Integrating Curricula with Replays: Its Effects on Continual Learning

TL;DR

This paper investigates how integrating curriculum strategies with replay methods can improve continual learning by reducing forgetting and enhancing knowledge transfer, inspired by human learning behaviors.

Contribution

It explores the effects of curricula on replay in continual learning, focusing on replay frequency, sequence, and exemplar selection, which are novel aspects in this context.

Findings

Curricula integration mitigates catastrophic forgetting.

Enhanced positive knowledge transfer observed.

Interleaved and easy-to-hard replay strategies are effective.

Abstract

Humans engage in learning and reviewing processes with curricula when acquiring new skills or knowledge. This human learning behavior has inspired the integration of curricula with replay methods in continual learning agents. The goal is to emulate the human learning process, thereby improving knowledge retention and facilitating learning transfer. Existing replay methods in continual learning agents involve the random selection and ordering of data from previous tasks, which has shown to be effective. However, limited research has explored the integration of different curricula with replay methods to enhance continual learning. Our study takes initial steps in examining the impact of integrating curricula with replay methods on continual learning in three specific aspects: the interleaved frequency of replayed exemplars with training data, the sequence in which exemplars are replayed, and the strategy for selecting exemplars into the replay buffer. These aspects of curricula design align with cognitive psychology principles and leverage the benefits of interleaved practice during replays, easy-to-hard rehearsal, and exemplar selection strategy involving exemplars from a uniform distribution of difficulties. Based on our results, these three curricula effectively mitigated catastrophic forgetting and enhanced positive knowledge transfer, demonstrating the potential of curricula in advancing continual learning methodologies. Our code and data are available: https://github.com/ZhangLab-DeepNeuroCogLab/Integrating-Curricula-with-Replays