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Best of The Neuroethics Blog: Intervening in the Brain: With What Benefit?

Throughout the year, The Neuroethics Blog will be highlighting the most impactful, exciting, and popular posts from our nearly ten-year history.

Today’s post is an update by Dr. Hannah Maslen and Dr. Julian Savulescu on their piece entitled Intervening in the Brain: With What Benefit?, which was originally published on August 6, 2013 and is republished below.

Image courtesy of Jisc

Since the publication of this blog post, the regulatory landscape for consumer brain stimulation devices has changed considerably, and the question of how to assess the benefits of non-medical uses for devices has been confronted head on by regulators. The authors have particular insight into how this has played out in the European regulatory context. Having argued for a particular model of regulation for direct-to-consumer brain stimulation devices,1 the authors participated in discussions with the UK Medicines and Healthcare Products Regulatory Agency (MHRA) and the European Commission’s New and Emerging Technologies Working Group, part of whose remit is to provide information and advice to European regulatory authorities on new and borderline medical devices.

In May 2020, the new Medical Devices Regulation will come into force in Europe. It includes a list of devices in an annex that, although not being sold for a medical purpose, are to be regulated under the medical devices regulation. The annex includes: 

Equipment intended for brain stimulation that applies electrical currents or magnetic or electromagnetic fields that penetrate the cranium to modify neuronal activity in the brain.

The issue of how to define and weigh the benefits of a device that, for example, claims to increase gaming focus or to improve mood, had to be addressed. For these annex devices, the approach taken will be to place a cap on the risk that devices can present and impose specific requirements relating to risk reduction. For example, even where a device has a risk classification that permits placement on the market, the manufacturer may also have to minimize risks such as unintentional over-use by way of building in auto-shut-off mechanisms.

Image courtesy of US Air Force website

Instead of “benefit,” the regulation uses the language of “performance,” which avoids the evaluative implication that using the device will be good for the consumer. The manufacturer will have to demonstrate that the device performs as claimed, including providing laboratory evidence for any claimed effects on cognition, mood etc. This two-pronged approach, involving minimization (but not preclusion) of risk and the requirement of demonstration of performance,  puts the consumer in the best possible position: she can be confident that the device normally does what it claims it will do and that she would not be incurring higher risk than necessary in order to obtain the effects. If she decides that the effects would be beneficial to her and that the risks are worth taking, then she can choose to use a device. Crucially, regulators have not made this assessment on her behalf.

  1. Maslen, H., Douglas, T., Cohen Kadosh, R., Levy, N., & Savulescu, J. (2014). The regulation of cognitive enhancement devices: extending the medical model. Journal of Law and the Biosciences, 1(1), 68-93. (See also

Intervening in the Brain: With What Benefit?

Novel neurotechnologies 

Last week, Nuffield Council on Bioethics released its report entitled Novel neurotechnologies: intervening in the brain. The aim of the report is to provide a reflective assessment of the ethical and social issues raised by the development and use of new brain intervention technologies. The technologies that the report examines include transcranial brain stimulation, deep brain stimulation, brain-computer interfaces and neural stem cell therapies. Having constructed and defended an ethical framework to navigate the ethical and social concerns raised by novel neurotechnologies, the report proceeds to discuss 1) the care of the patients and participants undergoing interventions, 2) what makes research and innovation in neurotechnologies responsible research and innovation, and 3) how novel neurotechnologies should be regulated.

The remainder of the report moves on to explore non-therapeutic applications of novel neurotechnologies (such as enhancement and gaming) and how research into these technologies should be communicated in the media. Amongst the Council’s conclusions is the view that whilst the ethical issues raised by novel neurotechnologies are not necessarily unique or exceptional, the significance of the brain in human existence (to sense of self and to personal relationships) generates powerful reasons both to intervene when function is damaged and to proceed with caution before intervening without good evidence of safety and benefit (para10.3).

Assessing the benefits of a technology 
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Flickr user delta_avi_delta

Requiring evidence of the benefits of a potentially risky technology is common to assessments of a technology’s overall permissibility, particularly within the clinical domain. We wish to focus here on the Council’s conception of benefit as outlined in its ethical framework, suggesting that whilst its approach is appropriate for assessing the permissibility of clinical applications, it should not transfer to discussions of neurotechnologies used for enhancement.

