Norms of Error Terms in Transformer Language Models Predict Human Reading Time Beyond Surprisal

Ziyuan Cao, William Schuler


Abstract
It is possible that expectation-based latency in reading time is caused by mechanistic latency in changing internal activation states to match observations; this is a primary motivation for predictive coding models (Ohams et al., 2026). This paper explores measurement of sentence processing effort that is based on the gradient signals of transformer language models during error backpropagation: the 2-norm of the gradient of surprisal w.r.t. the output of intermediate layers, i.e., the norm of the error terms at intermediate layers. Regression experiments on multiple human reading time datasets show that the norm of error terms at the output of intermediate layers of GPT-2 small add predictive power beyond baseline predictors including standard surprisal from the same model.
Anthology ID:
2026.emnlp-main.2364
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
53691–53699
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2364/
DOI:
10.18653/2026.emnlp-main.2364
Bibkey:
Cite (ACL):
Ziyuan Cao and William Schuler. 2026. Norms of Error Terms in Transformer Language Models Predict Human Reading Time Beyond Surprisal. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 53691–53699, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Norms of Error Terms in Transformer Language Models Predict Human Reading Time Beyond Surprisal (Cao & Schuler, EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.2364.pdf