scholarly journals Convolution Neural Network Architectures for Motor Imagery EEG Signal Classification

2021 ◽  
Vol 11 (1) ◽  
pp. 15-22
Author(s):  
Nagabushanam Perattur ◽  
S. Thomas George ◽  
D. Raveena Judie Dolly ◽  
Radha Subramanyam
Keyword(s):  
Motor Imagery ◽  
Network Architectures ◽  
Eeg Signal ◽  
Performance Simulation ◽  
Eyes Closed ◽  
Teaching Assessment ◽  
Number Of Layers ◽  
Coefficient Increase ◽  
Eyes Open ◽  
Deep Cnn

This paper has made a survey on motor imagery EEG signals and different classifiers to analyze them. Resolution for medical images like CT, MRI can be improved using deep sense CNN and improved resolution technology. Drowsiness of a student can be analyzed using deep CNN and it helps in teaching, assessment of the student. The authors have proposed 1D-CNN with 2 layers and 3 layers architecture to classify EEG signal for eyes open and eyes closed conditions. Various activation functions and combinations are tried for 2-layer 1D-CNN. Similarly, various loss models are applied in compile model to check the CNN performance. Simulation is carried out using Python 2.7 and 1D-CNN with 3 layers show better performance as it increases number of training parameters by increasing number of layers in the architecture. Accuracy and kappa coefficient increase whereas hamming loss and logloss decreases by increasing number of layers in CNN architecture.

scholarly journals Increased signal diversity/complexity of spontaneous EEG, but not evoked EEG responses, in ketamine-induced psychedelic state in humans

2019 ◽  
Author(s):  
Nadine Farnes ◽  
Bjørn E. Juel ◽  
André S. Nilsen ◽  
Luis G. Romundstad ◽  
Johan F. Storm
Keyword(s):  
Brain Activity ◽  
Altered States Of Consciousness ◽  
Altered States ◽  
Eeg Signal ◽  
Eyes Closed ◽  
Electrical Brain Activity ◽  
States Of Consciousness ◽  
Significant Difference ◽  
Eyes Open ◽  
Signal Diversity

AbstractObjectiveHow and to what extent electrical brain activity is affected in pharmacologically altered states of consciousness, where it is mainly the phenomenological content rather than the level of consciousness that is altered, is not well understood. An example is the moderately psychedelic state caused by low doses of ketamine. Therefore, we investigated whether and how measures of evoked and spontaneous electroencephalographic (EEG) signal diversity are altered by sub-anaesthetic levels of ketamine compared to normal wakefulness, and how these measures relate to subjective assessments of consciousness.MethodsHigh-density electroencephalography (EEG, 62 channels) was used to record spontaneous brain activity and responses evoked by transcranial magnetic stimulation (TMS) in 10 healthy volunteers before and after administration of sub-anaesthetic doses of ketamine in an open-label within-subject design. Evoked signal diversity was assessed using the perturbational complexity index (PCI), calculated from the global EEG responses to local TMS perturbations. Signal diversity of spontaneous EEG, with eyes open and eyes closed, was assessed by Lempel Ziv complexity (LZc), amplitude coalition entropy (ACE), and synchrony coalition entropy (SCE).ResultsAlthough no significant difference was found in the index of TMS-evoked complexity (PCI) between the sub-anaesthetic ketamine condition and normal wakefulness, all the three measures of spontaneous EEG signal diversity showed significantly increased values in the sub-anaesthetic ketamine condition. This increase in signal diversity also correlated with subjective assessment of altered states of consciousness. Moreover, spontaneous signal diversity was significantly higher when participants had eyes open compared to eyes closed, both during normal wakefulness and during influence of sub-anaesthetic ketamine doses.ConclusionThe results suggest that PCI and spontaneous signal diversity may be complementary and potentially measure different aspects of consciousness. Thus, our results seem compatible with PCI being indicative of the brain’s ability to sustain consciousness, as indicated by previous research, while it is possible that spontaneous EEG signal diversity may be indicative of the complexity of conscious content. The observed sensitivity of the latter measures to visual input seems to support such an interpretation. Thus, sub-anaesthetic ketamine may increase the complexity of both the conscious content (experience) and the brain activity underlying it, while the level, degree, or general capacity of consciousness remains largely unaffected.

