Brain–Computer Interface–Based Communication in the Completely Locked-In State as originally seen in PLOS Biology
Research for the win! This group of researchers has unlocked communication for those with Locked-In Syndrome. Locked-In Syndrome is where the brain stem is effected by a stroke or in the final stages of progressive neurological disease like ALS (with which all 4 of the study’s subjects were afflicted). Because the brain’s root is blocked, basically you’re completely conscious, but blocked from your body– no movement what so ever. The lucky ones can blink.
In this study, the researchers have developed a cap using “functional near-infared spectromoty” which basically means they’re using light waves through the scalp to monitor changes in blood flow. The changes indicate a “yes” or “no” answer to a question. The researchers started with simple questions they knew that the subjects knew the answer to like, “Is the sky blue?” and “Is the sky red?” to mark out what a true “yes” and “no” looked like in the blood flow of each person. Then they moved on to actually “talking”– asking them questions only they would know the answer to. One family wanted to ask dad for his permission for his daughter to marry her boyfriend. They got a “no” 9/10 trials! Maybe this communication thing isn’t all it’s cracked up to be. Just kidding.
This could be a giant leap forward for this population! But the study has lots of draw backs. First of all, the entire population that has Locked-In Syndrome is very small, although there isn’t a set in stone incidence rate out the interwebs I can find. And of that tiny population, the researchers found a sample size of FOUR people. Well, if you don’t have too many to begin with, 4 is probably pretty good really. But not very good to make a technology universally useful to all in the population. Then they only worked at decoding what each person’s “yes” and “no” blood flow patterns looked like until they got 75% accuracy. Which is a C in school… which says to me, “I don’t really know what I’m doing.” So maybe they know the answer they’re looking at in that blood flow… maybe not.
Overall the results are encouraging in the least and to me fascinating!
If you’re interested in learning more about Locked-In Syndrome, I encourage you to check out the book and film The Diving Bell and the Butterfly. It’s about a French guy with Locked-In Syndrome and how a speech therapist and he develop a communication method through blinking. Which he used to write the book!