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1.
Biometrics ; 80(2)2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38742907

ABSTRACT

We propose a new non-parametric conditional independence test for a scalar response and a functional covariate over a continuum of quantile levels. We build a Cramer-von Mises type test statistic based on an empirical process indexed by random projections of the functional covariate, effectively avoiding the "curse of dimensionality" under the projected hypothesis, which is almost surely equivalent to the null hypothesis. The asymptotic null distribution of the proposed test statistic is obtained under some mild assumptions. The asymptotic global and local power properties of our test statistic are then investigated. We specifically demonstrate that the statistic is able to detect a broad class of local alternatives converging to the null at the parametric rate. Additionally, we recommend a simple multiplier bootstrap approach for estimating the critical values. The finite-sample performance of our statistic is examined through several Monte Carlo simulation experiments. Finally, an analysis of an EEG data set is used to show the utility and versatility of our proposed test statistic.


Subject(s)
Computer Simulation , Models, Statistical , Monte Carlo Method , Humans , Electroencephalography/statistics & numerical data , Data Interpretation, Statistical , Biometry/methods , Statistics, Nonparametric
2.
Clin Neurophysiol ; 139: 23-27, 2022 07.
Article in English | MEDLINE | ID: mdl-35490437

ABSTRACT

OBJECTIVE: To assess, in adults with acute consciousness impairment, the impact of latency between hospital admission and EEG recording start, and their outcome. METHODS: We reviewed data of the CERTA trial (NCT03129438) and explored correlations between EEG recording latency and mortality, Cerebral Performance Categories (CPC), and modified Rankin Scale (mRS) at 6 months, considering other variables, using uni- and multivariable analyses. RESULTS: In univariable analysis of 364 adults, median latency between admission and EEG recordings was comparable between surviving (61.1 h; IQR: 24.3-137.7) and deceased patients (57.5 h; IQR: 22.3-141.1); p = 0.727. This did not change after adjusting for potential confounders, such as lower Glasgow Coma Score on enrolment (p < 0.001) and seizure or status epilepticus detection (p < 0.001). There was neither any correlation between EEG latency and mRS (rho 0.087, p 0.236), nor with CPC (rho = 0.027, p = 0.603). CONCLUSION: This analysis shows no correlation between delays of EEG recordings and mortality or functional outcomes at 6 months in critically ill adults. SIGNIFICANCE: These findings might suggest that in critically ill adults mortality correlates with underlying brain injury rather than EEG delay.


Subject(s)
Critical Illness , Electroencephalography/statistics & numerical data , Status Epilepticus , Adult , Analysis of Variance , Humans , Pyridines , Seizures/complications , Time Factors
3.
Comput Math Methods Med ; 2022: 8724536, 2022.
Article in English | MEDLINE | ID: mdl-35211188

ABSTRACT

The precise detection of epileptic seizure helps to prevent the serious consequences of seizures. As the electroencephalogram (EEG) reflects the brain activity of patients effectively, it has been widely used in epileptic seizure detection in the past decades. Recently, deep learning-based detection methods which automatically learn features from the EEG signals have attracted much attention. However, with deep learning-based detection methods, different input formats of EEG signals will lead to different detection performances. In this paper, we propose a deep learning-based epileptic seizure detection method with hybrid input formats of EEG signals, i.e., original EEG, Fourier transform of EEG, short-time Fourier transform of EEG, and wavelet transform of EEG. Convolutional neural networks (CNNs) are designed for extracting latent features from these inputs. A feature fusion mechanism is applied to integrate the learned features to generate a more stable syncretic feature for seizure detection. The experimental results show that our proposed hybrid method is effective to improve the seizure detection performance in few-shot scenarios.


Subject(s)
Deep Learning , Diagnosis, Computer-Assisted/methods , Electroencephalography/statistics & numerical data , Seizures/diagnosis , Algorithms , Computational Biology , Databases, Factual/statistics & numerical data , Diagnosis, Computer-Assisted/statistics & numerical data , Epilepsy/classification , Epilepsy/diagnosis , Fourier Analysis , Humans , Neural Networks, Computer , Signal Processing, Computer-Assisted , Wavelet Analysis
4.
Comput Math Methods Med ; 2022: 6331956, 2022.
Article in English | MEDLINE | ID: mdl-35222689

