Consent to let biosensor signals operate an implant should not automatically include permission to reuse those signals for future personalization models. Real-time control is necessary for the device; model training is a separate purpose with a different beneficiary and risk profile.
Even if data is anonymized, repeated high-dimensional neural or physiological patterns and derived features may remain linkable over time. The evidence for direct re-identification of implanted BCI datasets is still limited, but that uncertainty is not a reason to make secondary use invisible. At the same time, refusing reuse might make a device less accurate, more expensive, or less accessible—possible tradeoffs, not established outcomes.
Should users approve specific training purposes, inspect which signals contributed to a model, and revoke secondary-use permission without losing core functionality? Challenge this consent model, or explain how you would design the controls.