Device Reads Mind of Completely Paralysed Patients

I grant you, the title of this post makes a bold claim but I’m confident I’m not misrepresenting the science. A couple of weeks ago an interesting, open access paper was published in PLOS Biology. It detailed how people that were completely paralysed were able to use a brain-computer interface (BCI) to communicate.

The subjects in question were four people with amyotrophic lateral sclerosis (ALS); they were at such an advanced stage of the disease that two individuals had lost all ability to move except in their eyes and the other two had lost even that small amount of control. Those who can still move their eyes are said to be suffering from locked-in syndrome whist those who cannot even do that have completely locked-in syndrome (CLIS).

This, obviously, is a grim existence and all of them would have already died if they hadn’t opted to have a respirator breath for them. The general assumption is that their quality of life is low, but the reason the experiment was carried out was to test the hypothesis that people with CLIS were also not capable of the goal directed thinking necessary to use a BCI. If this were the case then they would be completely incapable of any kind of communication. To the surprise of research lead Professor Niels Birbaumer, not only were all four patients capable of communication but all four reported that they were happy with their lives.

I must admit that when I first saw what this story was about it raised my sceptical hackles. There have been many attempts at communicating with people that are otherwise unable to do so over the years, mainly in the guise of facilitated communication. This technique was often used on severely autistic or cognitively impaired children and resulted in highly distressing so called ‘revelations’ of child abuse. Facilitated communication was quickly debunked but continued to be popular for some years even though it could be easily shown that all the messages were actually coming from the adult facilitator and not the child.

In this instance, however, the effect does seem to be real. The procedure worked like this: the BCI in question is basically a skullcap with a load of electrodes on it. This can be quickly and easily placed over the subjects head and worn comfortably for some time. The electrodes are able to use infra red light to measure the oxygenation of the blood on the surface of the skull, a proxy for activity. The subject was asked a question with a yes/no answer, for example, “Your husband’s name is Joachim,” and the subject was instructed to repeatedly think  yes yes yes or no no no (actually ja or nein as the patients were all German) for 15 seconds.

After several training sessions the team were able to divine the correct answer from brain activity 70% of the time. This meant that, once the training sessions were over and the scientist wanted to start asking open ended questions to which they didn’t already know the answer, they had to ask the question ten times in a row. If they got the same answer seven or more times out of ten then they categorised that as a ‘correct’ answer. It was through this method that all four patients communicated that they were happy.

Though it is rather laborious, one of the good things about this method is that the yes/no determination is made by predetermined, objectively obtained criteria. There is no room here for the questioner to influence the outcome as with facilitated communication. The result, then, seems to be that there is genuine potential that people who are completely unable to make their bodies function can use their minds to express themselves. That is an ability that can’t be underestimated and will bring enormous relief and succour to families, carers, medical professionals and, crucially, the patients themselves.

As a slight aside and somewhat less sober analysis of this new work: how freaking cool is this? They are using a machine to read people’s thoughts!!! That is genuinely amazing, congratulations to all involved. Go science!

Title image courtesy of Eddie DuBorg

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