Understanding of neuro-dynamics of a complex higher cognitive process, Working Memory (WM) is
challenging. In WM, information processing occurs through four subsystems: phonological loop, visual
sketch pad, memory buffer and central executive function (CEF). CEF plays a principal role in WM. In this
study, our objective was to understand the neurospatial correlates of CEF during inhibition and set-shifting
processes. Thirty healthy educated subjects were selected. Event-Related Potential (ERP) related to visual
inhibition and set-shifting task was collected using 32 channel EEG system. Activation of those ERPs
components was analyzed using amplitudes of positive and negative peaks. Experiment was controlled
using certain parametric constraints to judge behavior, based on average responses in order to establish
relationship between ERP and local area of brain activation and represented using standardized low
resolution brain electromagnetic tomography. The average score of correct responses was higher for
inhibition task (87.5%) as compared to set-shifting task (59.5%). The peak amplitude of neuronal activity
for inhibition task was lower compared to set-shifting task in fronto-parieto-central regions. Hence this
proposed paradigm and technique can be used to measure inhibition and set-shifting neuronal processes in
understanding pathological central executive functioning in patients with neuro-psychiatric disorders.
Distinguishing Cognitive Tasks Using Statistical Analysis TechniquesIOSR Journals
- The document discusses distinguishing between cognitive tasks like mathematics, physics, and chemistry using EEG signal analysis and statistical techniques.
- EEG signals were recorded from students performing different cognitive tasks and analyzed using Kruskal-Wallis statistical testing.
- The results of the Kruskal-Wallis test showed a significant difference between the EEG signals corresponding to the different cognitive tasks.
EEG based Brain Computer Interface (BCI) establishes a new channel between human brain and the
surrounding environment in order to disseminate instructions to the outside world. It is based on the
recording of temporary EEG changes during different types of motor imagery such as imagination of
different hand movements. The spatial pattern of activated cortical areas during motor imagery is similar
to that of real time executed movement. Time domain features and frequency domain features are extracted
with emphasis on recognizing discriminative features representing EEG trials recorded during imagination
of different hand movements. Then, classification into different hand movements is carried out.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document describes an experiment that used EEG signals to detect mental stress in human subjects. EEG signals were collected from subjects using electrodes placed according to the 10-20 international system. Stress was induced using images from the IAPS dataset. Machine learning algorithms like ICA, DWT, and PCA were used to preprocess the signals, extract features, and reduce dimensions. SVM and neural networks were then used to classify states as stressed or calm, achieving accuracies of 82% and 80% respectively. The study aimed to determine a subject's mental state as stressed or not stressed, rather than determining causes or levels of stress.
IRJET- Precision of Lead-Point with Support Vector Machine based Microelectro...IRJET Journal
This document discusses using microelectrode recordings (MER) with support vector machine learning to study the function of subthalamic nucleus (STN) neurons in the human brain during deep brain stimulation for Parkinson's disease. The study aims to improve the signal-to-noise ratio of MER signals and precisely identify the location of the STN to ensure safety and efficacy of deep brain stimulation chip implantation. MER is found to confirm the presence of abnormal STN neurons and clear positioning of the microchip electrode in the target area. Access to functional data from neurons deep in the brain using MER may help further elucidate cryptic aspects of brain function.
Let’s master the digital toolkit to harness lifelong neuroplasticitySharpBrains
Four leading pioneers of applied neuroplasticity helped us navigate best practices to harness most promising non-invasive neurotechnologies, such as cognitive training, mindfulness apps, EEG and virtual/ augmented reality.
--Chair: Linda Raines, CEO of the Mental Health Association of Maryland
--Dr. Michael Merzenich, winner of the 2016 Kavli Prize in Neuroscience
--Dr. Judson Brewer, Founder & Research Lead of Claritas Mindsciences
--Tan Le, CEO of Emotiv
--Dr. Andrea Serino, Head of Neuroscience at MindMaze
Learn more at sharpbrains.com
Iaetsd recognition of emg based hand gesturesIaetsd Iaetsd
This document summarizes research on recognizing electromyography (EMG) signals from hand gestures to control prosthetics using artificial neural networks. EMG signals were collected from muscles during two hand gestures. Thirteen features were extracted from the signals and used to train and test several neural networks with different training algorithms. It was found that networks using the Levenberg-Marquardt algorithm achieved the best performance, with over 90% classification accuracy and the fastest training times, making it most suitable for accurate and rapid prosthetic control based on EMG pattern recognition.
This paper aims to classify grasp types from electromyography (EMG) data using artificial neural networks. EMG data was collected from six grasps and decomposed into intrinsic mode functions using empirical mode decomposition. Seven features were extracted from the frequency and time domains. Various feature subsets were used to train a neural network classifier, with the best results achieved using all features except variance from the EMG data and the first three intrinsic mode functions. The paper seeks to recognize intended grasps from EMG input data using neural networks in order to improve prosthetic control.
Distinguishing Cognitive Tasks Using Statistical Analysis TechniquesIOSR Journals
- The document discusses distinguishing between cognitive tasks like mathematics, physics, and chemistry using EEG signal analysis and statistical techniques.
- EEG signals were recorded from students performing different cognitive tasks and analyzed using Kruskal-Wallis statistical testing.
- The results of the Kruskal-Wallis test showed a significant difference between the EEG signals corresponding to the different cognitive tasks.
EEG based Brain Computer Interface (BCI) establishes a new channel between human brain and the
surrounding environment in order to disseminate instructions to the outside world. It is based on the
recording of temporary EEG changes during different types of motor imagery such as imagination of
different hand movements. The spatial pattern of activated cortical areas during motor imagery is similar
to that of real time executed movement. Time domain features and frequency domain features are extracted
with emphasis on recognizing discriminative features representing EEG trials recorded during imagination
of different hand movements. Then, classification into different hand movements is carried out.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document describes an experiment that used EEG signals to detect mental stress in human subjects. EEG signals were collected from subjects using electrodes placed according to the 10-20 international system. Stress was induced using images from the IAPS dataset. Machine learning algorithms like ICA, DWT, and PCA were used to preprocess the signals, extract features, and reduce dimensions. SVM and neural networks were then used to classify states as stressed or calm, achieving accuracies of 82% and 80% respectively. The study aimed to determine a subject's mental state as stressed or not stressed, rather than determining causes or levels of stress.
IRJET- Precision of Lead-Point with Support Vector Machine based Microelectro...IRJET Journal
This document discusses using microelectrode recordings (MER) with support vector machine learning to study the function of subthalamic nucleus (STN) neurons in the human brain during deep brain stimulation for Parkinson's disease. The study aims to improve the signal-to-noise ratio of MER signals and precisely identify the location of the STN to ensure safety and efficacy of deep brain stimulation chip implantation. MER is found to confirm the presence of abnormal STN neurons and clear positioning of the microchip electrode in the target area. Access to functional data from neurons deep in the brain using MER may help further elucidate cryptic aspects of brain function.
Let’s master the digital toolkit to harness lifelong neuroplasticitySharpBrains
Four leading pioneers of applied neuroplasticity helped us navigate best practices to harness most promising non-invasive neurotechnologies, such as cognitive training, mindfulness apps, EEG and virtual/ augmented reality.
--Chair: Linda Raines, CEO of the Mental Health Association of Maryland
--Dr. Michael Merzenich, winner of the 2016 Kavli Prize in Neuroscience
--Dr. Judson Brewer, Founder & Research Lead of Claritas Mindsciences
--Tan Le, CEO of Emotiv
--Dr. Andrea Serino, Head of Neuroscience at MindMaze
Learn more at sharpbrains.com
Iaetsd recognition of emg based hand gesturesIaetsd Iaetsd
This document summarizes research on recognizing electromyography (EMG) signals from hand gestures to control prosthetics using artificial neural networks. EMG signals were collected from muscles during two hand gestures. Thirteen features were extracted from the signals and used to train and test several neural networks with different training algorithms. It was found that networks using the Levenberg-Marquardt algorithm achieved the best performance, with over 90% classification accuracy and the fastest training times, making it most suitable for accurate and rapid prosthetic control based on EMG pattern recognition.
This paper aims to classify grasp types from electromyography (EMG) data using artificial neural networks. EMG data was collected from six grasps and decomposed into intrinsic mode functions using empirical mode decomposition. Seven features were extracted from the frequency and time domains. Various feature subsets were used to train a neural network classifier, with the best results achieved using all features except variance from the EMG data and the first three intrinsic mode functions. The paper seeks to recognize intended grasps from EMG input data using neural networks in order to improve prosthetic control.
CURRENT STATUS AND FUTURE RESEARCH DIRECTIONS IN MONITORING VIGILANCE OF INDI...ijsc
Working in monotonous environment often causes lack of concentration or fatigue in an operator and many
times such non-vigilance leads to accidents. Therefore early detection of fatigued state has become
essential in monotonous working environments like driving vehicle, operating machines etc. Such fatigued
state often gets developed gradually and can be identified by certain symptoms. Different types of symptoms
help in modelling non-vigilance in different ways. This paper reviews and compares current status of
research in modelling fatigue where fatigue is modelled using probabilistic models, machine learning
models, finite state machine etc. The paper also presents possible future research directions in the same
field like identifying non-fatigue non-vigilance mental states, extending non-vigilance monitoring for mass
audience etc.
SUITABLE MOTHER WAVELET SELECTION FOR EEG SIGNALS ANALYSIS: FREQUENCY BANDS D...sipij
Wavelet transform (WT) is a powerful modern tool for time-frequency analysis of non-stationary signals such as electroencephalogram (EEG). The aim of this study is to choose the best and suitable mother wavelet function (MWT) for analyzing normal, seizure-free and seizured EEG signals. Several MWTs can be used, but the best MWT is the one that conserves the quasi-totality of information of the original signal on wavelet coefficients and gather more EEG rhythms in terms of frequency. In this study, Daubechies, Symlets and Coiflets orthogonal families were used as bsis mother wavelet functions. The percentage rootmeans square difference (PRD), the signal to noise ratio (SNR) and the simulated frequencies as the selection metrics. Simulation results indicate Daubechies wavelet at level 4 (Db4) as the most suitable MWT for EEG frequency bands decomposition.Furthermore, due to the redundancy of the extracted features, linear discriminant analysis (LDA) is applied for feature selection. Scatter plot showed that the selected feature vector represents the amount of changes in frequency distribution and carries most of the discriminative and representative information about their classes. Then, this study can provide a reference for the selection of a suitable MWT and discriminativefeatures.