Effect of a Static Magnetic Field (1.5T) on Brain Oscillatory Activities in Resting State Condition

2008 ◽  
Vol 21 (5) ◽  
pp. 629-635 ◽  
Author(s):  
E. Formaggio ◽  
M. Avesani ◽  
S.F. Storti ◽  
F. Milanese ◽  
A. Gasparini ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Alpha Power ◽  
Eeg Signal ◽  
Eyes Closed ◽  
Prime Concern ◽  
Eeg Data ◽  
Significant Difference ◽  
Eyes Open ◽  
The Magnetic Field

The aim of the present study was to compare the EEG signal recorded outside and inside a 1.5T magnetic resonance (MR) scanner. The EEG was recorded in eyes open and eyes closed conditions using a digital recording MR-compatible system. To characterize how a static magnetic field induces changes in EEG signal, EEG data were analyzed using FFT frequency analysis. No significant difference between the alpha powers recorded outside and inside the magnetic field was observed in eyes closed conditions. However, in eyes open condition there was a significant increase in alpha power inside the magnet in comparison to the outside position. The changes in alpha power according to the eyes open/closed conditions could be inversely correlated to a subject's state of wakefulness and due to some physiological changes, rather than an effect of the magnetic field. This experiment suggests that subjects' state of wakefulness is of prime concern when performing functional MRI.

scholarly journals Increased signal diversity/complexity of spontaneous EEG, but not evoked EEG responses, in ketamine-induced psychedelic state in humans

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242056
Author(s):  
Nadine Farnes ◽  
Bjørn E. Juel ◽  
André S. Nilsen ◽  
Luis G. Romundstad ◽  
Johan F. Storm
Keyword(s):  
Subjective Experience ◽  
Brain Activity ◽  
Altered States Of Consciousness ◽  
Altered States ◽  
Eeg Signal ◽  
Eyes Closed ◽  
States Of Consciousness ◽  
Significant Difference ◽  
Eyes Open ◽  
Signal Diversity

How and to what extent electrical brain activity reflects pharmacologically altered states and contents of consciousness, is not well understood. Therefore, we investigated whether measures of evoked and spontaneous electroencephalographic (EEG) signal diversity are altered by sub-anaesthetic levels of ketamine compared to normal wakefulness, and how these measures relate to subjective experience. High-density 62-channel EEG was used to record spontaneous brain activity and responses evoked by transcranial magnetic stimulation (TMS) in 10 healthy volunteers before and during administration of sub-anaesthetic doses of ketamine in an open-label within-subject design. Evoked signal diversity was assessed using the perturbational complexity index (PCI), calculated from EEG responses to TMS perturbations. Signal diversity of spontaneous EEG, with eyes open and eyes closed, was assessed by Lempel Ziv complexity (LZc), amplitude coalition entropy (ACE), and synchrony coalition entropy (SCE). Although no significant difference was found in TMS-evoked complexity (PCI) between the sub-anaesthetic ketamine condition and normal wakefulness, all measures of spontaneous EEG signal diversity (LZc, ACE, SCE) showed significantly increased values in the sub-anaesthetic ketamine condition. This increase in signal diversity correlated with subjective assessment of altered states of consciousness. Moreover, spontaneous signal diversity was significantly higher when participants had eyes open compared to eyes closed, both during normal wakefulness and during influence of sub-anaesthetic ketamine. The results suggest that PCI and spontaneous signal diversity may reflect distinct, complementary aspects of changes in brain properties related to altered states of consciousness: the brain’s capacity for information integration, assessed by PCI, might be indicative of the brain’s ability to sustain consciousness, while spontaneous complexity, as measured by EEG signal diversity, may be indicative of the complexity of conscious content. Thus, sub-anaesthetic ketamine may increase the complexity of the conscious content and the brain activity underlying it, while the level or general capacity for consciousness remains largely unaffected.

scholarly journals Development of an EEG signal analysis application through a convolution of a complex Morlet wavelet: preliminary results

2019 ◽  
Vol 8 (2) ◽  
pp. B1-1-B1-19
Author(s):  
José Humberto Trueba Perdomo ◽  
◽  
Ignacio Herrera Aguilar ◽  
Francesca Gasparini ◽  
◽  
...  
Keyword(s):  
Morlet Wavelet ◽  
Eeg Signal ◽  
Eeg Signals ◽  
Eyes Closed ◽  
Eyes Open ◽  
Analysis Application ◽  
The Subject ◽  
Complex Morlet Wavelet ◽  
Electroencephalogram Eeg ◽  
Eeg Signal Analysis

This paper presents a new application for analyzing electroencephalogram (EEG) signals. The signals are pre-filtered through MATLAB's EEGLAB tool. The created application performs a convolution between the original EEG signal and a complex Morlet wavelet. As a final result, the application shows the signal power value and a spectrogram of the convoluted signal. Moreover, the created application compares different EEG channels at the same time, in a fast and straightforward way, through a time and frequency analysis. Finally, the effectiveness of the created application was demonstrated by performing an analysis of the alpha signals of healthy subjects, one signal created by the subject with eyes closed and the other, with which it was compared, was created by the same subject with eyes open. This also served to demonstrate that the power of the alpha band of the closed-eyed signal is higher than the power of the open-eyed signal.

