Research by the Medical Research Council in Cambridge may have a significant impact on the treatment of brain-damaged patients.

According to recent work published by Dr Owen and his team, one in five patients in a comatose state may be conscious of the outside world, suggesting that patients will eventually recover the ability to talk using voice synthesizers.

Measuring brain activity using a functional magnetic resonance imaging (fMRI) machine and later an electroencepholography machine (EEG), Dr Owen was able to question patients using a ‘yes’ or ‘no’ format to show that their cognitive functions had not been impaired.

Dr Owen commented "I would never have believed that within a few years we would be actually communicating with a patient who was in a persistent vegetative state."

The team asked patients to use motor imagery, such as playing tennis, to answer ‘yes’, and spatial imagery, such as moving around one’s house, for ‘no’. By detecting heightened activity in either the pre-motor cortex, the area at the front of the brain that responds to spatial movement, or the base of the brain which is stimulated by navigational problems, scientists were able to distinguish between yes or no responses.

Although the discovery is not a recent one within the medical profession, Dr Owen’s use of the smaller and more cost effective EEG machine for the same task as the cumbersome fMRI machine has enormous potential for medical treatment.

A portable EEG is commercially affordable at £30,000 and could be available on a wide scale in the near future. Already, its use at the Royal Hospital for Neurodisability in London has shown that 43 per cent of patients responded to the machine, which was double that of Dr Owen’s estimate of patients likely to be affected.

According to one Cambridge medic, the research would open up discussion about "ethical and moral issues surrounding medical practice". When asked about its future potential, Dr Owen responded that the machine could be used to ascertain whether patients were in any pain in order to administer medicine.

Doctors currently have no way of knowing this. Indeed, the technology may have a decisive impact on the decision to continue life support for patients in the hope that they may one day regain consciousness.

1,000 patients are kept alive in Britain ever day on life support.