Informed consent competency assessment for brain-computer interface clinical research and application in psychiatric disorders: A systematic review

Table 2 Summary of specific ethical issues in brain computer interface researches and applications

Key elements	Ref.	Specific ethical issues
Informed consent capacity	[90-97,126,130,136]	Patients with severe impairments (e.g. PD and AD) may lack capacity to consent, and psychiatric/ neurodegenerative patients with fluctuating decision-making abilities
		Requires assessing participants’ understanding of risks/benefits; surrogate informed consent (e.g., guardians) may be needed
		For pediatric BCI studies, legal guardians must consent, but child assent is critical for long-term engagement
		Safeguarding the rights and interests of vulnerable research subjects and ensuring their full understanding and voluntary participation
		Ensuring patient autonomy is essential and therefore emphasizes that the informed consent process should pay particular attention to the patient's expectation management and cognitive abilities
		BCI devices may affect cognitive abilities, e.g., STN may lead to ICD, which may affect the patient's ability to make decisions on his/her own
Ongoing consent & withdrawal	[94,98-103,114,135]	Irreversible interventions (e.g., invasive BCIs) require re-evaluating consent if identity/personality changes occur
		Informed consent should be a continuous process due to BCI’s long-term use
		Irreversible BCI implants may hinder withdrawal of consent (e.g., invasive BCIs)
		Refuse to complete the BCI research and remove BCI devices, due to their dependence on the technology and a lack of competency to fully understand future risks. This phenomenon is particularly common and distinct in the case of invasive BCIs, where withdrawal decisions are more complex and ethically challenging
Autonomy & control risks	[94,99,102-114,130]	Affective BCIs may manipulate emotions, threatening user autonomy
		Errors in decoding BCI signals could misinterpret intentions (e.g., legal declarations)
		BCIs may alter identity or personality, questioning consent validity post-implantation
		“Ambiguous agency” blurs user vs system control, undermining autonomy
Misunderstanding risks	[19,92,94,99,103,104,110,115-121,137]	Participants may lack understanding of BCI’s long-term effects or technical risks (e.g., surgery complications)
		Media hype (e.g., BCIs “read minds”) that distorts public understanding and consent validity and creates unrealistic expectations
Third-party consent ethics	[94,99,104,122-126,131,139]	Pediatric BCI decisions by guardians might conflict with a child’s evolving autonomy because they may not be able to undo the effects of these technologies in adulthood

BCI: Brain-computer interface; ICC: Informed consent competency; PD: Parkinson’s disease; AD: Alzheimer’s disease; STN: Stimulation of the thalamic nucleus; ICD: Impulse control disorder.