scholarly journals A Wearable Head Mounted Display Bio-Signals Pad System for Emotion Recognition

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 142
Author(s):  
Chunting Wan ◽  
Dongyi Chen ◽  
Zhiqi Huang ◽  
Xi Luo
Keyword(s):  
Emotion Recognition ◽  
Electrodermal Activity ◽  
Research Field ◽  
Acquisition System ◽  
Emotional States ◽  
Eeg Signal ◽  
Measuring Device ◽  
Head Mounted Display ◽  
Eyes Closed ◽  
Eyes Open

Multimodal bio-signals acquisition based on wearable devices and using virtual reality (VR) as stimulus source are promising techniques in emotion recognition research field. Numerous studies have shown that emotional states can be better evoked through Immersive Virtual Environments (IVE). The main goal of this paper is to provide researchers with a system for emotion recognition in VR environments. In this paper, we present a wearable forehead bio-signals acquisition pad which is attached to Head-Mounted Displays (HMD), termed HMD Bio Pad. This system can simultaneously record emotion-related two-channel electroencephalography (EEG), one-channel electrodermal activity (EDA), photoplethysmograph (PPG) and skin temperature (SKT) signals. In addition, we develop a human-computer interaction (HCI) interface which researchers can carry out emotion recognition research using VR HMD as stimulus presentation device. To evaluate the performance of the proposed system, we conducted different experiments to validate the multimodal bio-signals quality, respectively. To validate EEG signal, we have assessed the performance in terms of EEG eyes-blink task and eyes-open and eyes-closed task. The EEG eyes-blink task indicates that the proposed system can achieve comparable EEG signal quality in comparison to the dedicated bio-signals measuring device. The eyes-open and eyes-closed task proves that the proposed system can efficiently record alpha rhythm. Then we used signal-to-noise ratio (SNR) and Skin Conductance Reaction (SCR) signal to validate the performance for EDA acquisition system. A filtered EDA signal, with a high mean SNR of 28.52 dB, is plotted on HCI interface. Moreover, the SCR signal related to stimulus response can be correctly extracted from EDA signal. The SKT acquisition system has been validated effectively by the temperature change experiment when subjects are in unpleasant emotion. The pulse rate (PR) estimated from PPG signal achieved the low mean average absolute error (AAE), which is 1.12 beats per minute (BPM) over 8 recordings. In summary, the proposed HMD Bio Pad offers a portable, comfortable and easy-to-wear device for recording bio-signals. The proposed system could contribute to emotion recognition research in VR environments.

1D CNN Architectures for EEG Classification with Motor Imagery input of eyes open and eyes closed conditions

2020 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
SUBATHRA M. S. P ◽  
S. THOMAS GEORGE ◽  
NAGABUSHANAM PERATTUR ◽  
RADHA SUBRAMANYAM
Keyword(s):  
Motor Imagery ◽  
Eeg Classification ◽  
Eyes Closed ◽  
Eyes Open

scholarly journals Use of Both Eyes-Open and Eyes-Closed Resting States May Yield a More Robust Predictor of Motor Imagery BCI Performance

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 690 ◽  
Author(s):  
Moonyoung Kwon ◽  
Hohyun Cho ◽  
Kyungho Won ◽  
Minkyu Ahn ◽  
Sung Chan Jun
Keyword(s):  
Motor Imagery ◽  
Spectral Entropy ◽  
Eyes Closed ◽  
Spectral Bands ◽  
Brain Signals ◽  
Subject Variability ◽  
Eyes Open ◽  
Brain States ◽  
Single State ◽  
Lateral Sclerosis

Motor-imagery brain-computer interface (MI-BCI) is a technique that manipulates external machines using brain activities, and is highly useful to amyotrophic lateral sclerosis patients who cannot move their limbs. However, it is reported that approximately 15–30% of users cannot modulate their brain signals, which results in the inability to operate motor imagery BCI systems. Thus, advance prediction of BCI performance has drawn researchers’ attention, and some predictors have been proposed using the alpha band’s power, as well as other spectral bands’ powers, or spectral entropy from resting state electroencephalography (EEG). However, these predictors rely on a single state alone, such as the eyes-closed or eyes-open state; thus, they may often be less stable or unable to explain inter-/intra-subject variability. In this work, a modified predictor of MI-BCI performance that considered both brain states (eyes-open and eyes-closed resting states) was investigated with 41 online MI-BCI session datasets acquired from 15 subjects. The results showed that our proposed predictor and online MI-BCI classification accuracy were positively and highly significantly correlated (r = 0.71, p < 0.1 × 10 − 7 ), which indicates that the use of multiple brain states may yield a more robust predictor than the use of a single state alone.

