A review of ethical considerations for the medical applications of brain-computer interfaces

Abstract

The development and potential applications of brain-computer interfaces (BCIs) are directly related to the human brain and may have adverse effects on the users’ physical and mental health. Ethical issues, particularly those associated with BCIs, including both non-medical and medical applications, have captured societal attention. This article initially reviews the application of three ethical frameworks in BCI technology: consequentialism, deontology, and virtue ethics. Subsequently, it introduces the ethical standards under consideration within the medical objective framework for BCI medical applications. Finally, the paper discusses and forecasts the ethical standards for BCI medical applications. The paper emphasizes the necessity to differentiate between the ethical issues of implantable and non-implantable BCIs, to approach the research on BCI-based “controlling the brain” with caution, and to establish standardized operational procedures and efficacy evaluation methods for BCI medical applications. This paper aims to provide ideas for the establishment of ethical standards in BCI medical applications.

Introduction

The brain-computer interface (BCI) is a revolutionary human-computer interaction that aims to improve the quality of life for patients, disabled people, and healthy individuals (Graimann et al. 2010). However, the BCI user is not only the operator of the BCI system but also the source of control signals (brain signals) or the subject of monitoring/regulation within the system (central nervous system, CNS). Given that the research, development, and potential applications of BCI are intimately connected to the human brain, they could have adverse effects on the users’ physical and mental health. Consequently, addressing ethical issues and establishing norms related to BCIs are crucial.

Ethical issues related to BCIs, including those pertaining to non-medical applications as well as particularly the medical applications, have attracted societal attention. The paper argues for the necessity of distinguishing between the medical and non-medical applications of BCI in ethics. Among the most concerning are the ethics of invasive (implantable) BCIs, which involve collecting electrocorticograms (ECoGs) on the supradural or subdural cortical surface (Simeral et al. 2021), or implanting devices to record local field potentials (LFPs) and spikes within the cortex (Merk et al. 2022). Such practices have raised concerns about potential harm to the physical and mental well-being of participants and potential users. Additionally, there are apprehensions regarding the possible infringement of neural privacy and the impact on individuals’ sense of personal identity. Figure 1 demonstrates how BCI ethics are considered within an ethical framework.

Fig. 1.

Schematic diagram of the relationship among ethics, ethics for BCI, applications of BCI, and users

Regarding the ethical standards for BCI, some believe that no differentiation is needed between its medical and non-medical applications, while others contend that such a distinction is essential. Medical applications of BCI are specifically aimed at assisting patients with diagnosis, treatment, and rehabilitation, aligning with medical objectives and adhering to medical ethics. In contrast, non-medical applications, targeting healthy individuals for state monitoring, performance enhancement, and entertainment, such as consumer BCI and BCI for specific scenarios, must adhere to the ethical standards pertinent to non-medical uses. Therefore, this paper argues for the necessity of distinguishing between the medical and non-medical applications of BCI in ethical guidelines, emphasizing that this differentiation is crucial for ensuring that ethical considerations are suitably customized to each application domain.

This article initially examines the application of three ethical frameworks and theories—consequentialism, deontology, and virtue ethics—in the BCI domain, analyzing their unique perspectives and methodologies. It delves into their advantages and limitations in enhancing patient welfare, ensuring procedural justice, and fostering the development of virtuous qualities, and explores their application to ethical quandaries in particular medical settings. Then, the consideration of ethics for medical applications of BCIs within the framework for the goals of medicine (Klein 2020), including potential medical applications of BCIs, goals of medicine and BCIs, goals of BCI medicine, and ethics, is introduced. Finally, the ethics of BCI medicine are discussed.

Analysis and application of BCI ethical frameworks

In the BCI domain, diverse ethical frameworks including consequentialism, deontology, and virtue ethics offer distinct perspectives and methodologies for tackling ethical challenges.

BCI ethical frameworks

The application of consequentialism in the BCI domain centers on the outcomes of actions, specifically the consequences of deploying BCI technology (Keskinbora 2019). Within this framework, decision-makers meticulously evaluate both the positive and negative outcomes associated with BCI technology, aiming to optimize overall well-being. For example, in the development and utilization of BCI devices, researchers not only ponder the technologies’ potential advantages for enhancing patient functional recovery and life quality but also carefully balance these against possible risks, such as infringements on privacy or identity dilemmas. Consequentialism encourages developers to concentrate on the tangible impacts of technology, seeking to secure the most advantageous results for the greatest number of beneficiaries.

