Learning Dynamics of Meta-Learning in Small Model Pretraining

Fuente: arXiv
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Main Authors: Africa, David Demitri, Weiss, Yuval, Buttery, Paula, Martinez, Richard Diehl
Format: Preprint
Published: 2025
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author Africa, David Demitri
Weiss, Yuval
Buttery, Paula
Martinez, Richard Diehl
author_facet Africa, David Demitri
Weiss, Yuval
Buttery, Paula
Martinez, Richard Diehl
contents Large language models are powerful but costly. We ask whether meta-learning can make the pretraining of small language models not only better but also more interpretable. We integrate first-order MAML with subset-masked LM pretraining, producing four LLama-style decoder-only models (11M-570M params), and evaluate it on a fundamental NLP task with many settings and real-world applications. Compared with vanilla training, our model (i) reaches the same loss up to 1.6x sooner, (ii) improves F1 on multilingual Universal NER under equal compute, and (iii) makes the training dynamics easy to read: first the network's representations fan out ("diversify") and later they collapse into a smaller, shared subspace ("compress"). This two-stage shift shows up as a rise-and-fall in both effective-rank curves and attention-head entropy. The same curves pinpoint which layers specialise earliest and which later reconverge, giving a compact, interpretable signature of meta-adaptation. Code, checkpoints and WandB logs are released.
format Preprint
id arxiv_https___arxiv_org_abs_2508_02189
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Learning Dynamics of Meta-Learning in Small Model Pretraining
Africa, David Demitri
Weiss, Yuval
Buttery, Paula
Martinez, Richard Diehl
Computation and Language
Artificial Intelligence
Large language models are powerful but costly. We ask whether meta-learning can make the pretraining of small language models not only better but also more interpretable. We integrate first-order MAML with subset-masked LM pretraining, producing four LLama-style decoder-only models (11M-570M params), and evaluate it on a fundamental NLP task with many settings and real-world applications. Compared with vanilla training, our model (i) reaches the same loss up to 1.6x sooner, (ii) improves F1 on multilingual Universal NER under equal compute, and (iii) makes the training dynamics easy to read: first the network's representations fan out ("diversify") and later they collapse into a smaller, shared subspace ("compress"). This two-stage shift shows up as a rise-and-fall in both effective-rank curves and attention-head entropy. The same curves pinpoint which layers specialise earliest and which later reconverge, giving a compact, interpretable signature of meta-adaptation. Code, checkpoints and WandB logs are released.
title Learning Dynamics of Meta-Learning in Small Model Pretraining
topic Computation and Language
Artificial Intelligence
url https://arxiv.org/abs/2508.02189