A figurative proverb test for dementia: rapid detection of disinhibition, excuse and confabulation, causing discommunication

Language in Amnestic Mild Cognitive Impairment and Dementia of Alzheimer’s Type: Quantitatively or Qualitatively Different?

Background/Aims: The purpose of this study was to explore language differences between individuals diagnosed with amnestic mild cognitive impairment multiple domain (aMCIm) and those with probable Alzheimer’s disease, with a goal of (i) characterizing the language profile of aMCIm and (ii) determining whether the profiles of dementia of Alzheimer’s type (DAT) and aMCIm individuals are on a continuum of one diagnostic entity or represent two distinct ­cognitive disorders. Methods: Language data from 28 patients with consensus diagnosis of aMCIm and DAT derived from a retrospective chart review were compared to that of healthy controls. Results: A non-parametric statistic established that there was no significant difference between groups in age, years of education or duration of symptoms and that expressive language was found to be relatively intact in both patient groups. In contrast, both groups exhibited significant impairments on receptive language tests and on linguistically complex tasks that rely on episodic memory and executive functions. Individuals with aMCIm and DAT present with configurations of language features that are largely in parallel to each other and reflect predominantly quantitative differences. Conclusion: Language tests provide an important contribution to the diagnostic process in their capacity to identify language impairments at an early stage. Understanding the nature of language decline is critically important to the intervention process as this information would inform cognitive intervention approaches aimed at promoting quality of life in people living with MCI and dementia.

The importance of being apt: metaphor comprehension in Alzheimer's disease

We investigated the effect of aptness in the comprehension of copular metaphors (e.g., Lawyers are sharks) by Alzheimer's Disease (AD) patients. Aptness is the extent to which the vehicle (e.g., shark) captures salient properties of the topic (e.g., lawyers). A group of AD patients provided interpretations for metaphors that varied both in aptness and familiarity. Compared to healthy controls, AD patients produced worse interpretations, but interpretation ability was related to a metaphor's aptness rather than to its familiarity level, and patients with superior abstraction ability produced better interpretations. Therefore, the ability to construct figurative interpretations for metaphors is not always diminished in AD patients nor is it dependent only on the novelty level of the expression. We show that Alzheimer's patients' capacity to build figurative interpretations for metaphors is related to both item variables, such as aptness, and participant variables, such as abstraction ability.

Non-literal language deficits in mild cognitive impairment

BACKGROUND

Verbal language deteriorates in Alzheimer's disease, contributing to dramatic disturbances in the ability to communicate. The presence of language disturbances may be detected at earlier phases of the neurodegenerative process, like mild cognitive impairment (MCI). In daily verbal interactions, people mostly use literal language, but sometimes they employ non-literal language, which requires listeners to interpret messages beyond the plain meaning of the words and can be quite demanding. In the present study, we tested the hypotheses that patients with MCI may have deficits in non-literal language, and these deficits are more pronounced than deficits in literal language.

METHODS

Participants were recruited in a private memory clinic and senior universities. General cognitive evaluation included a comprehensive neuropsychological battery, the Mini-Mental State Examination, and the instrumental activities of daily living scale. Literal language was assessed with the semantic decision test, Token Test, and literal text comprehension test, and non-literal language with the proverbs comprehension, idiomatic expressions and non-literal text comprehension tests.

RESULTS

Fifty-two participants with MCI and 31 controls were recruited. Patients with MCI had lower scores in all complex language tests, both literal (Token Test, semantic decision and literal text) and non-literal (proverbs, idiomatic expressions, and non-literal text), than the controls; the difference in literal text score was marginally significant. As much as 69% of MCI participants had deficits (performance below 1.5 SD of the mean) on at least one of the complex language tasks. Deficits were more frequent on the proverbs comprehension and semantic decision tests, and the deficits on these tests did not significantly differ from that on the Token Test.

CONCLUSION

Patients with MCI are hindered in understanding complex language, both literal and non-literal. In daily living, these complex language deficits could compromise effective verbal interactions with the others. Amelioration of these deficits should be an important intervention target as part of a comprehensive rehabilitation strategy for patients with cognitive decline.

Communicative competence in Alzheimer's disease: metaphor and sarcasm comprehension

The purpose of this study was to evaluate the deficits of metaphor and sarcasm comprehension in Alzheimer's disease (AD), as pragmatic interpretation such as metaphor and sarcasm comprehension is required in social communication. A total of 31 young normal controls, 104 aged normal controls (ANC), 42 patients with amnesic mild cognitive impairment (aMCI), and 30 patients with mild AD were evaluated by Metaphoric and Sarcastic Scenario Test, which consists of 5 metaphoric and 5 sarcastic questions with 5 answer choices. Scores were analyzed using the repeated measures analysis of variance (metaphor/sarcasm vs 4 participant groups). Sarcasm comprehension, which requires second-order Theory of Mind (ToM), started to deteriorate in ANC, and metaphor comprehension, which requires first-order ToM, started to deteriorate in aMCI, and both deteriorated as disease progressed. Literal interpretation of pragmatic language is characteristic in patients with mild AD. Such misinterpretation would result in social miscommunication, even if they still retained semantic-lexical competence.

Pitfall Intention Explanation Task with Clue Questions (Pitfall task): assessment of comprehending other people's behavioral intentions in Alzheimer's disease

BACKGROUND

In Alzheimer's disease (AD) patients, deficits in contextual understanding and intentions/beliefs of other people (theory of mind; ToM) cause communication problems between patients and caregivers. To evaluate deficits of contextual understanding/ToM, we developed the Pitfall Intention Explanation Task with Clue Questions (Pitfall task).

METHODS

We recruited 26 healthy older adults in clinical dementia rating (CDR) 0, and 62 outpatients: 12 with amnestic mild cognitive impairment (aMCI) in CDR 0.5; 36 mild AD in CDR 1; and 14 moderate AD in CDR 2. The Pitfall task consists of a single-frame cartoon that shows a character's intention and seven serial questions that provide clues for contextual understanding/ToM.

RESULTS

The total score (0-7) was decreased with progression of AD (CDR 0, 5.4 ± 2.6; CDR 0.5, 3.7 ± 2.7; CDR 1, 1.9 ± 3.1; CDR 2, 0.0 ± 0.0; respectively). In CDR 0, two-third of the participants responded correctly without clue questions. In CDR 0.5, one-third of the participants responded correctly without clue questions, and half of them understood with the help of the clue questions. In CDR 1, one-fourth of the participants responded correctly without clue questions, and the clue questions did not increase the correct response. In CDR 2, none responded correctly. Additionally, the Pitfall task provided the chance for patients' families to observe patients' responses.

CONCLUSION

Contextual understanding/ToM, a kind of social cognition, was impaired with progression of AD. The Pitfall task evaluates the function quickly with low burden for memory function, and may provide helpful clues for caregivers to achieve good communication with AD patients.