Alzheimer Classification based on
Multi-Task Event-Specific EEG-fNIRS Feature Fusion

Table of Contents

  1. Abstract
  2. Getting Started
  3. Experimental Results
  4. Contact
  5. Acknowledgments

Abstract

As the population ages, the number of people with Alzheimer's disease is increasing dramatically. However, the use of functional Magnetic Resonance Imaging (fMRI) as a method for Alzheimer's diagnosis has several challenges. Its high cost can limit accessibility, the process is time-consuming, and physical discomfort experienced during the procedure often leads to reluctance among potential patients. Hence, recent studies have shifted towards more cost-effective, time-efficient, portable, and motion-insensitive tools such as Electroencephalography (EEG) and functional Near-Infrared Spectroscopy (fNIRS) for diagnosing Alzheimer's disease. The aim of this study is to use both EEG and fNIRS signal data collected through four simple tasks (resting state, oddball task, 1-back task, verbal fluency task) for Alzheimer classification, and to present an event-specific feature extraction method and feature selection method suitable for the data. EEG and fNIRS signals were collected from 144 subjects including 63 Healthy Controls (HC), 46 patients with Mild Cognitive Impairment (MCI), and 35 patients with Alzheimer's Disease (AD). Through our proposed event-specific feature extraction method, we extracted distinct features from each EEG and fNIRS signal, and the Recursive Feature Elimination with Cross-Validation (RFECV) algorithm was utilized to select hybrid EEG-fNIRS features useful for Alzheimer classification. The finally selected features achieved high performance across all three metrics - accuracy, F1 score, and AUC, with respective scores of 0.813, 0.821, and 0.915. These findings demonstrate that the proposed method can be used in real-world clinical settings to diagnose Alzheimer's stages, especially MCI.

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Getting Started

Prerequisites

TODO: Add requirements.txt

  • spkit
    pip install spkit

How to run

  1. Clone the repo

    git clone https://github.com/your_username_/Project-Name.git
  2. Install prerequisites

    pip install -r requirements.txt
  3. Run

    python main.py --data_root [Dataset Root (Root of 2nd+3rd+4th sorted data folders)]
                   --gpu [GPU ID to use]
                   --mode [segmentation | extraction | selection | classification(default)]
                   --exp [1(default) - Tasks | 2 - Modals | 3 - Previous study]
                   --task [R(Resting) | C(Oddball) | N(1-back) | V(Verbal fluency)]
                   --seed [Random seed number]
                   --cv_num [Number of cross-validation folds]
                   --clf_type [Tree(default) | SVM | RF | MLP]
    

    3-1. Segmentation Run Example

    python main.py --mode segmentation

    3-2. Extraction Run Example

    python main.py --mode extraction

    3-3. Selection Run Example

    python main.py --mode selection --exp 1 --task R 

    3-4. Classification Run Example

    python main.py --mode classification --exp 1 --task R

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Experimental Results

Experiment 1. Evaluating the Contribution of Each Task in Alzheimer’s Classification

Resting 1-back Oddball Verbal Accuracy F1 score AUC score
Exp 1-A O O O O 0.8126 0.8209 0.9149
Exp 1-B X O O O 0.8047 0.8095 0.9151
Exp 1-C O X O O 0.7845 0.7830 0.9030
Exp 1-D O O X O 0.7362 0.7440 0.8741
Exp 1-E O O O X 0.7357 0.7497 0.8798

Experiment 2. Evaluating the Contribution of Using Both EEG and fNIRS Signals in Alzheimer’s Classification

EEG fNIRS Accuracy F1 score AUC score
Exp 2-A O O 0.8126 0.8209 0.9149
Exp 2-B O X 0.7079 0.7002 0.8847
Exp 2-C X O 0.6345 0.6336 0.7349

Experiment 3. Comparative Analysis with Prior Research Method

Accuracy F1 score AUC score
Exp 3-A 0.8126 0.8209 0.9149
Exp 3-B 0.6855 0.6924 0.8359
Exp 3-C 0.6894 0.6753 0.8702
Exp 3-D 0.6975 0.6675 0.8777
Exp 3-E 0.5944 0.5944 0.6890

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Contact

Sunghyeon Kim - hahala25@yonsei.ac.kr

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Acknowledgments

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