AI Navigate

Pretraining with Token-Level Adaptive Latent Chain-of-Thought

arXiv cs.CL / 3/11/2026

Ideas & Deep AnalysisModels & Research

Key Points

  • The paper introduces a novel pretraining approach called Token-Level Adaptive Latent Chain-of-Thought (adaptive latent CoT), which dynamically adjusts the internal reasoning length for each token during language model training.
  • This method enhances model efficiency by internalizing CoT trajectories of variable lengths, allowing longer reasoning paths for difficult tokens and shorter or zero-length paths for easier tokens.
  • Adaptive latent CoT emerges naturally from standard pretraining without additional stages, reducing computational load in both training and inference through token-wise adaptive halting.
  • Experiments on Llama models demonstrate improved language modeling perplexity and downstream accuracy, even with fewer floating-point operations (FLOPs) compared to previous recurrent CoT-based methods.
  • The approach addresses the challenge of limited high-quality training data and rising communication costs by increasing per-token computation instead of scaling parameters or data volume.

Computer Science > Computation and Language

arXiv:2602.08220 (cs)
[Submitted on 9 Feb 2026 (v1), last revised 10 Mar 2026 (this version, v2)]

Title:Pretraining with Token-Level Adaptive Latent Chain-of-Thought

View a PDF of the paper titled Pretraining with Token-Level Adaptive Latent Chain-of-Thought, by Boyi Zeng and 10 other authors
View PDF HTML (experimental)
Abstract:Scaling large language models by increasing parameters and training data is increasingly constrained by limited high-quality corpora and rising communication costs. This work explores an alternative axis: increasing per-token computation without expanding parameters, by internalizing latent Chain-of-Thought (CoT) into pretraining. We propose Pretraining with Token-Level Adaptive Latent CoT (adaptive latent CoT), where the model generates a variable-length latent CoT trajectory before emitting each token -- allocating longer trajectories to difficult tokens and shorter (or even zero) trajectories to easy ones. Importantly, this behavior emerges naturally from one-stage pretraining on general text and reduces computation in both training and inference via token-wise adaptive halting. Experiments with Llama architectures show that adaptive latent CoT consistently improves language modeling perplexity and broad downstream accuracy, even with fewer training FLOPs than prior recurrent baselines.
Comments:
Subjects: Computation and Language (cs.CL)
Cite as: arXiv:2602.08220 [cs.CL]
  (or arXiv:2602.08220v2 [cs.CL] for this version)
  https://doi.org/10.48550/arXiv.2602.08220
Focus to learn more
arXiv-issued DOI via DataCite

Submission history

From: Yiqin Hao [view email]
[v1] Mon, 9 Feb 2026 02:49:15 UTC (5,197 KB)
[v2] Tue, 10 Mar 2026 05:18:24 UTC (5,197 KB)
Full-text links:

Access Paper:

Current browse context:
cs.CL
< prev   |   next >
Change to browse by:
cs

References & Citations

export BibTeX citation Loading...

BibTeX formatted citation

×
Data provided by:

Bookmark

BibSonomy logo Reddit logo
Bibliographic Tools

Bibliographic and Citation Tools

Bibliographic Explorer Toggle
Bibliographic Explorer (What is the Explorer?)
Connected Papers Toggle
Connected Papers (What is Connected Papers?)
Litmaps Toggle
Litmaps (What is Litmaps?)
scite.ai Toggle
scite Smart Citations (What are Smart Citations?)
Code, Data, Media

Code, Data and Media Associated with this Article

alphaXiv Toggle
alphaXiv (What is alphaXiv?)
Links to Code Toggle
CatalyzeX Code Finder for Papers (What is CatalyzeX?)
DagsHub Toggle
DagsHub (What is DagsHub?)
GotitPub Toggle
Gotit.pub (What is GotitPub?)
Huggingface Toggle
Hugging Face (What is Huggingface?)
Links to Code Toggle
Papers with Code (What is Papers with Code?)
ScienceCast Toggle
ScienceCast (What is ScienceCast?)
Demos

Demos

Replicate Toggle
Replicate (What is Replicate?)
Spaces Toggle
Hugging Face Spaces (What is Spaces?)
Spaces Toggle
TXYZ.AI (What is TXYZ.AI?)
Related Papers

Recommenders and Search Tools

Link to Influence Flower
Influence Flower (What are Influence Flowers?)
Core recommender toggle
CORE Recommender (What is CORE?)
About arXivLabs

arXivLabs: experimental projects with community collaborators

arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website.

Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them.

Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs.