fMRI Analysis of LLMs Reveals Concepts as Directions, Not Regions

TL;DR I've been running an "fMRI for LLMs" — capturing the full internal activations of dense open models (Qwen2.5-7B, Gemma-2-9B, Gemma-4-12B) and applying neuroscience methods to map how meaning is organized. The headline result, confirmed causally and across all three models: a concept is not sto