Learning Attentive Meta-Transfer

Meta-transfer learning seeks to improve the efficiency of learning a new task via both meta-learning and transfer-learning in a setting with a stream of evolving tasks. While standard attention has been effective in a variety of settings, we question its effectiveness in improving meta-transfer learning since the tasks being learned are dynamic, and the amount of context information can be substantially small. In this paper, using a recently proposed meta-transfer learning model, Sequential Neural Processes (SNP), we first empirically show that it suffers a similar underfitting problem observed in the functions inferred by Neural Processes. However, we further demonstrate that unlike the meta-learning setting, standard attention mechanisms are ineffective in meta-transfer learning.~To resolve, we propose a new attention mechanism, Recurrent Memory Reconstruction (RMR), and demonstrate that providing an imaginary context that is recurrently updated and reconstructed with interaction is crucial in achieving effective attention for meta-transfer learning. Furthermore, incorporating RMR into SNP, we propose Attentive Sequential Neural Processes (ASNP) and demonstrate in various tasks that ASNP significantly outperforms the baselines.