“Mind-reading machine allows people with ‘locked-in’ syndrome to communicate,” reports the Mail Online.
The report is based on a study that aimed to communicate with four patients unable to speak, move or blink due to a severe form of motor neurone disease (MND).
The patients were able to give “yes” or “no” answers to a series of questions via a computer, which interpreted their brain signals.
They were given statements such as “your husband’s name is Joachim” or “Berlin is the capital of France” and told to think either “yes” or “no” in response.
They wore head caps fitted with sensors which measured changes to blood oxygen levels in the brain to work out if their answer was a “yes” or a “no”.
Towards the end of the study, researchers asked open questions such as whether patients were in pain, and whether they felt positively about their quality of life. In line with previous studies of people who knew they would become completely paralysed and chose to be on ventilators, they said that they did feel positive.
Researchers say the system correctly relayed what the patients were thinking 70% of the time.
The patients, aged between 24 and 76, all had amyotrophic lateral sclerosis (ALS), the most common type of MND.
The average life expectancy of someone with ALS is from two to five years after symptoms first appear.
The patients were at different stages of Completely Locked-in State (CLIS), a condition where the patient can think and has emotions but is completely paralysed.
They had lost all eye movement and the ability to communicate with their families – some for several years. They were receiving round-the-clock care at home, with artificial breathing and feeding tubes.
This small experiment raises the possibility of meaningful communication for people with this type of condition.
However, it is a tiny study and the findings may not be applicable to people with other causes of CLIS, such as stroke.
Where did the story come from?
The study was carried out by researchers from the University of Tübingen and Central Institute of Mental Health in Germany, Shanghai Maritime University in China and the National Institute of Neurological Disorders and Stroke in the US.
It was funded by several organisations including the Deutsche Forschungsgemeinschaft, German Ministry of Education and Research, Eva and Horst Köhler-Stiftung, National Natural Science Foundation of China and an EU grant.
The UK media gave broadly accurate coverage to the study. The Daily Telegraph and Mail Online both talked about the computer being able to “read people’s thoughts” or being a “mind-reading machine”, which is over-stating the reality.
At present the computer is only programmed to record brain responses to questions with yes/no answers, and it is not entirely accurate.
What kind of research was this?
This was an experimental study on a small number of people, with no control group. As such, it provides useful evidence in support of a theory that this type of technology can be used to communicate with people with locked-in syndrome, but the results need to be replicated to be sure they are reliable.
What did the research involve?
Four people with completely locked-in syndrome (meaning they are unable to move even their eye muscles, and are dependent on artificial breathing and feeding) were recruited to the study.
Researchers fitted them with caps which measured electrical activity and oxygenation. They were trained to answer “yes” or “no” to a series of known questions – questions the patient would find easy to answer.
A computer programme analysed changes to their brains during the sessions, and learned which responses typified a correct positive or negative response.
The people in the study had ALS, a motor neurone disease which progressively shuts down the body’s ability to move muscles, even for automatic movements such as breathing or swallowing.
All the patients had moved past the stage at which they could communicate through blinking or eye movement.
Their families had completely lost the ability to communicate with them – one since 2010, two since August 2014 and the family of the youngest since January 2015. They were being cared for at home, with artificial breathing and feeding tubes.
The technology used to measure changes to brain oxygenation is called functional near-infrared spectroscopy (fNIRS).
The researchers also measured electroencephalogram (EEG) changes in the brain and activity in eye muscles, to see whether these could predict correct answers. The EEG results were also used to tell whether people were sleeping, or to identify times when their brains were inactive and less responsive to questions.
The main part of the study looked to see how often the computer could read an accurate “yes” or “no” response to a known question, in up to 46 sessions spread over several weeks.
They were asked 20 questions each session, with an equal mix of true and false statements being presented in the same format (for example, “Paris is the capital of France” and “Paris is the capital of Germany”).
In some sessions, people were asked open questions, such as whether they were in pain. Only three people were asked open questions in the study.
Researchers worried that the youngest (age 23), whose disease had progressed very fast over two years, might be emotionally unable to give reliable responses to open questions. Her brain pattern responses to yes and no were less distinct from each other than the other patients.
What were the basic results?
The correct response rate of the four people in the study for questions with known answers was over 70%, averaged across the several weeks of the study. This is higher than the level you would expect from chance alone.
Three people answered open questions and were given feedback about their perceived answers. The “correct” rate was estimated at 78.6%, 78.8% and 75.8% for these three people.
The researchers judged that they could be sufficiently certain of the answer if people gave the same answer to an open question seven out of 10 times, when questions were repeated over several weeks.
These patients answered open questions containing quality of life estimation repeatedly with “yes” response, according to the researchers. They say this indicated a positive attitude to their situation and to life in general.
How did the researchers interpret the results?
The researchers say their results are “potentially the first step towards abolition of completely locked-in states, at least for patients with ALS”.
They say the results need to be confirmed in other studies over a longer period of time, because of the importance of getting them right.
They also acknowledge that they cannot explain why blood oxygen levels in the brain were different when the response was “yes” compared with “no”. They added that any theories would be “highly speculative”.
It’s hard to imagine the situation of being alert, aware of what’s happening around you, but unable to move, respond or communicate with the outside world.
So it is comforting, then, to hear that people with complete locked-in syndrome may be able to communicate – and may be relatively content with their situation.
However, it’s important to remember the limitations of this study.
It’s very small. Only four people took part, and full results are available for only three of them.
The results may only apply to people with this very specific type of neurodegenerative disease, not to people with other types of paralysis or locked-in syndromes like those caused by a stroke or head injury.
People in the study were all being given intense nursing care in their homes, looked after by family members. They had all chosen to have artificial respiration – in other words, had chosen to live with locked-in syndrome rather than to allow nature to take its course. That might affect how they answer questions about quality of life.
It’s hard to know how accurate the results of the study are. We can’t directly test them, so we have to rely on likelihood and chance of people repeatedly giving the same answers, and the computer reading the patterns correctly.
As the authors note, we do not know why the oxygenation results would be different for “yes” and “no” answers. There was also no clear pattern in the responses between patients, which would be expected if there was truly a physiological reason for the results.