The Nuffield Council on Bioethics today launched a consultation on the ethics of new types of technologies and devices that ‘intervene’ in the brain, such as brain-computer interfaces, deep brain stimulation, and neural stem cell therapy.

These technologies are often being developed for use in the treatment of conditions including Parkinson’s disease, depression and stroke and it is thought they could bring significant medical benefits, especially for those who are severely affected by neurological disease or have a severe brain injury.

Outside of the health context, they could also be used in various military applications, for example to develop weapons or vehicles that are controlled remotely by brain signals. And there are commercial possibilities in the gaming industry, for example, the development of computer games that are controlled by people’s thoughts.

“Intervening in the brain has always raised both hopes and fears in equal measure” said Thomas Baldwin, Chair of the Council’s study and Professor of Philosophy at the University of York. “Hopes of curing terrible diseases, and fears about the consequences of trying to enhance human capability beyond what is normally possible. These challenge us to think carefully about fundamental questions to do with the brain: what makes us human, what makes us an individual, and how and why do we think and behave in the way we do.”

Clearly, some of these technologies have great potential. “Imagine a person who is disabled and cannot speak being able to move independently through a thought-controlled wheelchair or communicate via a computer voice”, said Professor Baldwin. On the other hand, concerns have been raised about safety of some of the techniques that are currently in development. “The impact on a person and on their mind has to be considered, for example, are there risks of unwanted changes in mood, behaviour or personality being introduced into the brain?”

There is also uncertainty over whether the techniques will be as effective in treating disease or aiding rehabilitation from brain injury as some claim they will be. Professor Baldwin said, “Many of these technologies are in the early stages of research, and patients who have high expectations of recovery or rehabilitation may sometimes be left disappointed and frustrated if the treatment doesn’t live up to expectations”.

The development of these technologies for use in warfare may be more troubling for some. “For example if brain-computer interfaces are used to control military aircraft or weapons from far away, who takes ultimate responsibility for the actions? Could this be blurring the line between man and machine?” said Professor Baldwin.

The Nuffield Council inquiry is focussing on technologies that intervene directly in the brain, often through the use of a device, or involving brain implants. The consultation runs until 23 April and the Council would like to hear the views of a wide range of people, including those who have used or are hoping to use these technologies, those involved in development or supply, researchers, academics, patients, medical professionals, regulators, policy makers and others. Responses to the consultation will be carefully considered, and a report setting out the Council’s findings is expected to be published in 2013.

BCI’s measure and analyse a person’s brain signals and converts it into an output such as movement. For example, a paralysed person could use a BCI to operate a wheelchair, or someone who has extreme difficulty speaking could use a BCI to communicate via a computer voice. These sorts of applications have been shown to be successful in a few reported cases, but the technology has not yet been developed for regular clinical use and there are questions over whether these technologies are reliable enough for use in everyday life.

Military applications, such as remote control of vehicles and machinery are not yet in wide use but are being researched and tested, and some commercial BCI developments are already on the market. Gamers can buy a wireless headset that aims to replace a joystick by controlling game play through brain signals.

The use of BCI’s will sometimes require surgery to implant electrodes into a person’s brain, although the most successful current developments are those that detect brain signals from the scalp, so they are less invasive.


Different regions of the brain are known to be linked to areas of perception, e.g. pain, sound, vision. Neurostimulation involves the application of an electric or magnetic stimulus to nerves to alter brain activity in a specific area.

The two best-known types are transcranial magnetic stimulation (TMS), which is usually applied through a hand-held or chair-bound device and is non-invasive, and deep brain stimulation (DBS) which requires brain surgery to place an electrode in the brain and wires under the skin.

TMS is in clinical use and it is currently used mainly to treat depression, although research is underway on possible applications for conditions including obsessive compulsive disorder, Alzheimer’s disease, and pain disorders such as migraine. It has been shown to have some potential for improving memory and learning and research is underway on non-medical enhancement uses e.g. for education.

DBS is already used in treatment of Parkinson’s disease, obsessive-compulsive disorders and movement disorders such as dystonia (which causes tremors). Research is underway on possible benefits for patients with epilepsy, stroke, Tourette’s syndrome and severe pain. Possible complications of DBS are thought to include: stroke, confusion, speech disorders, visual problems and possible damage to the brain tissue surrounding the implant, infection, seizure, depression and the risks associated with general anaesthetic.

Neural stem cell therapy

Researchers are developing neural stem cells that could be used in treating conditions which involve the loss of nerve cells in the brain, for example Alzheimer’s disease, stroke or Huntingdon’s disease. The stem cells are injected into the brain under general anaesthetic.

In stroke, nerve cells can be lost in a particular brain region, leading to a reduced ability of the function associated with that region, e.g. moving the left hand side of the body. Neural stem cell therapy is thought be able to benefit people with these conditions and there is considerable interest and investment in this area of research, both privately and publicly. Small scale preliminary human trials are underway but the treatment is not yet routinely available in the UK.

Neural stem cell therapies are less well understood than other types of brain surgery and there are some concerns associated with its use – e.g. a risk of tumours forming and the possibility of unwanted changes being introduced into the brain – for example in mood, behaviour and ability.

Find out more and download the consultation paper.