Do Active SAE Feature Planes Carry More Holonomy? A Preregistered Reversal in Gemma

Abstract

This paper tests whether holonomy concentrates on active sparse-autoencoder feature planes in Gemma 2 2B, a concrete operationalization of the broader semantic-concentration prediction. Holonomy is measured at the final-token layer-12 to layer-13 residual-stream readout by carrying a local frame around small loops using the instrument’s restricted-Jacobian transport rule, then normalizing the resulting rotation by enclosed area. The design, materiality threshold, analysis, and verdict rules were preregistered and frozen before the analysed measurements were inspected. The prediction was falsified in reverse: active-feature planes carried less holonomy than matched mixed-feature controls. The result is a narrow, auditable operational reversal, not a causal claim that meaning suppresses holonomy; several geometric and measurement explanations remain open.