This document compares the performance of three widely-used brain segmentation software packages (SPM, FSL, and Brainsuite) at segmenting brain MRI images into gray matter, white matter, and cerebrospinal fluid. It evaluates the packages using both simulated Brainweb MRI images and real MRI images from the IBSR dataset. For each package, it describes the segmentation methods and preprocessing steps. The accuracy of the segmented tissues from each package is assessed by calculating the similarity between the automated segmentations and corresponding ground truth segmentations. The results show variations in segmentation performance between the different packages and methods.
EMG Diagnosis using Neural Network Classifier with Time Domain and AR FeaturesIDES Editor
The shapes of motor unit action potentials
(MUAPs) in an electromyographic (EMG) signal
provide an important source of information for the
diagnosis of neuromuscular disorders. To extract this
information from the EMG signals, the first step is
identification of the MUAPs composed by the EMG
signal, second step is clustering of MUAPs with similar
shapes, third step is extraction of the features of MUAP
clusters and last step is classification of MUAPs. In this
work, the MUAPs are identified by using a data driven
segmentation algorithm, statistical pattern recognition
technique is used for clustering of MUAPs. Followed by
the extraction of time domain and autoregressive (AR)
features of the MUAP clusters. Finally, a neural
network (NN) classifier is used for classification of
MUAPs. A total of 12 EMG signals obtained from 3
normal (NOR), 5 myopathic (MYO) and 4 motor
neuron diseased (MND) subjects were analyzed. The
success rate for the segmentation technique is 95.90%
and for the statistical technique is 93.13%. The
classification accuracy of NN is 66.72% with time
domain parameters and 75.06 % with AR parameters.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This document discusses neural coding and how neurons encode information during cognitive tasks. It summarizes research using single-unit neural recordings in rats performing a directional control task. Three key findings are presented:
1) Neural firing rates in areas like PM and M1 encoded information about trial outcomes and the rat's learning progress over multiple sessions.
2) Precise spike timing provided information about the rat's cognitive state, with more synchronized activity observed early in learning.
3) Network modeling revealed changes in functional connectivity between neurons associated with synaptic plasticity, with more optimized patterns emerging as the rat became proficient at the task.
Improved target recognition response using collaborative brain-computer inter...Kyongsik Yun
One can achieve higher levels of perceptual and cognitive performance by leveraging the power of multiple brains through collaborative brain-computer interfaces
Minimizing Musculoskeletal Disorders in Lathe Machine WorkersWaqas Tariq
In production units, workers work under tough conditions to perform the desired task. These tough conditions normally give rise to various musculoskeletal disorders within the workers. These disorders emerge within the workers body due to repetitive lifting, differential lifting height, ambient conditions etc. For the minimization of musculoskeletal disorders it is quite difficult to model them with mathematical difference or differential equations. In this paper the minimization of musculoskeletal disorders problem has been formulated using fuzzy technique. It is very difficult to train non linear complex musculoskeletal disorders problem, hence in this paper a non linear fuzzy model has been developed to give solutions to these non linearities. This model would have the capability of representing solutions for minimizing musculoskeletal disorders needed for workers working in the production units.
EEG SIGNAL IDENTIFICATION USING SINGLE-LAYER NEURAL NETWORKIJCI JOURNAL
EEG signal analysis is applied in various fields such as medicine, communication and control. To control based on EEG signals achieved good result, the system must identify effectively EEG signals. In this paper,
a novel approach proposes the EEG signal identification based on image with the EEG signal processing via Wavelet transform and the identification via single-layer neural network. The system model is designed and evaluated with the dataset of 21,000 samples. The accuracy rate can obtain 91.15%.
This summary provides the key details from the document in 3 sentences:
The document discusses optimizing the parameters of an artificial neural network (ANN) model for predicting schizophrenia. It explores different numbers of hidden layers, epochs, and fold units to determine the configuration that results in the highest training accuracy and lowest error. The optimal parameters were found to be 8 hidden layers, 2 fold units, and up to 1000 epochs, achieving a peak training accuracy of 71.34% and prediction accuracy of 74.53%.
This study examined how neural signals from the primary motor cortex of macaque monkeys could be used to control a robotic arm in real time. Researchers implanted an array of microelectrodes in the motor cortex and found that neural activity strongly correlated with arm movements. They used a population vector algorithm to decode neural firing patterns into commands to position the robotic arm. Monkeys achieved high accuracy after training, demonstrating the potential for brain-machine interfaces to restore limb function. However, challenges remain in developing stable, long-term electrode interfaces and reducing system size for applications such as neural prosthetics.
The presentation by Cerenaut at the orientation (2021-06-05) for the 5th WBA Hackathon, an online AI competition to implement working memory
https://wba-initiative.org/en/18687/
- Neuroscientific issues
- Architecture details
- Instruction on the CodaLab competition
Classification of emotions induced by horror and relaxing movies using single-...IJECEIAES
It has been observed from recent studies that corticolimbic Theta rhythm from EEG recordings perceived as fear or threatening scene during neural processing of visual stimuli. In additions, neural oscillations’ patterns in Theta, Alpha and Beta sub-bands also play important role in brain’s emotional processing. Inspired from these findings, in this paper we attempt to classify two different emotional states by analyzing single-channel EEG recordings. A video clip that can evoke 3 different emotional states: neutral, relaxation and scary is shown to 19 college-aged subjects and they were asked to score their emotional outcome by giving a number between 0 to 10 (where 0 means not scary at all and 10 means the most scary). First, recorded EEG data were preprocessed by stationary wavelet transform (SWT) based artifact removal algorithm. Then power distribution in simultaneous time-frequency domain was analyzed using short-time Fourier transform (STFT) followed by calculating the average power during each 0.2s time-segment for each brain sub-band. Finally, 46 features, as the mean power of frequency bands between 4 and 50 Hz during each time-segment, containing 689 instances—for each subject —were collected for classification. We found that relaxation and fear emotions evoked during watching scary and relaxing movies can be classified with average classification rate of 94.208% using K-NN by applying methods and materials proposed in this paper. We also classified the dataset using SVM and we found out that K-NN classifier (when k = 1) outperforms SVM in classifying EEG dynamics induced by horror and relaxing movies, however, for K > 1 in K-NN, SVM has better average classification rate.
This study examined mirror neurons in macaque monkeys through electrophysiological recordings. The researchers recorded from 37 mirror neurons in the F5 region of the monkeys' brains. They found that mirror neurons responded both when the monkey performed hand actions like grasping and when they observed the experimenter perform the same actions. Mirror neurons responded more strongly during the late movement and holding periods of the observed actions. The results support the hypothesis that mirror neurons are involved in action recognition. The study provides evidence that mirror neurons encode the meaning and intention of observed actions.
A New Approach to Denoising EEG Signals - Merger of Translation Invariant Wav...CSCJournals
In this paper we present a new algorithm using a merger of Independent Component Analysis and Translation Invariant Wavelet Transform. The efficacy of this algorithm is evaluated by applying contaminated EEG signals. Its performance was compared to three fixed-point ICA algorithms (FastICA, EFICA and Pearson-ICA) using Mean Square Error (MSE), Peak Signal to Noise Ratio (PSNR), Signal to Distortion Ratio (SDR), and Amari Performance Index. Experiments reveal that our new technique is the most accurate separation method.
This thesis examines how attention affects the functional connectivity of the visual cortex using transcranial magnetic stimulation (TMS) and electroencephalography (EEG). Participants performed a covert attention task where they oriented their attention to one of two locations indicated by a central cue arrow. TMS was applied to occipital cortex, parietal cortex, or orthogonally to the scalp 600ms after cue onset. No effects of stimulation site were found on behavior, but the EEG data showed a late interaction between stimulation site and cue direction 340-390ms after the TMS pulse, suggesting a top-down attentional modulation of visual cortex connectivity. Further analyses will investigate this late effect.
The document is a thesis that examines the calculation of reward prediction in behaving animals. It provides background on the dopamine reward system in the brain and reinforcement learning. Key findings from experiments show that dopamine neuron firing encodes prediction error - the difference between expected and actual rewards. Over time as animals learn reward associations, dopamine firing decreases, reflecting reduced unpredictability. The thesis aims to model behavioral data from mice using a temporal difference learning algorithm and reinforcement learning principles.
IRJET- Depression Prediction System using Different MethodsIRJET Journal
This document summarizes a research paper that proposes a depression prediction system using different methods. The system would use three approaches: a question and answer part using standardized depression questionnaires; EEG signal processing to analyze brain activity; and sentiment analysis of social media posts. Machine learning algorithms like neural networks and naive Bayes would be used for classification. The goal is to help predict depression early through an online system that could be used by doctors and individuals. Key areas discussed include artificial intelligence, machine learning techniques for classification like support vector machines and logistic regression, and prior research analyzing EEG signals and social media posts to predict depression.
A BINARY TO RESIDUE CONVERSION USING NEW PROPOSED NON-COPRIME MODULI SETsipij
Residue Number System is generally supposed to use co-prime moduli set. Non-coprime moduli sets are a
field in RNS which is little studied. That's why this work was devoted to them. The resources that discuss
non-coprime in RNS are very limited. For the previous reasons, this paper analyses the RNS conversion
using suggested non-coprime moduli set.
This paper suggests a new non-coprime moduli set and investigates its performance. The suggested new
moduli set has the general representation as {2n
–2, 2n
, 2n+2}, where n ∈ {2,3,…..,∞}. The calculations
among the moduli are done with this n value. These moduli are 2 spaces apart on the numbers line from
each other. This range helps in the algorithm’s calculations as to be shown.
The proposed non-coprime moduli set is investigated. Conversion algorithm from Binary to Residue is
developed. Correctness of the algorithm was obtained through simulation program. Conversion algorithm
is implemented.
