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Intervening in the brain: with what benefit?

By Hannah Maslen, DPhil and Julian Savulescu, PhD

Hannah Maslen is based at the Oxford Martin School, University of Oxford

Julian Savulescu is Uehiro Professor of Practical Ethics at the University of Oxford, Fellow of St Cross College, Oxford and the Director of the Oxford Uehiro Centre for Practical Ethics. He is also a member of the AJOB Neuroscience editorial board.

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

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 .

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.


Nuffield Council on Bioethics, ‘Novel neurotechnologies: intervening in the brain’, published 24th June 2013.

Savulescu, J., Sandburg, A. and Kahane, G. (2011), ‘Well-being and Enhancement, in J. Savulescu, R. ter Meulen, and G. Kahane (eds.), Enhancing Human Capacities, Wiley-Blackwell.

Kahane, G. and Savulescu, J. 2009. “The welfarist account of disability”. In Disability and disadvantage, Edited by: Brownlee, K. and Cureton, A. 14-53. Oxford: Oxford University Press.

Mill, J.S., On Liberty

Maslen, H., Douglas, T., Cohen Kadosh, R., Levy, N. and Savulescu, J. (forthcoming), ‘Do-it-yourself brain stimulation: a regulatory model’, Journal of Medical Ethics.

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