Deontology emphasizes adhering to moral rules and fulfilling obligations, insisting that certain ethical principles and rules must be upheld irrespective of the consequences (Kreitmair 2019). Within the BCI context, this mandates that all research and applications conform to explicit ethical standards, including but not limited to ensuring user informed consent, upholding user autonomy, and safeguarding user privacy. For instance, a BCI technology that could substantially enhance patient quality of life would still be deemed unethical if it breaches patient autonomy or proceeds without proper consent. Deontology prioritizes the integrity of moral actions themselves, emphasizing their correctness beyond merely the results they produce.

Virtue ethics focuses on the character and intentions of the decision-maker, underscoring the importance of virtues and moral character in the context of ethical decision-making (Sullivan and Illes 2018). In the realm of BCI, virtue ethics advocates for the cultivation of virtues such as honesty, compassion, and a strong sense of responsibility among researchers and implementers. For example, in BCI research, scientists are encouraged to reflect not only on the scientific merit and potential utilities of their work but also on its broader implications for participants and society, ensuring the research embodies respect and care. By fostering these virtues, virtue ethics contributes significantly to the establishment of a more compassionate and accountable culture within BCI research and applications.

Different ethical frameworks provide multidimensional perspectives and solutions to the ethical issues associated with BCI due to their theoretical foundations and focal points. Consequentialism focuses on the outcomes of actions, emphasizing the maximization of benefits through the quantitative assessment of the benefits and risks brought by BCI technology, thus balancing the benefits with potential risks. Deontology emphasizes adherence to moral rules, regardless of the consequences, and stresses the morality of actions themselves, requiring BCI research and applications to strictly follow ethics and protect the basic rights of participants. Virtue ethics focuses on the character and intentions of BCI decision-makers, encouraging traits such as honesty, compassion, and responsibility among BCI developers.

Analysis of the advantages and limitations of BCI ethical frameworks

The utilitarian framework prioritizes the assessment of action outcomes, boasting the ability to quantify and juxtapose the results of various options. This promotes decision-making that aims for the greatest overall good, particularly beneficial in the BCI context for gauging the societal advantages of technologies, such as patient life quality enhancement and public health promotion (Keskinbora 2019). However, its significant limitation is its tendency to marginalize or diminish the importance of individual rights and dignity, a critical concern when personal benefits are at odds with collective gains. Furthermore, utilitarianism may face challenges in offering unequivocal direction in moral quandaries, notably in scenarios where individual privacy and public safety are in contention.

The deontological framework emphasizes strict adherence to inherent moral rules and obligations, offering the distinct advantage of protecting individual rights and dignity, irrespective of the outcomes. In the context of BCI applications, it fosters procedural justice, notably through endorsing the informed consent process, thus upholding the ethical legitimacy of both research and applications (Kreitmair 2019). Nevertheless, deontology can be overly rigid, exhibiting a lack of adaptability, especially in the context of swift technological advancements. It also encounters difficulties in reconciling conflicts among various duties or in offering explicit guidance for actions in specific scenarios.

Virtue ethics concentrates on an individual’s character and the decision-making process, highlighting virtues, intentions, and the broader social backdrop. Within the BCI domain, this approach motivates researchers and developers to nurture commendable virtues such as honesty, responsibility, and compassion, thereby encouraging a comprehensive reflection on the ramifications of technology (Sullivan and Illes 2018). However, virtue ethics encounters significant challenges due to its inherent subjectivity and reliance on cultural context. Diverse cultures and individuals may perceive “good virtues” differently, leading to challenges in standardizing these virtues and applying them concretely and quantitatively in practical scenarios.