An Innovative Moving Object Detection and Tracking System by Using Modified R...sipij
The ultimate goal of this study is to afford enhanced video object detection and tracking by eliminating the
limitations which are existing nowadays. Although high performance ratio for video object detection and
tracking is achieved in the earlier work it takes more time for computation. Consequently we are in need to
propose a novel video object detection and tracking technique so as to minimize the computational
complexity. Our proposed technique covers five stages they are preprocessing, segmentation, feature
extraction, background subtraction and hole filling. Originally the video clip in the database is split into
frames. Then preprocessing is performed so as to get rid of noise, an adaptive median filter is used in this
stage to eliminate the noise. The preprocessed image then undergoes segmentation by means of modified
region growing algorithm. The segmented image is subjected to feature extraction phase so as to extract
the multi features from the segmented image and the background image, the feature value thus obtained
are compared so as to attain optimal value, consequently a foreground image is attained in this stage. The
foreground image is then subjected to morphological operations of erosion and dilation so as to fill the
holes and to get the object accurately as these foreground image contains holes and discontinuities. Thus
the moving object is tracked in this stage. This method will be employed in MATLAB platform and the
outcomes will be studied and compared with the existing techniques so as to reveal the performance of the
novel video object detection and tracking technique.
CURRENT STATUS AND FUTURE RESEARCH DIRECTIONS IN MONITORING VIGILANCE OF INDI...ijsc
Working in monotonous environment often causes lack of concentration or fatigue in an operator and many
times such non-vigilance leads to accidents. Therefore early detection of fatigued state has become
essential in monotonous working environments like driving vehicle, operating machines etc. Such fatigued
state often gets developed gradually and can be identified by certain symptoms. Different types of symptoms
help in modelling non-vigilance in different ways. This paper reviews and compares current status of
research in modelling fatigue where fatigue is modelled using probabilistic models, machine learning
models, finite state machine etc. The paper also presents possible future research directions in the same
field like identifying non-fatigue non-vigilance mental states, extending non-vigilance monitoring for mass
audience etc.
SUITABLE MOTHER WAVELET SELECTION FOR EEG SIGNALS ANALYSIS: FREQUENCY BANDS D...sipij
Wavelet transform (WT) is a powerful modern tool for time-frequency analysis of non-stationary signals such as electroencephalogram (EEG). The aim of this study is to choose the best and suitable mother wavelet function (MWT) for analyzing normal, seizure-free and seizured EEG signals. Several MWTs can be used, but the best MWT is the one that conserves the quasi-totality of information of the original signal on wavelet coefficients and gather more EEG rhythms in terms of frequency. In this study, Daubechies, Symlets and Coiflets orthogonal families were used as bsis mother wavelet functions. The percentage rootmeans square difference (PRD), the signal to noise ratio (SNR) and the simulated frequencies as the selection metrics. Simulation results indicate Daubechies wavelet at level 4 (Db4) as the most suitable MWT for EEG frequency bands decomposition.Furthermore, due to the redundancy of the extracted features, linear discriminant analysis (LDA) is applied for feature selection. Scatter plot showed that the selected feature vector represents the amount of changes in frequency distribution and carries most of the discriminative and representative information about their classes. Then, this study can provide a reference for the selection of a suitable MWT and discriminativefeatures.
This document compares the performance of three widely-used brain segmentation software packages (SPM, FSL, and Brainsuite) at segmenting brain MRI images into gray matter, white matter, and cerebrospinal fluid. It evaluates the packages using both simulated Brainweb MRI images and real MRI images from the IBSR dataset. For each package, it describes the segmentation methods and preprocessing steps. The accuracy of the segmented tissues from each package is assessed by calculating the similarity between the automated segmentations and corresponding ground truth segmentations. The results show variations in segmentation performance between the different packages and methods.
EMG Diagnosis using Neural Network Classifier with Time Domain and AR FeaturesIDES Editor
The shapes of motor unit action potentials
(MUAPs) in an electromyographic (EMG) signal
provide an important source of information for the
diagnosis of neuromuscular disorders. To extract this
information from the EMG signals, the first step is
identification of the MUAPs composed by the EMG
signal, second step is clustering of MUAPs with similar
shapes, third step is extraction of the features of MUAP
clusters and last step is classification of MUAPs. In this
work, the MUAPs are identified by using a data driven
segmentation algorithm, statistical pattern recognition
technique is used for clustering of MUAPs. Followed by
the extraction of time domain and autoregressive (AR)
features of the MUAP clusters. Finally, a neural
network (NN) classifier is used for classification of
MUAPs. A total of 12 EMG signals obtained from 3
normal (NOR), 5 myopathic (MYO) and 4 motor
neuron diseased (MND) subjects were analyzed. The
success rate for the segmentation technique is 95.90%
and for the statistical technique is 93.13%. The
classification accuracy of NN is 66.72% with time
domain parameters and 75.06 % with AR parameters.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This document discusses neural coding and how neurons encode information during cognitive tasks. It summarizes research using single-unit neural recordings in rats performing a directional control task. Three key findings are presented:
1) Neural firing rates in areas like PM and M1 encoded information about trial outcomes and the rat's learning progress over multiple sessions.
2) Precise spike timing provided information about the rat's cognitive state, with more synchronized activity observed early in learning.
3) Network modeling revealed changes in functional connectivity between neurons associated with synaptic plasticity, with more optimized patterns emerging as the rat became proficient at the task.
Improved target recognition response using collaborative brain-computer inter...Kyongsik Yun
One can achieve higher levels of perceptual and cognitive performance by leveraging the power of multiple brains through collaborative brain-computer interfaces
Minimizing Musculoskeletal Disorders in Lathe Machine WorkersWaqas Tariq
In production units, workers work under tough conditions to perform the desired task. These tough conditions normally give rise to various musculoskeletal disorders within the workers. These disorders emerge within the workers body due to repetitive lifting, differential lifting height, ambient conditions etc. For the minimization of musculoskeletal disorders it is quite difficult to model them with mathematical difference or differential equations. In this paper the minimization of musculoskeletal disorders problem has been formulated using fuzzy technique. It is very difficult to train non linear complex musculoskeletal disorders problem, hence in this paper a non linear fuzzy model has been developed to give solutions to these non linearities. This model would have the capability of representing solutions for minimizing musculoskeletal disorders needed for workers working in the production units.
EEG SIGNAL IDENTIFICATION USING SINGLE-LAYER NEURAL NETWORKIJCI JOURNAL
EEG signal analysis is applied in various fields such as medicine, communication and control. To control based on EEG signals achieved good result, the system must identify effectively EEG signals. In this paper,
a novel approach proposes the EEG signal identification based on image with the EEG signal processing via Wavelet transform and the identification via single-layer neural network. The system model is designed and evaluated with the dataset of 21,000 samples. The accuracy rate can obtain 91.15%.
This summary provides the key details from the document in 3 sentences:
The document discusses optimizing the parameters of an artificial neural network (ANN) model for predicting schizophrenia. It explores different numbers of hidden layers, epochs, and fold units to determine the configuration that results in the highest training accuracy and lowest error. The optimal parameters were found to be 8 hidden layers, 2 fold units, and up to 1000 epochs, achieving a peak training accuracy of 71.34% and prediction accuracy of 74.53%.
This study examined how neural signals from the primary motor cortex of macaque monkeys could be used to control a robotic arm in real time. Researchers implanted an array of microelectrodes in the motor cortex and found that neural activity strongly correlated with arm movements. They used a population vector algorithm to decode neural firing patterns into commands to position the robotic arm. Monkeys achieved high accuracy after training, demonstrating the potential for brain-machine interfaces to restore limb function. However, challenges remain in developing stable, long-term electrode interfaces and reducing system size for applications such as neural prosthetics.
The presentation by Cerenaut at the orientation (2021-06-05) for the 5th WBA Hackathon, an online AI competition to implement working memory
https://wba-initiative.org/en/18687/
- Neuroscientific issues
- Architecture details
- Instruction on the CodaLab competition
Classification of emotions induced by horror and relaxing movies using single-...IJECEIAES
It has been observed from recent studies that corticolimbic Theta rhythm from EEG recordings perceived as fear or threatening scene during neural processing of visual stimuli. In additions, neural oscillations’ patterns in Theta, Alpha and Beta sub-bands also play important role in brain’s emotional processing. Inspired from these findings, in this paper we attempt to classify two different emotional states by analyzing single-channel EEG recordings. A video clip that can evoke 3 different emotional states: neutral, relaxation and scary is shown to 19 college-aged subjects and they were asked to score their emotional outcome by giving a number between 0 to 10 (where 0 means not scary at all and 10 means the most scary). First, recorded EEG data were preprocessed by stationary wavelet transform (SWT) based artifact removal algorithm. Then power distribution in simultaneous time-frequency domain was analyzed using short-time Fourier transform (STFT) followed by calculating the average power during each 0.2s time-segment for each brain sub-band. Finally, 46 features, as the mean power of frequency bands between 4 and 50 Hz during each time-segment, containing 689 instances—for each subject —were collected for classification. We found that relaxation and fear emotions evoked during watching scary and relaxing movies can be classified with average classification rate of 94.208% using K-NN by applying methods and materials proposed in this paper. We also classified the dataset using SVM and we found out that K-NN classifier (when k = 1) outperforms SVM in classifying EEG dynamics induced by horror and relaxing movies, however, for K > 1 in K-NN, SVM has better average classification rate.
This study examined mirror neurons in macaque monkeys through electrophysiological recordings. The researchers recorded from 37 mirror neurons in the F5 region of the monkeys' brains. They found that mirror neurons responded both when the monkey performed hand actions like grasping and when they observed the experimenter perform the same actions. Mirror neurons responded more strongly during the late movement and holding periods of the observed actions. The results support the hypothesis that mirror neurons are involved in action recognition. The study provides evidence that mirror neurons encode the meaning and intention of observed actions.
A New Approach to Denoising EEG Signals - Merger of Translation Invariant Wav...CSCJournals
In this paper we present a new algorithm using a merger of Independent Component Analysis and Translation Invariant Wavelet Transform. The efficacy of this algorithm is evaluated by applying contaminated EEG signals. Its performance was compared to three fixed-point ICA algorithms (FastICA, EFICA and Pearson-ICA) using Mean Square Error (MSE), Peak Signal to Noise Ratio (PSNR), Signal to Distortion Ratio (SDR), and Amari Performance Index. Experiments reveal that our new technique is the most accurate separation method.
This thesis examines how attention affects the functional connectivity of the visual cortex using transcranial magnetic stimulation (TMS) and electroencephalography (EEG). Participants performed a covert attention task where they oriented their attention to one of two locations indicated by a central cue arrow. TMS was applied to occipital cortex, parietal cortex, or orthogonally to the scalp 600ms after cue onset. No effects of stimulation site were found on behavior, but the EEG data showed a late interaction between stimulation site and cue direction 340-390ms after the TMS pulse, suggesting a top-down attentional modulation of visual cortex connectivity. Further analyses will investigate this late effect.
