shared framework. However, such a broad definition does not clearly separate QOL from similar—but distinct—constructs such as life satisfaction (Diener et al. 1985) and wellbeing (Ring et al. 2007).

There are currently two main approaches to determine QOL in old age: (a) the sQOL approach to measure the subjective evaluation of an individual’s overall life situation and QOL, and (b) the oQOL approach to infer QOL of an individual from the outside, e.g., by measuring health impairments. The former approach rests on the assumption that QOL is by definition a subjective state and, consequently, must be measured through subjective statements. Here, the reported sQOL is often understood to reflect the discrepancy between an individual’s current life situation and some subjectively ideal or optimal life situation. Examples of such measures are the SWLS (“Satisfaction with Life Scale”; Diener et al. 1985), the SEIQoL-DW (“Schedule of Evaluation of Individual Quality of Life—Direct Weighting”; Hickey et al. 1996) or the EUROHIS-QOL (Power et al. 2005). The instruments differ in determining sQOL either on the basis of global life satisfaction items (SWLS), or, via domain-specific satisfaction items (EUROHIS-QOL, SEIQoL-DW). However, the type and amount of domains that are used to define sQOL (e.g., physical health, environment, social relationships, autonomy, or spirituality) depend on the particular instrument and the population to be examined, thus making direct comparisons between different instruments difficult.

The second approach, which uses objective measures of QOL, is based on the assumption that oQOL is higher, the better—or less impaired—the given resources of a person are (independent of any subjective judgement). This way, oQOL can be determined more reliably, without individual report biases, and without requiring a statement from the person whose oQOL is being measured, such as in the case of dementia. However, it hardly takes into account interindividual differences in the functionality of available resources to achieve individually meaningful goals. What is more, the combined measurement of resources or resource impairments, is often positively labelled “quality of life” when in fact it is no more than a combination of resource impairment measures.

The fQOL model (Martin et al. 2012) defines QOL as the integration of multiple subjective representations of the functionality of ones’ resources. That is, it assumes that fQOL is higher, the more strongly individuals represent their resources as being functional to perform complex activities that serve individually central life or goal domains. This model can be distinguished from the existing approaches: First, despite using subjective assessments, these are not satisfaction judgements, but rather functionality judgements. That is, a person can have similar levels of sQOL with either high or low levels of objectively measured resources as long as the current levels of resources are represented as equally functional to achieve personally meaningful goals. If, for example, physical abilities are declining, one may no longer be able to run a farm to serve the goal of being close to nature, but one may be able to plant a small garden to achieve the same goal. If individuals manage to represent their physical abilities as equally functional to achieve the desired goal (and not to perform the same activity as before), their fQOL is stable.

3.3.4 Individual Coping Strategies

Cognitive health and QOL of a person depend strongly on the personal and environmental resources and on individuals’ ability to adapt to different environments and situations. One self-regulatory mechanism to achieve a successful and healthy personal development and adaption is the selective optimization with compensation (SOC) strategy (Baltes and Baltes 1990). Selection refers to the process by which individuals choose tasks that are of high individual importance and that match their abilities. It is furthermore subdivided into elective selection (ES) which is guided by preference or social norms and loss-based selection (LS) which refers to a shift in personal goals due to a loss of internal or external resources. This means that the process of selection leads to a narrowing of alternative options so that persons concentrate on a reduced range of achievable goals. Because of the loss of resources in old age, the number of achievable goals usually decreases with increasing age (Baltes 1997). To achieve a selected goal, persons have to optimize their strategies by acquiring, refining and deploying resources. Optimization can be realized through training, learning new skills and high motivation (Staudinger and Bowen 2010). Compensation refers to acquisition and utilization of alternative means to reach given goals and keep performance at desired levels in face of actual or anticipated decreases in resources (Marcoen et al. 2007). A correct utilization of the SOC strategy should lead to better health, successful ageing and improved relationship quality (Freund and Baltes 2002).

Another self-regulatory approach related to the SOC concept, but more specifically related to cognitive functioning is the concept of resource orchestration. It assumes that performance in complex cognitive tasks such as job performance or problem solving requires the use of multiple cognitive abilities to various degrees in the course of performing the task. It requires the dynamic orchestration and timing of multiple skills. Therefore, the maximum performance level in a specific ability is hardly related to performance in a complex behaviour and, thus, improvement in elementary abilities, a typical goal of cognitive interventions, is unlikely to lead to large improvements in the complex, integrated behaviour or to transfer. Interventions using this approach instead define individually meaningful goals, identify the relevant abilities and focus on improving the orchestration process itself, i.e., helping to identify goals, helping to identify relevant abilities, and optimizing decisions when to use particular strategies to achieve the best possible match between variable environmental demands and individual goals (Zöllig et al. 2010).

