arXiv Machine Learning

Represented Is Not Computed: A Causal Test of Candidate Algorithmic Intermediates in a Transformer

arXiv:2605. 22488v2 Announce Type: replace Abstract: Structured prompts require integrating components according to task-relevant relations.

arXiv Computation and Language
3d ago

Putting Transformer Theories to the Test

arXiv:2610.32104v1 Announce Type: cross Abstract: Several formal theories have been developed to characterize the capabilities and limitations of the transformer architecture, each employing differen...

By Awni Altabaa, Tobias Schnabel, Kiran Tomlinson
arXiv AI
Jun 9

How Transformers Reject Wrong Answers: Rotational Dynamics of Factual Constraint Processing

arXiv:2603. 13259v2 Announce Type: replace-cross Abstract: When a decoder-only transformer is forced to process matched correct and incorrect single-token continuations of a factual query, the two pathways through hidden-state space diverge in a specific way: displacement vectors from the query-only representation maintain approximately equal magnitude but rotate apart in direction.

By Javier Mar\'in
arXiv Machine Learning
Jul 27

Indexing: the Beginning and the End

arXiv:2607. 22361v1 Announce Type: new Abstract: We study information bottlenecks in modern deep-learning architectures -- RNNs, softmax transformers, linear-attention transformers and state-space models -- through the lens of the indexing primitive.

By Alexander Kozachinskiy, Vicente Opazo, Felipe Urrutia
arXiv Machine Learning
Oct 21

Present but Hard to Read: Probing Latent Reasoning with Minimal Pairs

The paper investigates how latent reasoning in language models is accessed by probing, focusing on a digit copied from the question in two models, Ouro-1.4B and Qwen2.5-1.5B. By comparing prompts that differ only in that digit, the authors show the digit is present in the final prompt token with a shared code readout of about 0.9, yet a standard single‑prompt probe reads it only weakly (0.36 in Ouro and 0.19 in Qwen). The study introduces a protocol with a synthetic null to test computed values against copies and mixtures of inputs, revealing that while the digit is readable, it is not used in subsequent reasoning steps.

By Aur Shalev Merin
arXiv AI
Sep 25

Every Component Is a Lookup: One Linear Graph for Interaction, Composition and Attribution

The paper proposes that two architectural assumptions—(1) attention and MLPs share a key‑value form <phi(S)>U, and (2) components read from an additive residual stream—are sufficient to answer three interpretability questions: component interaction, information routing, and token attribution. By treating these selections as a computational graph, the authors develop Unpack, a backward attribution method that validates interaction scores, recovered routes, and token attribution against established tests across models ranging from 160M to 6.9B parameters. The study also shows that contribution and causal effect can differ, with a recognizable signature in how components change when a task is removed.

By Po-Kai Chen, Aske Plaat, Niki van Stein