When a Conceptor Complement Becomes Gain: Operator Geometry and Behavioral Attribution in Language Models

Abstract:When a steering intervention changes a language model's behavior, which part of the intervention deserves the credit? We test this question for a target-centered, scaled conceptor complement by removing its fitted covariance filter while preserving the same target-specific center and gain. At the original aperture $\alpha=.05$ and gain $\beta=2$, all 21 fitted maps across three models and seven targets expand every direction at the generation intervention layers. The matrix correction is $0.093\%$--$7.815\%$ of the matched-control displacement on held-out extraction activations. In 480 paired comparisons within a 1,920-response study, retaining the matrix changes many individual texts but does not establish a consistent additional target-suppression benefit on the four-target panel. A geometric aperture sweep shows that the operating regime changes with the filter setting. Separately, an invertible soft filter preserves what an unrestricted affine readout can recover, whereas dedicated erasure methods reduce prediction by newly fitted probes. Together, the results show why a whole-intervention comparison cannot by itself attribute generated behavior to the fitted matrix: analyze the complete transformation, hold shared components fixed, and test its output consequences directly.

50 pages. Accepted at the NeurIPS 2026 NeurReps Workshop (Symmetry and Geometry in Neural Representations). Code: this https URL

Artificial Intelligence (cs.AI)

arXiv:2610.16325 [cs.AI]

(or arXiv:2610.16325v1 [cs.AI] for this version)

https://doi.org/10.48550/arXiv.2610.16325 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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