ABSTRACT

Event-related potentials (ERPs) can reflect the high-level thinking activities of the brain. In ERP analysis, the superposition and averaging method is often used to estimate ERPs. However, the single-trial ERP estimation can provide researchers with more information on cognitive activities. In recent years, more and more researchers try to find an effective method to extract single-trial ERPs, because most of the existing methods have poor generalization ability or suffer from strong assumptions about the characteristics of ERPs, resulting in unsatisfactory results under the condition of a very low signal-to-noise ratio. In this paper, an EEG classification-based method for single-trial ERP detection and estimation was proposed. This study used a linear generated EEG model containing templates of ERP local descriptors which include amplitude and latency, and this model can avoid the invalid assumption about ERPs taken by other methods. The purpose of this method is not to recover the whole ERP waveform but to model the amplitude and latency of ERP components. This method afterwards examined the three machine learning models including logistic regression, neural network, and support vector machine in the EEG signal classification for ERP detection and selected the best performed MLPNN model for detection. To get the utmost out of information produced in the classification process, this study also used extra information to propose a new optimization model, with which outperformed detection results were obtained. Performance of the proposed method is evaluated on simulated N170 and real P50 data sets, and the results show that the model is more effective than the Woody filter and the SingleTrialEM algorithm. These results are also consistent with the conclusion of sensory gating, which demonstrated good generalization ability.


Subject(s)
Electroencephalography/classification , Electroencephalography/methods , Evoked Potentials/physiology , Neural Networks, Computer , Adult , Brain/physiology , Computational Biology , Computer Simulation , Electroencephalography/statistics & numerical data , Female , Humans , Linear Models , Logistic Models , Male , Models, Neurological , Signal Processing, Computer-Assisted , Signal-To-Noise Ratio , Support Vector Machine , Young Adult
5.
Comput Math Methods Med ; 2022: 8501948, 2022.
Article in English | MEDLINE | ID: mdl-35132332

ABSTRACT

METHODS: We compare nine index values, select CNN+EEG, which has good correlation with BIS index, as an anesthesia state observation index to identify the parameters of the model, and establish a model based on self-attention and dual resistructure convolutional neural network. The data of 93 groups of patients were selected and randomly grouped into three parts: training set, validation set, and test set, and compared the best and worst results predicted by BIS. RESULT: The best result is that the model's accuracy of predicting BLS on the test set has an overall upward trend, eventually reaching more than 90%. The overall error shows a gradual decrease and eventually approaches zero. The worst result is that the model's accuracy of predicting BIS on the test set has an overall upward trend. The accuracy rate is relatively stable without major fluctuations, but the final accuracy rate is above 70%. CONCLUSION: The prediction of BIS indicators by the deep learning method CNN algorithm shows good results in statistics.


Subject(s)
Anesthetics, Intravenous/administration & dosage , Attention/drug effects , Intraoperative Neurophysiological Monitoring/methods , Neural Networks, Computer , Propofol/administration & dosage , Adult , Aged , Aged, 80 and over , Algorithms , Anesthetics, Intravenous/metabolism , Computational Biology , Deep Learning , Electroencephalography/statistics & numerical data , Humans , Intraoperative Neurophysiological Monitoring/statistics & numerical data , Male , Middle Aged , Propofol/metabolism , Young Adult
6.
Comput Math Methods Med ; 2022: 9398551, 2022.
Article in English | MEDLINE | ID: mdl-35132334

ABSTRACT

To analyze the application value of artificial intelligence model based on Visual Geometry Group- (VGG-) 16 combined with quantitative electroencephalography (QEEG) in cerebral small vessel disease (CSVD) with cognitive impairment, 72 patients with CSVD complicated by cognitive impairment were selected as the research subjects. As per Diagnostic and Statistical Manual (5th Edition), they were divided into the vascular dementia (VD) group of 34 cases and vascular cognitive impairment with no dementia (VCIND) group of 38 cases. The two groups were analyzed for the clinical information, neuropsychological test results, and monitoring results of QEEG based on intelligent algorithms for more than 2 hours. The accuracy rate of VGG was 84.27% and Kappa value was 0.7, while that of modified VGG (nVGG) was 88.76% and Kappa value was 0.78. The improved VGG algorithm obviously had higher accuracy. The test results found that the QEEG identified 8 normal, 19 mild, 10 moderate, and 0 severe cases in the VCIND group, while in the VD group, the corresponding numbers were 4, 13, 11, and 7; in the VCIND group, 7 cases had the normal QEEG, 11 cases had background changes, 9 cases had abnormal waves, and 11 cases had in both background changes and abnormal waves, and in the VD group, the corresponding numbers were 5, 2, 5, and 22, respectively; in the VCIND group, QEEG of 18 patients had no abnormal waves, QEEG of 11 patients had a few abnormal waves, and QEEG of 9 patients had many abnormal waves, and QEEG of 0 people had a large number of abnormal waves, and in the VD group, the corresponding numbers were 7, 6, 12, and 9. The above data were statistically different between the two groups (P < 0.05). Hence, QEEG based on intelligent algorithms can make a good assessment of CSVD with cognitive impairment, which had good clinical application value.


