Beyond surface form: A pipeline for semantic analysis in Alzheimer's Disease detection from spontaneous speech

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Phelps, Dylan, Wilkens, Rodrigo, Gow-Smith, Edward, Hubner, Lilian, Malcorra, Bárbara, Rennó-Costa, César, Idiart, Marco, Villa-Uriol, Maria-Cruz, Villavicencio, Aline
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917147752529920
author Phelps, Dylan
Wilkens, Rodrigo
Gow-Smith, Edward
Hubner, Lilian
Malcorra, Bárbara
Rennó-Costa, César
Idiart, Marco
Villa-Uriol, Maria-Cruz
Villavicencio, Aline
author_facet Phelps, Dylan
Wilkens, Rodrigo
Gow-Smith, Edward
Hubner, Lilian
Malcorra, Bárbara
Rennó-Costa, César
Idiart, Marco
Villa-Uriol, Maria-Cruz
Villavicencio, Aline
contents Alzheimer's Disease (AD) is a progressive neurodegenerative condition that adversely affects cognitive abilities. Language-related changes can be automatically identified through the analysis of outputs from linguistic assessment tasks, such as picture description. Language models show promise as a basis for screening tools for AD, but their limited interpretability poses a challenge in distinguishing true linguistic markers of cognitive decline from surface-level textual patterns. To address this issue, we examine how surface form variation affects classification performance, with the goal of assessing the ability of language models to represent underlying semantic indicators. We introduce a novel approach where texts surface forms are transformed by altering syntax and vocabulary while preserving semantic content. The transformations significantly modify the structure and lexical content, as indicated by low BLEU and chrF scores, yet retain the underlying semantics, as reflected in high semantic similarity scores, isolating the effect of semantic information, and finding models perform similarly to if they were using the original text, with only small deviations in macro-F1. We also investigate whether language from picture descriptions retains enough detail to reconstruct the original image using generative models. We found that image-based transformations add substantial noise reducing classification accuracy. Our methodology provides a novel way of looking at what features influence model predictions, and allows the removal of possible spurious correlations. We find that just using semantic information, language model based classifiers can still detect AD. This work shows that difficult to detect semantic impairment can be identified, addressing an overlooked feature of linguistic deterioration, and opening new pathways for early detection systems.
format Preprint
id arxiv_https___arxiv_org_abs_2512_13685
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Beyond surface form: A pipeline for semantic analysis in Alzheimer's Disease detection from spontaneous speech
Phelps, Dylan
Wilkens, Rodrigo
Gow-Smith, Edward
Hubner, Lilian
Malcorra, Bárbara
Rennó-Costa, César
Idiart, Marco
Villa-Uriol, Maria-Cruz
Villavicencio, Aline
Computation and Language
Alzheimer's Disease (AD) is a progressive neurodegenerative condition that adversely affects cognitive abilities. Language-related changes can be automatically identified through the analysis of outputs from linguistic assessment tasks, such as picture description. Language models show promise as a basis for screening tools for AD, but their limited interpretability poses a challenge in distinguishing true linguistic markers of cognitive decline from surface-level textual patterns. To address this issue, we examine how surface form variation affects classification performance, with the goal of assessing the ability of language models to represent underlying semantic indicators. We introduce a novel approach where texts surface forms are transformed by altering syntax and vocabulary while preserving semantic content. The transformations significantly modify the structure and lexical content, as indicated by low BLEU and chrF scores, yet retain the underlying semantics, as reflected in high semantic similarity scores, isolating the effect of semantic information, and finding models perform similarly to if they were using the original text, with only small deviations in macro-F1. We also investigate whether language from picture descriptions retains enough detail to reconstruct the original image using generative models. We found that image-based transformations add substantial noise reducing classification accuracy. Our methodology provides a novel way of looking at what features influence model predictions, and allows the removal of possible spurious correlations. We find that just using semantic information, language model based classifiers can still detect AD. This work shows that difficult to detect semantic impairment can be identified, addressing an overlooked feature of linguistic deterioration, and opening new pathways for early detection systems.
title Beyond surface form: A pipeline for semantic analysis in Alzheimer's Disease detection from spontaneous speech
topic Computation and Language
url https://arxiv.org/abs/2512.13685