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Reinforcement Learning with Unsupervised Auxiliary Tasks (arxiv.org)
47 points by tonybeltramelli on Nov 17, 2016 | hide | past | pdf | 6 comments on HN

In plain words: Besides chasing the game's real score, the agent practices self-invented goals sharing one internal picture of the world, with a switch that steers that picture toward what earns points. On 3D maze games it learned 10 times faster than the usual reward-only setup.

Abstract

Deep reinforcement learning agents have achieved state-of-the-art results by directly maximising cumulative reward. However, environments contain a much wider variety of possible training signals. In this paper, we introduce an agent that also maximises many other pseudo-reward functions simultaneously by reinforcement learning. All of these tasks share a common representation that, like unsupervised learning, continues to develop in the absence of extrinsic rewards. We also introduce a novel mechanism for focusing this representation upon extrinsic rewards, so that learning can rapidly adapt to the most relevant aspects of the actual task. Our agent significantly outperforms the previous state-of-the-art on Atari, averaging 880\% expert human performance, and a challenging suite of first-person, three-dimensional \emph{Labyrinth} tasks leading to a mean speedup in learning of 10$\times$ and averaging 87\% expert human performance on Labyrinth.

Max Jaderberg, Volodymyr Mnih, Wojciech Marian Czarnecki, Tom Schaul, Joel Z Leibo, David Silver, Koray Kavukcuoglu
arXiv:1611.05397 · cs.LG, cs.NE · submitted Nov 16, 2016
abstract · pdf · html

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Also discussed: Nov 2016 (2 points, 0 comments)

Interesting. I'm not a deep learning guy, but from what I can gather, the new auxiliary tasks are to be rewarded for "pixel changes" and "network features".

I haven't nearly finished reading the paper, but is it safe to say this is similar (at a very high level), to a type of "novelty search", where the agent is searching not only for a policy that is directly accomplishing the task at hand, but also for novel stimulus (in the case of pixel changes), and novel internal states (features, or maximally activated hidden nodes in the language of the paper), and that the benefit of this would be to more easily find relevant features that could be useful in the "big picture" task, and maybe not get as stuck in a non-optimal policy?

(I may be understanding this completely wrong...just an embedded guy looking to get more into this world, haha)

Quick reply to my own comment. But another reason it seems this is helpful is that in many reinforcement learning tasks, like games, rewards are few and far between, so these goals also give the agent oncentive to keep trying new things / learning about the environment / task in the presence of sparse rewards?
It seems to me like an attempt to model curiosity.
Exactly what I was thinking, and put much more succinctly!
I remember seeing a lecture on the importance of novelty in these kinds of things - good to see it applied.
Is this an attempt at unsupervised action decomposition or artificial curiosity?