New techniques and developments in brain imaging can raise tricky ethical questions
Researchers have devised a clever way of using fMRI to try to communicate with patients diagnosed as being in a vegetative state. To do so, they place a patient in the scanner and ask them simple questions. The patient is told to imagine playing a game of tennis if they want to answer “yes” and to imagine walking around their house if they want to answer “no”.
These thoughts produce different patterns of brain activity, which can be detected by the scanner: imagining playing tennis activates the premotor cortex, which is involved in planning movements, whereas imagining walking around a house activates the hippocampus and surrounding areas, which store maps of the environment and memories of how to navigate them.
Until recently, it was thought that patients in a vegetative state were completely unable to follow instructions like this. Using this method, however, researchers have found that at least one in ten of them can willfully modify their brain activity in this way and apparently answer simple questions correctly. Follow-up work has led some researchers to conclude that close to 20 per cent of patients who are thought to be vegetative are actually conscious.
The apparent ability to communicate with these patients raises some difficult ethical questions. Most of these patients are unresponsive and cannot communicate in any other way, so who should be responsible for giving the researchers permission to do this? Patients who can answer questions in this way probably have a better chance of recovering, but brain scans are expensive.
Questions for discussion
- How should the researchers decide which patients to test?
- And what questions should they ask the patients they do scan?
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