Despite being the workhorse of deep learning, the backpropagation algorithm is no panacea. It enforces sequential layer updates, thus preventing efficient parallelization of the training process. Furthermore, its biological plausibility is being challenged. Alternative schemes have been devised; yet, under the constraint of synaptic asymmetry, none have scaled to modern deep learning tasks and architectures. Here, we challenge this perspective, and study the applicability of Direct Feedback Alignment to neural view synthesis, recommender systems, geometric learning, and natural language processing. In contrast with previous studies limited to computer vision tasks, our findings show that it successfully trains a large range of state-of-the-art deep learning architectures, with performance close to fine-tuned backpropagation. At variance with common beliefs, our work supports that challenging tasks can be tackled in the absence of weight transport.

本文探讨了替代反向传播算法的方案，研究了直接反馈对神经视图合成、推荐系统、几何学习和自然语言处理的适用性，并发现该方案可以成功训练各种现代深度学习架构，其性能接近于微调的反向传播，支持在没有权重传输的情况下解决具有挑战性的任务。

直接反馈对齐在现代深度学习任务和架构中的拓展