Explainable artificial intelligence model to predict brain states from fNIRS signals

Objective: Most Deep Learning (DL) methods for the classification of functional Near-Infrared Spectroscopy (fNIRS) signals do so without explaining which features contribute to the classification of a task or imagery. An explainable artificial intelligence (xAI) system that can decompose the Deep Le...

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Main Authors: Caleb Jones Shibu, Sujesh Sreedharan, KM Arun, Chandrasekharan Kesavadas, Ranganatha Sitaram
Format: Article
Language:English
Published: Frontiers Media S.A. 2023-01-01
Series:Frontiers in Human Neuroscience
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fnhum.2022.1029784/full
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author Caleb Jones Shibu
Sujesh Sreedharan
KM Arun
Chandrasekharan Kesavadas
Ranganatha Sitaram
author_facet Caleb Jones Shibu
Sujesh Sreedharan
KM Arun
Chandrasekharan Kesavadas
Ranganatha Sitaram
author_sort Caleb Jones Shibu
collection DOAJ
description Objective: Most Deep Learning (DL) methods for the classification of functional Near-Infrared Spectroscopy (fNIRS) signals do so without explaining which features contribute to the classification of a task or imagery. An explainable artificial intelligence (xAI) system that can decompose the Deep Learning mode’s output onto the input variables for fNIRS signals is described here.Approach: We propose an xAI-fNIRS system that consists of a classification module and an explanation module. The classification module consists of two separately trained sliding window-based classifiers, namely, (i) 1-D Convolutional Neural Network (CNN); and (ii) Long Short-Term Memory (LSTM). The explanation module uses SHAP (SHapley Additive exPlanations) to explain the CNN model’s output in terms of the model’s input.Main results: We observed that the classification module was able to classify two types of datasets: (a) Motor task (MT), acquired from three subjects; and (b) Motor imagery (MI), acquired from 29 subjects, with an accuracy of over 96% for both CNN and LSTM models. The explanation module was able to identify the channels contributing the most to the classification of MI or MT and therefore identify the channel locations and whether they correspond to oxy- or deoxy-hemoglobin levels in those locations.Significance: The xAI-fNIRS system can distinguish between the brain states related to overt and covert motor imagery from fNIRS signals with high classification accuracy and is able to explain the signal features that discriminate between the brain states of interest.
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spelling doaj.art-46464bc0e6ab4e8d9f81d26e0e5854552023-01-19T06:22:45ZengFrontiers Media S.A.Frontiers in Human Neuroscience1662-51612023-01-011610.3389/fnhum.2022.10297841029784Explainable artificial intelligence model to predict brain states from fNIRS signalsCaleb Jones Shibu0Sujesh Sreedharan1KM Arun2Chandrasekharan Kesavadas3Ranganatha Sitaram4Department of Computer Science, University of Arizona, Tucson, AZ, United StatesDivision of Artificial Internal Organs, Department of Medical Devices Engineering, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, IndiaDepartment of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, IndiaDepartment of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, IndiaDepartment of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN, United StatesObjective: Most Deep Learning (DL) methods for the classification of functional Near-Infrared Spectroscopy (fNIRS) signals do so without explaining which features contribute to the classification of a task or imagery. An explainable artificial intelligence (xAI) system that can decompose the Deep Learning mode’s output onto the input variables for fNIRS signals is described here.Approach: We propose an xAI-fNIRS system that consists of a classification module and an explanation module. The classification module consists of two separately trained sliding window-based classifiers, namely, (i) 1-D Convolutional Neural Network (CNN); and (ii) Long Short-Term Memory (LSTM). The explanation module uses SHAP (SHapley Additive exPlanations) to explain the CNN model’s output in terms of the model’s input.Main results: We observed that the classification module was able to classify two types of datasets: (a) Motor task (MT), acquired from three subjects; and (b) Motor imagery (MI), acquired from 29 subjects, with an accuracy of over 96% for both CNN and LSTM models. The explanation module was able to identify the channels contributing the most to the classification of MI or MT and therefore identify the channel locations and whether they correspond to oxy- or deoxy-hemoglobin levels in those locations.Significance: The xAI-fNIRS system can distinguish between the brain states related to overt and covert motor imagery from fNIRS signals with high classification accuracy and is able to explain the signal features that discriminate between the brain states of interest.https://www.frontiersin.org/articles/10.3389/fnhum.2022.1029784/fullbrain state classificationfunctional near-infrared spectroscopybrain-computer interfacedeep learningconvolutional neural networkslong short-term memory
spellingShingle Caleb Jones Shibu
Sujesh Sreedharan
KM Arun
Chandrasekharan Kesavadas
Ranganatha Sitaram
Explainable artificial intelligence model to predict brain states from fNIRS signals
Frontiers in Human Neuroscience
brain state classification
functional near-infrared spectroscopy
brain-computer interface
deep learning
convolutional neural networks
long short-term memory
title Explainable artificial intelligence model to predict brain states from fNIRS signals
title_full Explainable artificial intelligence model to predict brain states from fNIRS signals
title_fullStr Explainable artificial intelligence model to predict brain states from fNIRS signals
title_full_unstemmed Explainable artificial intelligence model to predict brain states from fNIRS signals
title_short Explainable artificial intelligence model to predict brain states from fNIRS signals
title_sort explainable artificial intelligence model to predict brain states from fnirs signals
topic brain state classification
functional near-infrared spectroscopy
brain-computer interface
deep learning
convolutional neural networks
long short-term memory
url https://www.frontiersin.org/articles/10.3389/fnhum.2022.1029784/full
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