ki:elements

Cross-Linguistic Free-Speech Markers of Neuropsychiatric Symptoms in Individuals at Risk for Alzheimer’s Disease

Zampeta-Sofia Alexopoulou, Gonzalo Pérez, Hali Lindsay, Johannes Tröger, Nicklas Linz, Philippe Robert, Loreto Olavarría, Patricia Lillo, Daniela Thumala, Cecilia Okuma, Mauricio Cerda, Fernando Henríquez, Andrea Slachevsky, Valeria Manera, Adolfo M. García, Alexandra König

*Poster presented at AAIC 2026

Background: Neuropsychiatric symptoms (NPSs) are important prognostic factors in

Alzheimer’s disease (AD). Speech analysis is a promising approach for capturing NPSs in

early-AD stages, including mild cognitive impairment (MCI). However, existing evidence

largely derives from single-language cohorts, limiting cross-linguistic generalizability. Here,

we address this gap by examining speech-derived markers of NPSs across two linguistically

and culturally distinct cohorts.

Methods: We analyzed data from a French-speaking cohort from France (39 with MCI, 30

healthy controls(HC)) and a Spanish-speaking cohort from Chile (106 with MCI, 84 HC).

Participants completed two standardized free-speech tasks, recalling one positive and one

negative autobiographical story. Audio-recordings were preprocessed using TELL’s v.2.0

pipeline. Acoustic (i.e. spectral, frequency) and linguistic (i.e. syntax, sentiment) features

were extracted using ki:elements’ AI-driven pipeline. NPSs severity was assessed with the

Neuropsychiatric Inventory (depression, anxiety, apathy). Within-tasks/diagnostic groups,

feature-values were compared between languages using Wilcoxon tests (multiple-

comparisons corrected). Elastic net models (α = 0.3) predicted NPSs severity, adjusting for

diagnosis, age, sex, education, and MMSE, with regularization selected via cross-validation.

Feature-selection robustness was assessed via bootstrapping (1.000 iterations; 80%

subsamples), computing selection frequencies for non-zero coefficients.

Results: 105 speech features were analyzed with several being significantly different between

French and Spanish speakers. Accordingly, models were fitted separately by language/task.

Despite overall low NPSs burden, models identified speech-based predictors of depression,

while fewer predictors emerged for apathy/anxiety. Although individual selected features

differed between languages, certain depression-related predictors converged across cohorts

within shared feature-domains, including lexical-syntactic (conjunction use, verb-phrase

composition), temporal (pauses/utterance durations) and spectral dimensions (Figs. 1-3).

Model performance was highest for depression (R² up to 0.68 for French; up to 0.19 for

Spanish). Speech features showed stronger associations with NPSs than

cognitive/demographic covariates, with sex most consistently retained.

Conclusion: Despite low NPSs severity, similar types of speech-features (rather than identical

individual features) were associated with depression across two languages. These findings

support free-speech features as potentially cross-linguistic markers for NPSs assessment in

MCI, inviting validation in additional languages and clinically enriched samples.

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