3.4 What Does Gerontopsychology Tell Us about the Current State of Europe?

The demographic trend of the next years and decades in the more developed regions of the world shows an increasing life expectancy with older adults being the fastest growing group of the population (Dlugosz 2011; UN 2009). Europe currently has the highest median age of the population compared to all other parts of the world (Wancata et al. 2003). This involves numerous challenges for the society, the pension insurance, and the health care systems. One of the biggest challenges is the increase of the prevalence of dementia. Dementia is a disease that causes people to lose their cognitive ability faster than it would occur during the normal ageing process. As a result, people lose their memory, and later also their physical functioning. Between 5.9 and 9.4 % of all individuals aged 65 and older in Europe currently suffer from dementia (Berr et al. 2005) compared to less than 0.1 % in younger individuals (Harvey et al. 2003). Consequently, there is an increase of the prevalence of dementia with advancing age (Jorm and Jolley 1998; Ritchie and Kildea 1995). On average, the estimated prevalence of dementia in the population aged 60 and over in Europe is currently 6.2 % (Alzheimer’s Disease International 2010), 60–70 % of those patients suffering from Alzheimer’s disease (Berr et al. 2005; Bickel 2000). This prevalence rate is comparable to those of other more developed regions like North America or Australia, but is higher than those of other regions like Asia or Africa (Alzheimer’s Disease International 2010). This is not surprising, since the more developed regions are characterized by longer life expectancies. Therefore, the average prevalence rate in Europe reflects the high prevalence of countries in Western Europe (7.2 %), which also have the highest life expectancy, whereas the rates in Central Europe (4.7 %) or Eastern Europe (4.8 %) are lower.

Estimations for the year 2050 assume that the number of dementia diseases in Europe is going to double, and the number in less developed regions is going to more than triple (Alzheimer’s Disease International 2010). Here it becomes important that the life expectancy as well as the prevalence of dementia in Europe and other more developed regions is already comparatively high and in contrast to these regions, the population of the less developed regions is generally going to increase in the next decades, whereas in Europe only those parts of the population aged 60 and more is going to increase and the other parts of the population are expected to decrease. As a result, the ratio of older to younger individuals, especially those at working-age, will considerably increase in Europe. The same also applies to the ratio of demented persons. Were there still 69.4 persons in working-age per one demented person in 2000, this ratio will decrease until 2050 to 21.1 persons (Wancata et al. 2003). Currently, dementia costs in Europe reach 238 billion USD annually, 210 billion in Western Europe alone (Alzheimer’s Disease International 2010). Therefore, it is important to investigate and determine the factors that could contribute to a successful cognitive ageing process and people being able to maintain their functional level up to an old age without developing a dementia disease. On the other hand, it is just as important to arrange for adequate care provisions for those already suffering from dementia and to allow them a self-determined and independent life as long as possible. For that reason, we discuss how individual and environmental resources can contribute to maintaining this functional level and how an adaptation of the environment provides possibilities to live a mostly independent life despite dementia.

3.5 Current Debate in Gerontopsychology: Can We Stop Dementia?

The process of normal ageing generally involves a decline in cognitive abilities, but this does not imply that eventually everyone is losing his or her cognitive abilities or developing dementia. The majority of older adults are able to maintain their functional level up to very old age. To understand why some people suffer from dementia whereas others keep a functional level despite some losses, one must answer the question which individual or environmental resources may support successful cognitive ageing without developing dementia or help to compensate in case some cognitive abilities decrease. Although there are declines in many physical or cognitive resources, social resources and cognitive resources such as knowledge or strategic skills may increase with age. What is more, most resources can be improved through training interventions (Martin et al. 2011). When concerned with cognitively healthy ageing, the focus should, therefore, be on identifying these resources, the way they interact, and the factors that could contribute to strengthen them. Only this way is it possible to determine how the environment can be adapted to be adequate for different states of cognitive health or impairment.

3.5.1 Individual and Environmental Resources

Which are the specific resources and factors and how could they be influenced in a positive way? Clearly, cognitive resources are most relevant and engaging in cognitively demanding tasks should therefore represent one of the most promising strategies. Indeed, it has been shown that cognitive and intellectual stimulation seems to contribute to a cognitively healthy ageing process and prevent dementia (Qiu et al. 2001; Verghese et al. 2003; Wang et al. 2002; Wilson et al. 2002). Education itself is often reported to have a protective effect on dementia (Fratiglioni et al. 2007; Qiu et al. 2001). However, it is not clear if education is able to prevent dementia diseases or if educated people only are clinically diagnosed at a later date because of their capabilities and strategies to compensate for losses for some time. On the other hand, there are also physical conditions such as the absence of diabetes or even nutritional factors that are reported to have a protective effect on dementia (Fratiglioni et al. 2007; Ritchie et al. 2010), just as socially and physically stimulating activities (Fratiglioni et al. 2007; Laurin et al. 2001). However, most of the reported effects are based on retrospective data, whereas causal effects require intervention studies. There are a number of cognitive training intervention studies that could show benefits of training, mainly on the targeted cognitive ability in healthy older adults (Willis et al. 2006). Cognitive trainings are supposed to have a positive effect not only in cognitively healthy older adults but also in risk groups or individuals with mild cognitive impairment (Belleville 2008; Mowszowski et al. 2010) and even in patients already suffering from dementia or Alzheimer’s disease (Buschert et al. 2010). In addition to cognitive training interventions, a series of studies investigated the effect of physical training interventions on cognitive abilities and the progress of dementia. In general, they could show a positive effect of physical trainings on cognitive abilities in older adults (Colcombe and Kramer 2003). Even in individuals with cognitive impairment or dementia physical training improves cognitive function (Heyn et al. 2004), and, therefore, may protect against cognitive decline and dementia (Rolland et al. 2008).