Paragraph 4.20 of the report explains:
“The ethical challenges presented by uncertainty do not pertain to knowledge of risks alone; it is equally important that the benefits of intervening are well understood. … Even if, as in the case of non-invasive neurostimulation, risks are considered low, given the special status of the brain even less serious risks must be counterbalanced by clear indications of effectiveness in comparison with other therapeutic options if their use is to be supportable. (Second emphasis added)”

Whether the Council’s intention or not, this paragraph portrays the benefits of a technology as being closely linked – or perhaps even identical – to its effectiveness. This makes sense in the clinical domain where interventions are intended to have particular remedial or protective effects, easily measured as improvements to, or maintenance of, function or physiology. What constitutes an improvement or decline in health is mostly not controversial and can be measured objectively. For example, how far a person can walk after hip surgery is objectively measurable? Further, in the clinical domain, whilst the informed consent of patients is routinely obtained before proceeding with any intervention, a patient’s decline in health puts her in a vulnerable position where it is likely she will be inclined to accept the treatments on offer. This inclination may be bolstered by the perception that the intervention on offer is ‘endorsed’ by the medical profession, with its authority. This being the case, good evidence of effectiveness (benefit) must be gathered before offering interventions posing any risks.

The benefits of enhancement 

Some of the technologies under discussion by the Council are also being marketed for the purpose of enhancement. Brain stimulation devices and other neurotechnologies are, among other things, being used in pursuit of improvements to memory and concentration. The Council is of the view that the effectiveness of interventions used for enhancement is yet to be established (para 8.44), and further suggests that it is not even clear how the benefits of technologies used for enhancement should be assessed, nor what constitutes proportionate risk where an intervention is non-essential (para 8.30). Whilst equating benefit with effectiveness is a sound strategy for an ethical framework assessing the use of neurotechnologies in the clinical context, we suggest that, when technologies are marketed to competent individuals not considered unwell, 1) ‘benefit’ should be understood differently and 2) the requirement of strong evidence of benefit should (partly as a consequence) be relaxed.

Although the risks and side effects of neurotechnologies used for enhancement could be assessed in a similar way to the risks and side effects associated with their clinical application, it is less clear how the benefits of these interventions should be measured. It could be argued that, unlike clinical interventions – which succeed or fail in improving or maintaining health to a measurable degree – technologies used for enhancement confer benefits that are more subjective and context specific. Parallels might be drawn with cosmetic enhancements: a nose might be made smaller or straighter in a way that we can measure, but how beneficial this is will vary from person to person and culture to culture. Granted, it is possible to measure the size of any improvement to cognitive performance: an improvement to the memory of an individual using a brain-stimulating device will be something that could be determined through laboratory tests. However, whilst we can measure the size of improvements to cognitive function, it could be argued that the value of enhancement is something that varies between people to a greater extent than the value usually attached to health. This value will depend on the circumstances specific to each individual. Improvement of memory for a vigorous professor will have a different value to improvement of memory for a retired gardener, though both will have some objective value.

Consequently, we suggest that ‘benefit’ should be understood as an estimation of the technology’s propensity to increase wellbeing, where an increase in a person’s wellbeing is related to the chances of her leading a good life in the relevant set of circumstances. Crucially, what constitutes a good life will vary depending on the person’s goals and values, their nature and their circumstances. In fact, this ‘welfarist’ definition of enhancement also subsumes those effects commonly thought to be treatments: if a neurointervention is used to alleviate symptoms of Parkinson’s Disease, for example, it is likely to have increased the patient’s chances of leading a good life .

Image courtesy of Needpix
But, it could be asked, if this concept of increase-to-wellbeing is supposed to encompass both effects seen as treatments and effects seen as enhancements then why do we agree with the Council that benefit should be understood as effectiveness when assessing technologies used in the clinical context? We emphasize our earlier points: the first reason is that the ‘therapeutic’ effects of the clinical applications are likely to be valued by most people – to be necessary for leading a good life on most conceptions. Most people want to be able to walk around after hip surgery, and get back to the ‘activities of daily living’. This value accorded to health is likely to be more universal than the value accorded to enhancement. The second reason appeals to our argument that decisions about undergoing an intervention made in the clinical context are importantly different from the decisions made in the non-clinical context due to the particular vulnerabilities present when one’s health is in jeopardy. Understanding size of benefit as degree of effectiveness in the clinical context serves as a justifiable safeguard.

