NeurIPS 2020

Dynamic allocation of limited memory resources in reinforcement learning


Meta Review

This paper nicely bridges between neuroscience and RL, and considers the important topic of limited memory resources in RL agents. The topic is well-suited for NeurIPS (R2) as it has broader applicability toward e.g. model-based RL and planning, although this is not extensively discussed or shown in the paper itself. All reviewers agreed that it is well-motivated and written (R1, R2, R3, R4), although R3 did ask for a bit more explanation on some methodological details. It is also appropriately situated with respect to related work (R1, R2, R3) although R2 suggests a separate related works section, and R4 wanted to see more discussion of work outside of neuroscience, focused on optimizing RL with limited capacity. R1 pointed out that perhaps there’s a bit of confusion between memory precision and use of memory resources, as the former is more accurate for agents, the latter perhaps for real brains - ie more precise representations require more resources to encode in the brain, but this seems to be a minor point. R1 also asked to include standard baseline implementations to test for issues such how their model scales compared to other methods. R4 was the least positive, expressing that the contribution to AI is unclear, that the tasks are too easy and wouldn’t be expected to challenge memory resources. Also the connection to neuroscience is a bit tenuous as the implementation doesn’t seem particularly biologically plausible. In the rebuttal, authors argue that this approach will allow them to generate testable predictions regarding neural representations during learning, some of which are already included in the discussion. I find this adequate, but these predictions should maybe be foregrounded more so as to make clearer the neuroscientific contribution. I’m overall quite impressed with how responsive the authors were in their response, including almost all of the requested analyses. I think the final paper, with all of these changes incorporated, is likely to be much stronger, and so I recommend accept.