Most training interventions involve a single target domain such as for example physical or cognitive ability. However, it is well established that global cognitive stimulation is more effective than training of specific cognitive functions (Sitzer et al. 2006) and that enriched environments allowing to engage in activities that activate different mental, physical or social skills has been shown to be more beneficial than in one of those activities alone (Karp et al. 2006). Moreover, strengthening of different resources could allow individuals to better adapt and compensate in case of losses in particular domains. Unfortunately, there are only few studies that have investigated the effect of combining cognitive and physical trainings. They have reported a potential long-term effect of combined training interventions on cognitive performance in healthy older adults that is superior to the single trainings (Fabre et al. 2002).

Although there are some additional benefits when training different resources separately, to gain an optimal effect on the functional level of older adults it is not sufficient to improve all these resources separately. In daily life, multiple cognitive and motor resources are often engaged simultaneously. Situations involving the simultaneous recruitment of cognitive and physical resources are usually more difficult to manage for older adults (Theill et al. 2011). Therefore, to maintain or even improve the global functional level, one would have to train different resources simultaneously for the training to correspond with demands in everyday life (for an example see Schaefer and Schumacher 2011). Future research in this area of simultaneous multiple ability trainings that can be integrated into everyday life will be most informative about interventions that may help to maintain high levels of functioning and by definition protect against declines or dementia.

We have argued that cognitive health and Quality of Life as concepts of functional competence are complementary to single ability deficit-oriented models of ageing. Both assume that active ageing can orchestrate the stability of important goal functions of health, productivity, and wellbeing, and that their individual and subjective representation of the goal-relatedness of their behaviour drives the adaptive use of individual and social resources. Evidence for the effectiveness of interventions aiming at simultaneously supporting multiple resources that are dynamically related to complex performance and the stabilization of cognitive health and Quality of Life is now needed to develop interventions that can truly be considered relevant for the everyday lives of ageing individuals.

3.5.2 Adaptation of the Environment

The previous section has demonstrated that even patients with dementia can benefit from cognitively, physically or socially stimulating activities, as they could be able to positively influence the progress of disease. Strengthening these resources should, therefore, be a substantial part of treatment, since patients with dementia are especially at risk to reduce their activities and become socially isolated. But older adults with dementia also have specific housing and care needs due to their physical and cognitive status (Van Hoof and Kort 2009). Depending on the available resources, the environment has to be adapted so that an optimal person-environment fit provides adequate care and allows a self-determined and independent life for as long as possible. However, for an optimal person-environment fit one always has to consider the individual resources and goals of a person concerned, such as general mobility or the current social context situation, but also the presence of other physical or mental diseases that require treatment and care. Only with an individual adaptation a maximum wellbeing of patients can be guaranteed. Which are the care provisions in Europe and do they meet the requirements for an optimal adaptation of the environment?

There are huge differences in the offers for care provisions depending on the country across Europe. On the one hand, there are countries especially in Southern Europe like Greece, Italy or Spain, where the family predominantly provides care (Van Hoof et al. 2009). In this situation, the family usually makes the adaptation of the environment by supporting and taking care of their relatives suffering from dementia. The patients are therefore less frequently institutionalised, but in turn they are often not able to benefit from professional care and the situation could be a burden for the relatives and, as a consequence, for the patients as well. On the other hand, in most of the Western European countries, a collective responsibility exists for people who require intensive forms of care (Van Hoof et al. 2009). Here, although dementia is the major cause for institutionalisation in old age (Aguero-Torres et al. 2001), in the Western European countries the majority of patients with dementia are still cared for at home (De Vugt et al. 2006). Most European governments promote the construction of lifetime homes and different forms of non-institutional living in the own dwelling or assisted-living facilities (Van Hoof et al. 2009). However, in many cases institutional care is inevitable and the goal should then be to arrange these institutions as homelike as possible. One possibility for such care provisions are small-scale living or group living arrangements which can be found in the Netherlands, Belgium, France, Germany, Sweden, or the United Kingdom (Verbeek et al. 2009). These accommodations are characterized by a comparatively small size of six to eight people, and provide 24 h-care and surveillance by one or two staff members (Van Hoof et al. 2009). Some of the rooms are shared such as the kitchen, living room, and in most cases the sanitary units, whereas there are also private areas with patients’ own furniture and goods (Van Hoof et al. 2009). Such living arrangements are advantageous because they provide a homelike living community in combination with intensive professional care and treatment, which can be optimally adapted to the individual needs of the patients. Therefore, care provision should generally provide the adaptation of the environment to the individual needs and available resources of the patients, which in turn leads to different forms of interventions and care, but always support independence and a maximum perceived control for the person concerned.