Shahla Farzana


2024

pdf bib
CareCorpus+: Expanding and Augmenting Caregiver Strategy Data to Support Pediatric Rehabilitation
Shahla Farzana | Ivana Lucero | Vivian Villegas | Vera C Kaelin | Mary Khetani | Natalie Parde
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing

Caregiver strategy classification in pediatric rehabilitation contexts is strongly motivated by real-world clinical constraints but highly under-resourced and seldom studied in natural language processing settings. We introduce a large dataset of 4,037 caregiver strategies in this setting, a five-fold increase over the nearest contemporary dataset. These strategies are manually categorized into clinically established constructs with high agreement (đťś…=0.68-0.89). We also propose two techniques to further address identified data constraints. First, we manually supplement target task data with publicly relevant data from online child health forums. Next, we propose a novel data augmentation technique to generate synthetic caregiver strategies with high downstream task utility. Extensive experiments showcase the quality of our dataset. They also establish evidence that both the publicly available data and the synthetic strategies result in large performance gains, with relative F1 increases of 22.6% and 50.9%, respectively.

pdf bib
Domain Adaptation via Prompt Learning for Alzheimer’s Detection
Shahla Farzana | Natalie Parde
Findings of the Association for Computational Linguistics: EMNLP 2024

Spoken language presents a compelling medium for non-invasive Alzheimer’s disease (AD) screening, and prior work has examined the use of fine-tuned pretrained language models (PLMs) for this purpose. However, PLMs are often optimized on tasks that are inconsistent with AD classification. Spoken language corpora for AD detection are also small and disparate, making generalizability difficult. This paper investigates the use of domain-adaptive prompt fine-tuning for AD detection, using AD classification loss as the training objective and leveraging spoken language corpora from a variety of language tasks. Extensive experiments using voting-based combinations of different prompting paradigms show an impressive mean detection F1=0.8952 (with std=0.01 and best F1=0.9130) for the highest-performing approach when using BERT as the base PLM.

pdf bib
SLaCAD: A Spoken Language Corpus for Early Alzheimer’s Disease Detection
Shahla Farzana | Edoardo Stoppa | Alex Leow | Tamar Gollan | Raeanne Moore | David Salmon | Douglas Galasko | Erin Sundermann | Natalie Parde
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)

Identifying early markers of Alzheimer’s disease (AD) trajectory enables intervention in early disease stages when our currently-available interventions are most likely to be beneficial. Research has shown that alterations in speech, as well as linguistic and semantic deviations in spontaneous conversation detected using natural language processing, manifest early in AD prior to some other observed cognitive deficits. Recent studies show that cerebrospinal fluid (CSF) levels serve as useful early biomarkers for identifying early AD, but CSF biomarkers are challenging to collect. A simpler alternative that has seen very rapid development is based on the use of plasma biomarkers as a blood draw is minimally invasive. Associating verbal and nonverbal characteristics from speech data with CSF and plasma biomarkers may open the door to less invasive, more efficient methods for early AD detection. We present SLaCAD, a new dataset to facilitate this process. We describe our data collection procedures, analyze the resulting corpus, and present preliminary findings that relate measures extracted from the audio and transcribed text to clinical diagnoses, CSF levels, and plasma biomarkers. Our findings demonstrate the feasibility of this and indicate that the collected data can be used to improve assessments of early AD.

2023

pdf bib
Towards Domain-Agnostic and Domain-Adaptive Dementia Detection from Spoken Language
Shahla Farzana | Natalie Parde
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

Health-related speech datasets are often small and varied in focus. This makes it difficult to leverage them to effectively support healthcare goals. Robust transfer of linguistic features across different datasets orbiting the same goal carries potential to address this concern. To test this hypothesis, we experiment with domain adaptation (DA) techniques on heterogeneous spoken language data to evaluate generalizability across diverse datasets for a common task: dementia detection. We find that adapted models exhibit better performance across conversational and task-oriented datasets. The feature-augmented DA method achieves a 22% increase in accuracy adapting from a conversational to task-specific dataset compared to a jointly trained baseline. This suggests promising capacity of these techniques to allow for productive use of disparate data for a complex spoken language healthcare task.

2022

pdf bib
How You Say It Matters: Measuring the Impact of Verbal Disfluency Tags on Automated Dementia Detection
Shahla Farzana | Ashwin Deshpande | Natalie Parde
Proceedings of the 21st Workshop on Biomedical Language Processing

Automatic speech recognition (ASR) systems usually incorporate postprocessing mechanisms to remove disfluencies, facilitating the generation of clear, fluent transcripts that are conducive to many downstream NLP tasks. However, verbal disfluencies have proved to be predictive of dementia status, although little is known about how various types of verbal disfluencies, nor automatically detected disfluencies, affect predictive performance. We experiment with an off-the-shelf disfluency annotator to tag disfluencies in speech transcripts for a well-known cognitive health assessment task. We evaluate the performance of this model on detecting repetitions and corrections or retracing, and measure the influence of gold annotated versus automatically detected verbal disfluencies on dementia detection through a series of experiments. We find that removing both gold and automatically-detected disfluencies negatively impacts dementia detection performance, degrading classification accuracy by 5.6% and 3% respectively

pdf bib
Are Interaction Patterns Helpful for Task-Agnostic Dementia Detection? An Empirical Exploration
Shahla Farzana | Natalie Parde
Proceedings of the 23rd Annual Meeting of the Special Interest Group on Discourse and Dialogue

Dementia often manifests in dialog through specific behaviors such as requesting clarification, communicating repetitive ideas, and stalling, prompting conversational partners to probe or otherwise attempt to elicit information. Dialog act (DA) sequences can have predictive power for dementia detection through their potential to capture these meaningful interaction patterns. However, most existing work in this space relies on content-dependent features, raising questions about their generalizability beyond small reference sets or across different cognitive tasks. In this paper, we adapt an existing DA annotation scheme for two different cognitive tasks present in a popular dementia detection dataset. We show that a DA tagging model leveraging neural sentence embeddings and other information from previous utterances and speaker tags achieves strong performance for both tasks. We also propose content-free interaction features and show that they yield high utility in distinguishing dementia and control subjects across different tasks. Our study provides a step toward better understanding how interaction patterns in spontaneous dialog affect cognitive modeling across different tasks, which carries implications for the design of non-invasive and low-cost cognitive health monitoring tools for use at scale.

2020

pdf bib
Modeling Dialogue in Conversational Cognitive Health Screening Interviews
Shahla Farzana | Mina Valizadeh | Natalie Parde
Proceedings of the Twelfth Language Resources and Evaluation Conference

Automating straightforward clinical tasks can reduce workload for healthcare professionals, increase accessibility for geographically-isolated patients, and alleviate some of the economic burdens associated with healthcare. A variety of preliminary screening procedures are potentially suitable for automation, and one such domain that has remained underexplored to date is that of structured clinical interviews. A task-specific dialogue agent is needed to automate the collection of conversational speech for further (either manual or automated) analysis, and to build such an agent, a dialogue manager must be trained to respond to patient utterances in a manner similar to a human interviewer. To facilitate the development of such an agent, we propose an annotation schema for assigning dialogue act labels to utterances in patient-interviewer conversations collected as part of a clinically-validated cognitive health screening task. We build a labeled corpus using the schema, and show that it is characterized by high inter-annotator agreement. We establish a benchmark dialogue act classification model for the corpus, thereby providing a proof of concept for the proposed annotation schema. The resulting dialogue act corpus is the first such corpus specifically designed to facilitate automated cognitive health screening, and lays the groundwork for future exploration in this area.