A Distributional View for Visual Mechanistic Interpretability: KL-Minimal Soft-Constraint Principle
Pith reviewed 2026-05-20 13:49 UTC · model grok-4.3
The pith
A distributional view frames visual mechanistic interpretability as finding minimal shifts from the natural image distribution under a KL constraint.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
We model the influence of a feature activation on the natural image distribution, thereby formulating a Kullback-Leibler minimal optimization problem to model the MI task. Under this framework, statistical biases are identified within previous MI paradigms, which reveal that they may either be perceptually uninterpretable to humans or mechanistically unfaithful to the vision models. To resolve the biases under the distributional view, we propose a model with a KL-minimal soft-constraint principle for visual MI that theoretically balances interpretability and faithfulness, realized via energy-guided diffusion posterior sampling.
What carries the argument
The KL-minimal soft-constraint principle, which optimizes images to minimize divergence from the natural image distribution while ensuring the target feature activates inside the vision model.
If this is right
- Earlier heuristic methods for visual MI are shown to suffer systematic biases that make them either perceptually unnatural or mechanistically unfaithful.
- The soft-constraint principle supplies a single optimization objective that trades off the two requirements in a controlled way.
- Energy-guided diffusion posterior sampling supplies a concrete algorithm that satisfies the principle in practice.
- Experiments on DINOv3 confirm that the resulting visualizations improve both human ratings and feature-activation fidelity over prior approaches.
Where Pith is reading between the lines
- The same distributional framing could be tried on other vision architectures by swapping in a different generative model as the reference distribution.
- If the soft constraint generalizes, it may reduce reliance on hand-tuned regularization terms in optimization-based visualization pipelines.
- One could measure whether the method also improves human ability to debug model mistakes by inspecting the generated images.
Load-bearing premise
The natural image distribution captured by the diffusion model is the right reference for judging both human interpretability and mechanistic faithfulness of the visualizations.
What would settle it
If images produced by the energy-guided sampling activate the target feature less often than top-K retrieval or regularized optimization while also receiving lower naturalness ratings from human observers, the claimed balance would not hold.
Figures
read the original abstract
Most current paradigms in visual mechanistic interpretability (MI) remain confined to interpreting internal units of the vision model via heuristic methods (e.g., top-$K$ activation retrieval or optimization with regularization). In this work, we establish a theoretical distributional view for visual MI, which models the influence of a feature activation on the natural image distribution, thereby formulating a Kullback-Leibler (KL)-minimal optimization problem to model the MI task. Under this framework, statistical biases are identified within previous MI paradigms, which reveal that they may either be perceptually uninterpretable to humans (i.e., deviate from the natural image distribution), or mechanistically unfaithful to the vision models (i.e., unable to activate model features). To resolve the biases under the distributional view, we propose a model with a KL-minimal soft-constraint principle for visual MI that theoretically balances interpretability and faithfulness. We realize this principle via energy-guided diffusion posterior sampling. Extensive experiments validate the theoretical soundness of the proposed distributional view and demonstrate the practical effectiveness of our paradigm on the DINOv3 vision model.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript proposes a distributional framework for visual mechanistic interpretability that models feature influence through KL divergence to the natural image distribution captured by a pre-trained diffusion model. It identifies statistical biases in prior heuristic approaches (top-K retrieval and regularized optimization) that produce either perceptually uninterpretable or mechanistically unfaithful visualizations. To correct these, the authors introduce a KL-minimal soft-constraint principle claimed to theoretically balance interpretability and faithfulness, realized via energy-guided diffusion posterior sampling, and validate the approach through experiments on the DINOv3 vision model.
Significance. If the central construction holds, the work could supply a more principled alternative to heuristic feature visualization by grounding interpretations in distributional properties of natural images. The energy-guided sampling provides a concrete mechanism for trading off the two objectives. However, the significance is limited by the absence of a derivation showing that the KL objective preserves internal feature activation rather than merely producing plausible images.
major comments (3)
- [Abstract, §4] Abstract and §4: the claim that the KL-minimal soft-constraint principle 'theoretically balances interpretability and faithfulness' is stated without an explicit loss function, derivation, or proof that the constrained optimum coincides with the model's true feature direction; the guidance scale appears to function as an empirical knob rather than a derived quantity.
- [§5] §5 (energy-guided diffusion posterior sampling): it is unclear whether the KL-minimal objective remains independent of the diffusion model's training or reduces to a quantity already implicit in the pre-trained parameters, raising the risk that the method is circular with respect to the reference distribution.
