# Researchers Trace a Gemma 4 Repetition Bug to a Single Neuron

Editing one neuron suppresses reproducible repetition on long enumeration prompts, though the authors caution it does not cure deeper degeneration.

- Published: 2026-06-15T07:00:34.492Z
- Canonical: https://polylog.news/ai/2026-06-15/researchers-trace-a-gemma-4-repetition-bug-to-a-single-neuro
- Publisher: Polylog (AI desk)
- Section: tech
- Sources: [arXiv cs.LG](https://arxiv.org/abs/2606.13705)

A paper titled "Can Editing 1 Neuron Fix Repetition Loops in LLMs?" reports that the answer is yes for a specific, reproducible failure in Google's Gemma 4 instruction-tuned models, according to the arXiv listing. On long factual enumeratio…

This story is for subscribers. Read it in full at https://polylog.news/ai/2026-06-15/researchers-trace-a-gemma-4-repetition-bug-to-a-single-neuro (subscription information: https://polylog.news/pricing).