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LLM interpretability, editing, and unlearning

Locating a component, assigning a readable label, changing a fact, and proving removal are separate scientific claims with different interventions and tests.

11 maintained papers · literature reviewed through 2 October 2026

Attribution, circuits, sparse features, weight editing, and unlearning answer different questions. Removing hazardous benchmark performance is not proof that information is absent: localization, causal mediation, edit efficacy, specificity, side effects, persistence, relearning, and adaptive attacks require separate evidence.

Prerequisite contract

How the field developed

  1. 2017

    Input attribution prerequisites

    SHAP and Integrated Gradients clarify additive and path-based attribution assumptions before moving inside a language model.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    01.01A Unified Approach to Interpreting Model Predictions2017 · NeurIPS · Peer reviewedScott M. Lundberg and Su-In LeeSHAP defines a local explanation as an additive model over binary simplified features and proves that local accuracy, missingness, and consistency select one attribution: the Shapley value of a conditional-expectation game. The base value is the expected model output; feature attributions move that baseline to the prediction for the case being explained. The framework unifies several earlier additive explanation methods while making their hidden choices about missing features explicit.Official implementation
    01.02Axiomatic Attribution for Deep Networks2017 · ICML · Peer reviewedMukund Sundararajan, Ankur Taly, and Qiqi YanIntegrated Gradients attributes a model’s output difference between an input and a baseline by integrating ordinary input gradients along the straight path joining them. Multiplying each average path gradient by the input displacement yields feature credits that satisfy sensitivity, implementation invariance, and completeness. It needs no network modification and uses repeated gradient evaluations, but the answer remains relative to the selected baseline and output.—

    Work: Vary baselines, token groupings, target logits, and paraphrases for one generation.

    Exit evidence: State whether the result is sensitivity, contribution, or causal mediation.

  2. 2021–2022

    Circuits, causal tracing, and single edits

    Transformer Circuits develops residual and attention composition tools; ROME causally traces factual recall and performs a rank-one MLP update.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    02.01A Mathematical Framework for Transformer Circuits2021 · Transformer Circuits Thread · Technical reportNelson Elhage et al.Author-published technical article; not presented as a peer-reviewed conference paper.A Mathematical Framework for Transformer Circuits rewrites attention-only Transformers as sums of end-to-end computational paths through a shared residual stream. Each attention head separates into a QK circuit that decides where to read and an OV circuit that decides what output-direction change to write. Multiplying read/write matrices exposes virtual weights and head composition without treating intermediate query, key, and value vectors as the final explanatory objects.—
    02.02Locating and Editing Factual Associations in GPT2022 · NeurIPS · Peer reviewedKevin Meng, David Bau, Alex Andonian, and Yonatan BelinkovROME first uses causal tracing to locate computations decisive for recalling a subject–relation fact, then edits one middle-layer MLP projection with a rank-one update. The update makes the MLP map the subject’s key representation to a newly optimized value that raises the desired object, while a covariance-weighted constraint minimizes interference with other stored mappings.Official project and code

    Work: Localize a behavior, intervene on candidate components, then test one edit with counterfactual controls.

    Exit evidence: Report efficacy, paraphrase generalization, specificity, and unrelated-task change.

  3. 2023–2024

    Mass editing and sparse features

    MEMIT distributes updates for many facts across layers; sparse autoencoders learn feature dictionaries intended to reduce superposition.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    03.01Mass-Editing Memory in a Transformer2023 · ICLR · Peer reviewedKevin Meng, Arnab Sen Sharma, Alex Andonian, Yonatan Belinkov, and David BauMEMIT scales the associative-memory idea behind ROME from one fact in one layer to thousands of facts distributed across a range of causal middle-layer MLPs. It optimizes a target value for each subject–relation–object edit, divides the required residual change across selected layers, and solves batched covariance-regularized matrix updates that insert many key–value associations simultaneously.Official code
    03.02Sparse Autoencoders Find Highly Interpretable Features in Language Models2024 · ICLR · Peer reviewedHoagy Cunningham, Aidan Ewart, Logan Riggs Smith, Robert Huben, and Lee SharkeyCunningham et al. train overcomplete sparse autoencoders on internal Pythia activations to recover feature directions that need not align with individual neurons. A ReLU encoder maps each activation to sparse nonnegative coefficients; tied decoder directions reconstruct the activation. An L1 penalty trades reconstruction fidelity for sparsity, aiming to separate features that were superposed in the model’s native basis.—

    Work: Stress edit scale, sequential persistence, feature reconstruction, sparsity, and behavioral intervention.

    Exit evidence: Measure side effects and coverage rather than counting readable labels.

  4. 2024

    Hazardous-knowledge evaluation and unlearning

    WMDP creates hazardous-knowledge evaluations and tests representation misdirection, coupling an unlearning intervention to retained-utility and attack-aware measurement.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    04.01The WMDP Benchmark: Measuring and Reducing Malicious Use with Unlearning2024 · ICML · Peer reviewedNathaniel Li, Alexander Pan, Anjali Gopal, Summer Yue, Daniel Berrios, Alice Gatti, Justin D. Li, Ann-Kathrin Dombrowski, Shashwat Goel, Gabriel Mukobi, Nathan Helm-Burger, Rassin Lababidi, Lennart Justen, Andrew B. Liu, Michael Chen, Isabelle Barrass, Oliver Zhang, Xiaoyuan Zhu, Rishub Tamirisa, Bhrugu Bharathi, Ariel Herbert-Voss, Cort B. Breuer, Andy Zou, Mantas Mazeika, Zifan Wang, Palash Oswal, Weiran Lin, Adam A. Hunt, Justin Tienken-Harder, Kevin Y. Shih, Kemper Talley, John Guan, Ian Steneker, David Campbell, Brad Jokubaitis, Steven Basart, Stephen Fitz, Ponnurangam Kumaraguru, Kallol Krishna Karmakar, Uday Tupakula, Vijay Varadharajan, Yan Shoshitaishvili, Jimmy Ba, Kevin M. Esvelt, Alexandr Wang, and Dan HendrycksWMDP supplies 3,668 expert-curated multiple-choice questions in biosecurity, cybersecurity, and chemical security as proxy measurements of hazardous knowledge. The same paper introduces Representation Misdirection for Unlearning (RMU): fine-tune a few early-to-middle layers so hazardous-text activations approach a fixed random direction with large norm, while benign-text activations remain close to the frozen original model. Success requires reduced WMDP-Bio/Cyber accuracy without collapsing general utility.Official benchmark and RMU code · Project website

    Work: Measure target-domain suppression, broad utility, relearning, and white-box extraction before claiming unlearning.

    Exit evidence: State the threat model and show which evidence distinguishes suppression from removal.

  5. 2026

    Localized unlearning and cross-modal steering

    PALU localizes entropy maximization to sensitive prefixes/logits; CoSToM uses causal tracing for activation steering; textual vectors and multimodal-ICL analysis test whether language-derived mechanisms transfer into vision-language descendants.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    05.01Maximizing Local Entropy Where It Matters: Prefix-Aware Localized LLM Unlearning2026 · ACL · Peer reviewedNaixin Zhai, Pengyang Shao, Binbin Zheng, Yonghui Yang, Fei Shen, Long Bai, and Xun YangPeer-reviewed ACL 2026 long paper and Outstanding Paper award recipient.PALU makes LLM unlearning sparse along two axes. At the sequence axis it intervenes only at the first few tokens that initiate each sensitive span, preserves common tokens with a KL constraint, and ignores later redundant sensitive tokens. At the vocabulary axis it maximizes entropy only among the top-K next-token logits. The aim is to disrupt a memorized generation trajectory while perturbing fewer positions and fewer vocabulary dimensions than full-distribution entropy maximization.Author manuscript · Official code
    05.02CoSToM: Causal-oriented Steering for Intrinsic Theory-of-Mind Alignment in Large Language Models2026 · ACL · Peer reviewedMengfan Li, Xuanhua Shi, and Yang DengPeer-reviewed ACL 2026 long paper and Best Theme Paper award recipient.CoSToM turns a mechanistic probe into a training interface for Theory-of-Mind behavior. One copy of an LLM encodes a dialogue, a frozen second copy receives a patched intermediate activation and answers belief–desire–intention questions, and the resulting loss is backpropagated through the patch into shallow LoRA adapters of the encoder. The tuned encoder is then used alone to generate dialogue whose behavior is intended to reflect the inferred mental state.Author manuscript · Official code
    05.03Textual Steering Vectors Can Improve Visual Understanding in Multimodal Large Language Models2026 · ACL · Peer reviewedWoody Haosheng Gan, Deqing Fu, Julian Asilis, Ollie Liu, Vatsal Sharan, Robin Jia, and Willie NeiswangerPeer-reviewed ACL 2026 long paper; catalog authors follow the final proceedings record.This paper discovers steering directions using text-only activations in a language-model backbone and applies those directions inside a related multimodal model. Sparse-autoencoder features, class-mean differences, or linear probes define vectors associated with concepts such as spatial relations or counting. Adding a scaled vector at a selected layer during multimodal inference can improve visual-task accuracy without training on images or updating model weights.Earlier author manuscript
    05.04Why Multimodal In-Context Learning Lags Behind? Unveiling the Inner Mechanisms and Bottlenecks2026 · ACL · Peer reviewedYu Wang and Sharon LiPeer-reviewed ACL 2026 long paper.The study decomposes multimodal in-context learning into constructing a task mapping from demonstrations and transferring that mapping to the query. The tested MLLMs often form a useful mapping in middle layers, yet the signal weakens before late layers produce the answer. This suggests that weak multimodal ICL is not only failure to read demonstrations; it can be an internal information-transfer bottleneck. The proposed MGI intervention reinforces demonstration-derived information at selected layers and yields modest gains.Author manuscript · Official analysis code

    Work: Use matched behavioral, counterfactual, locality, persistence, and cross-modal interventions to compare localized unlearning, causal activation steering, text-derived multimodal steering, and multimodal in-context-learning bottlenecks.

