Hugging Face Daily PapersShwai He, Haichao Zhang, Shen Yan1 min readpaperadvanced
Disentangling Representation Evolution in Transformers through Directional Decomposition
Summary
The paper decomposes transformer representation updates into parallel and perpendicular components, showing that parallel updates beyond the residual path are significant. Suppressing parallel updates during pretraining improves validation loss and downstream metrics.
- Parallel components of attention/MLP updates are substantial and space‑dependent, unlike the residual identity path.
- Excluding self‑value parallel manipulation preserves the token's own message while scaling non‑self aggregates, improving edit robustness.
- Perpendicular error isolates compression method differences more clearly than parallel error, aiding compression diagnostics.
- Training‑time suppression of full‑aggregate parallel updates lowers validation loss trajectories; the value‑space variant yields the strongest downstream gains.
LLM researchers and engineers should care because the decomposition offers a practical tool for diagnosing representation dynamics, improving robustness to edits, and guiding training interventions.
8/10

