Paper Info
Title
Machine Learning Workflow to Explain Black-Box Models for Early Alzheimer’s Disease Classification Evaluated for Multiple Datasets
Abstract
Hard-to-interpret black-box Machine Learning (ML) was often used for early Alzheimer’s Disease (AD) detection. To interpret eXtreme Gradient Boosting (XGBoost), Random Forest (RF), and Support Vector Machine (SVM) black-box models, a workflow based on Shapley values was developed. All models were trained on the Alzheimer’s Disease Neuroimaging Initiative (ADNI) dataset and evaluated for an independent ADNI test set, as well as the external Australian Imaging and Lifestyle flagship study of Ageing (AIBL), and Open Access Series of Imaging Studies (OASIS) datasets. Shapley values were compared to intuitively interpretable Decision Trees (DTs), and Logistic Regression (LR), as well as natural and permutation feature importances. To avoid the reduction of the explanation validity caused by correlated features, forward selection and aspect consolidation were implemented. Some black-box models outperformed DTs and LR. The forward-selected features correspond to brain areas previously associated with AD. Shapley values identified biologically plausible associations with moderate-to-strong correlations with feature importances. The most important RF features to predict AD conversion were the volume of the amygdalae and a cognitive test score. Good cognitive test performances and large brain volumes decreased the AD risk. The models trained using cognitive test scores significantly outperformed brain volumetric models ( $$p<0.05$$ ). Cognitive Normal (CN) vs. AD models were successfully transferred to external datasets. In comparison to previous work, improved performances for ADNI and AIBL were achieved for CN vs. Mild Cognitive Impairment (MCI) classification using brain volumes. The Shapley values and the feature importances showed moderate-to-strong correlations.
Year
DOI
Venue
2022
10.1007/s42979-022-01371-y
SN Computer Science
Keywords
DocType
Volume
Interpretable machine learning, Early Alzheimer’s disease detection, Shapley values
Journal
3
Issue
ISSN
Citations 
6
2661-8907
0
PageRank 
References 
Authors
0.34
15
2
Name
Order
Citations
PageRank
Louise Bloch102.37
Christoph M. Friedrich218625.44