In the new text Cognition, Language and Aging, edited by Heather Harris Wright, the paths of cognition, psycholinguistics, and neurolinguistics merge into a succinct nine chapters of informative analysis. The importance of synthesizing the connections between language and cognition in older adults has grown due to a shift in the world’s aging population. According to the World Health Organization (2015), the adult population aged sixty and older will increase from 900 million in 2015 to nearly 2 billion by 2050. The predicted rapid increase in the older population calls for a close examination of the physical, psychological, and social changes accompanying older age. The book overall has a focus on the interconnectedness of cognition and language, which enables a clear discussion of cognitive–linguistic abilities themselves down to the cortical level.
Wright has opted to include notable areas of language and cognition historically implicated during aging, with language processing (i.e., language production, language comprehension, and reading) and corresponding cognitive abilities (i.e., executive functioning, working memory, and attention) as the specific focus. She outright describes the interdisciplinary nature of age-related changes in language and cognition and states that an interdisciplinary lens is necessary when considering both mechanisms and implications. Importantly, distinctions are made throughout the chapters and pointed out by the editor herself in Chapter 1, which emphasize the fact that production, comprehension, and reading do not usually mirror each other in their decline; rather, some individuals may present with notable declines in one area and intact or superior abilities in another area that are retained into very old age. On a related note, the often grim portrait of aging and cognition that is normally painted is not present in this text; instead, declines in areas of language and cognition are offset by evidence on how older adults match with or excel compared to their younger counterparts, such as in the use of compensatory strategies in language comprehension described by Gayle DeDe and Jessica Knilans Flax in Chapter 5. Moreover, sensory and motor changes, such as decreased visual acuity and hearing deficits, are discussed in several of the chapters as important contributing factors to changes in carrying out cognitive and linguistic tasks during aging. The book concludes with a more in-depth discussion on social aspects of aging and how they relate to and compound the cognitive and linguistic changes experienced by older adults.
Although the chapters vary significantly in their foci, the aforementioned themes are a uniting force. Each chapter begins with a summary paragraph that briefly describes the chapter’s focus, and ends with future directions. The future directions within each chapter offer students an exciting look into what could be pursued in these varied areas. The book is described as an ‘advanced text’, and is suitable for graduate students in any of the subfields named in Chapter 1, such as linguistics, psychology, and neuroscience. Chapters of the book could also be selected in tandem with outside seminal papers to emphasize desired areas of study.
Chapter 1, written by the editor and Amy Henderson, includes an introduction to the text and general information on cognition, language, and aging, as well as a brief outline of the successive chapters’ contents. In the substantial second chapter, Lise Abrams and Danielle K. Williams delve into the common cognitive annoyance known as the Tip-of-the-Tongue (TOT) phenomenon. Everyone has experienced this state of temporary word retrieval difficulty, characterized by knowing the characteristics of a word, such as the first letter, but being unable to retrieve and express it. Tip-of-the-Tongue states are experienced by older adults at a much higher rate than other age groups. Building on early work by William James (Reference James1893) and later Alan Brown and colleagues (see Brown, Reference Brown2012), the chapter introduces two sets of potential hypotheses as to why the phenomenon occurs especially often in older age, comparing inhibition models (i.e., the desired word is blocked by a more easily retrieved word) and models that suggest a problem in lexical selection being translated into phonological encoding (e.g., transmission theories). Complementary brain imaging and behavioral studies are provided during discussion of important factors influencing TOT states in older age, including word frequency, neighborhood effects, and syllabic effects. Seminal studies such as those by Cohen and colleagues describing the Baker–baker paradox in proper name retrieval (Cohen & Burke, Reference Cohen and Burke1993; Cohen & Faulkner, Reference Cohen and Faulkner1986), a section on priming studies, and discussion on TOT in pathological aging (e.g., during Alzheimer’s disease) round out the current evidence regarding this frustrating but common phenomenon that increases as we age.
