Ali Asghar Zarei

Amirkabir University of Technology

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Romulus Lontis

Aalborg University

Winnie Jensen

Aalborg University

Armita Faghani Jadidi

Copenhagen University Hospital

M. V. Takook

Laboratoire AstroParticule et Cosmologie

S. Farokh Atashzar

New York University

B. Forghan

Islamic Azad University of Parand

Farnaz Ghassemi

Amirkabir University of Technology

Mohammad Hassan Moradi

Bu-Ali Sina University

Abbas Moghimbeigi

Alborz University of Medical Sciences

Ehsan Nazerfard

Amirkabir University of Technology

Cooperative Institutions

Islamic Azad University, Science and Research Branch

Hamedan University of Medical Sciences

Amirkabir University of Technology

Islamic Azad University, Tehran

University of Oxford

Aalborg University

Nuffield Orthopaedic Centre

University of Tehran

Islamic Azad University of Hamedan

Sharif University of Technology

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From pulse width modulated TENS to cortical modulation: based on EEG functional connectivity analysis

Frontiers in Neuroscience (2023)

Armita Faghani Jadidi Winnie Jensen Ali Asghar Zarei Romulus Lontis S. Farokh Atashzar

Modulation in the temporal pattern of transcutaneous electrical nerve stimulation (TENS), such as Pulse width modulated (PWM), has been considered a new dimension in pain and neurorehabilitation therapy. Recently, the potentials of PWM TENS have been studied on sensory profiles and corticospinal activity. However, the underlying mechanism of PWM TENS on cortical network which might lead to pain alleviation is not yet investigated. Therefore, we recorded cortical activity using electroencephalography (EEG) from 12 healthy subjects and assessed the alternation of the functional connectivity at the cortex level up to an hour following the PWM TENS and compared that with the effect of conventional TENS. The connectivity between eight brain regions involved in sensory and pain processing was calculated based on phase lag index and spearman correlation. The alteration in segregation and integration of information in the network were investigated using graph theory. The proposed analysis discovered several statistically significant network changes between PWM TENS and conventional TENS, such as increased local strength and efficiency of the network in high gamma-band in primary and secondary somatosensory sources one hour following stimulation. Our findings regarding the long-lasting desired effects of PWM TENS support its potential as a therapeutic intervention in clinical research.

10.3389/fnins.2023.1239068

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Simultaneous Modulation of Cortical Activity and Phantom Pain in a Patient with Brachial Plexus Injury

Ali Asghar Zarei S. Farokh Atashzar Winnie Jensen Armita Faghani Jadidi Romulus Lontis

Brachial plexus injury may induce complete loss of sensation and motor control in parts of the affected arm, leading to phantom limb pain (PLP). PLP is associated with functional reorganization at the somatosensory cortex and alteration in the functional connectivity of the related pain brain areas. Several therapies have previously been suggested for PLP relief. Transcutaneous electrical nerve stimulation (TENS) is a non-invasive intervention used for pain relief and stroke rehabilitation. However, the underlying mechanism of TENS on cortical activity associated with PLP relief is not well-known. The effect of TENS (20Hz) intervention on somatosensory activity, cortical functional connectivity, and possible PLP reduction was investigated in this study in the case of a 55 year old subject with brachial plexus injury inducing complete paralysis below the elbow in the left arm. We recorded EEG data and the patient's pain level before and after the intervention. Somatosensory evoked potentials (SEPs) and functional connectivity between pain-related areas were assessed from EEG data. The results showed that the application of TENS suppressed somatosensory evoked potentials. In addition, the intervention enhanced the functional connectivity (a) between the primary somatosensory cortex and the anterior cingulate cortex (SI-ACC), also (b) between the primary somatosensory cortex and the medial prefrontal cortex (SI-MPC). Moreover, these results were associated with PLP reduction following TENS. We compared the results with our previous research on a large healthy population to assess the cortical changes.

Somatosensory evoked potential

Secondary somatosensory cortex

10.1109/ner52421.2023.10123824

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Krein regularization of QED

Annals of Physics (2012)

B. Forghan M. V. Takook Ali Asghar Zarei

Lamb shift

Regularization

Dimensional regularization

Self-energy

Feynman graph

10.1016/j.aop.2012.06.003

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Citations (22)

Combinational Standard Cells Adjacency Effect Analysis on Soft Error Occurrence Using Device-Level Simulations

Ali Asghar Zarei Amir M. Hajisadeghi Hamid R. Zarandi

Adjacency list

Soft error

Error Analysis

Combinational logic

10.1109/cpsat64082.2024.10745376

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Effect of Modulated TENS on Corticospinal Excitability in Healthy Subjects

Neuroscience (2022)

Armita Faghani Jadidi Andrew James Thomas Stevenson Ali Asghar Zarei Winnie Jensen Romulus Lontis

