Discursive measures to assess the evolution of Mild cognitive impaired and Alzheimer’s Disease patients: a scoping review

1.1. Rationale

A number of measures that objectivize the therapeutic effects of speech therapy based on lexico-semantic theories on the discourse of patients with initial to moderate AD are provided through studies in the review by Colliaux et al (2021). However, the authors note that most of the measures are far removed from the ecological and natural constraints of the discourse of the patients received in consultation or accompanied to their homes. In 2018, Mueller and his collaborators insisted on the need to focus exploratory research on the characterisation and elaboration of specific discursive measures. Theoretically valid measures are needed to characterise the language changes of these individuals within the ecological and natural constraints of patient discourse.

Several years before the emergence of these intervention studies, a substantial number of interdisciplinary studies analysing the verbal discourse of people with MCI and AD provided objective information that could be used to characterise a patient's language development over time.

ü From the point of view of clinical research, the aim of this SR is to identify theoretically valid measures to evaluate discourse and thus to commit researchers to this path.

ü From a clinical point of view, the aim of this SR is to identify criteria for the evolution of speech in AD, both from the point of view of intervention and its continuous evaluation.

1.2. Conditions being studied and definitions

Discourse: is an instance of language use that involves a speech act that leads the speaker to use a text (linguistic dimension), a context (sociological dimension), and an intention/interaction (communicative dimension). The production and comprehension of discourse rely on a large number of pragmatic processes. These processes allow to organize the discourse (structuring function) and to relate the mental states of the speakers (expressive function) through constraints that facilitate the interpretation of the discourse such as cohesion and coherence.

Validity: quality of an operational definition; in experiments, the principle of actually studying the variables you want to manipulate or measure

Mesure: systematic estimation of the quantity, size or quality of an observable fact.