Subject(s)
Cerebral Small Vessel Diseases/complications , Cerebral Small Vessel Diseases/diagnosis , Cognitive Dysfunction/complications , Cognitive Dysfunction/diagnosis , Diagnosis, Computer-Assisted/methods , Electroencephalography/methods , Aged , Algorithms , Artificial Intelligence , Cerebral Small Vessel Diseases/psychology , Cognitive Dysfunction/psychology , Computational Biology , Dementia, Vascular/complications , Dementia, Vascular/diagnosis , Dementia, Vascular/psychology , Diagnosis, Computer-Assisted/statistics & numerical data , Electroencephalography/statistics & numerical data , Female , Humans , Male , Middle Aged , Neuropsychological Tests
7.
PLoS One ; 17(2): e0263159, 2022.
Article in English | MEDLINE | ID: mdl-35202420

ABSTRACT

Parkinson's disease (PD) is one of the most serious and challenging neurodegenerative disorders to diagnose. Clinical diagnosis on observing motor symptoms is the gold standard, yet by this point nerve cells are degenerated resulting in a lower efficacy of therapeutic treatments. In this study, we introduce a deep-learning approach based on a recently-proposed 20-Layer Convolutional Neural Network (CNN) applied on the visual realization of the Wavelet domain of a resting-state EEG. The proposed approach was able to efficiently and accurately detect PD as well as distinguish subjects with PD on medications from subjects who are off medication. The gradient-weighted class activation mapping (Grad-CAM) was used to visualize the features based on which the approach provided the predictions. A significantly high accuracy, sensitivity, specificity, AUC, and Weighted Kappa Score up to 99.9% were achieved and the visualization of the regions in the Wavelet images that contributed to the deep-learning approach decisions was provided. The proposed framework can then serve as an effective computer-aided diagnostic tool that will support physicians and scientists in further understanding the nature of PD and providing an objective and confident opinion regarding the clinical diagnosis of the disease.


Subject(s)
Deep Learning , Electroencephalography/statistics & numerical data , Neural Networks, Computer , Parkinson Disease/diagnosis , Aged , Female , Humans , Machine Learning , Male , Membrane Potentials/physiology , Mental Health , Middle Aged , Parkinson Disease/diagnostic imaging , Parkinson Disease/physiopathology , Wavelet Analysis
8.
Comput Math Methods Med ; 2022: 7751263, 2022.
Article in English | MEDLINE | ID: mdl-35096136

ABSTRACT

Epileptic seizures occur due to brain abnormalities that can indirectly affect patient's health. It occurs abruptly without any symptoms and thus increases the mortality rate of humans. Almost 1% of world's population suffers from epileptic seizures. Prediction of seizures before the beginning of onset is beneficial for preventing seizures by medication. Nowadays, modern computational tools, machine learning, and deep learning methods have been used to predict seizures using EEG. However, EEG signals may get corrupted with background noise, and artifacts such as eye blinks and physical movements of muscles may lead to "pops" in the signal, resulting in electrical interference, which is cumbersome to detect through visual inspection for longer duration recordings. These limitations in automatic detection of interictal spikes and epileptic seizures are preferred, which is an essential tool for examining and scrutinizing the EEG recording more precisely. These restrictions bring our attention to present a review of automated schemes that will help neurologists categorize epileptic and nonepileptic signals. While preparing this review paper, it is observed that feature selection and classification are the main challenges in epilepsy prediction algorithms. This paper presents various techniques depending on various features and classifiers over the last few years. The methods presented will give a detailed understanding and ideas about seizure prediction and future research directions.


