论文标题
具有替代梯度下降的元学习尖峰神经网络
Meta-learning Spiking Neural Networks with Surrogate Gradient Descent
论文作者
论文摘要
自适应的“终身”学习在边缘和在线任务绩效期间是AI研究的理想目标。在这方面,实现尖峰神经网络(SNN)的神经形态硬件在这方面特别有吸引力,因为它们的实时,基于事件的本地计算范式使其适合于边缘实现和快速学习。但是,最先进的SNN培训的漫长而迭代的学习与神经形态硬件的物理性质和实时操作不相容。双层学习,例如元学习越来越多地用于深度学习来克服这些局限性。在这项工作中,我们使用替代梯度方法在SNN中演示了基于梯度的元学习,该方法近似于峰值阈值以进行梯度估计。因为可以使用替代梯度两倍,建立良好且有效的二阶梯度元学习方法,例如模型不可知的元学习(MAML)。我们表明,使用MAML匹配进行了SNN元训练,或超过了在基于事件的元数据上通过MAML训练的常规ANN的性能。此外,我们证明了来自元学习的特定优势:快速学习,而无需高精度权重或梯度。我们的结果强调了元学习技术如何在现实世界中部署神经形态学习技术方面发挥作用。
Adaptive "life-long" learning at the edge and during online task performance is an aspirational goal of AI research. Neuromorphic hardware implementing Spiking Neural Networks (SNNs) are particularly attractive in this regard, as their real-time, event-based, local computing paradigm makes them suitable for edge implementations and fast learning. However, the long and iterative learning that characterizes state-of-the-art SNN training is incompatible with the physical nature and real-time operation of neuromorphic hardware. Bi-level learning, such as meta-learning is increasingly used in deep learning to overcome these limitations. In this work, we demonstrate gradient-based meta-learning in SNNs using the surrogate gradient method that approximates the spiking threshold function for gradient estimations. Because surrogate gradients can be made twice differentiable, well-established, and effective second-order gradient meta-learning methods such as Model Agnostic Meta Learning (MAML) can be used. We show that SNNs meta-trained using MAML match or exceed the performance of conventional ANNs meta-trained with MAML on event-based meta-datasets. Furthermore, we demonstrate the specific advantages that accrue from meta-learning: fast learning without the requirement of high precision weights or gradients. Our results emphasize how meta-learning techniques can become instrumental for deploying neuromorphic learning technologies on real-world problems.