Effects of working memory deficits on the communicative functioning of Alzheimer’s dementia patients

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Abstract

Individuals with Alzheimer’s disease experience frontal lobe pathology and deficits in working memory processes are well documented. Less documented is how various working memory deficits impact communicative functioning. The performance data of individuals with mild and moderate Alzheimer’s dementia on five tests of language comprehension and four tests of language expression are presented and discussed in the context of possible contributions from impaired working memory functions. The argument is advanced that diminished scores on tests of language comprehension and production result primarily from attenuated span capacity, difficulty focusing attention, encoding, and activation of long-term knowledge rather than from loss of linguistic knowledge. Techniques that may advantage Alzheimer’s patients in the comprehension and expression of linguistic information are discussed.

Learning outcomes

(1) Readers will become familiar with the typical functioning of individuals with Alzheimer’s disease on common linguistic expression and comprehension tasks. (2) Readers will become familiar with the distinction between language knowledge and performance and its importance in understanding the cause of communication breakdowns in individuals with Alzheimer’s disease. (3) Readers will become familiar with techniques that may facilitate the communicative functioning of individuals with Alzheimer’s disease.

Section snippets

Communicative function and working memory

To understand the impact of WM deficits on communicative functioning, it is appropriate to first consider what occurs intellectually in normal language expression and comprehension. The genesis of communication is an individual’s intention to share information. A linguistic representation must be activated, sequenced, and programmed for production. As the information is shared, it is monitored for accuracy. For comprehension to occur, another person must perceive the information and hold it in

Impairment of WM and communicative function in Alzheimer’s disease

Few, if any, researchers have addressed this question directly because of its complexity. Knowledge of the extent and distribution of Alzheimer’s neuropathology and integrity of intellectual functioning is necessary to separate the contribution of WM deficits on communicative functioning from the impact of other cognitive deficits. It is extremely difficult to document the extent and distribution of neuropathology in individuals with AD while they are alive. Also problematic is separating the

Techniques for facilitating communicative functioning of individuals with Alzheimer’s dementia: what science suggests

Simply said, techniques that facilitate function are those that control the amount of information that must be maintained in consciousness, simplify the search of long-term memory and the ways information must be manipulated. The techniques recommended in this section have been used by cognitive scientists studying the facilitation of learning in healthy individuals.

Summary

Frontal lobe pathology in individuals with AD diminishes working memory by reducing span capacity, limiting attention, and disturbing search and retrieval functions. Because language comprehension and expression rely on the integrity of these functions, individuals with AD perform poorer than normals on myriad communication tasks. The degree of their impairment is a function of the complexity of the information processing required. Clinicians may improve communicative function by reducing

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