Privacy, neuroethics, and the abandoned implant
Neural data privacy laws, agency and identity questions, the neurorights movement, and what actually happened to patients when their implant company went out of business. The questions companies now hire people to think about.
On this page14 min
The neural coding page argued that mind-reading is not near. That does not make the ethics easy; it makes them specific. Who owns a recording of your motor cortex? Can a company sell your EEGElectroencephalography (EEG) Recording the brain's electrical activity from electrodes on the scalp, a few tens of microvolts of blurred, summed cortical activity. Related: Electrocorticography (ECoG)Electrocorticography (ECoG) Recording from electrodes placed on the surface of the brain under the skull, usually during epilepsy surgery evaluation; cleaner and sharper than EEG. , Magnetoencephalography (MEG)Magnetoencephalography (MEG) Recording the tiny magnetic fields produced by cortical currents with superconducting sensors in a shielded room; less blurred by the skull than EEG, and far more expensive. , Volume conductionVolume conduction The spreading of currents from a source through the conductive tissues of the head, which is why one source shows up on many electrodes and why scalp EEG is blurry. , Microvolt (µV)Microvolt (µV) One millionth of a volt. Scalp EEG is tens of microvolts; a AA battery is 1.5 million of them. . Glossary entry to an insurer? What does a person owe, and what is owed to them, when a device is part of their body? And the one with a documented answer: what happens to a patient when the company that made their implant goes bankrupt. Companies in this field now hire people who can think clearly about these, and clear thinking starts with the cases.
Neural data privacy
EEGElectroencephalography (EEG) Recording the brain's electrical activity from electrodes on the scalp, a few tens of microvolts of blurred, summed cortical activity. Related: Electrocorticography (ECoG)Electrocorticography (ECoG) Recording from electrodes placed on the surface of the brain under the skull, usually during epilepsy surgery evaluation; cleaner and sharper than EEG. , Magnetoencephalography (MEG)Magnetoencephalography (MEG) Recording the tiny magnetic fields produced by cortical currents with superconducting sensors in a shielded room; less blurred by the skull than EEG, and far more expensive. , Volume conductionVolume conduction The spreading of currents from a source through the conductive tissues of the head, which is why one source shows up on many electrodes and why scalp EEG is blurry. , Microvolt (µV)Microvolt (µV) One millionth of a volt. Scalp EEG is tens of microvolts; a AA battery is 1.5 million of them. . Glossary entry and intracortical recordingsIntracortical recording Recording from tiny electrodes inserted into the cortex itself, close enough to hear individual neurons. Related: Utah ArrayUtah Array The 10-by-10 grid of 1.5 mm silicon needles invented at the University of Utah, the electrode in nearly every human intracortical BCI study to date. , Extracellular recordingExtracellular recording Recording with an electrode near neurons rather than inside one; you see small, fast blips from nearby cells rather than the full membrane swing. . Glossary entry are health data when a clinician collects them and often are not when a consumer headband does; the gap is where the concern lies. Consumer neurotech companies’ privacy policies have, in reviews, allowed broad sharing of recorded brain data with third parties. What can be inferred from it today is limited (attention, drowsiness, some emotional states, medical conditions such as epilepsyEpilepsy A tendency to recurrent seizures; its monitoring units are where seizure-detection algorithms get validated and where ECoG data comes from. Related: Epilepsy monitoring unit (EMU)Epilepsy monitoring unit (EMU) The hospital ward where patients are recorded on video-EEG for days to capture seizures before surgery. , Seizure detectionSeizure detection Automatically flagging seizures in EEG, a real clinical need and a good first machine-learning project on the TUH corpus. . Glossary entry) but the recordings persist and inference improves. Colorado in 2024Colorado HB24-1058, neural data added to sensitive dataThe first US law classifying neural data as sensitive personal information, with consent and deletion rights. and California soon after amended their privacy laws to treat neural data as sensitive personal information, with consent and deletion rights; other states and countries have followed or are debating. Chile wrote mental privacy into its constitution in 2021.
For a designer: collect the minimum, store locally where possible (this site’s own choice), make deletion real, and write the privacy policy in a sentence a person can understand. If you would not want your own recordings handled that way, do not build it that way.
A person uses an implanted BCI for years. The company goes bankrupt. What happened, in the real cases?
Patients were left with unsupported implants. Second Sight’s Argus II retinal implantTheir bionic eyes are now obsolete and unsupportedWhat happened to Second Sight retinal implant users when the company moved on, and why support plans matter.: the company stopped supporting the device in 2019 and later merged away; hundreds of users had implants that could no longer be repaired, with software and parts unavailable, and some faced explantation surgery or interference with MRI. Similar situations occurred with an early cochlear implantCochlear implant The most successful neural prosthesis: an electrode array in the inner ear that stimulates the auditory nerve in up to 22 bands. Related: Vocoder (noise vocoder)Vocoder (noise vocoder) A simulation of what a cochlear implant delivers: the loudness envelope of each frequency band, applied to noise in that band. . Glossary entry company and with a deep brain stimulation trial for depression whose funding ended. The question “what is the plan for these patients if the company fails” is now asked by ethicists, regulators, and, increasingly, by the patients before they consent.
The abandoned implant
The Second Sight case made explicit what an implant is: a relationship, not a product. The patient depends on the company for software, batteries, external components, and surgical support, indefinitely. Proposed fixes include escrow of designs and source code that is released if the company fails, requirementsRequirements Testable statements of what the device must do, such as "input-referred noise below 1 microvolt RMS from 0.5 to 40 Hz." Related: VerificationVerification Testing that the device meets its requirements; did you build what you specified. . Glossary entry for continuity plans in trial protocols, open standards so another company’s hardware could take over, and funds set aside for explantation. None is standard yet. A student who can explain this case and the proposed remedies is having a conversation the field is having right now.
