PET-GPRA: Rethinking PET with Gradient-Aware Prompting and Router-Free Adapters for Few-shot Class-Incremental Learning

Few-Shot Class-Incremental Learning (FSCIL) aims to continuously learn novel concepts from limited training samples without forgetting previously encountered classes. Recent advancements have leveraged Parameter-Efficient Tuning (PET) strategies on pre-trained models to enhance FSCIL performance. However, current PET-based FSCIL approaches still suffer from the challenges posed by catastrophic collapse of general prompt and limited adaptability of specific prompt . To this end, we redefine the function of the PET paradigm with both gradient-aware prompting (GAP) and router-free adapters (RFA) to boost the performance of FSCIL, termed as "PET-GPRA". To dynamically balance the retention of previously learned general knowledge and the acquisition of novel class information across sessions, the GAP paradigm adaptively adjusts the updated gradient of the general prompt by leveraging the angular relationship between the general knowledge gradient and the novel knowledge gradient. Meanwhile, the RFA mechanism utilizes the semantic similarity between class attributes to replace the routing network, guiding the integration of adapter information, in which adapters serve as specific prompts to enhance the adaptability. Extensive experiments on multiple benchmark datasets consistently demonstrate the superiority and effectiveness of our proposed PET-GPRA framework over state-of-the-art baselines.