The Price of Locality: Why Forward-Forward Underperforms Backpropagation?
The Forward-Forward Algorithm (FFA) replaces backpropagation (BP) with layer-wise local contrastive objectives, eliminating the backward pass and the need to retain intermediate activations, yet suffers a persistent performance gap with BP that worsens with depth. This paper diagnoses two structural failure modes: an o...
Zhao-Xian Wu, Hai-Chuan Liu, Tian-Yi Chen
· 0 citations