Training High-Performance Low-Latency Spiking Neural Networks by Differentiation on Spike Representation
Qingyan MengMingqing XiaoShen YanYisen WangZhouchen LinZhi-Quan Luo
Presents the Differentiation on Spike Representation method to train spiking neural networks via sub-differentiable mapping of firing rates, eliminating expensive backpropagation through time to achieve ANN-competitive accuracy at low latency across static and neuromorphic benchmarks.
Spiking neural networks (SNNs) are brain-inspired artificial intelligence models that process information using discrete pulses or spikes. When deployed on specialized neuromorphic hardware, they offer substantial energy efficiency compared to conventional deep artificial neural networks (ANNs). However, training high-performing SNNs remains difficult because spike generation is non-differentiable, preventing standard gradient-based optimization. Existing training approaches either require hundreds of simulation time steps to match standard model accuracy, causing high latency, or rely on computationally heavy surrogate gradient methods that struggle to scale and match top-tier performance.
The article introduces and evaluates the Differentiation on Spike Representation (DSR) method, a training technique designed to deliver high accuracy with low latency across both standard image datasets and neuromorphic event-based streams.
The proposed approach encodes temporal spike trains into rate-based continuous representations and mathematically maps the forward network operations to sub-differentiable functions. Gradients are then propagated directly through these mappings across network layers, completely bypassing temporal backpropagation. To counter the representation error that arises when simulating with very few time steps, the authors introduce two mechanisms: dynamically training the firing thresholds of neurons with regularized optimization, and introducing a firing-control hyperparameter to cut quantization error.
The evaluation demonstrates that DSR achieves state-of-the-art accuracy across several benchmark datasets while maintaining short simulation latencies of 5 to 20 time steps. On CIFAR-100, the method achieves 78.50% accuracy, surpassing prior spiking approaches by 5% to 10% and matching standard ANN baselines. On CIFAR-10, it reaches 95.40% accuracy at 20 time steps and maintains over 94.4% accuracy down to an ultra-low latency of 5 time steps. On neuromorphic DVS-CIFAR10 data, it attains 77.27% accuracy, outperforming competing methods. Furthermore, the approach scales successfully to deep residual networks exceeding 100 layers without performance degradation.
These results show that spiking neural networks can achieve standard deep learning accuracy without incurring large computational and memory overheads during training or long inference delays. By enabling faster, low-power processing, the method improves the viability of deploying energy-efficient neuromorphic systems in edge computing and real-time sensory applications.
Organizations developing low-power AI systems should consider adopting representation-based differentiation frameworks for neuromorphic applications and evaluating these models on target hardware platforms. Further research and hardware-in-the-loop validation are recommended to assess real-world energy savings and performance trade-offs under extreme latency conditions below five time steps, where representation errors may increase.
- Paper: Spatio-Temporal Backpropagation for Training High-Performance Spiking Neural Networks, Yujie Wu et al. (2017). This seminal work introduces spatio-temporal backpropagation for spiking neural networks, establishing the core framework of surrogate gradient training that DSR directly compares against and aims to improve upon.
- Paper: Surrogate Gradient Learning in Spiking Neural Networks: Bringing the Power of Gradient-based optimization to spiking neural networks, Emre O. Neftci et al. (2019). This paper provides the foundational formulation for training spiking neural networks with continuous surrogate gradients, presenting the standard optimization paradigm that DSR bypasses via spike representation differentiation.
- Paper: Deep Learning in Spiking Neural Networks, Amirhossein Tavanaei et al. (2018). This comprehensive survey outlines the key methodologies and challenges in deep spiking neural networks, detailing the trade-offs between direct training and ANN-to-SNN conversion methods relevant to low-latency training.
- Paper: Event-Based Vision: A Survey, Guillermo Gallego et al. (2019). This paper provides essential background on event-based neuromorphic vision datasets like DVS-CIFAR10, which serve as primary empirical benchmarks for validating DSR.
- Paper: Adaptive Smoothing Gradient Learning for Spiking Neural Networks, Ziming Wang et al. (2023). This paper extends direct spiking network optimization by adaptively modulating the surrogate smoothing degree to eliminate gradient estimation errors.
- Paper: RecDis-SNN: Rectifying Membrane Potential Distribution for Directly Training Spiking Neural Networks, Yufei Guo et al. (2022). This work tackles gradient mismatch and potential saturation during direct SNN training by rectifying membrane potential distributions across time steps.
- Paper: Temporal Efficient Training of Spiking Neural Network via Gradient Re-weighting, Shikuang Deng et al. (2022). This work presents an alternative temporal training scheme for low-latency SNNs by re-weighting loss evaluations at individual time steps to improve generalization.
- Paper: Parallel Spiking Neurons with High Efficiency and Ability to Learn Long-term Dependencies, Wei Fang et al. (2023). This paper explores an architectural approach to eliminate serial time-step dependencies, providing an alternative parallel mechanism to overcome latency and training bottlenecks in spiking models.
- Paper: SpikingResformer: Bridging ResNet and Vision Transformer in Spiking Neural Networks, Xinyu Shi et al. (2024). This work scales ultra-low-latency direct spiking networks to vision transformer backbones using dual spike transformations.
- Paper: ESL-SNNs: An Evolutionary Structure Learning Strategy for Spiking Neural Networks, Jiangrong Shen et al. (2023). This paper investigates dynamic synaptic pruning during SNN training, building upon efficient direct-training paradigms to optimize parameter redundancy.