The document is a thesis that examines the calculation of reward prediction in behaving animals. It provides background on the dopamine reward system in the brain and reinforcement learning. Key findings from experiments show that dopamine neuron firing encodes prediction error - the difference between expected and actual rewards. Over time as animals learn reward associations, dopamine firing decreases, reflecting reduced unpredictability. The thesis aims to model behavioral data from mice using a temporal difference learning algorithm and reinforcement learning principles.
IRJET- Depression Prediction System using Different MethodsIRJET Journal
This document summarizes a research paper that proposes a depression prediction system using different methods. The system would use three approaches: a question and answer part using standardized depression questionnaires; EEG signal processing to analyze brain activity; and sentiment analysis of social media posts. Machine learning algorithms like neural networks and naive Bayes would be used for classification. The goal is to help predict depression early through an online system that could be used by doctors and individuals. Key areas discussed include artificial intelligence, machine learning techniques for classification like support vector machines and logistic regression, and prior research analyzing EEG signals and social media posts to predict depression.
A BINARY TO RESIDUE CONVERSION USING NEW PROPOSED NON-COPRIME MODULI SETsipij
Residue Number System is generally supposed to use co-prime moduli set. Non-coprime moduli sets are a
field in RNS which is little studied. That's why this work was devoted to them. The resources that discuss
non-coprime in RNS are very limited. For the previous reasons, this paper analyses the RNS conversion
using suggested non-coprime moduli set.
This paper suggests a new non-coprime moduli set and investigates its performance. The suggested new
moduli set has the general representation as {2n
–2, 2n
, 2n+2}, where n ∈ {2,3,…..,∞}. The calculations
among the moduli are done with this n value. These moduli are 2 spaces apart on the numbers line from
each other. This range helps in the algorithm’s calculations as to be shown.
The proposed non-coprime moduli set is investigated. Conversion algorithm from Binary to Residue is
developed. Correctness of the algorithm was obtained through simulation program. Conversion algorithm
is implemented.
An Innovative Moving Object Detection and Tracking System by Using Modified R...sipij
The ultimate goal of this study is to afford enhanced video object detection and tracking by eliminating the
limitations which are existing nowadays. Although high performance ratio for video object detection and
tracking is achieved in the earlier work it takes more time for computation. Consequently we are in need to
propose a novel video object detection and tracking technique so as to minimize the computational
complexity. Our proposed technique covers five stages they are preprocessing, segmentation, feature
extraction, background subtraction and hole filling. Originally the video clip in the database is split into
frames. Then preprocessing is performed so as to get rid of noise, an adaptive median filter is used in this
stage to eliminate the noise. The preprocessed image then undergoes segmentation by means of modified
region growing algorithm. The segmented image is subjected to feature extraction phase so as to extract
the multi features from the segmented image and the background image, the feature value thus obtained
are compared so as to attain optimal value, consequently a foreground image is attained in this stage. The
foreground image is then subjected to morphological operations of erosion and dilation so as to fill the
holes and to get the object accurately as these foreground image contains holes and discontinuities. Thus
the moving object is tracked in this stage. This method will be employed in MATLAB platform and the
outcomes will be studied and compared with the existing techniques so as to reveal the performance of the
novel video object detection and tracking technique.
Ultrasound images and SAR i.e. synthetic aperture radar images are usually corrupted because of speckle
noise also called as granular noise. It is quite a tedious task to remove such noise and analyze those
corrupted images. Till now many researchers worked to remove speckle noise using frequency domain
methods, temporal methods, and adaptive methods. Different filters have been developed as Mean and
Median filters, Statistic Lee filter, Statistic Kuan filter, Frost filter, Srad filter. This paper reviews filters
used to remove speckle noise.
A FLUXGATE SENSOR APPLICATION: COIN IDENTIFICATIONsipij
Today, coins are used to operate many electric devices that are open to the public service. Washing machines, play stations, computers, auto brooms, foam machines, beverage machines, telephone chargers, hair dryers and water heaters are some examples of these devices These devices include coin recognition systems. In these systems, there are coils at two different radius, which become electromagnets when the
current is passed through them. The AC current supplied to the coils creates a variable magnetic field, which induces the eddy current on the coil during the passing of money. The magnetic field generated by the Eddy current reduces the current passing through the coil. The amount of change of current in the coil gives information about the coin; the type of metal (element) and the amount of metal (element). In this
study, a new coin identification system (magnetic measurement system) is designed. In this system, the
magnetic anomaly generated by the coin as a result of applying direct current to the coils is tried to be
detected by fluxgate sensor. In this study, sensor voltages are acquired in computer environment by using
developed electronic unit and LabVIEW based software. In the paper, experimental results have been
discussed in detail.
The document describes an optical character recognition (OCR) system for recognizing characters in historical records written in the Kannada language. The system uses Gabor and zonal feature extraction along with an artificial neural network for classification. It was tested on nearly 150 samples of ancient Kannada epigraphs from the Ashoka and Hoysala periods, achieving average recognition accuracies of 80.2% and 75.6% respectively. The key steps of the OCR system include preprocessing images, segmenting characters, extracting Gabor and zonal features, training an ANN classifier, and mapping recognized characters to a modern form.
TARGET LOCALIZATION IN WIRELESS SENSOR NETWORKS BASED ON RECEIVED SIGNAL STRE...sipij
We consider the problem of localizing a target taking the help of a set of anchor beacon nodes. A small
number of beacon nodes are deployed at known locations in the area. The target can detect a beacon
provided it happens to lie within the beacon’s transmission range. Thus, the target obtains a measurement
vector containing the readings of the beacons: ‘1’ corresponding to a beacon if it is able to detect the
target, and ‘0’ if the beacon is not able to detect the target. The goal is twofold: to determine the location
of the target based on the binary measurement vector at the target; and to study the behaviour of the
localization uncertainty as a function of the beacon transmission range (sensing radius) and the number of
beacons deployed. Beacon transmission range means signal strength of the beacon to transmit and receive
the signals which is called as Received Signal Strength (RSS). To localize the target, we propose a gridmapping
based approach, where the readings corresponding to locations on a grid overlaid on the region
of interest are used to localize the target. To study the behaviour of the localization uncertainty as a
function of the sensing radius and number of beacons, extensive simulations and numerical experiments
are carried out. The results provide insights into the importance of optimally setting the sensing radius and
the improvement obtainable with increasing number of beacons.
Optimized Biometric System Based on Combination of Face Images and Log Transf...sipij
The biometrics are used to identify a person effectively. In this paper, we propose optimised Face
recognition system based on log transformation and combination of face image features vectors. The face
images are preprocessed using Gaussian filter to enhance the quality of an image. The log transformation
is applied on enhanced image to generate features. The feature vectors of many images of a single person
image are converted into single vector using average arithmetic addition. The Euclidian distance(ED) is
used to compare test image feature vector with database feature vectors to identify a person. It is
experimented that, the performance of proposed algorithm is better compared to existing algorithms.
A Hybrid Architecture for Tracking People in Real-Time Using a Video Surveill...sipij
This paper describes a novel method for tracking customers using images taken from video-surveillance
cameras. This system analyzes the number of customers and their motions through the aisles of big-box
stores (supermarkets) in real-time. The originality of our approach is based on the study of the blobs
properties for managing the splitting/merging issues using a mathematical morphology operator. In the
order hand, in order to manage a high number of customers in real-time, we combine the advantage of two
tracking algorithms.
Stem calyx recognition of an apple using shape descriptorssipij
This paper presents a novel method to recognize stem - calyx of an apple using shape descriptors. The main
drawback of existing apple grading techniques is that stem - calyx part of an apple is treated as defects,
this leads to poor grading of apples. In order to overcome this drawback, we proposed an approach to
recognize stem-calyx and differentiated from true defects based on shape features. Our method comprises
of steps such as segmentation of apple using grow-cut method, candidate objects such as stem-calyx and
small defects are detected using multi-threshold segmentation. The shape features are extracted from
detected objects using Multifractal, Fourier and Radon descriptor and finally stem-calyx regions are
recognized and differentiated from true defects using SVM classifier. The proposed algorithm is evaluated
using experiments conducted on apple image dataset and results exhibit considerable improvement in
recognition of stem-calyx region compared to other techniques.
Efficient pu mode decision and motion estimation for h.264 avc to hevc transc...sipij
H.264/AVC has been widely applied to various applications. However, a new video compression standard,
High Efficient Video Coding (HEVC), had been finalized in 2013. In this work, a fast transcoder from
H.264/AVC to HEVC is proposed. The proposed algorithm includes the fast prediction unit (PU) decision
and the fast motion estimation. With the strong relation between H.264/AVC and HEVC, the modes,
residuals, and variance of motion vectors (MVs) extracted from H.264/AVC can be reused to predict the
current encoding PU of HEVC. Furthermore, the MVs from H.264/AVC are used to decide the search
range of PU during motion estimation. Simulation results show that the proposed algorithm can save up to
53% of the encoding time and maintains the rate-distortion (R-D) performance for HEVC.
Automatic meal inspection system using lbp hf feature for central kitchensipij
This paper proposes an intelligent and automatic meal inspection system which can be applied to the meal
inspection for the application of central kitchen automation. The diet specifically designed for the patients are required with providing personalized diet such as low sodium intake or some necessary food. Hence,
the proposed system can benefit the inspection process that is often performed manually. In the proposed
system, firstly, the meal box can be detected and located automatically with the vision-based method and
then all the food ingredients can be identified by using the color and LBP-HF texture features. Secondly,
the quantity for each of food ingredient is estimated by using the image depth information. The experimental results show that the meal inspection accuracy can approach 80%, meal inspection efficiency can reach1200ms, and the food quantity accuracy is about 90%. The proposed system is expected to increase the capacity of meal supply over 50% and be helpful to the dietician in the hospital for saving the time in the diet inspection process.
