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Zare, M.

Publications and source records attributed to Zare, M..

3 recordsLinked to original sources

Impact of the Excitatory-Inhibitory Neurons Ratio on Scale-Free Dynamics in a Leaky Integrate-and-Fire Model

The relationship between ratios of excitatory to inhibitory neurons and the brains dynamic range of cortical activity is crucial. However, its full understanding within the context of cortical scale-free dynamics remains an ongoing investigation. To provide insightful observations that can improve the current understanding of this impact, and based on studies indicating that a fully excitatory neural network can induce critical behavior under the influence of noise, it is essential to investigate the effects of varying inhibition within this network. Here, the impact of varying ratios on neural avalanches and phase transition diagrams, considering a range of control parameters in a leaky integrate-and-fire model network, is examined. Our computational results show that the network exhibits critical, sub-critical, and super-critical behavior across different control parameters. In particular, a certain ratio leads to a significantly extended dynamic range compared to others and increases the probability of the system being in the critical regime. To address differences between various ratios, we utilized the Kuramoto order parameter and conducted a finite-size scaling analysis to determine the critical exponents associated with phase transitions. In order to characterize the criticality, we examined the distribution of neuronal avalanches at the critical point and the scaling behavior characterized by specific exponents.

neuroscience↗

Age-related complexity of the resting state MEG signals: a multiscale entropy analysis

The effects of aging on the brain can be studied by examining the changes in complexity of brain signals and fluid cognitive abilities. This paper is a relatively large-scale study in which the complexity of the resting-state MEG (rsMEG) signal was investigated in 602 healthy participants (298 females and 304 males) aged 18 to 87. In order to quantify the brain signals complexity, the multiscale entropy is applied. This study investigates the relationship between age and fluid intelligence with brain complexity and the variations of the complexity asymmetry between the left-right brain hemispheres across the life span. In the analysis of the brain signals, the gender difference was considered. The results showed that the complexity of rsMEG decreases across the lifespan. However, the complexity difference between the left-right brain hemispheres positively correlates with age. Furthermore, the results demonstrated that fluid intelligence and age have a positive correlation. Finally, the frequency analysis revealed a significant increase in the relative power of low and high gamma rhythms in females compared to males in all age groups.

neuroscience↗

Machine learning Classification of Dyslexic Children based on EEG Local Network Features

Machine learning can be used to find meaningful patterns characterizing individual differences. Deploying a machine learning classifier fed by local features derived from graph analysis of electroencephalographic (EEG) data, we aimed at designing a neurobiologically-based classifier to differentiate two groups of children, one group with and the other group without dyslexia, in a robust way. We used EEG resting-state data of 29 dyslexics and 15 typical readers in grade 3, and calculated weighted connectivity matrices for multiple frequency bands using the phase lag index (PLI). From the connectivity matrices, we derived weighted connectivity graphs. A number of local network measures were computed from those graphs, and 37 False Discovery Rate (FDR) corrected features were selected as input to a Support Vector Machine (SVM) and a common K Nearest Neighbors (KNN) classifier. Cross validation was employed to assess the machine-learning performance and random shuffling to assure the performance appropriateness of the classifier and avoid features overfitting. The best performance was for the SVM using a polynomial kernel. Children were classified with 95% accuracy based on local network features from different frequency bands. The automatic classification techniques applied to EEG graph measures showed to be both robust and reliable in distinguishing between typical and dyslexic readers.

neuroscience↗