Subject(s)
Deep Learning , Diagnosis, Computer-Assisted/methods , Electroencephalography/methods , Machine Learning , Seizures/diagnosis , Algorithms , Bayes Theorem , Computational Biology , Databases, Factual/statistics & numerical data , Diagnosis, Computer-Assisted/statistics & numerical data , Electroencephalography/statistics & numerical data , Epilepsy/diagnosis , Humans , Logistic Models , Neural Networks, Computer , Seizures/classification , Signal Processing, Computer-Assisted , Signal-To-Noise Ratio , Support Vector Machine
9.
Pediatr Neurol ; 126: 125-130, 2022 01.
Article in English | MEDLINE | ID: mdl-34864306

ABSTRACT

BACKGROUND: Neuromonitoring is the use of continuous measures of brain physiology to detect clinically important events in real-time. Neuromonitoring devices can be invasive or non-invasive and are typically used on patients with acute brain injury or at high risk for brain injury. The goal of this study was to characterize neuromonitoring infrastructure and practices in North American pediatric intensive care units (PICUs). METHODS: An electronic, web-based survey was distributed to 70 North American institutions participating in the Pediatric Neurocritical Care Research Group. Questions related to the clinical use of neuromonitoring devices, integrative multimodality neuromonitoring capabilities, and neuromonitoring infrastructure were included. Survey results were presented using descriptive statistics. RESULTS: The survey was completed by faculty at 74% (52 of 70) of institutions. All 52 institutions measure intracranial pressure and have electroencephalography capability, whereas 87% (45 of 52) use near-infrared spectroscopy and 40% (21/52) use transcranial Doppler. Individual patient monitoring decisions were driven by institutional protocols and collaboration between critical care, neurology, and neurosurgery attendings. Reported device utilization varied by brain injury etiology. Only 15% (eight of 52) of institutions utilized a multimodality neuromonitoring platform to integrate and synchronize data from multiple devices. A database of neuromonitoring patients was maintained at 35% (18 of 52) of institutions. Funding for neuromonitoring programs was variable with contributions from hospitals (19%, 10 of 52), private donations (12%, six of 52), and research funds (12%, six of 52), although 73% (40 of 52) have no dedicated funds. CONCLUSIONS: Neuromonitoring indications, devices, and infrastructure vary by institution in North American pediatric critical care units. Noninvasive modalities were utilized more liberally, although not uniformly, than invasive monitoring. Further studies are needed to standardize the acquisition, interpretation, and reporting of clinical neuromonitoring data, and to determine whether neuromonitoring systems impact neurological outcomes.


Subject(s)
Critical Care/statistics & numerical data , Intensive Care Units, Pediatric/statistics & numerical data , Neurophysiological Monitoring/statistics & numerical data , Electroencephalography/statistics & numerical data , Health Care Surveys , Humans , Intracranial Pressure/physiology , Neurophysiological Monitoring/instrumentation , North America , Practice Patterns, Physicians'/statistics & numerical data , Ultrasonography, Doppler, Transcranial/statistics & numerical data
10.
Crit Care Med ; 50(2): 329-334, 2022 02 01.
Article in English | MEDLINE | ID: mdl-34582427

ABSTRACT

OBJECTIVES: To investigate electroencephalogram (EEG) features' relation with mortality or functional outcome after disorder of consciousness, stratifying patients between continuous EEG and routine EEG. DESIGN: Retrospective analysis of data from a randomized controlled trial. SETTING: Multiple adult ICUs. PATIENTS: Data from 364 adults with acute disorder of consciousness, randomized to continuous EEG (30-48 hr; n = 182) or repeated 20-minute routine electroencephalogram (n = 182). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Correlations between electrographic features and mortality and modified Rankin scale at 6 months (good 0-2) were assessed. Background continuity, higher frequency, and reactivity correlated with survival and good modified Rankin scale. Rhythmic and periodic patterns carried dual prognostic information: lateralized periodic discharges were associated with mortality and bad modified Rankin scale. Generalized rhythmic delta activity correlated with survival, good modified Rankin scale, and lower occurrence of status epilepticus. Presence of sleep-spindles and continuous EEG background was associated with good outcome in the continuous EEG subgroup. In the routine EEG group, a model combining background frequency, continuity, reactivity, sleep-spindles, and lateralized periodic discharges was associated with mortality at 70.91% (95% CI, 59.62-80.10%) positive predictive value and 63.93% (95% CI, 58.67-68.89%) negative predictive value. In the continuous EEG group, a model combining background continuity, reactivity, generalized rhythmic delta activity, and lateralized periodic discharges was associated with mortality at 84.62% (95%CI, 75.02-90.97) positive predictive value and 74.77% (95% CI, 68.50-80.16) negative predictive value. CONCLUSIONS: Standardized EEG interpretation provides reliable prognostic information. Continuous EEG provides more information than routine EEG.