DESIGN REALIZATION AND PERFORMANCE EVALUATION OF AN ACOUSTIC ECHO CANCELLATIO...sipij
Nowadays, in the field of communications, AEC (acoustic echo cancellation) is truly essential with respect
to the quality of multimedia transmission. In this paper, we designed and developed an efficient AEC based
on adaptive filters to improve quality of service in telecommunications against the phenomena of acoustic
echo, which is indeed a problem in hands-free communications.The main advantage of the proposed algorithm is its capacity of tracking non-stationary signals such as acoustic echo. In this work the acoustic echo cancellation (AEC) is modeled using a digital signal
processing technique especially Simulink Blocksets. The algorithm’s code is generated in Matlab Simulink
programming environment. At simulation level, results of simulink implementation prove that module
behavior is realistic when it comes to cancellation of echo in hands free communication using adaptive algorithm.Results obtained with our algorithm in terms of ERLE criteria are confronted to IUT-T recommendation
G.168.
Objective Quality Assessment of Image Enhancement Methods in Digital Mammogra...sipij
Breast cancer is the most common cancer among women worldwide constituting more than 25%
of all cancer incidences occurring in the world [1]. Statistics show that US, India and China
account for more than one third of all breast cancer cases [2]. Also, there has been a steady
increase in the breast cancer incidence among young generation in the world. In India, one out of
two women die after being detected with breast cancer where as in China it is one in four and in
USA it is one in eight [2]. Therefore, the statistics show that cancer mortality is highest in India
among all other nations in the world. In US, though the number of women diagnosed with cancer
is more than that in India, their mortality
MULTIPLE OBJECTS TRACKING IN SURVEILLANCE VIDEO USING COLOR AND HU MOMENTSsipij
Multiple objects tracking finds its applications in many high level vision analysis like object behaviour
interpretation and gait recognition. In this paper, a feature based method to track the multiple moving
objects in surveillance video sequence is proposed. Object tracking is done by extracting the color and Hu
moments features from the motion segmented object blob and establishing the association of objects in the
successive frames of the video sequence based on Chi-Square dissimilarity measure and nearest neighbor
classifier. The benchmark IEEE PETS and IEEE Change Detection datasets has been used to show the
robustness of the proposed method. The proposed method is assessed quantitatively using the precision and
recall accuracy metrics. Further, comparative evaluation with related works has been carried out to exhibit
the efficacy of the proposed method.
FUZZY CLUSTERING BASED GLAUCOMA DETECTION USING THE CDR sipij
This document presents a new method for glaucoma detection using cup-to-disc ratio (CDR) calculation on fundus eye images. The method uses fuzzy C-means clustering combined with thresholding to extract the optic disc and optic cup from color fundus images. It calculates the vertical CDR automatically. The method was tested on 365 fundus images from public databases and an ophthalmologist, showing promising results for clinical use in glaucoma screening.
AN MINIMUM RECONFIGURATION PROBABILITY ROUTING ALGORITHM FOR RWA IN ALL-OPTIC...sipij
In this paper, we present a detailed study of Minimum Reconfiguration Probability Routing (MRPR) algorithm, and its performance evaluation in comparison with Adaptive unconstrained routing (AUR) and Least Loaded routing (LLR) algorithms. We have minimized the effects of failures on link and router failure in the network under changing load conditions, we assess the probability of service and number of light path failures due to link or route failure on Wavelength Interchange(WI) network. The computation complexity is reduced by using Kalman Filter(KF) techniques. The minimum reconfiguration probability
routing (MRPR) algorithm selects most reliable routes and assign wavelengths to connections in a manner that utilizes the light path(LP) established efficiently considering all possible requests.
A R EVIEW P APER : N OISE M ODELS IN D IGITAL I MAGE P ROCESSINGsipij
Noise is always presents in digital images during
image acquisition, coding, transmission, and proces
sing
steps. Noise is very difficult to remove it from t
he digital images without the prior knowledge of no
ise
model. That is why, review of noise models are esse
ntial in the study of image denoising techniques. I
n this
paper, we express a brief overview of various noise
models. These noise models can be selected by anal
ysis
of their origin. In this way, we present a complete
and quantitative analysis of noise models availabl
e in
digital images.
This study developed an assay to quantify the soluble epoxide hydrolase inhibitor t-TUCB in plasma and brain samples from immature rats. A pharmacokinetic study determined an optimal dose of 1 mg/kg intravenous t-TUCB, which achieved brain concentrations over 2 times the IC50 at 2 and 6 hours. While t-TUCB treatment did not significantly alter cerebral blood flow or epoxyeicosatrienoic acid levels after asphyxial cardiac arrest compared to vehicle, higher doses of t-TUCB may be needed to effectively inhibit sEH and improve outcomes following pediatric cardiac arrest.
from Prof. Hussien Khairy lectures
professor of general Surgery KasrAlainy school of medicine - Cairo university
prepared by Mohamed Alasmar - General Surgery resident
Surveillance and disease control approaches for pigs and their application to...ILRI
Presented by Raymond (Bob) Rowland at the African Swine Fever Diagnostics, Surveillance, Epidemiology and Control Workshop, Nairobi, Kenya, 20-21 July 2011
ANALYSIS OF BRAIN COGNITIVE STATE FOR ARITHMETIC TASK AND MOTOR TASK USING EL...sipij
- The document analyzes brain cognitive states during an arithmetic task and motor task using electroencephalography (EEG) signals.
- EEG data was collected from 10 healthy volunteers during resting states, a motor task, and performing arithmetic calculations.
- The EEG signals were analyzed using standardized low resolution brain electromagnetic tomography (sLORETA) to generate 3D cortical distributions and localize the neuronal generators responsible for different cognitive states.
- The results were consistent with previous neuroimaging research, showing that EEG can demonstrate neuronal activity at the cortical level with good spatial resolution and provide both spatial and temporal information about cognitive functions.
The Preface Layer for Auditing Sensual Interacts of Primary Distress Conceali...IIRindia
This document summarizes a research paper that proposes a new multimodal method for emotional state identification using efficient practical near-infrared spectroscopy (EPNIS) signals and electroencephalography (EEG) signals. The paper presents results showing that the proposed EPNIS method enhances performance over using EPNIS alone. Specifically, the proposed method improves mean time by 209.15 milliseconds, standard deviation by 101.4 milliseconds, and accuracy by 4.45% compared to previous methods. The paper analyzes EPNIS and EEG signals captured while participants viewed facial expressions to identify neural correlates related to facial emotion recognition.
Classification of EEG Signal for Epileptic Seizure DetectionusingEMD and ELMIJTET Journal
Abstract—This paper proposes the classification of EEG signal for epilepsy diagnosis. Epilepsy is a neurological disorder which occurs due to synchronous neuronal activity in brain. Empirical Mode Decomposition (EMD), Extreme Learning Machine (ELM) are the techniquedelivered in the proposed method.Input EEG signal, which is available in online as Bonn Database is decomposed into five Intrinsic Mode Functions (IMFs) using EMD.Higher Order Statistical moments such as Variance, Skewness and Kurtosis are drawn out as features from the decomposed signals. Extreme Learning Machine is used as a classifier to classify the EEG signals with the taken features, under various categories that include healthy and ictal, interictal and ictal, Non seizure and seizure, healthy, interictal and ictal. The proposed method gives 100%accuracy, 100%sensitivity in discriminating interictal and ictal, non seizure and seizure, healthy and ictal, healthy, interictal and ictal, 100% specificity in classifying healthy and ictal, interictal and ictal and 100% and 99%accuracy in case of discriminating interictal and ictal, non seizure and seizure.
Classification of EEG Signals for Brain-Computer InterfaceAzoft
This e-book gives you a sneak peak into how the classification of right hand movements via EEG could contribute to the development of a brain-computer interface. The Azoft R&D department, along with Sergey Alyamkin and Expasoft provide detailed data from research done for the "Grasp-and-Lift EEG Detection" competition organized by Kaggle. You’ll learn why the deep learning algorithms can be effective in various types of signal classifications and how to apply convolutional neural networks for a specific task such as identifying hand motions from EEG recordings.
See more details on our website: http://rnd.azoft.com/classification-eeg-signals-brain-computer-interface/
he main idea of the current work is to use a wireless Electroencephalography (EEG) headset as a remote control for the mouse cursor of a personal computer. The proposed system uses EEG signals as a communication link between brains and computers. Signal records obtained from the PhysioNet EEG dataset were analyzed using the Coif lets wavelets and many features were extracted using different amplitude estimators for the wavelet coefficients. The extracted features were inputted into machine learning algorithms to generate the decision rules required for our application. The suggested real time implementation of the system was tested and very good performance was achieved. This system could be helpful for disabled people as they can control computer applications via the imagination of fists and feet movements in addition to closing eyes for a short period of time
This document describes a brain-computer interface (BCI) design that uses electroencephalogram (EEG) signals from a single mental task. The method extracts spectral power from 4 brainwave bands (delta/theta, alpha, beta, gamma) across 6 electrode channels. It then uses the power and power differences as features for a neural network classifier to detect the mental task versus a resting state. Testing on 4 subjects performing 4 tasks showed classification accuracy up to 97.5% was possible when using each subject's most suitable task. The proposed BCI could potentially be used to move a cursor or select letters to allow communication.
EEG S IGNAL Q UANTIFICATION B ASED ON M ODUL L EVELS sipij
This article proposes a contribution to quantify EE
G signals outline. This technique uses two tools fo
r EEG
signal characteristics extraction. Our tests were r
ealized on the basis of 32 canals EEG canals using
Neuroscan software. EEG example demonstration is re
ferenced CZ and is sampled at 1000HZ. The
principal aim of this technique is to reduce the im
portant volume of EEG signal data Without losing an
y
information. EEG signals are quantified on the basi
s of a whole predefined levels The obtained results
show that an EEG alignment can be posted in a quant
ified form.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Implementation and Evaluation of Signal Processing Techniques for EEG based B...Damian Quinn
This document compares two approaches for classifying EEG signals from a brain-computer interface - a multi-layer perceptron neural network with Levenberg-Marquardt learning, and an Adaptive Neuro-Fuzzy Inference System. It analyzes EEG data from a dataset involving motor imagery tasks of left and right hand movement. Features are extracted from the EEG signals and both the neural network and ANFIS are used to classify the signals based on the features. The performance of the two classification approaches are then compared to determine if the hybrid ANFIS method can outperform the established neural network approach.
