Sharpness Aware Surrogate Training for Spiking Neural Networks
Summary
Sharpness Aware Surrogate Training (SAST) is a novel method for optimizing Spiking Neural Networks (SNNs) that addresses the "surrogate to hard transfer gap" by applying Sharpness Aware Minimization (SAM) to a smooth surrogate forward SNN. Unlike conventional methods that couple a non-smooth forward model with a biased gradient estimator, SAST optimizes a smooth empirical risk, ensuring an exact training gradient for the auxiliary model. The method provides theoretical guarantees including state stability, input Lipschitz bounds, smoothness of the surrogate objective, and nonconvex convergence for stochastic SAST. Empirically, SAST significantly reduces the transfer gap on datasets like N-MNIST (from 65.7% to 94.7% hard spike accuracy) and DVS Gesture (from 31.8% to 63.3% hard spike accuracy), while maintaining high surrogate forward accuracy and improving corruption robustness. The approach requires careful controls for compute matching and threshold calibration for a comprehensive practical assessment.
Key takeaway
Research Scientists developing Spiking Neural Networks should consider integrating Sharpness Aware Surrogate Training (SAST) into their workflow, especially when aiming for robust hard spike deployment. SAST demonstrably improves hard spike accuracy and reduces the critical surrogate-to-hard transfer gap, which is vital for real-world neuromorphic hardware applications. You should rigorously evaluate SAST against compute-matched and calibration-aware baselines to confirm its efficiency and practical superiority for your specific SNN architectures and datasets.
Key insights
SAST optimizes SNNs by applying SAM to a smooth surrogate forward model, reducing the surrogate-to-hard transfer gap.
Principles
- Smooth forward models enable exact gradient computation.
- Sharpness-aware optimization improves generalization and robustness.
- Explicit stability bounds are crucial for recurrent SNNs.
Method
SAST applies SAM to a surrogate forward SNN, using backpropagation through time to compute exact gradients of a smooth objective. It involves two SAM passes with state resets and independent minibatches for convergence guarantees.
In practice
- Use SAST to reduce the surrogate-to-hard transfer gap in SNN deployments.
- Evaluate both surrogate and hard spike accuracy to quantify transfer gap.
- Consider compute-matched baselines for fair performance comparison.
Topics
- Spiking Neural Networks
- Sharpness Aware Minimization
- Surrogate Gradients
- Neuromorphic Computing
- Transfer Gap Reduction
Best for: Research Scientist, AI Researcher, AI Scientist, Deep Learning Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by cs.NE updates on arXiv.org.