Emergence of Brain-inspired Small-world Spiking Neural Network through Neuroevolution

Human brain is the product of evolution during hundreds over millions of years and can engage in multiple advanced cognitive functions with low energy consumption. Brain-inspired artificial intelligence serves as a computational continuation of this natural evolutionary process, is imperative to take inspiration from the evolutionary mechanisms of brain structure and function. Studies suggest that the human brain's high efficiency and low energy consumption may be closely related to its small-world topology and critical dynamics. However, existing efforts on the performance-oriented structural evolution of spiking neural networks (SNNs) are time-consuming and ignore the core structural properties of the brain. In this paper, we propose a multi-objective Evolutionary Liquid State Machine (ELSM) with the combination of small-world coefficient and criticality as evolution goals and simultaneously integrate the topological properties of spiking neural networks from static and dynamic perspectives to guide the emergence of brain-inspired efficient structures. Extensive experiments show a consistent and comparable performance of the proposed model compared to LSM-based and hierarchical SNNs algorithms: it achieves 97.23\% on NMNIST, and reaches the state-of-art performance compared to all LSM models on MNIST and Fashion-MNIST (98.05\% and 88.81\%, respectively). A thorough analysis reveals the spontaneous emergence of hub nodes, short paths, long-tailed degree distributions, and numerous community structures in evolutionary models. This work evolves recurrent spiking neural networks into brain-inspired efficient structures and dynamics, providing the potential to achieve adaptive general aritficial intelligence.