Saved in:
Bibliographic Details
Main Authors: Qiu, Haomiao, Zhang, Miao, Qiao, Ziyue, Nie, Liqiang
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2505.22389
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918165996371968
author Qiu, Haomiao
Zhang, Miao
Qiao, Ziyue
Nie, Liqiang
author_facet Qiu, Haomiao
Zhang, Miao
Qiao, Ziyue
Nie, Liqiang
contents Continual Learning (CL) aims to enable models to continuously acquire new knowledge from a sequence of tasks with avoiding the forgetting of learned information. However, existing CL methods only rely on the parameters of the most recent task for inference, which makes them susceptible to catastrophic forgetting. Inspired by the recent success of model merging techniques, we propose \textbf{Perturb-and-Merge (P\&M)}, a novel continual learning framework that integrates model merging into the CL paradigm to mitigate forgetting. Specifically, after training on each task, P\&M constructs a new model by forming a convex combination of the previous model and the newly trained task-specific model. Through theoretical analysis, We minimize the total loss increase across all tasks and derive a closed-form solution for the merging coefficient under mild assumptions. To further improve the performance of the merged model, we observe that the degradation introduced during merging can be alleviated by a regularization term composed of the task vector and the Hessian matrix of the loss function. Interestingly, we show that this term can be efficiently approximated using second-order symmetric finite differences, and a stochastic perturbation strategy along the task vector direction is accordingly devised which incurs no additional forward or backward passes while providing an effective approximation of the regularization term. Finally, we combine P\&M with LoRA, a parameter-efficient fine-tuning method, to reduce memory overhead. Our proposed approach achieves state-of-the-art performance on several continual learning benchmark datasets. The code is available at https://github.com/qhmiao/P-M-for-Continual-Learning.
format Preprint
id arxiv_https___arxiv_org_abs_2505_22389
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Train with Perturbation, Infer after Merging: A Two-Stage Framework for Continual Learning
Qiu, Haomiao
Zhang, Miao
Qiao, Ziyue
Nie, Liqiang
Machine Learning
Artificial Intelligence
Continual Learning (CL) aims to enable models to continuously acquire new knowledge from a sequence of tasks with avoiding the forgetting of learned information. However, existing CL methods only rely on the parameters of the most recent task for inference, which makes them susceptible to catastrophic forgetting. Inspired by the recent success of model merging techniques, we propose \textbf{Perturb-and-Merge (P\&M)}, a novel continual learning framework that integrates model merging into the CL paradigm to mitigate forgetting. Specifically, after training on each task, P\&M constructs a new model by forming a convex combination of the previous model and the newly trained task-specific model. Through theoretical analysis, We minimize the total loss increase across all tasks and derive a closed-form solution for the merging coefficient under mild assumptions. To further improve the performance of the merged model, we observe that the degradation introduced during merging can be alleviated by a regularization term composed of the task vector and the Hessian matrix of the loss function. Interestingly, we show that this term can be efficiently approximated using second-order symmetric finite differences, and a stochastic perturbation strategy along the task vector direction is accordingly devised which incurs no additional forward or backward passes while providing an effective approximation of the regularization term. Finally, we combine P\&M with LoRA, a parameter-efficient fine-tuning method, to reduce memory overhead. Our proposed approach achieves state-of-the-art performance on several continual learning benchmark datasets. The code is available at https://github.com/qhmiao/P-M-for-Continual-Learning.
title Train with Perturbation, Infer after Merging: A Two-Stage Framework for Continual Learning
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2505.22389