This document summarizes a study that investigated emotion recognition from physiological data using different classifiers and setups. Physiological signals were collected from subjects watching videos and their emotional states were recorded. Features were extracted from the signals and classified using models like random forests. Subject-based and trial-based cross-validation was used to evaluate the impact of personalization. The results showed the classifiers performed best in a personalized model that grouped similar subjects, achieving enhanced emotional state prediction from physiological data without additional feedback.
Recognition of emotional states using EEG signals based on time-frequency ana...IJECEIAES
The recognition of emotions is a vast significance and a high developing field of research in the recent years. The applications of emotion recognition have left an exceptional mark in various fields including education and research. Traditional approaches used facial expressions or voice intonation to detect emotions, however, facial gestures and spoken language can lead to biased and ambiguous results. This is why, researchers have started to use electroencephalogram (EEG) technique which is well defined method for emotion recognition. Some approaches used standard and pre-defined methods of the signal processing area and some worked with either fewer channels or fewer subjects to record EEG signals for their research. This paper proposed an emotion detection method based on time-frequency domain statistical features. Box-and-whisker plot is used to select the optimal features, which are later feed to SVM classifier for training and testing the DEAP dataset, where 32 participants with different gender and age groups are considered. The experimental results show that the proposed method exhibits 92.36% accuracy for our tested dataset. In addition, the proposed method outperforms than the state-of-art methods by exhibiting higher accuracy.
HUMAN EMOTION ESTIMATION FROM EEG AND FACE USING STATISTICAL FEATURES AND SVMcsandit
An approach is presented in this paper for automated estimation of human emotions from
combination of multimodal data: electroencephalogram and facial images. The used EEG
features are the Hjorth parameters calculated for theta, alpha, beta and gamma bands taken
from pre-defined channels. For face emotion estimation PCA feature are selected. Classification
is performed with support vector machines. Since the human emotions are modelled as
combinations from physiological elements such as arousal, valence, dominance, liking, etc.,
these quantities are the classifier’s outputs. The best achieved correct classification
performance for EEG is about 76%. Classifier combination is used to return the final score for
the particular subject.
This document summarizes a case study that explored neuroplastic changes in a patient after undergoing 7 weeks of auditory working memory training. The patient had survived multiple strokes affecting several brain regions. Testing before and after training found improved performance on working memory, attention, and short-term memory tasks. Functional MRI scans during a working memory task pre- and post-training identified regions where neural activation decreased after training, suggesting enhanced neural efficiency. The study aimed to better understand how working memory training induces neuroplastic changes and potential cognitive benefits for stroke patients.
The document discusses compressive wideband power spectrum analysis for EEG signals using FastICA and neural networks. It first provides background on EEG signals and how they are measured. It then describes using FastICA to extract independent components from EEG signals related to detecting epileptic seizures. The independent components are then used to train a backpropagation neural network for effective detection of epileptic seizures. The proposed method involves preprocessing EEG signals, performing spectral estimation using FastICA, and classifying brain activity patterns using the neural network.
Brain research journal regional differences nova Vladimír Krajča
This document analyzes regional differences in neonatal sleep EEG recordings through quantitative analysis. 21 healthy full-term newborns underwent polygraphic recordings including 8-channel EEG during sleep. EEG signals from different brain regions were automatically analyzed and described using 13 variables. Statistical analysis found significant differences between brain regions, with posterior-medial regions exhibiting higher spectral feature values and variability. Differences were also seen between left and right anterior regions. The automatic analysis method was able to detect physiological regional differences in neonatal EEG.
Eeg time series data analysis in focal cerebral ischemic rat modelijbesjournal
The mammalian brain exists in a number of attractors. In order to characterize these attractors we have collected the time series data from the EEG recording of rat models. The time series was obtained by recording of the frontoparietal, occipital and temporal regions of the rat brain. Significant changes have
been observed in the dimensionalities of these brain attractors between the normal state, focal ischemic
state and the drug induced state. Thus, these three states were characterized by unique lyapunov exponents,
correlation dimensions and embedding dimensions. The inverse of the lyapunov exponent gave us the long
term coherence of the rat brain and was found to differ for the three states. The autocorrelation function
measured the mean similarity of the EEG signal with itself after a time t. The degree of decay was high indicating that there was maximum correlation in the time series. Thus, the autocorrelation functions clearly indicate the effect of focal cerebral ischemia and drugs induced on the rat brain.
Transfer learning for epilepsy detection using spectrogram imagesIAESIJAI
Epilepsy stands out as one of the common neurological diseases. The neural activity of the brain is observed using electroencephalography (EEG). Manual inspection of EEG brain signals is a slow and arduous process, which puts heavy load on neurologists and affects their performance. The aim of this study is to find the best result of classification using the transfer learning model that automatically identify the epileptic and the normal activity, to classify EEG signals by using images of spectrogram which represents the percentage of energy for each coefficient of the continuous wavelet. Dataset includes the EEG signals recorded at monitoring unit of epilepsy used in this study to presents an application of transfer learning by comparing three models Alexnet, visual geometry group (VGG19) and residual neural network ResNet using different combinations with seven different classifiers. This study tested the models and reached a different value of accuracy and other metrics used to judge their performances, and as a result the best combination has been achieved with ResNet combined with support vector machine (SVM) classifier that classified EEG signals with a high success rate using multiple performance metrics such as 97.22% accuracy and 2.78% the value of the error rate.
Robot Motion Control Using the Emotiv EPOC EEG SystemjournalBEEI
Brain-computer interfaces have been explored for years with the intent of using human thoughts to control mechanical system. By capturing the transmission of signals directly from the human brain or electroencephalogram (EEG), human thoughts can be made as motion commands to the robot. This paper presents a prototype for an electroencephalogram (EEG) based brain-actuated robot control system using mental commands. In this study, Linear Discriminant Analysis (LDA) and Support Vector Machine (SVM) method were combined to establish the best model. Dataset containing features of EEG signals were obtained from the subject non-invasively using Emotiv EPOC headset. The best model was then used by Brain-Computer Interface (BCI) to classify the EEG signals into robot motion commands to control the robot directly. The result of the classification gave the average accuracy of 69.06%.
MHEALTH APPLICATIONS DEVELOPED BY THE MINISTRY OF HEALTH FOR PUBLIC USERS INK...hiij
mHealth applications have shown promise in supporting the delivery of health services in peoples’ daily life. Recently, the Ministry of Health in the Kingdom of Saudi Arabia (MOH) has launched several mHealth applications to develop work mechanisms. Our study aimed to identify and understand the design of mHealth apps by classifying their persuasive features using the Persuasive Systems Design (PSD) model and expert evaluation method. This paper presents the distinct persuasive features applied in recent applications launched by MOH for public users called “Sehha & Mawid” Apps. The results revealed the extensive use of persuasive features; particularly features related to credibility support, dialogue support and primary task support respectively. The implementation and design of social support features were found to be poor; this could be due to the nature of the apps or lack of knowledge from the developers’
perspectives. The findings suggest some features that may improve the persuasion for the evaluated apps.
Spike removal through multiscale wavelet and entropy analysis of ocular motor...Giuseppe Fineschi
Wavelet decomposition of ocular motor signals was investigated with a view to its use for noise analysis and filtering. Ocular motor noise may be physiological, depending on brain activities, or experimental, depending on the eye recording machine, head movements and blinks. Experimental noise, such as spikes, must be removed, preserving noise due to neuro-physiological activities. The proposed method uses wavelet multiscale decomposition to remove spikes and optimizes the procedure by means of the covariance of the eye signals. To measure the noise on eye motor control, we used the wavelet entropy. The method was tested on patients with cerebellar disorders and healthy subjects. A significant difference in wavelet entropy was observed, indicating this quantity as a valuable measure of physiological motor noise.
Similar to INHIBITION AND SET-SHIFTING TASKS IN CENTRAL EXECUTIVE FUNCTION OF WORKING MEMORY: AN EVENT-RELATED POTENTIAL (ERP) STUDY (20)
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The Department of Veteran Affairs (VA) invited Taylor Paschal, Knowledge & Information Management Consultant at Enterprise Knowledge, to speak at a Knowledge Management Lunch and Learn hosted on June 12, 2024. All Office of Administration staff were invited to attend and received professional development credit for participating in the voluntary event.
The objectives of the Lunch and Learn presentation were to:
- Review what KM ‘is’ and ‘isn’t’
- Understand the value of KM and the benefits of engaging
- Define and reflect on your “what’s in it for me?”
- Share actionable ways you can participate in Knowledge - - Capture & Transfer
AppSec PNW: Android and iOS Application Security with MobSFAjin Abraham
Mobile Security Framework - MobSF is a free and open source automated mobile application security testing environment designed to help security engineers, researchers, developers, and penetration testers to identify security vulnerabilities, malicious behaviours and privacy concerns in mobile applications using static and dynamic analysis. It supports all the popular mobile application binaries and source code formats built for Android and iOS devices. In addition to automated security assessment, it also offers an interactive testing environment to build and execute scenario based test/fuzz cases against the application.
This talk covers:
Using MobSF for static analysis of mobile applications.
Interactive dynamic security assessment of Android and iOS applications.
Solving Mobile app CTF challenges.
Reverse engineering and runtime analysis of Mobile malware.
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INHIBITION AND SET-SHIFTING TASKS IN CENTRAL EXECUTIVE FUNCTION OF WORKING MEMORY: AN EVENT-RELATED POTENTIAL (ERP) STUDY
1. Signal & Image Processing : An International Journal (SIPIJ) Vol.7, No.1, February 2016
DOI : 10.5121/sipij.2016.7105 43
INHIBITION AND SET-SHIFTING TASKS IN
CENTRAL EXECUTIVE FUNCTION OF
WORKING MEMORY: AN EVENT-RELATED
POTENTIAL (ERP) STUDY
Pankaj,1
Jamuna Rajeswaran,1*
Divya Sadana1
1
Deptartment of Clinical Psychology, National Institute of Mental Health and
Neurosciences (NIMHANS), Bangalore, India 560 029
ABSTRACT
Understanding of neuro-dynamics of a complex higher cognitive process, Working Memory (WM) is
challenging. In WM, information processing occurs through four subsystems: phonological loop, visual
sketch pad, memory buffer and central executive function (CEF). CEF plays a principal role in WM. In this
study, our objective was to understand the neurospatial correlates of CEF during inhibition and set-shifting
processes. Thirty healthy educated subjects were selected. Event-Related Potential (ERP) related to visual
inhibition and set-shifting task was collected using 32 channel EEG system. Activation of those ERPs
components was analyzed using amplitudes of positive and negative peaks. Experiment was controlled
using certain parametric constraints to judge behavior, based on average responses in order to establish
relationship between ERP and local area of brain activation and represented using standardized low
resolution brain electromagnetic tomography. The average score of correct responses was higher for
inhibition task (87.5%) as compared to set-shifting task (59.5%). The peak amplitude of neuronal activity
for inhibition task was lower compared to set-shifting task in fronto-parieto-central regions. Hence this
proposed paradigm and technique can be used to measure inhibition and set-shifting neuronal processes in
understanding pathological central executive functioning in patients with neuro-psychiatric disorders.