Chapter 3, by Andrea Marini and Sara Andreetta, focuses on age-related changes in language production from a joint psycho- and neurolinguistic perspective. First, a concise explanation of psycholinguistic production theories is provided, including theories such as Levelt’s (Reference Levelt1989) that postulate conceptual, formulation, and expression stages in normal production, and during which, in abnormal production, difficulty can occur. The authors next describe the gradual decline in production abilities during aging, including the effects of changes in executive functioning associated with planning and topic maintenance. The authors cite overall slowed processing time as a significant factor in production difficulty during aging, although text comprehension remains resistant to aging effects. Similarly, lexical knowledge continues to increase with age, while retrieval issues such as TOT states become more problematic. The authors point out that both the microlinguistic (i.e., intrasentential) and macrolinguistic (i.e., intersentential) levels of production may be affected by aging, although discourse production in text by older adults may be characterized by high structural ability and lower coherence. The chapter concludes with a discussion of the neural bases of production, including structural correlates of production, such as the ever-important frontal regions involved with planning speech and inhibiting irrelevant responses, which also happen to significantly atrophy during aging.
In Chapter 4, Steven Kintz, Gerasimos Fergadiotis, and Wright describe discourse production changes during aging more in depth. They focus on individuals’ lexical diversity and global coherence as the more significant factors affecting discourse from the perspective of the interactive-construction discourse model (Kintsch & van Dijk, Reference Kintsch and van Dijk1978). The model describes an interactive representational system comprised of four levels: surface (i.e., phonemic and morphemic levels), semantic (i.e., conceptual meaning), situational (i.e., conceptual relationships), and structural (i.e., temporal or sequential organization). Memory is implicated as a major factor in maintaining both local and global coherence during discourse production: short-term memory for utterances themselves and long-term memory for cross-utterance maintenance of coherence. Statements about changes in cognition may explain why coherence declines during aging. Although the time taken to produce discourse may increase with age, lexical diversity is identified by the authors as a difficult-to-synthesize but potentially promising area that may be resistant to decline during aging.
Chapter 5 is written by Gayle DeDe and Jessica Knilans Flax and focuses on changes in comprehension during aging. The authors discuss how age-related changes in syntactic parsing may result in effects such as slowed word recognition during online tasks, an effect that has been shown to be compounded by decreased word frequency. Auditory effects of slowed word recognition have also been demonstrated, which the authors point out may be due to the interaction between sensory and cognitive factors in auditory processing. They also discuss how older adults’ performance on offline tasks such as comprehension accuracy may decline due to factors such as increasing sentence complexity (Obler, Fein, Nicholas, & Albert, Reference Obler, Fein, Nicholas and Albert1991). More recent studies point to the crucial factor of working memory ability as a defining characteristic in successful sentence processing. Sections on changes in sensory abilities such as vision and audition included by the authors speak to the continued interaction of physical and cognitive modalities during aging. Importantly, the chapter includes a substantial section on compensatory strategies used by older adults during comprehension, which have been studied by researchers such as Keith Rayner and colleagues (Rayner, Reichle, Stroud, Williams, & Pollatsek, Reference Rayner, Reichle, Stroud, Williams and Pollatsek2006), and have been characterized by older adults using their experience with language to predict (sometimes correctly, sometimes incorrectly) future words in a sentence. This has been tied to older adults’ more frequent use of heuristics during processing.
David E. Copeland, Nicole J. Bies-Hernandez, and Kris Gunawan discuss the role of cognition in models of age-related changes in language in Chapter 6. The focus of the chapter lies in examining which abilities decline and which are maintained during aging, especially in relation to how they affect the use of mental models. Salthouse’s (Reference Salthouse2012) review on cognitive abilities declining with age is the cornerstone for discussion regarding slowed processing speed, working memory, and inhibition. Span tests and their relation to comprehension abilities are discussed at length, as well as work on event and situation models. The authors discuss the fact that older and younger adults access situation models similarly, although there is some evidence that older adults may have more difficulty with aspects such as new character integration, presumably due to working memory deficits. The authors also provide trends in older adults’ inferential and emotional processing during comprehension, such as the fact that older adults tend to focus more on positive information. Studies on stereotypes and reasoning are also summarized, as well as age-related changes in event processing.