Subject(s)
Electroencephalography/methods , Outcome Assessment, Health Care/statistics & numerical data , Seizures/diagnosis , Time Factors , Adult , Area Under Curve , Critical Illness/therapy , Electroencephalography/standards , Electroencephalography/statistics & numerical data , Female , Humans , Intensive Care Units/organization & administration , Intensive Care Units/statistics & numerical data , Male , Middle Aged , Outcome Assessment, Health Care/methods , Prognosis , ROC Curve , Retrospective Studies , Seizures/epidemiology , Seizures/physiopathology
11.
Comput Math Methods Med ; 2021: 3130747, 2021.
Article in English | MEDLINE | ID: mdl-34970329

ABSTRACT

The outdoor light environment significantly affects aspects of public psychological and physiological health. This study conducted experiments to quantify the effects of the light environment on visitor light comfort in urban park pedestrian space. Nine sets of lighting conditions with different average horizontal illuminance (2 lx, 6 lx, 10 lx) and colour temperatures (5600 K, 4300 K, 3000 K) were established virtual reality scenarios. Subjective light comfort was evaluated, and electroencephalogram (EEG) was measured on 18 subjects to comprehensively study the effects of different light environments on human light comfort. The results of the comprehensive evaluation showed that colour temperature had a very significant impact on subjective light comfort, with warm light being generally more favourable than cool light in enhancing human subjective light comfort. The results of the EEG analysis show that the average horizontal illuminance is an important factor in the level of physiological fatigue, and that physiological fatigue can be maintained in a superior state at an appropriate level of illuminance. Based on the results of both subjective and objective factors, a comprehensive analysis was carried out to propose a range of average horizontal illuminance (4.08 lx, 6.99 lx) and a range of colour temperature (3126 K, 4498 K) for the comprehensive light comfort zone in urban park pedestrian space.


Subject(s)
Lighting , Parks, Recreational , Pedestrians , Adult , Color , Computational Biology , Computer Simulation , Darkness , Electroencephalography/instrumentation , Electroencephalography/statistics & numerical data , Female , Humans , Light , Male , Pedestrians/psychology , Urban Health , Virtual Reality , Wearable Electronic Devices , Young Adult
12.
Ann Clin Transl Neurol ; 8(12): 2270-2279, 2021 12.
Article in English | MEDLINE | ID: mdl-34802196

ABSTRACT

OBJECTIVES: The purpose of this study was to examine critical care continuous electroencephalography (cEEG) utilization and downstream anti-seizure treatment patterns, their association with outcomes, and generate hypotheses for larger comparative effectiveness studies of cEEG-guided interventions. METHODS: Single-center retrospective study of critically ill patients (n = 14,523, age ≥18 years). Exposure defined as ≥24 h of cEEG and subsequent anti-seizure medication (ASM) escalation, with or without concomitant anesthetic. Exposure window was the first 7 days of admission. Primary outcome was in-hospital mortality. Multivariable analysis was performed using penalized logistic regression. RESULTS: One thousand and seventy-three patients underwent ≥24 h of cEEG within 7 days of admission. After adjusting for disease severity, ≥24 h of cEEG followed by ASM escalation in patients not on anesthetics (n = 239) was associated with lower in-hospital mortality (OR 0.76 [0.53-1.07]), though the finding did not reach significance. ASM escalation with concomitant anesthetic use (n = 484) showed higher odds for mortality (OR 1.41 [1.03-1.94]). In the seizures/status epilepticus subgroup, post cEEG ASM escalation without anesthetics showed lower odds for mortality (OR 0.43 [0.23-0.74]). Within the same subgroup, ASM escalation with concomitant anesthetic use showed higher odds for mortality (OR 1.34 [0.92-1.91]) though not significant. INTERPRETATION: Based on our findings we propose the following hypotheses for larger comparative effectiveness studies investigating the direct causal effect of cEEG-guided treatment on outcomes: (1) cEEG-guided ASM escalation may improve outcomes in critically ill patients with seizures; (2) cEEG-guided treatment with combination of ASMs and anesthetics may not improve outcomes in all critically ill patients.