KEYWORDS
Working Memory (WM), Central Executive Function (CEF), Inhibition Task, Set-Shifting Task, Event
Related Potential (ERP), sLORETA
1. INTRODUCTION
Working memory (WM) is a part of the higher cognitive mental functions (HMFs) [1]. Baddeley
and Hitch generated the first model of WM that represents the role of CEF [2]. WM has a
temporary storage system that involves small packets of spatially distributed information
processing systems [3]. It involves a four subsystem i.e., phonological loop, visual sketch pad,
memory buffer and central executive function (CEF) [4]. They integrate to perform the following
cognitive functions i.e., temporary storage, learning, reasoning, comprehension, manipulation and
updating. This involves various parts of the sensory-motor cortices in the frontoparietal lobes,
where the experience is recorded and integrated and subsequently brought to the conscious
domain [5]. The information of CEF drifts through these circuits and it is coordinated by neurons
in the prefrontal cortex [6]. The CEF is studied as a component of Baddeley’s WM model. It’s
further divided in four sub components, inhibition, set-shifting, dual-tasking and updating [7].
2. Signal & Image Processing : An International Journal (SIPIJ) Vol.7, No.1, February 2016
44
Electroencephalography (EEG) measures the electrical activity of the brain from the electrodes on
the scalp [8]. Event-related potentials (ERPs) are averaged EEG responses to a specific time-
locked stimuli involving complex mental processing. ERPs are used to assess brain function and
observe electro-physiological manifestations of cognitive activities in both the time domain and
spatial extents. In general, ERPs are typically described in terms of components based on polarity
and latency. ERPs provide good temporal resolution to certify studies of any cognitive processes
in real time. When the subjects were made to perform tasks involving revision of various
memories in short-term which were presented as a specific train of stimulus sequence, the
responses could be measured and spatiotemporally correlated real-time using ERP [9]. EEG
records the correct and incorrect responses of both the inhibition and set-shifting tasks and the
ERPs associated with cognitive process and control potentials in brain are derived from this
signal.
Overall, the ERPs associated with the task are correlated with CEF activity. CEF of inhibition and
set-shifting tasks is manifest in the P200 (or P2), P300 (or P3) and N200 (OR N2) components of
the human ERP and EEG maps show peak activity in the fronto-parietal cortices [10]. This study
was aimed at understanding the brain dynamics of CEF and to find the spatial neural correlates in
CEF during inhibition and set-shifting tasks. For this we designed a paradigm to study the CEF of
WM and modelled the EEG signal to find out neural spatial domains during the aforementioned
tasks.
2. MATERIAL AND METHODS
2.1. Subjects:
We recruited 30 educated healthy subjects (male: female=15:15, right handed, age: 28±5.9years)
in NIMHANS (National Institute of Mental Health and Neuroscience, Bangalore, India) for the
Event Related Potential (ERP) study. All 30 participants were selected for study after assessing
them with clinical interview and normal or corrected vision (Visual Acuity < +1.5/-1.5). A written
informed consent was obtained after explaining the tasks and recording procedure. Subjects with
history of any neurological and mental disorders and use of substances such as alcohol and
tobacco prior to session were excluded. Individuals with frequent headaches or migraine problem
were excluded from the study. Completion of tasks was mandatory for inclusion in the analysis.
Four participants were excluded due to bad electroencephalography (EEG) signal.
2.2. EEG Data Acquisitions
Electroencephalography was recorded using 32 channels Ag-AgCl electrodes arranged to the
revised 10-20 system (to improve spatial sampling) and mounted in uniform fit, highly elastic cap
(ECI, Electro Cap Int®, USA). EEG signal were acquired by SynAmps amplifier™ and recorded
by NeuroScan™ (version 4.4) software. We used mastoid electrodes as reference. Electro-
oculographic (EOG) activity was recorded by the electrodes of on the outer canthus of each eye
for horizontal and below the left eye for vertical movements. Impedance of input signal of
electrode was kept below less than 5kΩ (sampling rate: 1kHz). This study contains one hour EEG
session. Before the start of the tasks, 3 minutes rest state EEG recording was done. Both the task
paradigms were designed using “Stim2” software (Compumedics®
, Neuroscan™). A button box
with millisecond accuracy measured the reaction time (RT) for these computerized tasks.
2.3. Paradigm for the Tasks
The following two types of tasks were performed followed to eye open and eye close at relax
resting condition and measure the CEF process.
3. Signal & Image Processing : An International Journal (SIPIJ) Vol.7, No.1, February 2016
45
2.3.1 Inhibition task:
The ‘inhibition task’, subject was shown four geometric different shapes such as a triangle, circle,
plus and square in four quadrants of the monitor (Figure 1). The geometric shapes were presented
randomly in four quadrants checker board that were positioned in the center of the screen with a
white background. The shapes are presented for 800ms at intervals of 200ms. In the four
geometric shapes, if triangle ( ) geometric shape comes with black color, then the subject was
instructed to press the button 1 or else to continue to press the button 2 of the response box. The
participant was instructed to respond as quickly and accurately as possible. The whole inhibition
WM task had 160 rounds and 3 minutes of completion.
Figure 1. Experimental design for inhibition task. “S” - stimulus, which presented for 800ms, “R” - rest
period kept for 200ms, “Target” – Targeted stimuli.
2.3.2 Set-shifting task:
In the Set-shifting task, subjects were shown a set of patterns on a monitor (Figure 2). The set-
shifting task consisted of three pictures in a row and fourth picture column was left empty. There
were four options (1, 2, 3, 4) given to the subject below the pattern. Subject chooses the one of
the right option. All pictures were positioned in the center of the screen in a white back ground.
The subject were instructed to press the key either “1” or “2” or “3” or “4” with their response. In
the task, three patterns (similar, pair, process) were present and among them each pattern had a
set of 10 stimuli of similar type which were presented successively. The stimuli were presented
for 4000ms at intervals of 1000ms. The participant was instructed to respond as quickly and
accurately as possible. The whole set-shifting WM task had 30 rounds and 3minutes of
completion.
Figure 2. Experimental design for set-shifting task. “S” - stimulus, which presented for 4000ms, “R” - rest
period kept for 1000ms.
3. DATA ANALYSIS:
3.1 Pre-processing and Artifact Removal from EEG signal
Raw EEG data analysis was performed on Neuroscan™ and MATLAB®
software. The data was
down-sampled to 250Hz. A cut-off frequency of 0.01 to 60 Hz done by 4th
order band pass
Butterworth FIR filter [9] and after 50Hz notch filter was applied for power line interference [11]
[12]. Preprocessing was done by eye movement artifact correction, muscle artifact correction and
4. Signal & Image Processing : An International Journal (SIPIJ) Vol.7, No.1, February 2016
46
singular value decomposition (SVD) for artifact free data and created linear derivation (LDR)
EEG file. The artifact free EEG was epoched to a particular time window for both CEF tasks. In
‘inhibition’ task, EEG file were epoched to a window of 100ms pre-stimulus to 700ms post-
stimulus by selecting trigger and in set-shifting task. Low pass filter of 1Hz was applied on these
epoched data and were corrected to baseline. High amplitude artifacts were rejected using the
artifact rejection criteria of +/-75µV. After artifact rejection, these epochs were averaged in both
time and frequency domain. After this, EEG data was taken for further analysis.
3.2 Post Processing for EEG and ERP Signal:
ERPs were calculated from the epoched EEG data obtained by time domain averaging.
Smoothening was applied on this averaged data. In the electrodes where ERP components were
present as per the visual inspection, the ERP components (N200, P200, P300) were identified for
inhibition task and set-shifting task. The designated time window for identification of the ERPs,
which we considered in the whole experimental tasks were as follows: a) N200 - most negatively
deflecting potential occurring 150ms to 250ms after the stimulus, , b) P200 - most positively
deflecting potential occurring 150ms to 250ms after the stimulus and c) P300 - most positively
deflecting potential occurring 250ms to 350ms after the stimulus. The group averaged EEG files
contain all the ERP components to which 2D maps were generated and collected to get the
activation areas during both the CEF - Working Memory tasks. We computed the activation value
of amplitude in frontal cluster (F3, F7, Fz, F4, F8) and parietal cluster (P3, P7, Pz, P4, P8).
The neural activity for inhibition and set-shifting process of central executive function were
mapped using “spectopo” functions of EEGLAB on 2D head view. Then the signal was computed
for three dimensional cortical distributions on realistic head model with MNI152 template using
standardized low resolution brain electromagnetic tomography (sLORETA). This was followed
by an appropriate standardization of the current density, producing images of electric neuronal
activity without localization bias [13]. sLORETA images represent the electric activity at each
voxel in neuroanatomic Talairach space as the squared standardized magnitude of the estimated
current density. It was found that in all noise free simulations, although the image was blurred,
sLORETA had exact, zero error localization when reconstructing single sources, that is, the
maximum of the current density power estimate coincided with the exact dipole location. In all
noisy simulations, it had the lowest localization errors when compared with the minimum norm
solution and the Dale method [14].
3.3 Statistics data Analysis:
Electrophysiological variables included N200, P200 and P300 peak amplitudes and latencies for
Fz and Pz electrodes for both tasks. N200 to P300 latency ratio for inhibition process (Table 1)
and P200 to P300 latency ratio for set-shifting process (Table 2) were used for paired T-test
statistics. All ERP value found highly significant (>0.05).
