  Continual learning algorithms which keep the parameters of new tasks close to
that of previous tasks, are popular in preventing catastrophic forgetting in
sequential task learning settings. However, 1) the performance for the new
continual learner will be degraded without distinguishing the contributions of
previously learned tasks; 2) the computational cost will be greatly increased
with the number of tasks, since most existing algorithms need to regularize all
previous tasks when learning new tasks. To address the above challenges, we
propose a self-paced Weight Consolidation (spWC) framework to attain robust
continual learning via evaluating the discriminative contributions of previous
tasks. To be specific, we develop a self-paced regularization to reflect the
priorities of past tasks via measuring difficulty based on key performance
indicator (i.e., accuracy). When encountering a new task, all previous tasks
are sorted from "difficult" to "easy" based on the priorities. Then the
parameters of the new continual learner will be learned via selectively
maintaining the knowledge amongst more difficult past tasks, which could well
overcome catastrophic forgetting with less computational cost. We adopt an
alternative convex search to iteratively update the model parameters and
priority weights in the bi-convex formulation. The proposed spWC framework is
plug-and-play, which is applicable to most continual learning algorithms (e.g.,
EWC, MAS and RCIL) in different directions (e.g., classification and
segmentation). Experimental results on several public benchmark datasets
demonstrate that our proposed framework can effectively improve performance
when compared with other popular continual learning algorithms.
