Transformer FFNs

FFN: Feed-Forward Network

Overview

Transformer FFNs, also called MLPs, transform each token’s representation between attention operations, providing much of a model’s nonlinear processing and capacity. Work studies activation choices such as GELU, SwiGLU, and mixtures of activations, as well as changes to the block itself, including sparse experts, tree routing, low-rank branches, and linear alternatives. Researchers evaluate these designs using language-model loss and downstream benchmarks, and use pruning, probing, causal interventions, and geometric analyses to understand which neurons matter and how FFNs shape representations. A central open tension is how much dense nonlinear computation is needed: sparsity and simplification may reduce cost, but must preserve useful interactions that can vary by layer, token, and task.

Latest papers

CardsList

42 papers7 papers in the last four weeks, up 40% on the four weeks before. 0.0% of all new papers.

  1. Orthogonal Quadratic Complements for Vision Transformer Feed-Forward Networks

    Apr 8, 2026Wang ZixianTransformer FFNsVision Transformer

  2. Variational Neurons in Transformers for Language Modeling

    Mar 30, 2026Yves RuffenachLLM Uncertainty EstimationTransformer

  3. Dynamic sparsity in tree-structured feed-forward layers at scale

    Mar 18, 2026Reza Sedghi, Robin Schiewer, Anand Subramoney +1Transformer FFNsStructured Sparsity

  4. Layer by layer, module by module: Choose both for optimal OOD probing of ViT

    Mar 5, 2026Ambroise Odonnat, Vasilii Feofanov, Laetitia Chapel +2Vision TransformerOOD Generalization

  5. GLUScope: A Tool for Analyzing GLU Neurons in Transformer Language Models

    Feb 27, 2026Sebastian Gerstner, Leonor Veloso, Hinrich SchützeNeuron-Level InterpretabilityTransformer Interpretability

  6. Revisiting the Shape Convention of Transformer Language Models

    Feb 6, 2026Feng-Ting Liao, Guan-Ting Yi, Tzu-Quan Lin +2Efficient Transformer InferenceTransformer FFNs

  7. Equivalence of Context and Parameter Updates in Modern Transformer Blocks

    Nov 22, 2025Adrian Goldwaser, Michael Munn, Javier Gonzalvo +1Transformer InterpretabilityTransformer FFNs