Table 1. Inhibition task Paired T-test
Paired T-test inhibition task
frontal electrode stimulus distracter p value t value DF SED
P300 P300 0.0001 17.43 58 0.34
N200 N200 0.0001 4.83 58 0.23
parietal electrode stimulus distracter p value t value DF SED
P300 P300 0.0001 9.7 58 0.91
N200 N200 0.0482 0.76 58 0.23
5. Signal & Image Processing : An International Journal (SIPIJ) Vol.7, No.1, February 2016
47
Table 2. Set-shifting data Paired T-test
Paired T-test set-shifting task
frontal electrode value 1 value 2 p value t value DF SED
similar P300 pair P300 0.2086 1.27 58 0.61
similar P300 process P300 0.0001 5.18 58 0.56
pair P300 process P300 0.009 2.7 58 0.79
similar P200 pair P200 0.0004 3.73 58 0.18
similar P200 process P200 0.9705 0.03 58 0.215
pair P200 process P200 0.0019 3.25 58 0.212
parietal electrode value 1 value 2 p value t value DF SED
similar P300 pair P300 0.0001 4.32 58 0.421
similar P300 process P300 0.0001 5.69 58 0.554
pair P300 process P300 0.0441 2.05 58 0.648
similar P200 pair P200 0.0001 21.46 58 0.208
similar P200 process P200 0.0001 6.73 58 0.292
pair P200 process P200 0.0001 21.46 58 0.307
4. RESULTS:
4.1 Response accuracy:
The participants were performed well in CEF tasks. Accuracy and response time were analyzed in
inhibition and set-shifting working memory paradigm. Comparative curves were plotted in
between the inhibition and set-shifting task. We found that average score of correct response was
higher in ‘inhibition task’ (87.5%) in comparison to ‘set-shifting task’ (59.5%).
4.2 ERP Peaks in Inhibition and Set-Shifting Task:
(a) (b)
Figure 3 Event related Potentials in (a) Inhibition task (b) Set-shifting task.
6. Signal & Image Processing : An International Journal (SIPIJ) Vol.7, No.1, February 2016
48
Figure 3 represents the average ERPs for the N200, P200, P300 components. We measured the
amplitudes for fronto-central (Fz) and parieto-central (Pz) electrode. These electrodes were
significantly attenuated compared. We found that Fz electrode have less amplitude value than Pz
electrode. In comparison of both tasks, inhibition process had less amplitude than set-shifting
process.
4.3 EEG ERP results:
We found that lower peak amplitude activity of brain area in inhibition process than set-shifting
process, which reveals that inhibition process utilize less activation of brain areas to perform
tasks. In order to show this, we examined the frontal and parietal activity of brain in same tasks.
We found that brain uses the fronto-parietal connectivity when it performs CEF of WM related
tasks. We also found that the midline frontal (FZ, F4, F6) and parietal (PZ, P4, P6) electrodes
were activated at the same time with prominent pattern of negative potentials and other had
positive potentials in both tasks.
Figure 4 (a). Neuronal activation in EEGLab®
head-view (3D & 2D) for Inhibition task.
Figure 4 (b). Neuronal activation in EEGLab®
head-view (3D & 2D) for Set-shifting task.
Figure 5(a) . Neuronal activation in MNI template for Inhibition task computed from EEG signal.
Figure 5 (b). Neuronal activation in MNI template for Set-shifting task computed from EEG signal.
Most significant results were found in both tasks. After the post processing we got 3D and 2D
head-views in EEGLAB [Figure 4 (a,b)] and sLORETA [Figure 5 (a,b)]. In EEGLAB we
7. Signal & Image Processing : An International Journal (SIPIJ) Vol.7, No.1, February 2016
49
measured the activation on 100, 200 and 300 ms after the stumuli come. In both head-views we
found the Inhibition process have less activation on fronto-parietal lobs than set-shifting process.
5. DISCUSSION
Till today, a lot of research has been done on both central executive function of working memory
but little efforts have been made to find the behavioural and neural connections between the two
processes. This study examined the brain activation pattern. We find out ERPs and behavioural
interpretations, during the inhibition and set-shifting tasks. In this study our objective was to
understand the brain dynamics for CEF of WM functions and find out neural spatial domain in
central executive function during inhibition and set-shifting process. The behavioural results
showed that among the population of normal individuals, inhibition process score was high in
comparison to set-shifting task.
These behavioural changes were accompanied by a number of changes in transient ERPs and task
related EEG activations. This study is mainly focused on finding the EEG correlation between
components of CEF. In EEG findings, by using time domain analysis [15] and bivalent 2-D and
3-D cartoon maps, positive and negative potentials were observed across the pre-frontal, frontal,
central and parietal electrodes, during both the tasks.
Electric potential distribution on the basis of the scalp recording was measured by sLORETA that
compute the cortical three- dimensional smoothest of all possible neural current density
distribution, where neighbouring voxels have maximally similar activity. Low Resolution
Electromagnetic Tomography (LORETA) is used for source localization, based on R. D. Pascual-
Marqui and its virtual MR anatomical images are based on Montreal Neurological Institute (MNI)
of McGill University. LORETA is a linear distribution method and it calculates the current
density voxel by voxel in the brain as a linear, weighted sum of scalp electrical potential.
Computations were made in a realistic head model using the MNI 152 template with the three
dimensional solution space restricted to cortical grey matter.
The EEG method is the dipole source with fixed location and orientation method and it is
distributed in the whole brain volume or cortical surface. There are six parameters that specify the
dipole, three special coordinates (x,y,z) and three dipole components (orientation, angle, and
strength). In the LORETA, the electrode potentials and matrix X are considered to be related as
X=LS
Where S is the actual current density and L is Ne×3m matrix representation the forward
transmission coefficients form each source to the array of sensors. There are number of sensors
Ne, extra cranial measurements in the surface of brain and Nv, voxels in the brain. In the real
world applications where more concentrated focal source methods fail and choose smoothness of
the inverse solution as
S=LT
(LLT
)X
The sloreta uses the minimum norm solution is to create a space solution with zero contribution
from the source. However, the variance of the current density estimate is based only on the
measurement noise, in contrast to sLORETA , which takes into account the actual source variance
as well.
Time domain analysis of EEG and ERPs: After averaging in time domain 2-D head maps were
taken to represent the surface potential distribution patterns. Central executive WM tasks were
8. Signal & Image Processing : An International Journal (SIPIJ) Vol.7, No.1, February 2016
50
analyzed at both the retrieval and encoding phases in epochs of 800 and 1000ms. Result was seen
throughout the whole brain electrodes. In the encoding and retrieval phase of the CEF of WM
activation patterns were seen [16].
ERPs comparison studies for inhibition and set-shifting process: Visually evoked potentials
(P100) were present throughout the CEF WM task [17]. Delay in early N200 latencies in Fz of
encoding showed that visual attention took time. In late P300 peaks in Pz of retrieval phase
showed that matching system of visually attend objects. We also found the increase in the
amplitude of the frontal visual N200 has been observed in a number of studies, this response
shows the Inhibition and attention performance. These delays in ERPs are also observed in 2D
and 3D maps in EEGLAB. So we can conclude that functioning of inhibition process is found in
fronto-parietal area of brain.
In both encoding and retrieval phase of CEF WM all desired ERPs were found. Visually evoked
potentials (P100) were seen in parietal area suggesting the stimulus representation extrastriate
cortex (BA 6 and 18) [18]. N100 component was seen in frontal and pre-frontal electrodes
showing the unpredictability of stimulus. N200 component was present in parietal electrodes.
Encoding phase showing delayed N200 latencies but in retrieval phase N200 latencies were
shorter due to attending the visual stimuli. Early-latency visual ERPs are enhanced when stimuli
are presented in an attended visual field. Reaction times are also shorter to stimuli presented in an
attended visual field than to those presented in an unattended visual field. In retrieval phase,
delayed P200 latency of Fz electrodes suggesting for a matching system that compares sensory
inputs with the stored memory. P200 latencies were present in both phases but most prominently
it was elicited in retrieval phase.
ERPs analysis is suggested for activation network during CEF of WM. In Encoding phase initial
activations occurred in the visual cortex where stimuli were attended for the visual search. The
information from the stimuli was coded to the Fz and Pz electrodes as the late P300 peaks were
present in the parietal electrodes suggesting the demand of focusing. Likewise, all the ERP
patterns were seen in the retrieval phase. The only difference was the delayed P200 latencies
suggesting for a matching system related to make comparison of present stimulus with the
previous ones. This whole ERPs analysis is consistent with EEGLAB and sLORETA maps
achieved in the time domain analysis. So, a network of activation patterns from frontal to parietal
area in the both inhibition and set-shifting process of Central Executive Function of Working
Memory.
6. CONCLUSION
Findings from this study will give a better understanding of CEF and brain activity in inhibition
and set-shifting process. Our findings demonstrate a paradigm combined with a technique to be
used to measure of inhibition and set-shifting neuronal processes. This would help in under-
standing the alteration of central executive function in patient with neurological and psychiatric
disorder.
ACKNOWLEDGMENT
Preparation of this paper was supported by Department of clinical Neuro-psychology, National
Institute of Mental Health and Neuroscience (NIMHANS), Bangalore, India. We are grateful to
Ganne Chaitanya, Deepak Ullal and Rajnikant Panda for providing thoughtful remarks and
suggestions regarding EEG and ERP analysis.
9. Signal & Image Processing : An International Journal (SIPIJ) Vol.7, No.1, February 2016
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AUTHORS
*The Corresponding author for this paper is Dr. Jamuna Rajeswaran
Mr. Pankaj, received M.Tech degree in Cognitive Neuroscience from Centre for
Converging Technologies, University of Rajasthan, India, in 2015. He has more than one
year of research experience on clinical psychology, Neuro-imaging and EEG signal
processing on cognition at National Institute of Mental Health and Neurosciences,
Bangalore, India. He has clinical research experience with many National institutes. He
also got Mani Bhomik research-fellowship (2015) in National Institute of Advanced
Studies (NIAS), Indian Institute of Science campus, Bangalore, India.
Dr. Jamuna Rajeswaran, Additional Professor, Consultant & Head Neuropsychology
Unit, National Institute of Mental Health and Neurosciences, Bangalore, India. She
completed her M.Phil and PhD from Dept. of Clinical Psychology, National Institute of
Mental Health and Neurosciences, Bangalore, India.
Dr. Divya Sadana, Senior Research Fellow, Department of Clinical psychology,
National Institute of Mental Health and Neurosciences, Bangalore, India. She completed
her M.Phil and PhD from Dept. of Clinical Psychology, National Institute of Mental
Health and Neurosciences, Bangalore, India.