Poster
in
Workshop: Decision Awareness in Reinforcement Learning
Toward Human Cognition-inspired High-Level Decision Making For Hierarchical Reinforcement Learning Agents
Rousslan F. J. Dossa · Takashi Matsubara
The ability of humans to efficiently understand and learn to solve complex tasks with relatively limited data is attributed to our hierarchically organized decision-making process.Meanwhile, sample efficiency is a long-standing challenge for reinforcement learning (RL) agents, especially in long-horizon, sequential decision-making tasks with sparse and delayed rewards.Hierarchical reinforcement learning (HRL) augments RL agents with temporal abstraction to improve their efficiency in such complex tasks.However, the decision-making process of most HRL methods is often based directly on dense low-level information, while also using fixed temporal abstraction.We propose the hierarchical world model (HWM), which is geared toward capturing more flexible high-level, temporally abstract dynamics, as well as low-level dynamics of the task.Preliminary experiments on using the HWM with model-based RL resulted in improved sample efficiency and final performance.An investigation of the state representations learned by the HWM also shows their alignment with human intuition and understanding.Finally, we provide a theoretical foundation for integrating the proposed HWM with the HRL framework, thus building toward RL agents with hierarchically structured decision-making which aligns with the theorized principles of human cognition and decision process.