Reading is discussed at length in Chapter 7, which is written by Peter C. Gordon, Matthew W. Lowder, and Renske S. Hoedemaker, and contrasts with other abilities in that reading ability is largely retained throughout older adulthood. Of special importance is the discussion of the continuation of reading as an older adult in order to maintain independence in everyday life, as well as engaging in this cognitively active task that may serve as a protective factor over time. The authors point out the multiple factors contributing to older adults demonstrating slower reading speed, such as decreased cognitive processing overall, and changes in visual acuity and oculomotor control. Even so, the authors report that eye movements themselves during the skilled reading process remain similar to younger adults, although older adults do show higher instances of regressive saccades and longer average saccades (likely related to visual acuity changes). The authors also discuss how both intact crystallized and changing fluid intelligence during older age may affect reading, such that crystallized intelligence contributions such as print exposure may serve as compensatory strategies.
Chapters 8 and 9 are somewhat different compared to the rest of the book and touch on two areas that will prove to be especially useful moving forward. While the language processing literature is well established and essential for understanding age effects, considerations regarding individual differences as discussed in Chapter 8 and social effects on language and cognition as described in Chapter 9 are vital in our larger understanding of the bigger picture for older adults’ functioning. Chapter 8, written by Jennifer A. Margrett, Peter Martin, John L. Woodard, and Leonard W. Poon, focuses specifically on the oldest old (adults aged 90 and older). The authors discuss the importance of understanding the heterogeneity of the oldest old, especially as it relates to healthcare, research, and policy needs. They point out that it is reasonable to assume that sixty-year-olds in older adulthood comprise a very different sample of individuals than those aged ninety and older, although the term ‘older adulthood’ is applied to all of these individuals. Cohort and generational differences among older adults are also an important point to consider. The authors also point out differences in assessing cognition in the oldest old, and how difficult it may be methodologically. Notably, with increased age comes increased risk of dementias and other neurodegenerative diseases, which the authors contrast with cognitive symptoms of normative aging. The authors call for further study of cognitive, linguistic, and social occurrences in the group of highly varied individuals known as the oldest old.
In Chapter 9, Boyd Davis and Margaret Maclagan shift the book’s focus to social aspects of older adults’ language and considerations regarding changes in pragmatic abilities. The chapter is written from a sociolinguistic perspective and provides a qualitative look at pragmatics. The authors discuss older adults’ use of narrative, which contributes to feelings of identity, as well as cultural tradition that can affect individual differences in language. The authors also bring to light the effect of gender on language and aging, including how it has helped structure social status and identity in older adults. A section on how language is used to describe older adults in widespread media emphasizes the importance of word choice on how we have shaped varied perceptions of older adults. The authors also provide case-study examples to illustrate differences in older adults’ use of extenders and other linguistic devices.
Collectively, the areas of age-related changes discussed in the book suggest a need for interdisciplinary research moving forward. Our knowledge of aging can be more complete when applying not only behavioral measures of language processing, but also integration of brain imaging technology and qualitative reports of older adults’ experiences themselves. The interactive nature of the systems involved in language and cognition makes it difficult to tease them apart; the point of view expressed in the text is that dissociation is not desirable or authentic. Notably, the inclusion of discussion on social changes unique to older adults provides an often-absent aspect of research that must be considered when examining aging’s effect on older adults’ cognitive and linguistic abilities. The influence that aging can have on social communication and pragmatics is significant. In addition, the issue of population heterogeneity will be key in considering how to most effectively understand, treat, and support older adults. Wright seeks to paint a picture of how important this knowledge will be not only currently but also in the future as the older population continues to grow.