However, absent these particular vulnerabilities, the concept of benefit should be understood as the broader notion of increase-to-wellbeing. Both these factors speak in favour of giving individuals more choice about how to assess the risks and benefits of any particular device in the context of their own values, nature and life circumstances. As medical need falls, consumer freedom-to-choose should rise, other things being equal. People are generally the best judge of what is best for themselves, a point made a long time ago by John Stuart Mill.

Implications of the well-being framework for enhancement regulation

As noted, the Council suggests that it is neither clear how the benefits of technologies used for enhancement are to be assessed nor what constitutes proportionate risk where an intervention is not essential for maintaining an individual’s health. However, given their recommendation that neurotechnologies used for enhancement should be regulated in the same way as medical devices (para 8.52; we have argued for a similar model elsewhere ), these issues are important ones to resolve: the legislation controlling the placing of medical devices on the market requires a comprehensive risk-benefit assessment. For clinical neurointerventions, we have argued that there is a good case for imposing strict restrictions based on risk and efficacy in order to protect vulnerable patients. By contrast, when technologies are intended for enhancement we have suggested that, whilst it will be very important that potential consumers are well informed about an intervention’s mechanism, risks and effectiveness, the assessment of benefits and the weight they should be accorded should be made by the consumer. This points to a regulatory model whereby the most dangerous enhancement technologies will be filtered out of the market, leaving individuals free to choose which small-to-moderate risks they are willing to take in pursuit of their wellbeing.


Hannah Maslen is the Deputy Director of the Oxford Uehiro Centre for Practical Ethics. Hannah is a Research Fellow at New College and at the Oxford Martin School. She works on a wide range of topics in applied philosophy and ethics, from neuroethics, to moral emotions and criminal justice. She is a Principal Investigator on the European Commission Horizon 2020 BrainCom project, which aims to advance understanding of speech networks in the cerebral cortex, and to develop rehabilitation solutions using innovative brain-computer interfaces. Hannah is the Editor-in-Chief for the journal Neuroethics. You can find more information about Hannah’s research on her website.

Professor Julian Savulescu has held the Uehiro Chair in Practical Ethics at the University of Oxford since 2002. He has degrees in medicine, neuroscience and bioethics. He directs the Oxford Uehiro Centre for Practical Ethics within the Faculty of Philosophy, and leads a Wellcome Trust Senior Investigator award on Responsibility and Health Care. He directs the Oxford Martin Programme for Collective Responsibility for Infectious Disease at the Oxford Martin School at the University of Oxford. He co-directs the interdisciplinary Wellcome Centre for Ethics and Humanities. He spent 10 years as Editor of the Journal of Medical Ethics, the highest impact journal in the field, and is founding editor of Journal of Practical Ethics, an open access journal in Practical Ethics. His 2019 book with Dominic Wilkinson, Ethics, Conflict, and Medical Treatment for Children was awarded the 2019 British Medical Association’s President’s Choice Award.


  1. Nuffield Council on Bioethics. (2013). Novel neurotechnologies: intervening in the brain.
  2. Savulescu, J., Sandburg, A., & Kahane, G. (2011). Well-being and Enhancement. In J. Savulescu, R. ter Meulen, & G. Kahane (Eds.), Enhancing Human Capacities. Wiley-Blackwell.
  3. Kahane, G., & Savulescu, J. (2009). The welfarist account of disability. In K. Brownlee, & A. Cureton (Eds.), Disability and disadvantage (pp. 14-53). Oxford: Oxford University Press.
  4. Mill, J. S. (1859). On Liberty.
  5. Maslen, H., Douglas, T., Cohen Kadosh, R., Levy, N., & Savulescu, J. (2015). Do-it-yourself brain stimulation: a regulatory model. Journal of Medical Ethics, 41, 413-414.

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Maslen, H & Savulescu, J. (2019). Best of The Neuroethics Blog: Intervening in the Brain: With What Benefit? The Neuroethics Blog. Retrieved on , from


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