A Machine Learning Approach to Analyze the Effects of Alzheimer's Disease on Handwriting through Lognormal Features
Tiziana D'Alessandro, Cristina Carmona-Duarte, Claudio De Stefano, Moises Diaz, Miguel A. Ferrer, Francesco Fontanella
TL;DR
The paper addresses the challenge of early Alzheimer’s disease detection by analyzing handwriting through features derived from the Sigma-Lognormal model. It proposes a three-stage ML framework—classification, stacking, and ranking/majority voting—to classify AD versus healthy controls using 25 tasks collected from 174 participants. Key contributions include a rich feature set from lognormal parameters, an extensive ML evaluation with multiple classifiers and aggregation strategies, and insights into how handwriting dynamics relate to age and education. While results show promising discriminative power (up to 82.5% accuracy via majority vote), the authors acknowledge limitations and outline avenues to improve diagnostic utility and generalization to other conditions.
Abstract
Alzheimer's disease is one of the most incisive illnesses among the neurodegenerative ones, and it causes a progressive decline in cognitive abilities that, in the worst cases, becomes severe enough to interfere with daily life. Currently, there is no cure, so an early diagnosis is strongly needed to try and slow its progression through medical treatments. Handwriting analysis is considered a potential tool for detecting and understanding certain neurological conditions, including Alzheimer's disease. While handwriting analysis alone cannot provide a definitive diagnosis of Alzheimer's, it may offer some insights and be used for a comprehensive assessment. The Sigma-lognormal model is conceived for movement analysis and can also be applied to handwriting. This model returns a set of lognormal parameters as output, which forms the basis for the computation of novel and significant features. This paper presents a machine learning approach applied to handwriting features extracted through the sigma-lognormal model. The aim is to develop a support system to help doctors in the diagnosis and study of Alzheimer, evaluate the effectiveness of the extracted features and finally study the relation among them.