A systematic review and meta-analysis on efficacy of exercise on posture and balance in patients suffering from Diabetic Neuropathy

2020 ◽  
Vol 16 ◽  
Author(s):  
Neerja Thukral ◽  
Jaspreet Kaur ◽  
Manoj Malik
Keyword(s):  
Diabetes Mellitus ◽  
Diabetic Neuropathy ◽  
Meta Analysis ◽  
Berg Balance Scale ◽  
Risk Of Bias ◽  
Core Stability ◽  
Balance Scale ◽  
Eyes Closed ◽  
Significant Difference ◽  
Eyes Open

Background: Peripheral neuropathy is a major and chronic complication of diabetes mellitus affecting more than 50% of patients suffering from diabetes. There is involvement of both large and small diameter nerve fibres leading to altered somatosensory and motor sensations, thereby causing impaired balance and postural instability. Objective: To assess the effects of exercises on posture and balance in patients suffering from diabetes mellitus. Method: Mean changes in Timed Up and Go test(TUGT), Berg Balance Scale and Postural Sway with eyes open and eyes closed on Balance System were primary outcome measures. RevMan 5.3 software was used for the meta-analyses. Eighteen randomized controlled trials met the selection criteria and were included in the study. All the studies ranked high on PEDro Rating scale. Risk of bias was assessed by Cochrane collaboration tool of risk of bias. Included studies had low risk of bias. Sixteen RCT’s were included for the meta-analysis. Result: Results of meta-analysis showed that there was statistically significant improvement in TUGT with p≤ 0.05 and substantial heterogeneity (I 2 = 84%, p < 0.00001) in experimental group as compared to control group. There was statistically significant difference in Berg Balance Scale scores and heterogeneity of I 2 = 62%, p < 0.00001 and significant changes in postural stability (eyes open heterogeneity of I 2 = 100%, p =0.01 and eyes closed, heteogeneity I 2 = 0%, p =0.01). Sensitivity analysis causes change in heterogeneity. Conclusion: It can be concluded that various exercises like balance training, core stability, Tai-Chi, proprioceptive training etc. have a significant effect in improving balance and posture in diabetic neuropathy.

scholarly journals Gender Differences in Postural Stability among 13-Year-Old Alpine Skiers

2020 ◽  
Vol 17 (11) ◽  
pp. 3859 ◽  
Author(s):  
Agnieszka D. Jastrzębska
Keyword(s):  
Gender Differences ◽  
Postural Balance ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Body Sway ◽  
Foot Pressure ◽  
Eyes Closed ◽  
Before And After ◽  
Eyes Open ◽  
Alpine Skiers

This experiment examined changes in body sway after Wingate test (WAnT) in 19 adolescents practicing alpine skiing, subjected to the same type of training load for 4–5 years (10 girls and nine boys). The postural examinations were performed with eyes open (EO), eyes closed (EC), and sway reverenced vision (SRV) in the medial-lateral (ML) and anterior-posterior (AP) planes. The displacement of center of foot pressure (CoP), range of sway (RS), mean sway velocity (MV), way length, and surface area were measured in bipedal upright stance before and after the WAnT to assess the influence of fatigue on postural balance. There were no significant differences in WAnT parameters between girls and boys. Relative peak power (RPP), relative total work (RWtot) were (girls vs. boys) 8.89 ± 0.70 vs. 9.57 ± 1.22 W/kg, p < 0.05 and 227.91 ± 14.98 vs. 243.22 ± 30.24 W/kg, p < 0.05 respectively. The fatigue index (FI) was also on similar level in both genders; however, blood lactate concentration (BLa) was significantly higher in boys (10.35 ± 1.16 mM) than in girls (8.67 ± 1.35 mM) p = 0.007. In the EO examination, statistically significant differences between resting and fatigue conditions in the whole group and after the division into girls and boys were found. In fatigue conditions, significant gender differences were noted for measurements in the ML plane (sway path and RS) and RS in the AP plane. Comparison of the three conditions shows differences between EO vs. EC and SRV in AP plane measured parameters, and for RS in ML plane in rest condition in girls. The strong correlations between FI and CoP parameters mainly in ML plane in the whole group for all examination conditions were noted. By genders, mainly RS in ML plane strongly correlates with FI (r > 0.7). No correlation was found between BLa and CoP parameters (p > 0.06). The presented results indicate that subjecting adolescents of both genders to the same training may reduce gender differences in the postural balance ability at rest but not in fatigue conditions and that girls are significantly superior in postural balance in the ML plane than boys. It was also shown that too little or too much information may be destructive to postural balance in young adolescents.

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