Why Meditation Wearables Fail: Reward Misspecification in Closed-Loop EEG and Biofeedback Systems
arXiv:2605.28223v1 Announce Type: new Abstract: Consumer EEG headbands, HRV biofeedback devices, and closed-loop neurostimulation systems share a fundamental design flaw: they reward measurable proxy signals rather than the outcomes they claim to produce. When a user optimises for calm EEG, HRV coherence, or breathing resonance, their brain learns to produce those signals through whatever strategy is most efficient, including strategies unrelated to the intended benefit. We formalise this as reward misspecification: the policy maximising proxy reward R_proxy is not the policy maximising true intended outcome V_target. This produces three failure modes: proxy mismatch, strategy shortcutting, and transfer failure. We review how existing devices including Muse, HeartMath, Unyte IOM2, and clinical neurofeedback systems instantiate these failures. We introduce a four-tier measurability taxonomy distinguishing reliably measurable wearable targets (Tier 1) from targets that are currently or p