Critical Positions in LLM Reasoning: A Metacognitive Lens on Intervention-Sensitive Locations

Wendi Cui, Anni Huang, Wei Wang, Damien Lopez, Sirui Bi


Abstract
Large Language Models (LLMs) achieve strong reasoning performance by generating intermediate reasoning trajectories through autoregressive decoding. Existing approaches such as self-consistency, tree-based reasoning, and critical token analysis improve reasoning by exploring diverse trajectories or identifying influential tokens. In this work, we identify a distinct phenomenon in LLM reasoning: **critical positions** — locations where re-sampling continuations disproportionately influences the final outcome, independent of the specific token at that position. Motivated by this, we propose **Metacognitive Influence Tracing (MIT)**, the first unsupervised framework for identifying critical positions from a single reasoning trace using only attention structure. MIT models reasoning trajectories as influence graphs and estimates propagated influence through a diffusion process, enabling the discovery of structurally important reasoning positions without supervision or contrastive trajectories. Building on these insights, we further propose **Adaptive Critical Sampling (ACS)**, an intervention framework that selectively re-samples at critical positions instead of regenerating entire reasoning traces. Across six benchmark tasks and five models, ACS improves accuracy by an average of **7.78 points** over CoT while reducing computational cost by **59.83%** over Self-Consistency.
Anthology ID:
2026.findings-emnlp.1474
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
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SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
31357–31390
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URL:
https://aclanthology.org/2026.findings-emnlp.1474/
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Cite (ACL):
Wendi Cui, Anni Huang, Wei Wang, Damien Lopez, and Sirui Bi. 2026. Critical Positions in LLM Reasoning: A Metacognitive Lens on Intervention-Sensitive Locations. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 31357–31390, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Critical Positions in LLM Reasoning: A Metacognitive Lens on Intervention-Sensitive Locations (Cui et al., Findings 2026)
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https://aclanthology.org/2026.findings-emnlp.1474.pdf