    Exit evidence: Report target suppression or steering, paraphrase and modality transfer, unrelated-task damage, relearning or extraction attacks, causal controls, layer/token sensitivity, and seed variance.

Research branches

Localized unlearning and cross-modal activation mechanisms

Does an intervention remove information, alter one behavior, or expose a bottleneck—and does the mechanism transfer across a multimodal descendant?

Maximizing Local Entropy Where It Matters: Prefix-Aware Localized LLM Unlearning · CoSToM: Causal-oriented Steering for Intrinsic Theory-of-Mind Alignment in Large Language Models · Textual Steering Vectors Can Improve Visual Understanding in Multimodal Large Language Models · Why Multimodal In-Context Learning Lags Behind? Unveiling the Inner Mechanisms and Bottlenecks

Comparison table

Interpretation and intervention scopes
Family or stageScientific distinctionMain riskAnchors
Input attributionMaps an output score to token or feature contributions.Baseline and correlated tokens make attribution non-unique.2017 · 2017
Circuit / feature analysisProposes internal computational units and tests interventions.A located component may be neither sufficient nor complete.2021 · 2024
Weight editingChanges parameters to alter selected model behavior.Collateral changes, reversion, and sequential interference can be hidden.2022 · 2023
Unlearning interventionOptimizes away selected hazardous behavior while attempting to retain general utility.Benchmark suppression can fail under relearning, paraphrase, or stronger extraction attacks.2024
Localized unlearning and cross-modal steeringPALU localizes entropy-based unlearning; CoSToM causally traces and steers ToM-related states; textual vectors probe cross-modal steering; multimodal-ICL analysis tests inherited language-model bottlenecks.Behavior suppression is not certified deletion, steering success is not a faithful semantic circuit, and shared ancestry does not prove the same mechanism operates across modalities.2026 · 2026 · 2026 · 2026

Concept lineage

Failure modes to audit

  • Naming a feature without testing its causal role.
  • Evaluating edits only on the exact prompt.
  • Ignoring unrelated capabilities and distribution shift.
  • Treating model deletion or unlearning as established without attack tests.
  • Inferring human-like concepts from a few activating examples.

Questions for every paper

  1. What behavior is localized?
  2. Which intervention tests causality?
  3. How broad should the edit generalize?
  4. Which side effects and persistence are measured?

11 canonical readings · 2017–2026· route reviewed through October 2, 2026.

This is the complete structured list for this chapter, ordered chronologically from earlier foundations toward current work. The explanatory ladder above highlights the shortest conceptual route; this list also includes important branches, benchmarks, and current endpoints. It is generated from the same deduplicated catalog used by the AI background registry and My Library, so a future catalog update appears here automatically.

Show all 11 readings in maintained order
  1. #72024ICMLPeer reviewedL2–L3

    The WMDP Benchmark: Measuring and Reducing Malicious Use with Unlearning

    Nathaniel Li, Alexander Pan, Anjali Gopal, Summer Yue, Daniel Berrios, Alice Gatti, Justin D. Li, Ann-Kathrin Dombrowski, Shashwat Goel, Gabriel Mukobi, Nathan Helm-Burger, Rassin Lababidi, Lennart Justen, Andrew B. Liu, Michael Chen, Isabelle Barrass, Oliver Zhang, Xiaoyuan Zhu, Rishub Tamirisa, Bhrugu Bharathi, Ariel Herbert-Voss, Cort B. Breuer, Andy Zou, Mantas Mazeika, Zifan Wang, Palash Oswal, Weiran Lin, Adam A. Hunt, Justin Tienken-Harder, Kevin Y. Shih, Kemper Talley, John Guan, Ian Steneker, David Campbell, Brad Jokubaitis, Steven Basart, Stephen Fitz, Ponnurangam Kumaraguru, Kallol Krishna Karmakar, Uday Tupakula, Vijay Varadharajan, Yan Shoshitaishvili, Jimmy Ba, Kevin M. Esvelt, Alexandr Wang, and Dan Hendrycks

    Official artifacts: Official benchmark and RMU code · Project website

    Metadata checked