The ethical issues around technologies that 'intervene' in the brain are set to come under scrutiny as part of a consultation by The Nuffield Council on Bioethics.

Brain-computer interfaces (BCI) are of particular concern, as they could be used in various military applications, to develop weapons or vehicles that are controlled remotely by brain signals. These are not yet in wide use but are being researched and tested, and some commercial BCI developments are already on the market.

“If brain-computer interfaces are used to control military aircraft or weapons from far away, who takes ultimate responsibility for the actions?” asked Thomas Baldwin, chair of the Council’s study and Professor of Philosophy at the University of York. “Could this be blurring the line between man and machine?”

BCI measures and analyses a person’s brain signals and converts them into an output such as movement. The use of BCI 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.

This kind of technology can have very positive applications. For example, a person who is disabled and cannot speak might be able to move independently through a thought-controlled wheelchair, or communicate via a computer voice. There are also commercial possibilities in the gaming industry – the development of thought-controlled computer games, for example.

However, many of these technologies are in the early stages of research, and Nuffield Council has raised concerns about the 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?” said  Baldwin.

The consultation will also examine the ethics of deep brain stimulation, and neural stem cell therapy. Deep brain stimulation (DBS) is a form of neurostimulation that requires brain surgery to place an electrode in the brain and wires under the skin. Electric or magnetic stimuli are then applied to nerves to alter brain activity in a specific area.

DBS is currently used in the treatment of Parkinson’s disease, obsessive-compulsive disorders and movement disorders such as dystonia (which causes tremors). However, possible complications include stroke, speech disorders and visual problems.

Meanwhile, neural stem cell therapy involves stem cells being injected into the brain under general anaesthetic. Researchers are looking at using this method to treat conditions such as Alzheimer’s or Huntingdon’s disease.

“Intervening in the brain has always raised both hopes and fears in equal measure. Hopes of curing terrible diseases, and fears about the consequences of trying to enhance human capability beyond what is normally possible,” said Baldwin.

“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.”

The consultation runs until 23 April and the Council wants to hear the views of those who have used the technologies, as well as those involved in development or supply, researchers, academics, patients, medical professionals, regulators, policy makers and others. A report setting out the Council’s findings will be published in 2013.