Subject(s)
Anticonvulsants/administration & dosage , Critical Care/statistics & numerical data , Electroencephalography/statistics & numerical data , Electronic Health Records/statistics & numerical data , Neurophysiological Monitoring/statistics & numerical data , Outcome and Process Assessment, Health Care/statistics & numerical data , Seizures , Aged , Female , Hospital Mortality , Humans , Intensive Care Units/statistics & numerical data , Male , Middle Aged , Patient Discharge , Retrospective Studies , Seizures/diagnosis , Seizures/drug therapy , Seizures/prevention & control
13.
Comput Math Methods Med ; 2021: 1972662, 2021.
Article in English | MEDLINE | ID: mdl-34721654

ABSTRACT

In recent years, the research on electroencephalography (EEG) has focused on the feature extraction of EEG signals. The development of convenient and simple EEG acquisition devices has produced a variety of EEG signal sources and the diversity of the EEG data. Thus, the adaptability of EEG classification methods has become significant. This study proposed a deep network model for autonomous learning and classification of EEG signals, which could self-adaptively classify EEG signals with different sampling frequencies and lengths. The artificial design feature extraction methods could not obtain stable classification results when analyzing EEG data with different sampling frequencies. However, the proposed depth network model showed considerably better universality and classification accuracy, particularly for EEG signals with short length, which was validated by two datasets.


Subject(s)
Deep Learning , Electroencephalography/statistics & numerical data , Epilepsy/diagnosis , Algorithms , Brain-Computer Interfaces , Computational Biology , Databases, Factual , Diagnosis, Computer-Assisted/statistics & numerical data , Electroencephalography/classification , Epilepsy/classification , Humans , Neural Networks, Computer , Signal Processing, Computer-Assisted
14.
Comput Math Methods Med ; 2021: 9961998, 2021.
Article in English | MEDLINE | ID: mdl-34594398

ABSTRACT

BACKGROUND: In intensive care, monitoring the depth of anesthesia during surgical procedures is a key element in the success of the medical operation and postoperative recovery. However, despite the development of anesthesia thanks to technological and pharmacological advances, its side effects such as underdose or overdose of hypnotics remain a major problem. Observation and monitoring must combine clinical observations (loss of consciousness and reactivity) with tools for real-time measurement of changes in the depth of anesthesia. Methodology. In this work, we will develop a noninvasive method for calculating, monitoring, and controlling the depth of general anesthesia during surgery. The objective is to reduce the effects of pharmacological usage of hypnotics and to ensure better quality recovery. Thanks to the overall activity of sets of neurons in the brain, we have developed a BIS technique based on bispectral analysis of the electroencephalographic signal EEG. Discussion. By collecting the electrical voltages from the brain, we distinguish light sleep from deep sleep according to the values of the BIS indicator (ranging from 0 : sleep to 100 : wake) and also control it by acting on the dosage of propofol and sevoflurane. We showed that the BIS value must be maintained during the operation and the anesthesia at a value greater than 60. CONCLUSION: This study showed that the BIS technology led to an optimization of the anesthetic management, the adequacy of the hypnotic dosage, and a better postoperative recovery.


Subject(s)
Anesthesia, General , Electroencephalography/statistics & numerical data , Intraoperative Neurophysiological Monitoring/methods , Algorithms , Anesthetics, Inhalation/administration & dosage , Brain Waves/physiology , Computational Biology , Electrophysiological Phenomena , Humans , Hypnotics and Sedatives/administration & dosage , Intraoperative Neurophysiological Monitoring/statistics & numerical data , Propofol/administration & dosage , Sevoflurane/administration & dosage , Sleep Stages/physiology , Wavelet Analysis
15.
Comput Math Methods Med ; 2021: 2520394, 2021.
Article in English | MEDLINE | ID: mdl-34671415

ABSTRACT

Emotion recognition plays an important role in the field of human-computer interaction (HCI). Automatic emotion recognition based on EEG is an important topic in brain-computer interface (BCI) applications. Currently, deep learning has been widely used in the field of EEG emotion recognition and has achieved remarkable results. However, due to the cost of data collection, most EEG datasets have only a small amount of EEG data, and the sample categories are unbalanced in these datasets. These problems will make it difficult for the deep learning model to predict the emotional state. In this paper, we propose a new sample generation method using generative adversarial networks to solve the problem of EEG sample shortage and sample category imbalance. In experiments, we explore the performance of emotion recognition with the frequency band correlation and frequency band separation computational models before and after data augmentation on standard EEG-based emotion datasets. Our experimental results show that the method of generative adversarial networks for data augmentation can effectively improve the performance of emotion recognition based on the deep learning model. And we find that the frequency band correlation deep learning model is more conducive to emotion recognition.


