Sharif Digital Repository

In this paper, the field theory tools will be used to study none-equilibrium statistical processes and eventually analyze the dynamic of the neocortex. Assuming the neocortex is Markovian, a model is proposed which contains fluctuations of the neuron activities as well as response to the stimulations. The experimental data shows that the fluctuation and correlation have a vital impact on the dynamics of the cortex, and many of its characteristics can only be justified by it.The paper will study the model that considers correlations and fluctuations to reach a more accurate evaluation of the cortex than the mean field approximation  

Experiments conducted in recent two decades indicated critical behavior in neural activity at different scales. Theoretically occurrences of these critical and power-law behavior can significantly facilitate brain activities correspondent to computation and memory tasks, but attaining the critical point essentially demands externally fine-tuning which has not been established yet. This fine-tuning often lies with placing system at transition point. Recent studies of group showed that a transition from synchronous to asynchronous phase could be achievable by a change in external parameters. At the very transition point, neuronal avalanches statistically demonstrate a power-law behavior which... 

Neural systems are the threshold ones. It means if the electrical potential passed through a specific amount then they could spike and cause the activity of other cells. The models that really mimic the action of neurons are usually complicated and are not suitable when you put them on a network to study the collective behavior of the neurons. Simple threshold models have been designed for such purposes. One on most studied ones is the ’integrate and fire’ model, in which cells integrate the inputs until the threshold potential and then spike. usually, a network of these objects are simulated and different properties of such network are investigated.However, this model has some shortcomings...