A man with amyotrophic lateral sclerosis (ALS) has been able to "talk" again, according to a report published today in Science. ALS is known to cause a loss of muscle control resulting in - among many other things - an inability to communicate. Some people with ALS have been able to communicate nonverbally through eye movements such as choosing a yes or no answer, or using an eye-tracking camera to spell out artwork.
As the condition worsens, however, even minor eye movements become impossible and render these methods useless in the process.As Science points out, while brain implants that help “locked-in” patients maintain some degree of expressiveness can be helpful for both research and the patient’s overall health, there are many ethical issues to consider. For example, if a patient agrees to the procedure but later loses the ability to communicate, they will not be able to let anyone know if their decision has changed. Another issue is that complex discussions such as hospice care are more or less impossible because of the limitations of the implant.
Two square electrode arrays were surgically implanted into the area of the man’s brain that controls movement. Once installed, the researchers began testing the most effective brain signals available for interpretation. When attempts at various motor signals proved too inconsistent, they turned to a more successful system in which the patient would try to use the implants to match the sound signals being played.
Building on this, the system was extended so that the patient could hold the signal at different levels to indicate a “yes” or “no” response, and then eventually a single letter. While this did allow him to form complete sentences, it was not a quick process. In fact, it takes about a minute per character – or about 30 minutes or more per sentence.
The effect of the implant also diminished over time, though the reason behind this is still not entirely clear. Researchers believe that the scar tissue that forms around the implant is a factor, but it could also be due to the progression of the disease and the damage it causes to the patient’s brain. Unfortunately, however, the technology is still in the experimental stage and its ethical implications are still under review, so implants like this one are unlikely to be an option for all ALS patients any time soon.
