The literature on Alzheimer’s Disease (AD) emphasizes the centrality of progressive deficits in memory and other aspects of cognition as the key diagnostic criterion of the disease (DSM-IV-TR, American Psychiatric Association 2000; Reisberg et al. 1982; Helkala et al. 1988). In an effort to conceptualize how progressive impairment proceeds in the illness, cognitive impairment is a central feature of academic models of such disease. For example, Geldmacher’s (2012:130) model of impairment in AD refers to “domains of cognitive impairment”. In this model, “memory” is conceptualized as deficits in learning, semantic knowledge failure, repetitiveness; “executive functioning” is viewed as poor planning, poor judgment, impairment on complex tasks, disinhibition; “orientation” is understood in terms of distorted time sense, “praxis” is defined as ideomotor apraxia, limb-kenetic apraxia; “visual processing” as poor object or person recognition, spatial confusion, impaired directed attention. The definition of “language impairment” is restricted to anomia and difficult word-finding, poor speech content, impaired prosody (Geldmacher 2012:130). A diagnosis of AD requires memory impairment and impairment in at least one other “cognitive domain” (Geldmacher 2012:129). Such models are based on the idea that deficits resulting from synaptic dysfunction and neuronal loss follow a predictable distribution in the brain (Arab et al. 2011) and will result in the total global cognitive decline and total dependence of the AD patient on others.
Language and language decline is sometimes discussed as a discrete, separate capacity of AD decline but it too has been generally treated in global terms as a model of predicting eventual total language impairment (Grand et al. 2011). For example, Blair et al. (2007:241) argue that at early Alzheimer’s, word finding difficulty and circumlocution in conversation are present. Yet, speech deteriorates with disease progression becoming “verbose and circuitous…empty and lacking meaningful content” (Appell et al. 1982). Vocabulary decreases and irrelevancies increase. It becomes difficult to maintain a topic (Mentis et al. 1995). Ultimately, progressive aphasia leads to eventual mutism.
There is also a small literature focusing exclusively on the linguistic aspects of decline in AD and its effect on social interaction. Nevertheless, this literature also posits a uni-linear model of global linguistic decline. According to Wray (2015b), language processing is undermined by damage to the language areas of the brain. NLP features (lexicon, syntax errors) are evident in the natural speech of even early Alzheimer’s patients, as AD persons produce syntactically poorer sentences, mention lesser number of ideas and words, produce redundant, less precise and informative discourse; there is also rare use of the modalizers, and pronouns miss their intended reference, which implies a loss of the semantic cohesion (Boyé et al. 2014:4). The progressive loss of ability to communicate begins with early AD language deficits (word substitutions, aborted phrases), then progresses to comprehension deficits, paraphasic errors, and semantic jargon in mid-to-late stage Alzheimer (Tappen et al. 2002:63). Semantic and lexical speech features are multiple and include stutters, self-corrections, incomplete sentences, a greater number of empty pauses and lesser number of non-empty pauses or a very high percentage of personal pronouns (Boyé et al. 2014). Speech becomes formulaic and the patient might produce appropriate utterances even when there is doubt about whether they are really meant (Wray 2013; Hamilton 1994).
Ultimately, the effect of this loss of linguistic functions has significant social and pragmatic effects; more specifically, social isolation from other speakers. This negative spiral downward is interactive. As language becomes compromised by “short term memory loss, distortions in perception, disturbed semantic representation and disorientation brought on by lost contextual information”, linguistic behavior changes (Wray 2015b). People with [early to mid-stage AD] will apply “their remaining linguistic and communicative resources to rescue the situation, developing strategies for avoiding, compensating for, and covering up their problems”. Nevertheless, as a result of “loss of confidence, depression, altered power relationships, the social construction of AD as an illness, and the discourse contexts in which people with AD find themselves, such as how carers speak to them” (Wray 2015b), declines may be exaggerated due to the individual’s awareness of the problem and resultant frustration, embarrassment, or anxiety, “leading to further withdrawal” (Cohen 1991).
This, in turn, often provokes a negative reaction in caregivers who, in responding to the AD patient’s communicative difficulties, feel discomfort which can then inhibit their attempts to communicate with the patient which further reduces opportunities for the AD sufferer’s meaningful interaction (Hendryx-Bedalov 1999). Comprehension problems and their attempted resolution become products of social interaction and reflect pragmatic impairment (Perkins 2007). According to Tappen et al. (2002:63): “One of the most tragic symptoms of Alzheimer’s disease (AD) is the progressive loss of ability to communicate”. This loss has obvious adverse consequences for the older individual and their loved ones. For the person with AD, sequelae include “isolation, depression, disturbed behavior, and decreased quality of life” (Zanetti et al. 1998). Caregiver stress due to low levels of real communication with the patient is endemic (Wray 2014). The reduction in the AD patient’s capacity for empathic concern (other-centered emotional responses) can also have a negative effect on caregivers and marital relationships especially in later stages of the disease (de Vugt et al. 2003).
Thus, previous models of the decline of cognitive and specifically linguistic capacities in the disease course of AD have all posited a global model of decline as deficits in each of these areas progress to the endpoint of total cognitive decline and mutism. Untreated AD is, as Schioth et al. (2012:7) note, a “devastating disease”. In this article we advocate a model that focuses on pragmatic competence and the loss and re-gaining of cognitive/pragmatic functions.
