An Unsupervised Spiking Neural Network Inspired By Biologically Plausible Learning Rules and Connections

The backpropagation algorithm has promoted the rapid development of deep learning, but it relies on a large amount of labeled data, and there is still a large gap with the way the human learns. The human brain can rapidly learn various concept knowledge in a self-organized and unsupervised way, which is accomplished through the coordination of multiple learning rules and structures in the human brain. Spike-timing-dependent plasticity (STDP) is a widespread learning rule in the brain, but spiking neural network trained using STDP alone are inefficient and performs poorly. In this paper, taking inspiration from the short-term synaptic plasticity, we design an adaptive synaptic filter, and we introduce the adaptive threshold balance as the neuron plasticity to enrich the representation ability of SNNs. We also introduce an adaptive lateral inhibitory connection to dynamically adjust the spikes balance to help the network learn richer features. To accelerate and stabilize the training of the unsupervised spiking neural network, we design a sample temporal batch STDP which update the weight based on multiple samples and multiple moments. We have conducted experiments on MNIST and FashionMNIST, and have achieved state-of-the-art performance of the current unsupervised spiking neural network based on STDP. And our model also shows strong superiority in small samples learning.