How BCI ethical frameworks apply to resolving ethical dilemmas in specific medical scenarios

Brain-controlled robotic arms are extensively employed to aid amputees or patients with motor function impairments, enhancing their mobility and life quality (Jeong et al. 2020). By applying the utilitarian framework, one assesses the broad impact on patient quality of life, yet attention must also be given to any potential neglect of individual rights. The deontological framework mandates that patients are fully informed, underscoring the importance of informed consent and privacy protection to maintain procedural ethics. Virtue ethics prompts technology developers to prioritize personal character, ensuring that their development and application processes reflect a deep consideration for the patients’ needs and perspectives.

BCI-based neural stimulation devices are utilized to treat neurological disorders, such as chronic pain and Parkinson’s disease, by targeting and stimulating specific brain regions to improve symptoms (Zhuang et al. 2020). From the utilitarian perspective, the technology’s efficacy in symptom relief for specific conditions is assessed, alongside its broader societal benefits from widespread application. The deontological framework emphasizes the patients’ rights to comprehensive information and autonomous decision-making, ensuring they are fully apprised before undergoing treatment. Virtue ethics encourages medical professionals to uphold exemplary ethical standards, focusing on understanding and compassion towards patients’ experiences, and promoting honesty and transparency in the therapeutic process.

Ethical considerations for the medical applications of BCIs within the framework for the goals of medicine

Zhang et al. have discussed how BCI ethical standards can be framed within the BCI human factors engineering context, as illustrated in Fig. 2 (Zhang Zhe et al. 2023). The human factors engineering approach in BCI mandates a human-centered design and assessment of BCI systems (Lü Xiaotong et al. 2021), serving as a foundational element for ethical scrutiny in BCI, as depicted in Fig. 2 (a). By aligning BCI system designs with human traits, abilities, and necessities across varied usage scenarios, human factors engineering enhances system user satisfaction and augments the overall user experience (Lyu et al. 2023). Consequently, this paper advocates for ethical deliberations within the BCI human factors engineering framework, focusing on user-centric and socially responsible BCI ethical standards, as detailed in Fig. 2 (b).

Fig. 2.

Ethical considerations for BCI within the framework for human factor engineering of BCI. (a) Schematic diagram of the relationship among human factor engineering of BCI, ethical considerations for BCI, BCI systems, and human. (b) Key aspects of the ethical considerations for BCI within human factor engineering of BCI

Figure 3 illustrates the relationships among specific groups or individuals, the goals of medicine, the ethical considerations in BCI medicine, and medical applications, including those of BCI. These goals of medicine provide a foundational framework for BCI ethics, necessitating that BCI research and development align with these objectives. Any BCI-related activities or behaviors that diverge from these medical goals might be ethically questionable or arguably should not be recognized as part of medical practice (Klein 2020). While BCI technology is not a cure-all and may not fulfill every aim of contemporary medicine, it is expected to significantly contribute toward achieving specific goals within the field.

Fig. 3.

Schematic diagram depicting the relationship among goals of medicine, ethics for BCI medicine, medical applications, and specific groups/individuals

Potential medical applications of BCIs

A key objective of BCI research is to offer alternative methods for individuals with severe motor impairments or disabilities to interact with and control external devices, aiming to enhance their life quality. As BCI technology advances and undergoes clinical translation in the field of medicine, the patient demographic that could benefit from its potential medical applications continues to broaden.

Potential applications of BCIs in patients with stroke

BCIs hold promising potential for stroke patient treatment and rehabilitation. The neurobiological mechanisms associated with stroke-related injury and recovery offer a solid scientific foundation for employing BCI-based interventions. Through bidirectional closed-loop BCIs, which facilitate interaction between the brain and peripheral devices, stroke patients can undergo rehabilitation training. This process enhances brain plasticity, which is pivotal in improving both motor and cognitive deficits (Klein 2020), as depicted in Fig. 4.

Fig. 4.

Patients with stroke can receive rehabilitation training with bidirectional closed-loop BCI to promote their brains plasticity and improve their functional impairment

Potential applications of BCIs for patients with amyotrophic lateral sclerosis (ALS)

Many ALS patients develop speech impairments as the disease progresses, eventually losing all forms of intelligible speech in its late stages (Mefferd et al. 2014). In terminal conditions, ensuring effective communication becomes vital to uphold the autonomy and dignity of patients (Long et al. 2019). BCIs hold promise for facilitating improved communication for ALS patients (Vansteensel et al. 2023).

