Critical Patch-Aware Sparse Prompting with Decoupled Training for Continual Learning on the Edge

Continual learning (CL) on edge devices requires not only high accuracy but also training-time efficiency to support on-device adaptation under strict memory and computational constraints. While prompt-based continual learning (PCL) is parameter-efficient and achieves competitive accuracy, prior work has focused mainly on accuracy or inference-time performance, often overlooking the memory and computational costs of on-device training. In this paper, we propose CPS-Prompt, a critical patch-aware sparse prompting framework that explicitly targets training-time memory usage and computational cost by integrating critical patch sampling (CPS) for task-aware token reduction and decoupled prompt and classifier training (DPCT) to reduce backpropagation overhead. Experiments on three public benchmarks and real edge hardware show that CPS-Prompt improves peak memory, training time, and energy efficiency by about 1.6x over the balanced CODA-Prompt baseline, while maintaining accuracy within 2% of the state-of-the-art C-Prompt on average and remaining competitive with CODA-Prompt in accuracy. The code is available at https://github.com/laymond1/cps-prompt.

Continual Multimodal Egocentric Activity Recognition via Modality-Aware Novel Detection

Multimodal egocentric activity recognition integrates visual and inertial cues for robust first-person behavior understanding. However, deploying such systems in open-world environments requires detecting novel activities while continuously learning from non-stationary streams. Existing methods rely on the main logits for novelty scoring, without fully exploiting the complementary evidence available from individual modalities. Because these logits are often dominated by RGB, cues from other modalities, particularly IMU, remain underutilized, and this imbalance worsens over time under catastrophic forgetting. To address this, we propose MAND, a modality-aware framework for multimodal egocentric open-world continual learning. At inference, Modality-aware Adaptive Scoring (MoAS) estimates sample-wise modality reliability from energy scores and adaptively integrates modality logits to better exploit complementary modality cues for novelty detection. During training, Modality-wise Representation Stabilization Training (MoRST) preserves modality-specific discriminability across tasks via auxiliary heads and modality-wise logit distillation. Experiments on a public multimodal egocentric benchmark show that MAND improves novel activity detection AUC by up to 10\% and known-class classification accuracy by up to 2.8\% over state-of-the-art baselines.