- [§3, §6] The weakest assumption (natural image distribution as reference for mechanistic faithfulness) is load-bearing: faithfulness is defined by reliable elicitation of the target unit's internal response, yet no argument or experiment demonstrates that minimizing KL to p_natural necessarily maximizes or preserves this activation rather than trading it off empirically.
minor comments (2)
- [§5] Notation for the energy function and guidance scale should be introduced with an explicit equation in the main text rather than deferred to the appendix.
- [§6] Quantitative comparisons in the experiments would benefit from reporting both the achieved KL values and the corresponding feature activation strengths to allow direct verification of the claimed balance.
Simulated Author's Rebuttal
We thank the referee for the detailed and insightful comments on our manuscript. We address each of the major comments point by point below, providing clarifications and indicating where revisions will be made to strengthen the presentation of our distributional view for visual mechanistic interpretability.
read point-by-point responses
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Referee: [Abstract, §4] Abstract and §4: the claim that the KL-minimal soft-constraint principle 'theoretically balances interpretability and faithfulness' is stated without an explicit loss function, derivation, or proof that the constrained optimum coincides with the model's true feature direction; the guidance scale appears to function as an empirical knob rather than a derived quantity.
Authors: We agree that the manuscript would benefit from a more explicit derivation. The KL-minimal soft-constraint principle is defined as the optimization problem: minimize KL(q_θ || p_natural) subject to E_{x~q_θ}[f(x)] >= c, where f is the feature activation and c is the target level. This is converted to a soft constraint using a Lagrangian multiplier λ, leading to the energy function E(x) = KL term + λ * (c - f(x)). The guidance scale in the diffusion sampling corresponds to this λ, which can be tuned but is theoretically grounded in the constraint strength. In the revision, we will include this explicit loss function and a sketch of the derivation in §4 to show how the optimum balances the objectives without deviating from the feature direction. revision: yes
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Referee: [§5] §5 (energy-guided diffusion posterior sampling): it is unclear whether the KL-minimal objective remains independent of the diffusion model's training or reduces to a quantity already implicit in the pre-trained parameters, raising the risk that the method is circular with respect to the reference distribution.
Authors: The KL-minimal objective is independent in the sense that it uses the diffusion model solely as an approximator of p_natural to define the reference distribution for interpretability. The optimization itself is driven by the energy term derived from the target vision model's (DINOv3) feature activation, which is external to the diffusion model's parameters. The sampling process modifies the trajectory using this external energy, rather than relying on implicit quantities from the diffusion training. We will revise §5 to explicitly state this separation and provide a step-by-step explanation of how the posterior sampling incorporates the KL term without circularity. revision: yes
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Referee: [§3, §6] The weakest assumption (natural image distribution as reference for mechanistic faithfulness) is load-bearing: faithfulness is defined by reliable elicitation of the target unit's internal response, yet no argument or experiment demonstrates that minimizing KL to p_natural necessarily maximizes or preserves this activation rather than trading it off empirically.
Authors: This is a fair point regarding the foundational assumption. Our argument is that by using the soft-constraint, we explicitly enforce the activation level while minimizing deviation from p_natural, thus avoiding the trade-off seen in hard optimization or retrieval methods. Experiments in §6 demonstrate higher activation scores and better perceptual quality compared to baselines. However, we do not claim a universal proof that KL minimization always maximizes activation for arbitrary models; it holds under the distributional view where faithfulness is tied to natural statistics. We will add a brief discussion in §3 and an additional plot in §6 showing the correlation between KL reduction and activation preservation to support this empirically. revision: partial
Circularity Check
Derivation self-contained; no reduction of claims to fitted inputs or self-citations
full rationale
The paper introduces a distributional framing that defines the MI task as KL minimization against an externally pre-trained diffusion model capturing the natural image distribution. The KL-minimal soft-constraint principle is explicitly proposed as a new modeling choice to trade off two separately defined objectives (perceptual closeness to natural images versus internal feature activation in the target vision model). Realization via energy-guided diffusion posterior sampling relies on standard conditional sampling techniques rather than any derivation internal to the present work. No equation or step reduces the claimed balance or faithfulness property to a quantity already implicit in the diffusion training objective; the diffusion model remains an independent reference distribution. The central claims therefore retain independent content beyond the inputs.