Conventional transcutaneous electrical nerve stimulation (TENS) has been reported to effectively alleviate chronic pain, including phantom limb pain (PLP). Recently, literature has focused on modulated TENS patterns, such as pulse width modulation (PWM) and burst modulation (BM), as alternatives to conventional, non-modulated (NM) sensory neurostimulation to increase the efficiency of rehabilitation. However, there is still limited knowledge of how these modulated TENS patterns affect corticospinal (CS) and motor cortex activity. Therefore, our aim was to first investigate the effect of modulated TENS patterns on CS activity and corticomotor map in healthy subjects. Motor evoked potentials (MEP) elicited by transcranial magnetic stimulation (TMS) were recorded from three muscles before and after the application of TENS interventions. Four different TENS patterns (PWM, BM, NM 40 Hz, and NM 100 Hz) were applied. The results revealed significant facilitation of CS excitability following the PWM intervention. We also found an increase in the volume of the motor cortical map following the application of the PWM and NM (40 Hz). Although PLP alleviation has been reported to be associated with an enhancement of corticospinal excitability, the efficiency of the PWM intervention to induce pain alleviation should be validated in a future clinical study in amputees with PLP.

Neurostimulation

Facilitation

10.1016/j.neuroscience.2022.01.004

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The Relationships Among Role Ambiguity, Team Cohesion, Role Acceptance and Role Satisfaction of Basketball Players

Taher Bahlekeh Farshad Tojari Ali Asghar Zarei Farideh Ashraf Ganjooee

The purpose of this study was to determine the nature of the relationships among Role Ambiguity, Role Acceptance, Role Satisfaction and Team Cohesion. It was hypothesized that Role Ambiguity would predict both Role Acceptance and Role Satisfaction and Role Acceptance and Role Satisfaction would predict both Team Cohesion. Participants included 171 male basketball players from Iran basketball super league. Measures included the Role Perception Scale, a Role Acceptance and Role Satisfaction measure and Group Environment Questionnaire. Stepwise multiple regression analysis showed that Role Ambiguity regarding role evaluation was predictive of Role Satisfaction and Role Ambiguity regarding scope of responsibilities was predictive of Role Acceptance. Stepwise multiple regression also showed that Role Satisfaction to be the predictor of Role Ambiguity as well as the only predictor of Team Cohesion with regard to individual attractions to the group-task.

Basketball

Cohesion (chemistry)

Group cohesiveness

Source

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Spatial Filter Bank based on Probabilistic Common Spatial Pattern in Motor Imagery BCI systems

Ali Asghar Zarei Farnaz Ghassemi

Recently, Motor Imagery (MI) based on Brain Computer Interface (BCI) systems have been noticed for neuro-rehabilitation methods. The challenging key is to correct detection of MI tasks. Probabilistic Common Spatial Pattern (P-CSP) is the most recent and efficient method for discriminating two classes of electroencephalogram (EEG) from Motor Imagery (MI) Task. P-CSP resolves the overfitting which is the main issue of spatial filters. The accuracy of true detection tasks is related to some initial values, like the number of sources. In this paper, we generate a feature set by extracted features of each unique filter and select discriminant features by sparse dictionary learning method. Optimal sparse regularization parameter is selected by cross-validation on training data and the maximum accuracy with the corresponding parameter is reported for each subject. The performance of the proposed method is evaluated on publicly available BCI Competition IV dataset 2a to detect two pair classes. Our results have been compared with P-CSP, by sweeping the Best number of source and using automatic selection methods. The results show that sparse features selection from feature set outperforms the existing P-CSP in terms of classification accuracy, and reduces the computational time of selecting the best number of the sources by sparse selection.

Motor Imagery

Overfitting

Regularization

10.1109/icbme.2016.7890933

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Information based source number estimation for probabilistic common spatial pattern in motor imagery BCI system

Ali Asghar Zarei Farnaz Ghassemi Mohammad Hassan Moradi

Common Spatial Pattern (CSP) is one of the popular and effective methods for discriminating two class electroencephalogram (EEG) measurements. Its probabilistic counterpart by resolving the problem of overfitting as the main limitation of CSP attracted much attention, especially in the motor imaginary based brain computer interface (BCI) applications. Since the computational efficiency is a paramount issue in real-time EEG classification, in this paper, assuming additive isotropic noise, maximum a posteriori (MAP)-based iterative updating algorithm is applied. However, the performance of this algorithm depends on the model size which must be predetermined. To this end, three information based source number estimations including Akaike Information Criterion (AIC), Minimum Description Length (MDL) and Bayesian Information Criteria (BIC) were used. The experimental results on a publicly available Ilia dataset from BCI competition III demonstrate higher classification accuracy compared to CSP and existing Tikhonov regularized CSP (TR-CSP) models. In addition, a significant decrease in run-time was achieved using the proposed method.

Overfitting

Akaike information criterion

Bayesian information criterion

Motor Imagery

Minimum description length

10.1109/iraniancee.2016.7585584

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Erratum to: QED in Krein Space Quantization

International Journal of Theoretical Physics (2012)

Ali Asghar Zarei B. Forghan M. V. Takook

Second quantization