arXiv Computation and Language

Vectors from Larger Language Models Predict Human Reading Time and fMRI Data More Poorly when Dimensionality Expansion is Controlled

arXiv Computation and Language
Sep 30

Reader Proficiency Shapes Layer-wise Surprisal Profiles

The study examines how reader proficiency influences the relationship between layer-wise surprisal from large language models (LLMs) and eye-tracking gaze measures. Using the MECO L2 corpus, researchers compared high- and low-proficiency readers on first-pass gaze duration (FPGD) and total gaze duration (TGD), finding that lower-proficiency readers exhibit deeper Predictive Depth for FPGD, while TGD shows deeper Predictive Depth across both groups. The results suggest that the distribution of predictive power across LLM layers relates to the timing and breadth of reading processes and varies with reader proficiency.

By Akio Hayakawa, Horacio Saggion
arXiv AI
Oct 7

STRUCTURALCOST: A controlled reading time dataset for modeling human sentence processing difficulty

STRUCTURALCOST is a self‑paced reading dataset comprising 475 participants and 40,800 observations that isolates the processing cost of long‑distance subject‑verb dependency resolution. The study replicates a known psycholinguistic finding at NLP scale: human reading times at the main verb increase with dependency length, driven by syntactic embedding beyond linear distance. Various language models—n‑gram, SSMs, and transformers—partially mirror this graded difficulty profile but consistently underestimate the integration cost humans incur, a gap that persists across architectures and model sizes.

By Nina Nusbaumer, Iria de-Dios-Flores, Corentin Bel, Christophe Pallier, Guillaume Wisniewski, Beno\^it Crabb\'e
arXiv Machine Learning
Aug 31

Negligible in Size, Significant in Effect: On Scale Vectors in Large Language Models

The paper investigates the often-overlooked scale vectors in large language models, showing that despite their tiny size they are crucial for pre‑training performance. The authors provide theoretical insights that scale vectors mainly aid optimization rather than expressivity, and they analyze how weight decay affects different normalization layers. Building on these findings, they propose lightweight improvements—branch‑specific heterogeneity, better placement, and magnitude‑direction reparameterization—that consistently reduce loss across a range of model sizes and training settings.

By Mingze Wang, Shuchen Zhu, Yuxin Fang, Binghui Li, Kai Shen, Shu Zhong
arXiv Computation and Language
Sep 11

Cross-lingual brain-language model alignment is robust but challenges hierarchical and computational accounts

The study examined whether brain-language model alignment reflects shared computational mechanisms or merely stable lexical‑semantic correspondences. Using whole‑brain encoding across Mandarin, English, and French, transformer representations predicted activity in a distributed network that overlapped across languages and remained stable across layers. Contextual embeddings and measures of prediction or compression did not outperform static lexical embeddings, suggesting that alignment is robust but not informative about shared computational processes.

By Ni Yang, Rui He, Philipp Homan, Iris Sommer, Davide Staub, Wolfram Hinzen
arXiv Machine Learning
Sep 24

A Scaling Study for fMRI Foundation Models

The study investigates how data volume, model size, and training duration affect the performance of fMRI foundation models. Using over 200 datasets and 10,000 GPU‑hours, the authors find that larger models benefit more from additional data, and that at a fixed compute budget, increasing data yields greater gains than enlarging the model. By selecting optimal combinations of data, size, and duration, they produce models that outperform existing fMRI foundation models on out‑of‑distribution tasks while requiring less pretraining compute.

By Wenhao Ye, Xuanye Pan, Junfeng Xia, Junxiang Zhang, Mo Wang, Quanying Liu