Axiom & Free-Parameter Ledger
axioms (1)
- domain assumption There exists a natural image distribution that serves as the reference for both perceptual interpretability and mechanistic faithfulness.
Lean theorems connected to this paper
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IndisputableMonolith/Cost/FunctionalEquation.leanwashburn_uniqueness_aczel unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
KLSC Principle defines the induced distribution as the KL-minimal distribution in Q_m: q_KLSC_β ∈ arg min_{q∈Q_m} KL(q∥p). Lemma D.4 ... q_KLSC_β(x) = p(x) exp(β s(x)) / Z(β)
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IndisputableMonolith/Foundation/RealityFromDistinction.leanreality_from_one_distinction unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
We establish a theoretical distributional view for visual MI, which models the influence of a feature activation on the natural image distribution
What do these tags mean?
- matches
- The paper's claim is directly supported by a theorem in the formal canon.
- supports
- The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
- extends
- The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
- uses
- The paper appears to rely on the theorem as machinery.
- contradicts
- The paper's claim conflicts with a theorem or certificate in the canon.
- unclear
- Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.
Reference graph
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11 A Distributional View for Visual Mechanistic Interpretability A. Related Work A.1. Mechanistic Interpretability in Vision Models To understand the internal mechanisms of the model, we need to study its internal computational units. Neurons are the most direct internal units of a model, and abundant researches have focused on them to reveal the internal...
work page 2024
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[12]
To move beyond attribution, concept-based methods (Poeta et al., 2023; Kim et al.,
trace the models in under specific stimuli, but they do not reveal “what” internal features are being computed (Fel et al., 2025). To move beyond attribution, concept-based methods (Poeta et al., 2023; Kim et al.,
work page 2025
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[13]
shift the focus to interpreting the latent representations within the model (e.g., neurons). However, this neuron-centric methods faces fundamental theoretical limitations: individual neurons frequently exhibit polysemanticity, lack a privileged basis representation, and implicitly premise that the semantic feature space is dimensionally bounded by the nu...
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[14]
Under the LRH, we can learn this polysemantic concepts through the dictionary learning methods
crystallized intoLinear Representation Hypothesis(LRH), which holds that models contain many more features than neurons, arranged as sparse, quasi-orthogonal directions (Fel et al., 2025). Under the LRH, we can learn this polysemantic concepts through the dictionary learning methods. SAE has been proven to be an effective research method. The polysemantic...
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[15]
demonstrate that unconstrained optimization may lead to uninterpretable patterns. The vast image distribution may contain “fooling” inputs that excite the internal units without resembling natural images (Pennisi et al., 2025). To address this issue, previous activation maximization paradigms design specific regularization to constraint the image distribu...
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[16]
introduce adiffusion-based proxy paradigms, which optimize a soft or hard prompt to generate the preferred stimuli for specific internal units. These methods rely on prompt-guided diffusion models to obtain the natural image prior, but this process from image to prompt inevitably results in information loss. This information loss is not severe in visualiz...
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[17]
C. The Detailed Formulation of SAE We first restate the sparse autoencoder (SAE) formulation, which serves as the base model throughout this paper. Let x∈RB×S×ddenote a batch of intermediate representations (e.g., patch-/token-wise activations), whereB is the batch size, S the number of spatial positions/tokens, andd the channel dimension. A standard SAE ...
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[18]
and applies guidance via∇xts(ˆx0). This guidance can be viewed as a practical 30 A Distributional View for Visual Mechanistic Interpretability surrogate for the ideal correction in (193): it injects the intrinsic signal directly into the reverse dynamics while retaining the diffusion prior. A key advantage is that this construction isscore-agnostic: given...
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[19]
J. Implementation Details for DINOv3 Experiments This appendix specifies the exact experimental configurations used in Section 3, including (i) transcoder training on DINOv3 activations, (ii) intrinsic-score construction and stabilization, and (iii) method-specific settings for activation maximization (MACO (Fel et al., 2023a)), proxy-guided generation (D...
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[20]
We sample 1,000,000images from ImageNet-1K, resized to256×256
For an input imagex∈X, the hooked feature map has shaped×H×W= 768×16×16. We sample 1,000,000images from ImageNet-1K, resized to256×256. Training objective and hyperparameters.We train a transcoder (Appendix C) with top- 64 sparsification and reconstruc- tion loss only (no auxiliary losses). We use learning rate 1×10−4. Training is continued until the expl...
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