Saved in:
Bibliographic Details
Main Authors: Wang, Shenran, Tse, Timothy Tin-Long, Zhu, Jian
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2510.23006
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914354956337152
author Wang, Shenran
Tse, Timothy Tin-Long
Zhu, Jian
author_facet Wang, Shenran
Tse, Timothy Tin-Long
Zhu, Jian
contents We perform in-depth evaluations of in-context learning (ICL) on state-of-the-art transformer, state-space, and hybrid large language models over two categories of knowledge-based ICL tasks. Using a combination of behavioral probing and intervention-based methods, we have discovered that, while LLMs of different architectures can behave similarly in task performance, their internals could remain different. We discover that function vectors (FVs) responsible for ICL are primarily located in the self-attention and Mamba layers, and speculate that Mamba2 uses a different mechanism from FVs to perform ICL. FVs are more important for ICL involving parametric knowledge retrieval, but not for contextual knowledge understanding. Our work contributes to a more nuanced understanding across architectures and task types. Methodologically, our approach also highlights the importance of combining both behavioural and mechanistic analyses to investigate LLM capabilities.
format Preprint
id arxiv_https___arxiv_org_abs_2510_23006
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Understanding In-Context Learning Beyond Transformers: An Investigation of State Space and Hybrid Architectures
Wang, Shenran
Tse, Timothy Tin-Long
Zhu, Jian
Computation and Language
Artificial Intelligence
We perform in-depth evaluations of in-context learning (ICL) on state-of-the-art transformer, state-space, and hybrid large language models over two categories of knowledge-based ICL tasks. Using a combination of behavioral probing and intervention-based methods, we have discovered that, while LLMs of different architectures can behave similarly in task performance, their internals could remain different. We discover that function vectors (FVs) responsible for ICL are primarily located in the self-attention and Mamba layers, and speculate that Mamba2 uses a different mechanism from FVs to perform ICL. FVs are more important for ICL involving parametric knowledge retrieval, but not for contextual knowledge understanding. Our work contributes to a more nuanced understanding across architectures and task types. Methodologically, our approach also highlights the importance of combining both behavioural and mechanistic analyses to investigate LLM capabilities.
title Understanding In-Context Learning Beyond Transformers: An Investigation of State Space and Hybrid Architectures
topic Computation and Language
Artificial Intelligence
url https://arxiv.org/abs/2510.23006