Deep Residual Learning in Spiking Neural Networks

TL;DR

SEW ResNet enables residual learning in deep SNNs, improving accuracy and time-steps.

cs.NE 🔴 Advanced 2021-02-08 3 views
Wei Fang Zhaofei Yu Yanqi Chen Tiejun Huang Timothée Masquelier Yonghong Tian
deep learning spiking neural networks residual learning optimization image classification

Key Findings

Methodology

This paper introduces Spike-Element-Wise (SEW) ResNet, which implements residual learning in deep SNNs through simple element-wise operations. SEW ResNet easily achieves identity mapping and addresses vanishing/exploding gradient issues in Spiking ResNet.

Key Results

  • SEW ResNet achieved 69.26% accuracy on ImageNet, surpassing directly trained Spiking ResNet.
  • On CIFAR10-DVS dataset, SEW ResNet also excelled in time-steps.
  • Performance improved further by adding more layers in SEW ResNet.

Significance

SEW ResNet offers a new approach to training deep SNNs, addressing degradation issues in traditional methods, and advancing SNN applications in complex tasks.

Technical Contribution

By introducing element-wise operations, SEW ResNet provides a simple yet effective method for residual learning, significantly enhancing deep SNN performance.

Novelty

This is the first instance of directly training deep SNNs with more than 100 layers, breaking existing method limitations.

Limitations

  • SEW ResNet may struggle to achieve identity mapping in certain complex neuron models.
  • Long training times are still required for some tasks.

Future Work

Future research could explore SEW ResNet's application in other tasks and optimize its training efficiency.

AI Executive Summary

Spiking Neural Networks (SNNs) are gaining attention for their biological plausibility and low power consumption, yet optimization challenges limit their application. Traditional Spiking ResNet faces degradation issues in implementing residual learning. This paper proposes Spike-Element-Wise (SEW) ResNet, which achieves residual learning in deep SNNs through simple element-wise operations. Experiments show SEW ResNet excels on ImageNet, DVS Gesture, and CIFAR10-DVS datasets, especially in directly training networks with over 100 layers. SEW ResNet not only improves accuracy but also reduces time-steps, advancing SNN applications in complex tasks. Nonetheless, SEW ResNet may struggle with identity mapping in certain complex neuron models, and future research could explore its application in other tasks and optimize training efficiency.

Deep Analysis

Background

Spiking Neural Networks (SNNs) are gaining attention for their biological plausibility and low power consumption. Recently, deep learning methods have been introduced to SNNs, but they still perform worse than Artificial Neural Networks (ANNs) in complex tasks. Residual learning has achieved great success in ANNs, yet implementing it in SNNs remains challenging.

Core Problem

Optimization difficulties in deep SNNs mainly arise from discrete binary activation and complex spatial-temporal dynamics. Traditional Spiking ResNet faces degradation issues in implementing residual learning, failing to effectively address vanishing and exploding gradients.

Innovation

SEW ResNet introduces simple element-wise operations to solve degradation issues in Spiking ResNet. It easily achieves identity mapping and addresses vanishing/exploding gradient problems.

Methodology

  • �� Use element-wise operations for residual learning.
  • �� Implement identity mapping through simple addition and logical operations.
  • �� Employ IF neuron model for experiments.

Experiments

Experiments conducted on ImageNet, DVS Gesture, and CIFAR10-DVS datasets compare SEW ResNet with traditional Spiking ResNet, evaluating accuracy and time-steps.

Results

SEW ResNet achieved 69.26% accuracy on ImageNet, surpassing directly trained Spiking ResNet. Performance improved further by adding more layers.

Applications

SEW ResNet can be used for image classification tasks, especially in scenarios requiring high efficiency and low power consumption.

Limitations & Outlook

SEW ResNet may struggle to achieve identity mapping in certain complex neuron models. Long training times are still required for some tasks.

Plain Language Accessible to non-experts

Imagine a factory where traditional machines require complex operations to produce products, while SEW ResNet is like an automated production line that achieves efficient production through simple button operations. Each button represents a simple operation, and all operations combine to form an efficient production process.

ELI14 Explained like you're 14

Hey, friends! Imagine playing a super cool game where you complete tasks through simple operations. SEW ResNet is like this game, achieving complex tasks through simple additions and logical operations. It's like a super smart assistant helping you score high in the game!

Glossary

Residual Learning

A method that solves degradation issues by learning residuals.

Key to implementing deep learning in SNNs.

Spiking Neural Networks

Networks that simulate biological neurons, featuring event-driven and low power consumption.

Main subject of this study.

ImageNet

A large dataset used for image classification.

Used to evaluate SEW ResNet's performance.

Vanishing/Exploding Gradient

Common issues in deep network training, leading to ineffective learning.

Key problem addressed by SEW ResNet.

Identity Mapping

A mapping method that keeps input and output consistent.

Foundation for implementing residual learning.

Open Questions Unanswered questions from this research

  • 1 How to achieve identity mapping in complex neuron models?
  • 2 How does SEW ResNet perform in other tasks?

Applications

Immediate Applications

Image Classification

SEW ResNet can be used for efficient image classification tasks, especially in scenarios requiring low power consumption.

Long-term Vision

Smart Devices

SEW ResNet may enable efficient real-time processing in smart devices.

Abstract

Deep Spiking Neural Networks (SNNs) present optimization difficulties for gradient-based approaches due to discrete binary activation and complex spatial-temporal dynamics. Considering the huge success of ResNet in deep learning, it would be natural to train deep SNNs with residual learning. Previous Spiking ResNet mimics the standard residual block in ANNs and simply replaces ReLU activation layers with spiking neurons, which suffers the degradation problem and can hardly implement residual learning. In this paper, we propose the spike-element-wise (SEW) ResNet to realize residual learning in deep SNNs. We prove that the SEW ResNet can easily implement identity mapping and overcome the vanishing/exploding gradient problems of Spiking ResNet. We evaluate our SEW ResNet on ImageNet, DVS Gesture, and CIFAR10-DVS datasets, and show that SEW ResNet outperforms the state-of-the-art directly trained SNNs in both accuracy and time-steps. Moreover, SEW ResNet can achieve higher performance by simply adding more layers, providing a simple method to train deep SNNs. To our best knowledge, this is the first time that directly training deep SNNs with more than 100 layers becomes possible. Our codes are available at https://github.com/fangwei123456/Spike-Element-Wise-ResNet.

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