Towards Interactive Reinforcement Learning with Intrinsic Feedback
Benjamin Poole, Minwoo Lee
TL;DR
This tutorial surveys intrinsic feedback as a bridge between reinforcement learning and brain–computer interfaces, elucidating how neural signals can serve as a feedback medium within interactive RL. It formalizes feedback components (type, medium, interpretation, modeling, integration) and reviews foundational LfF approaches (TAMER, COACH, LfP) and their extensions, highlighting how they can be adapted to leverage brain-derived signals like ErrPs. The survey covers motivational justifications, signaling modalities, and proof-of-concept to adaptive strategies for intrinsic feedback, while candidly addressing major challenges such as non-stationary brain signals, credit assignment, and sample efficiency, and it proposes future directions including multi-channel feedback and standardized benchmarking. The work aims to equip BCI and RL researchers with technical grounding to develop robust intrinsic feedback methods and to explore their practical impact on aptness and alignment in real-world human–agent systems.
Abstract
Reinforcement learning (RL) and brain-computer interfaces (BCI) have experienced significant growth over the past decade. With rising interest in human-in-the-loop (HITL), incorporating human input with RL algorithms has given rise to the sub-field of interactive RL. Adjacently, the field of BCI has long been interested in extracting informative brain signals from neural activity for use in human-computer interactions. A key link between these fields lies in the interpretation of neural activity as feedback such that interactive RL approaches can be employed. We denote this new and emerging medium of feedback as intrinsic feedback. Despite intrinsic feedback's ability to be conveyed automatically and even unconsciously, proper exploration surrounding this key link has largely gone unaddressed by both communities. Thus, to help facilitate a deeper understanding and a more effective utilization, we provide a tutorial-style review covering the motivations, approaches, and open problems of intrinsic feedback and its foundational concepts.