Agency, identity, and responsibility
Deep brain stimulation for Parkinson’s disease has, in a minority of patients, produced personality changes: impulsivity, apathy, mania. Patients and families have asked whether the person is still themselves and whether the device or the person is responsible for what they do. Closed-loop systems that act without the user’s moment-to-moment awareness sharpen the question. For BCIsBrain-computer interface (BCI) A system that turns measured brain activity into control of something outside the body, from a cursor to a wheelchair to a speech synthesizer. Related: DecoderDecoder The algorithm that maps neural signals to intended actions, such as a classifier or a Kalman filter. , Closed loopClosed loop A system in which the output feeds back to influence the input, such as a user adjusting their brain activity while watching the cursor it controls. . Glossary entry that decode intent: if the decoderDecoder The algorithm that maps neural signals to intended actions, such as a classifier or a Kalman filter. Related: ClassifierClassifier An algorithm that assigns each trial a label, such as left hand or right hand, after being trained on labelled examples. , Kalman filterKalman filter An estimator that blends a prediction from a motion model with a noisy measurement, weighting each by how much it trusts it; the decoder behind most intracortical cursor control. , Brain-computer interface (BCI)Brain-computer interface (BCI) A system that turns measured brain activity into control of something outside the body, from a cursor to a wheelchair to a speech synthesizer. . Glossary entry errs and the wheelchair hits someone, whose action was it? These questions do not have settled answers; the responsible position is to design so that the user’s control is maximal, the device’s actions are transparent and logged, and the person can always turn it off.
Consent for the unknowable
A person consenting to an implanted BCIBrain-computer interface (BCI) A system that turns measured brain activity into control of something outside the body, from a cursor to a wheelchair to a speech synthesizer. Related: DecoderDecoder The algorithm that maps neural signals to intended actions, such as a classifier or a Kalman filter. , Closed loopClosed loop A system in which the output feeds back to influence the input, such as a user adjusting their brain activity while watching the cursor it controls. . Glossary entry trial is consenting to something whose long-term effects, including the effect of eventually losing it, nobody can fully describe. Ethicists argue for consent as an ongoing process, revisited, with explicit discussion of the end of the study and the end of the company. The participants in current BCIBrain-computer interface (BCI) A system that turns measured brain activity into control of something outside the body, from a cursor to a wheelchair to a speech synthesizer. Related: DecoderDecoder The algorithm that maps neural signals to intended actions, such as a classifier or a Kalman filter. , Closed loopClosed loop A system in which the output feeds back to influence the input, such as a user adjusting their brain activity while watching the cursor it controls. . Glossary entry trials are, by every account, extraordinarily well informed and brave. The field owes them the continuity plans it does not yet have.
Neurorights
A movement, led by Rafael Yuste and othersFour ethical priorities for neurotechnologies and AIThe short comment that set the neuroethics agenda: privacy, identity, agency, and access., to establish rights to mental privacy, personal identity, free will, fair access to cognitive enhancement, and protection from algorithmic bias, as a framework for the coming technologies. Chile adopted a version constitutionallyConstitutional reform on neurorights, Law 21.383The constitutional amendment that made Chile the first country to protect mental privacy at that level.. Critics say existing human rights law already covers most of it and that new categories may confuse; supporters say the specificity is needed before the technology arrives. Know both arguments.
Enhancement and fairness
If a BCIBrain-computer interface (BCI) A system that turns measured brain activity into control of something outside the body, from a cursor to a wheelchair to a speech synthesizer. Related: DecoderDecoder The algorithm that maps neural signals to intended actions, such as a classifier or a Kalman filter. , Closed loopClosed loop A system in which the output feeds back to influence the input, such as a user adjusting their brain activity while watching the cursor it controls. . Glossary entry or a stimulation device improves memory or attention in healthy people (the evidence that current devices do is weak), who gets it, and what happens to those who do not? The military and the wellness industry are both interested. This site’s safety rule against self-stimulation is a small local answer; the large one is a policy question a technically literate person should be able to discuss.
Deep dive What a company's ethics work actually looks like 2 min
Data governance policies that say who can access neural recordings and for what. Privacy-by-design reviews of every feature. Patient advisory boards. Continuity-of-care planning in trial protocols. Publications in neuroethicsNeuroethics The study of the ethical questions raised by measuring and changing brains, from privacy of neural data to who owns an implant. Related: NeurorightsNeurorights Proposed rights to mental privacy, identity, and agency, already written into Chile's constitution and debated elsewhere. , Neural data privacyNeural data privacy The question of who may collect, store, and sell recordings of brain activity, now addressed by laws in several US states. . Glossary entry journals by company scientists. An undergraduate with technical skill who has read the Second Sight case, the Colorado law, and the FDA BCIBrain-computer interface (BCI) A system that turns measured brain activity into control of something outside the body, from a cursor to a wheelchair to a speech synthesizer. Related: DecoderDecoder The algorithm that maps neural signals to intended actions, such as a classifier or a Kalman filter. , Closed loopClosed loop A system in which the output feeds back to influence the input, such as a user adjusting their brain activity while watching the cursor it controls. . Glossary entry guidance is qualified to sit in those meetings and add something, which is a rare combination.
Explain what this page was about to your roommate in three sentences. No jargon they would not know.
We treat brain recordings like health data because Colorado law since 2024 calls neural data sensitive personal information with consent and deletion rights. We remember the Argus II retinal implant case after 2019 when hundreds of users lost repairs and software support because the company failed. We design for control by keeping the user able to turn the device off and by logging what the device does.
Yours does not have to match. Check that the three ideas are there.