Subject(s)
Brain-Computer Interfaces/statistics & numerical data , Electroencephalography/statistics & numerical data , Emotions/physiology , Neural Networks, Computer , Computational Biology , Databases, Factual , Deep Learning , Emotions/classification , Humans
16.
PLoS Comput Biol ; 17(9): e1009358, 2021 09.
Article in English | MEDLINE | ID: mdl-34534211

ABSTRACT

The human brain tracks amplitude fluctuations of both speech and music, which reflects acoustic processing in addition to the encoding of higher-order features and one's cognitive state. Comparing neural tracking of speech and music envelopes can elucidate stimulus-general mechanisms, but direct comparisons are confounded by differences in their envelope spectra. Here, we use a novel method of frequency-constrained reconstruction of stimulus envelopes using EEG recorded during passive listening. We expected to see music reconstruction match speech in a narrow range of frequencies, but instead we found that speech was reconstructed better than music for all frequencies we examined. Additionally, models trained on all stimulus types performed as well or better than the stimulus-specific models at higher modulation frequencies, suggesting a common neural mechanism for tracking speech and music. However, speech envelope tracking at low frequencies, below 1 Hz, was associated with increased weighting over parietal channels, which was not present for the other stimuli. Our results highlight the importance of low-frequency speech tracking and suggest an origin from speech-specific processing in the brain.


Subject(s)
Auditory Perception/physiology , Brain/physiology , Music , Speech Perception/physiology , Speech/physiology , Acoustic Stimulation/methods , Adolescent , Adult , Computational Biology , Computer Simulation , Electroencephalography/statistics & numerical data , Female , Humans , Linear Models , Male , Models, Neurological , Principal Component Analysis , Speech Acoustics , Young Adult
17.
PLoS Comput Biol ; 17(9): e1009456, 2021 09.
Article in English | MEDLINE | ID: mdl-34570753

ABSTRACT

A number of neuroimaging techniques have been employed to understand how visual information is transformed along the visual pathway. Although each technique has spatial and temporal limitations, they can each provide important insights into the visual code. While the BOLD signal of fMRI can be quite informative, the visual code is not static and this can be obscured by fMRI's poor temporal resolution. In this study, we leveraged the high temporal resolution of EEG to develop an encoding technique based on the distribution of responses generated by a population of real-world scenes. This approach maps neural signals to each pixel within a given image and reveals location-specific transformations of the visual code, providing a spatiotemporal signature for the image at each electrode. Our analyses of the mapping results revealed that scenes undergo a series of nonuniform transformations that prioritize different spatial frequencies at different regions of scenes over time. This mapping technique offers a potential avenue for future studies to explore how dynamic feedforward and recurrent processes inform and refine high-level representations of our visual world.


Subject(s)
Brain Mapping/methods , Electroencephalography/statistics & numerical data , Visual Pathways/physiology , Adolescent , Brain Mapping/instrumentation , Brain Mapping/statistics & numerical data , Computational Biology , Electrodes , Electroencephalography/instrumentation , Female , Functional Neuroimaging/statistics & numerical data , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging/statistics & numerical data , Male , Photic Stimulation , Spatio-Temporal Analysis , Visual Cortex/physiology , Young Adult
18.
PLoS Comput Biol ; 17(8): e1009252, 2021 08.
Article in English | MEDLINE | ID: mdl-34379638

ABSTRACT

People with Alzheimer's disease (AD) are 6-10 times more likely to develop seizures than the healthy aging population. Leading hypotheses largely consider hyperexcitability of local cortical tissue as primarily responsible for increased seizure prevalence in AD. However, in the general population of people with epilepsy, large-scale brain network organization additionally plays a role in determining seizure likelihood and phenotype. Here, we propose that alterations to large-scale brain network organization seen in AD may contribute to increased seizure likelihood. To test this hypothesis, we combine computational modelling with electrophysiological data using an approach that has proved informative in clinical epilepsy cohorts without AD. EEG was recorded from 21 people with probable AD and 26 healthy controls. At the time of EEG acquisition, all participants were free from seizures. Whole brain functional connectivity derived from source-reconstructed EEG recordings was used to build subject-specific brain network models of seizure transitions. As cortical tissue excitability was increased in the simulations, AD simulations were more likely to transition into seizures than simulations from healthy controls, suggesting an increased group-level probability of developing seizures at a future time for AD participants. We subsequently used the model to assess seizure propensity of different regions across the cortex. We found the most important regions for seizure generation were those typically burdened by amyloid-beta at the early stages of AD, as previously reported by in-vivo and post-mortem staging of amyloid plaques. Analysis of these spatial distributions also give potential insight into mechanisms of increased susceptibility to generalized (as opposed to focal) seizures in AD vs controls. This research suggests avenues for future studies testing patients with seizures, e.g. co-morbid AD/epilepsy patients, and comparisons with PET and MRI scans to relate regional seizure propensity with AD pathologies.


