Three factor delay learning rules for spiking neural networks
Summary
A new method introduces three-factor learning rules for synaptic and axonal delays in Spiking Neural Networks (SNNs) and Spiking Recurrent Neural Networks (SRNNs), enabling online learning of these temporal parameters. This approach utilizes a smooth Gaussian surrogate for spike derivatives, exclusively for eligibility trace calculation, combined with a top-down error signal to update parameters. Experiments on the SHD speech recognition dataset demonstrate that incorporating delays improves accuracy by up to 20% over a weights-only baseline. When jointly learning weights and delays, the method achieves up to 14% higher accuracy for networks with similar parameter counts. Compared to existing offline backpropagation-based methods, this online learning approach achieves similar accuracy while reducing model size by 6.6x and inference latency by 67%, with only a 2.4% drop in classification accuracy. This benefits the design of power and area-constrained neuromorphic processors by facilitating on-device learning and reducing memory requirements.
Key takeaway
For AI Scientists and Research Scientists developing neuromorphic systems, integrating these three-factor delay learning rules offers a practical solution to enhance SNN performance on temporal tasks. You can achieve significant accuracy improvements (up to 20%) and efficiency gains (6.6x smaller models, 67% lower latency) compared to offline methods, especially in sparse or small network configurations. This enables on-device learning in memory-constrained environments without compromising accuracy.
Key insights
Online learning of synaptic and axonal delays significantly enhances SNN performance and efficiency for temporal tasks.
Principles
- Learnable delays improve temporal pattern recognition in SNNs.
- Three-factor learning rules enable online, real-time parameter updates.
- Sparsity amplifies the accuracy benefits of delay learning.
Method
The method uses three-factor learning rules with a smooth Gaussian surrogate for spike derivatives to enable online updates of synaptic and axonal delays in LIF-based SNNs and SRNNs, approximating BPTT performance.
In practice
- Implement online delay learning for resource-constrained neuromorphic systems.
- Consider joint weight and delay learning for improved accuracy-to-parameter ratio.
- Apply delay learning in sparse network configurations for enhanced benefits.
Topics
- Spiking Neural Networks
- Online Learning
- Three-Factor Learning Rules
- Synaptic and Axonal Delays
- Neuromorphic Computing
Best for: AI Scientist, Research Scientist, AI Researcher, Machine Learning Engineer, AI Hardware Engineer
Related on AIssential
Editorial summary, takeaway, and curation by AIssential. Original article published by cs.NE updates on arXiv.org.