From Isolated Conversations to Hierarchical Schemas: Dynamic Tree Memory Representation for LLMs

Alireza Rezazadeh, Zichao Li, Wei Wei, Yujia Bao

Keywords: Tree-based Memory, Inference-time Reasoning, Large language models, Long-term memory

TL;DR: MemTree is a dynamic algorithm that organizes memory hierarchically, using tree-structured representations with different levels of abstraction to enhance information retrieval and context-awareness in large language models.

Abstract: Recent advancements in large language models have significantly improved their context windows, yet challenges in effective long-term memory management remain. We introduce MemTree, an algorithm that leverages a dynamic, tree-structured memory representation to optimize the organization, retrieval, and integration of information, akin to human cognitive schemas. MemTree organizes memory hierarchically, with each node encapsulating aggregated textual content, corresponding semantic embeddings, and varying abstraction levels across the tree's depths. Our algorithm dynamically adapts this memory structure by computing and comparing semantic embeddings of new and existing information to enrich the model’s context-awareness. This approach allows MemTree to handle complex reasoning and extended interactions more effectively than traditional memory augmentation methods, which often rely on flat lookup tables. Evaluations on benchmarks such as the Multi-Session Chat (MSC) and MultiHop RAG show that MemTree significantly enhances performance in scenarios that demand structured memory management.

Submission Number: 24