In comparison with conventional muscle-based AAC methods, BCI-enabled AAC systems are potentially more accessible for ALS patients, offering significant enhancements in communication efficiency (16–17). They may also contribute to notable improvements in mobility (Sorbello et al. 2017).

Potential applications of BCIs in patients with traumatic brain injury (TBI)

Neurofeedback, a form of BCI, leverages EEG-based training that could beneficially impact cognitive impairments and mood disorders in TBI patients (Munivenkatappa et al. 2014). Beyond their use for communication or control, BCIs encompass methods like deep brain stimulation (DBS) and non-invasive brain stimulation (NIBS) (Klein 2020). NIBS interventions are known to trigger bidirectional plasticity changes. When integrated with neuroimaging, these BCI systems, both open and closed-loop, can be tailored to modify neural connection patterns, potentially enhancing cerebral functionality post-TBI (20–21).

Potential applications of BCIs in patients with spinal cord injury (SCI)

SCI results in damage to spinal nerve fiber tracts, leading to consequential motor, sensory, and autonomic dysfunctions below the injury level (Klein 2020). Rehabilitation or functional support for these impairments is vital for enhancing the life quality of SCI patients. Due to the limitations inherent in conventional user interfaces, BCIs are particularly aimed at providing compensatory solutions for motor impairments in patients with complete motor SCI, particularly those with high-level injuries and quadriplegia (Bouton et al. 2016).

Potential applications of BCIs for patients with locked-in syndrome (LIS)

Patients with LIS maintain autonomous consciousness and cognitive function, yet they lack the ability to move or speak (Klein 2020). For some of these patients, the residual muscle activity is insufficient to operate traditional AAC devices. BCIs can circumvent this challenge by leveraging central neural signals, bypassing impaired peripheral nerve and muscle functions to enable communication or improve mobility.

Numerous studies have employed non-invasive brain signal acquisition techniques to develop BCIs aimed at enhancing the communicative abilities and mobility of LIS patients. While EEG-based BCI studies specific to this demographic are scarce, the existing research indicates that such interventions can significantly facilitate their communication (Lesenfants et al. 2014).

Potential applications of BCIs in patients with disorders of consciousness (DOC)

DOC often stems from brain injuries (Klein 2020), with typical clinical presentations including coma, unresponsive wakefulness syndrome (UWS), and the minimally conscious state (MCS) (Laureys et al. 2004). Traditional treatment methods predominantly involve clinical assessments to identify the consciousness disorder before administering appropriate care, yet these assessments carry a notable risk of misdiagnosis (Stender et al. 2014).

BCIs offer a novel approach to assess consciousness in DOC patients, identifying the specific nature of their impairments to inform tailored therapeutic strategies. Furthermore, BCIs facilitate activities such as obeying commands and engaging in communication with the external environment (Klein 2020). Additionally, BCIs hold the promise of decoding phonemes from the sensorimotor and ventral motor cortex (Ramsey et al. 2018), potentially enabling voice production for non-communicative DOC patients.

Potential applications of BCIs in patients with emotional disorders and autism spectrum disorders etc

BCI-based neurofeedback (NF) leverages operant learning mechanisms (Sherlin et al. 2011) for real-time modulation of the brain’s neural activity, aiming to bolster attention control and reward responsiveness. This process is anticipated to enhance brain plasticity, potentially leading to noninvasive improvements in cognitive and physical performance (Chaudhary et al. 2016).

For example, incorporating NF into video games could potentially mitigate symptoms associated with depression and anxiety (Schoneveld et al. 2016), as well as promote social interaction, imitation skills, and emotional responsiveness in children with autism spectrum disorder (ASD) (Friedrich et al. 2015).

Potential applications of BCIs for patients with Parkinson’s disease (PD)

PD is a common neurodegenerative disorder prevalent among the middle-aged and elderly population, characterized by resting tremor, bradykinesia, rigidity, and postural instability. These symptoms lead to a significant decline in quality of life, loss of independence, and various comorbidities. Deep brain stimulation (DBS), a form of BCI, emerges as an effective intervention for managing PD symptoms, especially when they are inadequately controlled by pharmacological treatments (Klein 2020).

