Leveraging Knowledge Graph-Based Human-Like Memory Systems to Solve Partially Observable Markov Decision Processes

Humans observe only part of their environment at any moment but can still make complex, long-term decisions thanks to our long-term memory system. To test how an AI can learn and utilize its long-term memory system, we have developed a partially observable Markov decision processes (POMDP) environment, where the agent has to answer questions while navigating a maze. The environment is completely knowledge graph (KG) based, where the hidden states are dynamic KGs. A KG is both human- and machine-readable, making it easy to see what the agents remember and forget. We train and compare agents with different memory systems, to shed light on how human brains work when it comes to managing its own memory systems. By repurposing the given learning objective as learning a memory management policy, we were able to capture the most likely belief state, which is not only interpretable but also reusable.