790 research outputs found
EEG-Based User Reaction Time Estimation Using Riemannian Geometry Features
Riemannian geometry has been successfully used in many brain-computer
interface (BCI) classification problems and demonstrated superior performance.
In this paper, for the first time, it is applied to BCI regression problems, an
important category of BCI applications. More specifically, we propose a new
feature extraction approach for Electroencephalogram (EEG) based BCI regression
problems: a spatial filter is first used to increase the signal quality of the
EEG trials and also to reduce the dimensionality of the covariance matrices,
and then Riemannian tangent space features are extracted. We validate the
performance of the proposed approach in reaction time estimation from EEG
signals measured in a large-scale sustained-attention psychomotor vigilance
task, and show that compared with the traditional powerband features, the
tangent space features can reduce the root mean square estimation error by
4.30-8.30%, and increase the estimation correlation coefficient by 6.59-11.13%.Comment: arXiv admin note: text overlap with arXiv:1702.0291
Single channel wireless EEG device for real-time fatigue level detection
© 2015 IEEE. Driver fatigue problem is one of the important factors of traffic accidents. Recent years, many research had investigated that using EEG signals can effectively detect driver's drowsiness level. However, real-time monitoring system is required to apply these fatigue level detection techniques in the practical application, especially in the real-road driving. Therefore, it required less channels, portable and wireless, real-time monitoring and processing techniques for developing the real-time monitoring system. In this study, we develop a single channel wireless EEG device which can real-time detect driver's fatigue level on the mobile device such as smart phone or tablet. The developed device is investigated to obtain a better and precise understanding of brain activities of mental fatigue under driving, which is of great benefit for devolvement of detection of driving fatigue system. This system consists of a Bluetooth-enabled one channel EEG, a regression model, and smartphone, which was a platform recording and transforming the raw EEG data to useful driving status. In the experiment, this was a sustained-attention driving task to implement in a virtual-reality (VR) driving simulator. To training model and develop the system, we were performed for 15 subjects to study Electroencephalography (EEG) brain dynamics by using a mobile and wireless EEG device. Based on the outstanding training results, the leave-one-subject-out cross validation test obtained 90% fatigue detection accuracy. These results indicate that the combination of a smartphone and wireless EEG device constitutes an effective and easy wearable solution for detecting and preventing driver fatigue in real driving environments
The effects of different fatigue levels on brain–behavior relationships in driving
© 2019 The Authors. Brain and Behavior published by Wiley Periodicals, Inc. Background: In the past decade, fatigue has been regarded as one of the main factors impairing task performance and increasing behavioral lapses during driving, even leading to fatal car crashes. Although previous studies have explored the impact of acute fatigue through electroencephalography (EEG) signals, it is still unclear how different fatigue levels affect brain–behavior relationships. Methods: A longitudinal study was performed to investigate the brain dynamics and behavioral changes in individuals under different fatigue levels by a sustained attention task. This study used questionnaires in combination with actigraphy, a noninvasive means of monitoring human physiological activity cycles, to conduct longitudinal assessment and tracking of the objective and subjective fatigue levels of recruited participants. In this study, degrees of effectiveness score (fatigue rating) are divided into three levels (normal, reduced, and high risk) by the SAFTE fatigue model. Results: Results showed that those objective and subjective indicators were negatively correlated to behavioral performance. In addition, increased response times were accompanied by increased alpha and theta power in most brain regions, especially the posterior regions. In particular, the theta and alpha power dramatically increased in the high-fatigue (high-risk) group. Additionally, the alpha power of the occipital regions showed an inverted U-shaped change. Conclusion: Our results help to explain the inconsistent findings among existing studies, which considered the effects of only acute fatigue on driving performance while ignoring different levels of resident fatigue, and potentially lead to practical and precise biomathematical models to better predict the performance of human operators
EEG-Based Reaction Time Prediction with Fuzzy Common Spatial Patterns and Phase Cohesion using Deep Autoencoder Based Data Fusion
Drowsiness state of a driver is a topic of extensive discussion due to its