Ethical risk analysis and ethical issues in BCI medical applications

Ethical risk analysis in BCI medical applications

In the realm of medical research and applications, ethical risks are typically categorized based on the potential level of harm they pose to participants (Skierka and Michels 2018). While classification criteria may vary across different organizations and nations, a commonly accepted method of grading includes:

(1) Low risk: The research or application is expected to cause minimal inconvenience or risk to the participants, substantially less than what they might encounter in everyday life.

(2) Moderate risk: The research or application could result in a certain level of inconvenience or risk, which is comparable to or slightly exceeds what is typically experienced in daily life.

(3) High risk: The research or application could lead to significant inconvenience or risk for the participants, surpassing the risks associated with normal daily activities.

For the ethical risk levels of BCI medical applications, a tailored classification should be considered, incorporating BCI-specific concerns such as neural privacy, physical and psychological safety, and the preservation of autonomy (Burwell et al. 2017). Examples include:

(1) Low risk: Simple non-invasive BCI applications, such as utilizing EEG for elementary game control or entertainment, generally present minimal risk to individuals.

(2) Moderate risk: Applications in this category might engage deeper personal data processing or require extended periods of use, posing moderate risks to individual privacy or mental health.

(3) High risk: Applications involving invasive methodologies, like implantable brain electrodes, or those intended for clinical interventions, could significantly impact a user’s physical or psychological well-being.

Ethical issues in BCI medical applications for patients

Utilizing BCI technology enables paralyzed patients to communicate and control wheelchairs (Chaudhary et al. 2017). The BCI system interprets the patients’ brain waves to discern their intentions, subsequently translating these into control commands for electronic devices, such as cursor movements on a computer or wheelchair navigation. Although this innovation affords paralyzed individuals the opportunity to regain communicative abilities and a measure of autonomy, it concurrently introduces various ethical considerations:

(1) Autonomy and Consent: It is crucial to ensure that patients fully comprehend the workings of the BCI system, along with its potential risks and benefits, particularly in instances where a patient’s cognitive functions might be compromised. This necessity prompts a deeper examination of strategies for securing truly informed consent.

(2) Attribution of Responsibility: Determining responsibility in scenarios where BCI-assisted operations fail, especially when such failures could lead to harm, is imperative. The delineation of accountability in these contexts must be unambiguous.

(3) Equitable Access: The considerable costs associated with the development and upkeep of sophisticated BCI systems might limit access for specific demographics. Strategies must be devised to facilitate equitable distribution, ensuring that all patients who require the technology have access to it.

(4) Psychological Impact: Dependency on BCI technology for fundamental communication could significantly influence patients’ psychological state and social interactions, impacting their self-identity and interpersonal relationships.

Goals of BCI medicine and BCI

Beyond the conventional medical goal of diagnosis and treatment, new objectives in medicine advocate a human-centric, patient-focused approach emphasizing prevention, health enhancement, caring for the well-being of patients, providing pain relief, and offering support to incurable patients up to end-of-life care. These objectives highlight the importance of life quality at various human life stages (Allert et al. 1996).

The ethical framework for BCI medicine requires alignment with these medical objectives, asserting that BCI research and development should not contravene established medical goals. Activities or behaviors within BCI that do not accord with these goals may be considered ethically dubious or unsuitable for classification as medical practices (Klein 2020). Although BCIs may not universally address all modern medicine’s goals, they are anticipated to significantly contribute toward achieving particular medical objectives. The redefined goals of medicine emphasize person-oriented care, prevention, health promotion, and quality of life throughout all life stages.

The prevention of disease and injury and the promotion and maintenance of health

Preventing disease and enhancing health stand as foundational objectives in medicine, where BCI technologies hold promising capabilities. For instance, BCI-driven self-health monitoring and wearable neurotechnology offer significant prospects for proactive medical prevention (Klein 2020). Online BCI systems can analyze EEG signals to anticipate epileptic seizures, facilitating preemptive actions to mitigate or prevent episodes (Klein 2020). Furthermore, utilizing BCI-enabled DBS aims to forestall the initiation of depressive episodes in psychiatric conditions (Widge et al. 2014), underscoring prevention as a pivotal aspect of therapeutic strategies.