Subject(s)
Alzheimer Disease/complications , Alzheimer Disease/physiopathology , Brain/physiopathology , Models, Neurological , Seizures/etiology , Seizures/physiopathology , Aged , Aged, 80 and over , Algorithms , Alzheimer Disease/pathology , Brain/pathology , Case-Control Studies , Computational Biology , Computer Simulation , Disease Susceptibility , Electroencephalography/statistics & numerical data , Electrophysiological Phenomena , Female , Humans , Male , Nerve Net/pathology , Nerve Net/physiopathology , Neural Networks, Computer , Seizures/pathology
19.
Medicine (Baltimore) ; 100(33): e27001, 2021 Aug 20.
Article in English | MEDLINE | ID: mdl-34414988

ABSTRACT

ABSTRACT: This study aimed to investigate evidence of gray matter brain lesions in multiple sclerosis (MS) patients by evaluating the resting state alpha rhythm of brain electrical activity.The study included 50 patients diagnosed with MS recruited from the MS clinic with 50 age and gender-matched control participants. The study investigated parameters of posterior dominant rhythm (PDR) in the electroencephalography (EEG) recordings including wave frequency and amplitude. Functional disability among the patients was evaluated according to the expanded disability status scale. Univariate statistical analysis was completed using one-way analysis of variance and t test with a P value of less than .05 to indicate statistical significance.Patients with MS had significantly lower PDR frequency and amplitude values compared to the controls (P value < .01) and 34% of the MS patients had a PDR frequency of less than 8.5 Hz. The PDR frequency was negatively associated with the level of functional disability among the patients (P value <.001) and 4% of the patients had abnormal epileptiform discharges.Background slowing of resting alpha rhythms and epileptiform discharges are suggestive of gray matter degeneration and may help in the prediction and follow-up of cortical damage and functional disabilities among MS patients. Therefore, electroencephalography monitoring of the PDR spectrum may serve as an alternative or complementary tool with other imaging techniques to detect and monitor cerebral cortical lesions.


Subject(s)
Electroencephalography/statistics & numerical data , Gray Matter/abnormalities , Multiple Sclerosis/complications , Adult , Case-Control Studies , Electroencephalography/methods , Female , Gray Matter/diagnostic imaging , Humans , Iraq , Male , Middle Aged , Multiple Sclerosis/physiopathology
20.
J Alzheimers Dis ; 83(1): 191-207, 2021.
Article in English | MEDLINE | ID: mdl-34308906

ABSTRACT

BACKGROUND: Extra virgin olive oil (EVOO) constitutes a natural compound with high protection over cognitive function that could positively alter brain dynamics and the mixture of within and between-frequency connectivity. OBJECTIVE: The balance of cross-frequency coupling over within-frequency coupling can build a nonlinearity index (NI) that encapsulates the over-excitation of information flow between brain areas and across experimental time. The present study investigated for the very first time how the Greek High Phenolic Early Harvest Extra Virgin Olive Oil (HP-EH-EVOO) versus Moderate Phenolic (MP-EVOO) and Mediterranean Diet (MeDi) intervention in people with mild cognitive impairment (MCI) could affect their spontaneous EEG dynamic connectivity. METHODS: Forty-three subjects (14 in MeDi, 16 in MP-EVOO, and 13 in HP-EH-EVOO) followed an EEG resting-state recording session (eyes-open and closed) before and after the treatment. Following our dominant coupling mode model, we built a dynamic integrated dynamic functional connectivity graph that tabulates the functional strength and the dominant coupling mode model of every pair of brain areas. RESULTS: Signal spectrum within 1-13 Hz and theta/beta ratio have decreased in the HP-EH-EVOO group in the eyes-open condition. The intervention improved the FIDoCM across groups and conditions but was more prominent in the HP-EH-EVOO group (p < 0.001). Finally, we revealed a significant higher post-intervention reduction of NI (ΔNITotal and α) for the HP-EH-EVOO compared to the MP-EVOO and MeDi groups (p < 0.0001). CONCLUSION: Long-term intervention with HP-EH-EVOO reduced the over-excitation of information flow in spontaneous brain activity and altered the signal spectrum of EEG rhythms.


Subject(s)
Cognition , Cognitive Dysfunction/diet therapy , Diet, Mediterranean , Electroencephalography/statistics & numerical data , Olive Oil , Aged , Brain , Female , Greece , Humans , Male , Neuropsychological Tests/statistics & numerical data , Phenols , Protective Agents
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