Emergence Mechanisms of Brain Functions from Synaptic Dynamics

There is a key problem that how brain uses the properties of synaptic dynamics to implement its macro-functions. The dynamic synapse model made by J. S. Liaw and T. W. Berger provided an example of implementing speech recognition function with dynamic synaptic mechanisms. The emergence mechanisms of recognition function in the dynamic synapse model are qualitatively analyzed in this paper. The nonlinear dynamic mechanisms in the model, such as threshold effects, feedback mechanisms and synaptic plasticity are discussed. Together with the neuron´s character of integrate-and-fire, the whole transferring process is a special kind of coding. So we firstly analyzed the filtering function emerge from the synaptic dynamics with a neural circuit. Furthermore, there are key parameters for the emergences of recognition function. With the nonlinear dynamic mechanisms, the changes of the 120 key parameters would make the synaptic connections of the model emerge into a spatial structure. Under this structure, each output neuron has a specific synaptic connection to integrate its specific trains, so the recognition function emerges.