The relief of pain and suffering caused by maladies

Pain and suffering from diseases manifest through physical alterations and psychological distress. A key objective in medicine, which extends to BCI applications, is the alleviation of such anxiety. Decisions concerning BCI utilization necessitate a personalized approach to weighing the risks and benefits, irrespective of a patient’s eligibility for BCI use (Kübler et al. 2015).

BCIs are primarily aimed at overcoming disabilities. While they might not cure the underlying disease or repair physical damage directly, they can empower patients and disabled individuals to regain various functions, thereby reducing the pain or impairment associated with their conditions. For example, BCIs are explored for modulating pain related to physical injuries (e.g., SCI and TBI) and for addressing mental suffering in conditions like depression and anxiety.

The care and cure of those with a malady and the care of those who cannot be cured

Contemporary medicine’s healing functions integrate both therapeutic treatment and nurturing care. There is an anticipation that BCIs will not only facilitate therapeutic interventions for certain conditions but also extend substantial support in patient care (Allert et al. 1996).

Diagnosing diseases or injuries remains a pivotal goal in both traditional and modern medical practices (Allert et al. 1996), with accurate diagnosis serving as the cornerstone for targeted treatment and effective rehabilitation. BCIs, evolving from tools for environmental interaction to dynamic monitors of cerebral activity, offer innovative approaches for self-health monitoring, thereby presenting novel methodologies for disease or injury diagnosis (Klein 2020).

The avoidance of death and the pursuit of a peaceful death

One compelling aspect of BCIs used for communication is their capacity to significantly enhance patient autonomy. For example, BCIs enable individuals, such as those with ALS, to articulate their treatment preferences as their condition progresses. In circumstances where all alternative interventions are exhausted, the thoughtful discontinuation or adjustment of BCI systems is envisioned to facilitate a dignified and serene departure for patients (Klein 2020).

Goals and ethical considerations for BCI medicine

Beyond achieving the previously mentioned medical goals, there are distinct objectives concerning the use of BCIs in medical contexts. Klein (Klein 2020) emphasized the need to frame the practice of BCI medicine and its ethical challenges within established medical goals, proposing four specific objectives to guide ethical deliberation in BCI medicine’s evolving field. These objectives include adapting to individuals’ neural diversity, safeguarding neural privacy, aiding patients in making genuine life decisions, and supporting patients in exercising and sharing decision-making (Zhang Zhe et al. 2023; Ma Yixin et al. 2022). Additionally, Zhang et al. emphasized the importance of ensuring patient benefits from implantable BCIs, an essential consideration for the ethical deployment of BCI technology (Zhang et al. 2024).

Invasive BCIs, recognized for their enhanced spatial resolution and signal-to-noise ratio due to proximity or direct integration with the cerebral cortex, show significant promise for medical applications. These systems may offer improved efficacy for certain conditions. Nevertheless, these BCIs involve risks of brain tissue damage as they often necessitate surgical implantation of electrodes within the cranium to capture neural signals. Techniques include recording local field potentials through epidural or subdural ECoG, monitoring individual neuron activity with intracortical electrodes (spike firing) (Vansteensel et al. 2023), measuring neural activity in deep brain structures via stereo EEG (Herff et al. 2020), and acquiring brain signals near cortical areas using minimally invasive intravascular electrodes (Oxley et al. 2016). Therefore, the careful assessment of potential medical benefits against the safety risks to brain tissue is imperative, ensuring that the advantages significantly outweigh the hazards and that risks are minimized or altogether avoided. Table 1 outlines the essential ethical considerations for the application of invasive BCIs.

Table 1.

Ethical considerations for the medical applications of invasive brain-computer interfaces (BCIs)

Ethical considerations
(1) Ensuring informed consent rights for patients participating in invasive BCIs research or use
(2) Minimizing the risk of brain tissue damage caused by implantable electrodes
(3) Providing customized personalized/precise invasive BCIs treatment for patients
(4) Reducing the risk that invasive BCIs affecting patient’s sense of identity
(5) Assisting patients who use invasive BCIs in exercising and sharing agency rights
(6) Protecting the neuro-privacy of patients who use invasive BCIs
(7) Ensuring interdisciplinary collaboration in the clinical applications of invasive BCIs
(8) Adhering to the principle of benefits outweighing harms and using invasive BCIs responsibly
(9) Ensuring that patients can obtain and continue to use invasive BCIs
(10) Objectivity of research report and popularization of science for invasive BCIs
(11) Specific ethical considerations are needed for specific diseases, specific disease stages, or specific patients

Discussion and prospects for ethics related to BCI medicine

Discussion of the ethics for BCI medicine

Should we differentiate ethics between invasive and non-invasive BCIs?