significant role in causing traffic accidents. This research presents a novel
approach that combines Fuzzy Common Spatial Patterns (CSP) optimised Phase
Cohesive Sequence (PCS) representations and fuzzy CSP-optimized signal
amplitude representations. The research aims to examine alterations in
Electroencephalogram (EEG) synchronisation between a state of alertness and
drowsiness, forecast drivers' reaction times by analysing EEG data, and
subsequently identify the presence of drowsiness. The study's findings indicate
that this approach successfully distinguishes between alert and drowsy mental
states. By employing a Deep Autoencoder-based data fusion technique and a
regression model such as Support Vector Regression (SVR) or Least Absolute
Shrinkage and Selection Operator (LASSO), the proposed method outperforms using
individual feature sets in combination with a regressor model. This superiority
is measured by evaluating the Root Mean Squared Error (RMSE), Mean Absolute
Percentage Error (MAPE), and Correlation Coefficient (CC). In other words, the
fusion of autoencoder-based amplitude EEG power features and PCS features, when
used in regression, outperforms using either of these features alone in a
regressor model. Specifically, the proposed data fusion method achieves a
14.36% reduction in RMSE, a 25.12% reduction in MAPE, and a 10.12% increase in
CC compared to the baseline model using only individual amplitude EEG power
features and regression
Applications of brain imaging methods in driving behaviour research
Applications of neuroimaging methods have substantially contributed to the
scientific understanding of human factors during driving by providing a deeper
insight into the neuro-cognitive aspects of driver brain. This has been
achieved by conducting simulated (and occasionally, field) driving experiments
while collecting driver brain signals of certain types. Here, this sector of
studies is comprehensively reviewed at both macro and micro scales. Different
themes of neuroimaging driving behaviour research are identified and the
findings within each theme are synthesised. The surveyed literature has
reported on applications of four major brain imaging methods. These include
Functional Magnetic Resonance Imaging (fMRI), Electroencephalography (EEG),
Functional Near-Infrared Spectroscopy (fNIRS) and Magnetoencephalography (MEG),
with the first two being the most common methods in this domain. While
collecting driver fMRI signal has been particularly instrumental in studying
neural correlates of intoxicated driving (e.g. alcohol or cannabis) or
distracted driving, the EEG method has been predominantly utilised in relation
to the efforts aiming at development of automatic fatigue/drowsiness detection
systems, a topic to which the literature on neuro-ergonomics of driving
particularly has shown a spike of interest within the last few years. The
survey also reveals that topics such as driver brain activity in semi-automated
settings or the brain activity of drivers with brain injuries or chronic
neurological conditions have by contrast been investigated to a very limited
extent. Further, potential topics in relation to driving behaviour are
identified that could benefit from the adoption of neuroimaging methods in
future studies
Exploring the Brain Responses to Driving Fatigue through Simultaneous EEG and fNIRS Measurements
© 2020 World Scientific Publishing Company. Fatigue is one problem with driving as it can lead to difficulties with sustaining attention, behavioral lapses, and a tendency to ignore vital information or operations. In this research, we explore multimodal physiological phenomena in response to driving fatigue through simultaneous functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) recordings with the aim of investigating the relationships between hemodynamic and electrical features and driving performance. Sixteen subjects participated in an event-related lane-deviation driving task while measuring their brain dynamics through fNIRS and EEGs. Three performance groups, classified as Optimal, Suboptimal, and Poor, were defined for comparison. From our analysis, we find that tonic variations occur before a deviation, and phasic variations occur afterward. The tonic results show an increased concentration of oxygenated hemoglobin (HbO2) and power changes in the EEG theta, alpha, and beta bands. Both dynamics are significantly correlated with deteriorated driving performance. The phasic EEG results demonstrate event-related desynchronization associated with the onset of steering vehicle in all power bands. The concentration of phasic HbO2 decreased as performance worsened. Further, the negative correlations between tonic EEG delta and alpha power and HbO2 oscillations suggest that activations in HbO2 are related to mental fatigue. In summary, combined hemodynamic and electrodynamic activities can provide complete knowledge of the brain's responses as evidence of state changes during fatigue driving
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