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Dehghani-Habibabadi, M.

Publications and source records attributed to Dehghani-Habibabadi, M..

2 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↗

Incremental Self-Organization of Spatio-Temporal Spike Pattern Detection

Nervous systems utilize temporally precise patterns of activity. However, the mechanisms by which spike patterns are processed are not known. In particular, the fact that during learning different patterns are distributed over time raises the question of how groups of neurons become selective for new spike patterns without overwriting already learned patterns. A simple one-layer spiking neural network model is presented that learns to recognize spatiotemporal spike patterns sequentially. The approach integrates biological synaptic mechanisms, including Hebbian learning, heterosynaptic plasticity, and synaptic scaling, allowing groups of neurons to self-organize selectivity for a set of spike patterns. Spoken words, transformed by a cochlear model into spatio-temporal spike patterns, are learned without supervision. This work suggests how the brain can use temporal spike codes and provides a novel, scalable, efficient, and noise-tolerant solution to the stability-plasticity dilemma.

neuroscience↗