FSTA-SNN:Frequency-based Spatial-Temporal Attention Module for Spiking Neural Networks

TL;DR

This paper introduces FSTA-SNN, a frequency-based spatial-temporal attention module that enhances feature learning in spiking neural networks, reduces spike firing rates, and improves accuracy and energy efficiency.

Contribution

The paper presents a novel FSTA module that leverages frequency analysis to optimize spike feature learning and energy efficiency in SNNs, addressing limitations of traditional approaches.

Findings

FSTA reduces spike firing rates significantly.

FSTA improves accuracy on multiple datasets.

Spatial and temporal analysis guides the design of FSTA.

Abstract

Spiking Neural Networks (SNNs) are emerging as a promising alternative to Artificial Neural Networks (ANNs) due to their inherent energy efficiency. Owing to the inherent sparsity in spike generation within SNNs, the in-depth analysis and optimization of intermediate output spikes are often neglected. This oversight significantly restricts the inherent energy efficiency of SNNs and diminishes their advantages in spatiotemporal feature extraction, resulting in a lack of accuracy and unnecessary energy expenditure. In this work, we analyze the inherent spiking characteristics of SNNs from both temporal and spatial perspectives. In terms of spatial analysis, we find that shallow layers tend to focus on learning vertical variations, while deeper layers gradually learn horizontal variations of features. Regarding temporal analysis, we observe that there is not a significant difference in feature learning across different time steps. This suggests that increasing the time steps has limited effect on feature learning. Based on the insights derived from these analyses, we propose a Frequency-based Spatial-Temporal Attention (FSTA) module to enhance feature learning in SNNs. This module aims to improve the feature learning capabilities by suppressing redundant spike features.The experimental results indicate that the introduction of the FSTA module significantly reduces the spike firing rate of SNNs, demonstrating superior performance compared to state-of-the-art baselines across multiple datasets.