The debate over BCI medical ethics includes differing opinions on whether to distinguish between invasive and non-invasive BCIs. While some believe this differentiation is unnecessary, others view it as essential. Given that non-invasive BCIs do not entail brain tissue harm, they are recognized for their safety, making them more acceptable, practical, and widely applicable for both patients and healthy individuals. Existing ethical standards already advocate for the enhancement and broader application of non-invasive BCIs (Klein 2020). Conversely, invasive BCIs, significant for brain science and prospective applications, face issues like potential tissue damage, infection risks, and electrode compatibility concerns, challenging their long-term brain stability. These critical areas demand further research and breakthroughs, focusing particularly on implant safety and sensor assessment.

Is BCI-based study on “controlling the brain” allowed?

There is contention over the legitimacy of BCI-based research focused on “brain control”, with some endorsing its advancement while others call for its outright ban. Considering our limited grasp of human brain architecture and functions, the notion of “brain control” remains nascent, with existing studies demonstrating BCI applications for guiding animals through mazes or directing turtle movements (41–42)]. Such research predominantly targets the modification of inherent navigational abilities, avoiding total domination over the subjects. Human-centric BCI research, especially concerning direct brain manipulation, faces stringent ethical scrutiny, likely encountering substantial opposition internationally and possibly being deemed criminal. Essential research intentions must center on enhancing the subjects’ quality of life, explicitly forbidding objectives detrimental to participant welfare. Moreover, given the complexity of the human brain compared to that of animals, the issues of sensor and electrode compatibility with human brain tissue have yet to be resolved, posing considerable challenges for precise BCI applications on the human brain.

Is it necessary to establish standardized operating procedures and evaluation methods for efficacy of medical applications of BCI?

BCI medical applications are presently undergoing clinical testing and investigation stages. Their effectiveness for specific conditions should be gauged against established clinical benchmarks for diagnoses and therapeutic interventions. Clinicians bear the crucial duty of engaging with patients to ascertain both the beneficial and adverse effects of BCIs (Zhang Zhe et al. 2023). The selection of BCIs for patient rehabilitation should adhere to the principle of maximizing benefits while minimizing harms (Attiah and Farah 2014).

Yet, the field lacks comprehensive standardized protocols and methods for evaluating the effectiveness of BCI applications, especially for designated ailments. To facilitate BCI’s clinical translation and patient benefit, a concerted approach is needed, enlisting the collaboration of physicians, patients, BCI technologists, bioethicists, legal professionals, and other pertinent stakeholders (Goering and Yuste 2016).

Can humans cope with ethics issues for BCI medicine?

BCI, like any other technology, has its inherent performance limitations and defined scopes of application (Zhang Zhe et al. 2023). Haselage emphasized that the anticipated efficacy and value of BCI significantly influence ethical considerations and the way BCI scientists interact with the media (Haselager et al. 2009). Currently, there is a tendency to overestimate BCI’s potential and to overly focus on its ethical implications, suggesting a need for more realistic and measured expectations.

Additionally, both BCI researchers and clinicians have started preparing to confront potential ethical dilemmas. Clausen highlighted that while BCIs introduce unique ethical challenges, these are conceptually akin to those faced in various therapeutic contexts, suggesting that bioethicists are adequately equipped to address these issues (Clausen 2009).

Prospects of ethics for BCI

Ethics for BCI medicine will be continuously improved

As BCI technology advances, achieving innovation or significant breakthroughs, new medical objectives specific to BCI applications are likely to develop. Consequently, there is a continual need to refine and enhance BCI medical ethics to align with these evolving objectives and ensure that they serve broader medical goals effectively.

