2019

Ray Interference: a Source of Plateaus in Deep Reinforcement Learning

Schaul, Tom, Borsa, Diana, Modayil, Joseph et al.

Understand

Rather than proposing a new method, this paper investigates an issue present in existing learning algorithms.

  • We study the learning dynamics of reinforcement learning (RL), specifically a characteristic coupling between learning and data generation that arises because RL agents control their future data distribution.
  • In the presence of function approximation, this coupling can lead to a problematic type of 'ray interference', characterized by learning dynamics that sequentially traverse a number of performance plateaus, effectively constraining the agent to learn one thing at a time even when learning in parallel is better.
  • We establish the conditions under which ray interference occurs, show its relation to saddle points and obtain the exact learning dynamics in a restricted setting.

Reading the bibliography…