Theme · 23 episode(s)

Mechanistic Interpretability

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Definition

Mechanistic interpretability is the project of reverse-engineering trained neural networks into human-readable descriptions of how they work: what features they compute, how those features combine, what algorithms emerge. The bet is that this kind of understanding is necessary to trust the systems we build.

Episodes covering this

  1. 204
    The Length Estimate Hiding Inside a Word-by-Word Model
    How Much is Left? LLMs Linearly Encode Their Remaining Output Length
    · ·14 min·Jul 07, 2026
  2. 203
    The Thought a Model Doesn't Say — and the Lens That Reads It
    Verbalizable Representations Form a Global Workspace in Language Models
    Gurnee, Sofroniew, Pearce et al. · Anthropic·16 min·Jul 07, 2026
  3. 199
    Finding a Model's Hidden Behaviors Without Knowing What You're Looking For
    Mechanistically Eliciting Latent Behaviors in Language Models
    Mack, Panickssery, Turner · Principles of Intelligence·15 min·Jul 04, 2026
  4. 193
    Freeze Most of the Network: Where RL Improvement Actually Lives in a Transformer
    Is One Layer Enough? Training A Single Transformer Layer Can Match Full-Parameter RL Training
    Zhang, Hu, Glentis et al. · University of Minnesota·22 min·Jul 02, 2026
  5. 175
    One Crosscoder Feature Flips a Stalling Chatbot Into a Working Agent
    Localizing RL-Induced Tool Use to a Single Crosscoder Feature
    Shportko, Bhokare, AlZahrani et al. · Northwestern University·26 min·Jun 26, 2026
  6. 171
    The Safety Decision a Model Makes Before It Thinks a Word
    Do Thinking Tokens Help with Safety?
    Ri, Panigrahi, Arora · Princeton Language and Intelligence·25 min·Jun 25, 2026
  7. 153
    Catching a Lie From the Inside, When the Words Look Completely Honest
    Rift: A Conflict Signature for Deception in Language Models
    Nyoma · Harmonic Labs·26 min·Jun 18, 2026
  8. 152
    Training a Model to Mean What It Says, And Why That Isn't the Same as Being Good
    Self-CTRL: Self-Consistency Training with Reinforcement Learning
    Pres, Ruis, Ghebreselassie et al. · MIT CSAIL·26 min·Jun 18, 2026
  9. 145
    Building Forgetting Into a Language Model With One Extra Line of Code
    Natively Unlearnable Large Language Models
    Ghosal, Maini, Raghunathan · Carnegie Mellon University·22 min·Jun 15, 2026
  10. 141
    How Two Tokens Reopened a Reasoning Method the Field Had Given Up On
    Demystifying Hidden-State Recurrence: Switchable Latent Reasoning with On-Policy Reinforcement Learning
    Yang, Chen, Wu et al. · HKUST(GZ)·29 min·Jun 12, 2026
  11. 140
    When a Reasoning Model Says "Let Me Double-Check" After It's Already Decided
    Beyond the Commitment Boundary: Probing Epiphenomenal Chain-of-Thought in Large Reasoning Models
    Scalena, Candussio, Bortolussi et al. · University of Groningen / University of Milano-Bicocca·27 min·Jun 12, 2026
  12. 098
    Finding Millions of Readable Concepts Inside a Real, Deployed AI Model
    Scaling Monosemanticity: Extracting Interpretable Features from Claude 3 Sonnet
    Templeton, Conerly, Marcus et al. · Anthropic·28 min·May 29, 2026
  13. 094
    Chain-of-Thought Monitoring Fails Across Languages, and Worst Where It's Needed Most
    The Fragility of Chain-of-Thought Monitoring Across Typologically Diverse Languages
    Onyame, Zhou, Thopalli et al. · University of Virginia·24 min·May 28, 2026
  14. 055
    Why LLM Judges Flip Their Verdicts When You Change the Question Format
    Judge Circuits
    Feldhus, Baeumel, Golimblevskaia et al. · Technische Universität Berlin / BIFOLD·26 min·May 19, 2026
  15. 038
    How LLMs Get Persuaded: One Attention Head, A Tetrahedron, And A Single Dial
    How LLMs Are Persuaded: A Few Attention Heads, Rerouted
    Sun, Kong, Zhang et al. · Northeastern University·23 min·May 12, 2026
  16. 037
    Why Hallucination Detectors Miss Stale Facts: A Geometric Story About What Models Know But Don't Say
    The Geometry of Forgetting: Temporal Knowledge Drift as an Independent Axis in LLM Representations
    Elbadry, Heakl, Zhang et al. · Mohamed bin Zayed University of Artificial Intelligence (MBZUAI)·27 min·May 12, 2026
  17. 033
    Echo: The Paper Arguing You Never Needed a KV Cache for Retrieval
    Echo: KV-Cache-Free Associative Recall with Spectral Koopman Operators
    Sridhar, Johansen · California·24 min·May 11, 2026
  18. 032
    A Sticky-Note for Every Layer: Letting Transformers Remember What They Were Just Thinking
    State Stream Transformer (SST) V2: Parallel Training of Nonlinear Recurrence for Latent Space Reasoning
    Aviss · Fifth Dimension·23 min·May 09, 2026
  19. 026
    What RL Actually Does to Language Models, at the Token Level
    Rethinking RL for LLM Reasoning: It's Sparse Policy Selection, Not Capability Learning
    Akgül, Kannan, Neiswanger et al. · University of Southern California·24 min·May 08, 2026
  20. 023
    Why a Small Agent Confidently Overwrites Memories It Doesn't Understand
    What Happens Inside Agent Memory? Circuit Analysis from Emergence to Diagnosis
    Mao, Zhao, Penn et al. · City University of Hong Kong·23 min·May 07, 2026
  21. 018
    Language Models Compute the Rational Move, Then Override It
    What Suppresses Nash Equilibrium Play in Large Language Models? Mechanistic Evidence and Causal Control
    Lekeas, Stamatopoulos · DreamWorks Animation·29 min·May 03, 2026
  22. 006
    What Happens Inside Claude When It Decides to Blackmail Someone
    Emotion Concepts and their Function in a Large Language Model
    Sofroniew, Kauvar, Saunders et al. · Anthropic·22 min·May 02, 2026
  23. 004
    The Sycophancy Circuit That Survives Alignment Training
    LLMs Know They're Wrong and Agree Anyway: The Shared Sycophancy-Lying Circuit
    Pandey · Georgia Institute of Technology·29 min·May 01, 2026

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