The study for “controlling brain " based on BCI will be rigorously examined

BCI technology remains in its nascent stages, and some individuals erroneously claim to be victims of “brain control,” a belief incongruent with the current technological capabilities. The concept of “controlling the brain” is more susceptible to misconceptions, misuse, and psychological apprehensions compared to “brain control” scenarios. To mitigate concerns regarding the negative psychological impact of perceived “brain control” among BCI users, the terminology “neuromodulation” should be preferred, and the phrase “controlling the brain” should be avoided. Concurrently, the competencies, development stages, and potentials of BCI technology should be objectively assessed to guide the public accurately. Future BCI-based “brain control” research is expected to undergo more rigorous standardization processes.

Rational understanding of the ethical issues for BCI

The ethical implications of BCI elicit a range of viewpoints among scholars and BCI practitioners, largely influenced by the individual’s comprehension of BCI technology, its inherent limitations, and its specific challenges. This variability often stems from an understanding of the technology’s constraints, particularly the limitations of current brain imaging and analytical methodologies. As the field matures, it is anticipated that discussions on BCI ethics will evolve toward a more reasoned and informed perspective, fostering a deeper, more nuanced discourse on the ethical and societal impacts of BCIs.

Future research directions in ethical issues and standards for BCI medical applications

Current insights into the long-term usage of BCI technology are scant, emphasizing the need for future investigations to scrutinize its extended impacts on users’ psychological health, cognitive functions, and societal interactions. Moreover, the understanding of core ethical values such as privacy, autonomy, and fairness varies across diverse cultural and societal landscapes, urging subsequent research to examine how these variances shape BCI’s ethical frameworks (Kosal and Putney 2023). With the advancement of BCI technology introducing novel application realms, it becomes imperative to establish tailored ethical guidelines for these burgeoning contexts. Concurrently, addressing BCI-induced ethical dilemmas warrants the establishment of cross-disciplinary alliances among ethicists, technologists, medical practitioners, and policymakers, fostering collective engagements and solution crafting to navigate these complexities effectively (Bergeron et al. 2023).

To further promote interdisciplinary collaboration, it is recommended to establish a permanent ethics review committee that includes ethicists, BCI developers, clinicians, and legal experts. The primary task of the committee is to oversee all phases of BCI projects, from research design to technology implementation, ensuring that all activities comply with ethics and legal requirements. Additionally, regular interdisciplinary workshops should be held to facilitate communication among experts from different fields, share the latest research findings and ethical considerations, and discuss the current challenges and potential solutions. With the evolution of BCI, new ethical challenges are likely to emerge. Different cultures have varying perspectives on privacy, autonomy, and fairness, which could lead to ethical conflicts when applying BCI globally. Researching how to develop consensus on ethics for BCI in a multicultural context is an important direction for future studies. Additionally, long-term use of BCI may affect users' psychological, cognitive, and social interactions, but the specific mechanisms and extent are not yet clear.

Conclusion

BCI technologies hold significant potential for therapeutic benefits but may also pose unexpected physical and psychological risks to users. Compared to existing research, the innovation and main contribution of the paper is the proposal of a comprehensive ethical framework for BCI medical applications, intended to standardize clinical research in BCI. It not only covers medical applications but also addresses non-medical uses, placing user welfare at the core. To ensure the development of BCI follows ethics and promotes responsible use in the medical field, it is recommended to strengthen interdisciplinary collaboration to address the complex ethical and legal issues that BCI may present; it is also advisable to regularly update BCI ethics to ensure they reflect the latest developments in BCI. The insights provided in this article aim to inform and guide the development of ethical standards in BCI medicine.

Author contributions

Zhe Zhang: search and analyze literature materials, paper writing; Yanxiao Chen: Chart design, integrating paper structure; Xu Zhao: Guidance on the writing of papers; Peng Ding and Fan Wang: review and revision of the paper; Lei Zhao and Tianwen Li: supervision and guidance; Yunfa Fu: Funding Support and Paper Revision. All authors have made significant contributions to the submission and have agreed to the final version of the manuscript.

Funding

The study was supported by the National Natural Science Foundation of China (82172058, 62376112, 62366026, 81771926, 61763022).

Declarations

Ethics statement

This paper does not address studies with human participants.

Conflict of interest

All authors of the article declare that there is no conflict of interest.