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Several months ago major news sites reported that a Belgian man, paralyzed for 23 years and supposedly in a vegetative state, was interacting with caregivers through the use of “facilitated communication.” James Randi and other skeptics raised questions about the validity of the technique.
Faculty from the Department of Neurology at Liege University Hospital are now reporting that subsequent controlled studies have failed to confirm the initial findings.
Dr Steven Laureys, one of the doctors treating him, acknowledged that his patient could not make himself understood after all. Facilitated communication, the technique said to have made Houben’s apparent contact with the outside world possible, did not work, Laureys declared. “We did not have all the facts before,” he said. “To me, it’s enough to say that this method doesn’t work.”
In the recent studies a facilitator, who helped the patient type answers on a computer screen, was not present when the test objects and words were presented to Mr. Houben.
Links at NPR and The Guardian.
Previously on Neatorama: Is This Man Fully Alert and Communicating – or Not? (with video of facilitated communication). Photo credit AFP/Getty Images.
A brain-machine interface has been developed that has been successfully tested on a patient with Locked-in Syndrome {wiki}. An unnamed 26-year-old man paralyzed for ten years by a brain stem stroke was implanted with electrodes five years ago. Researchers waited as the brain grew around the electrodes.
Three years after implantation, the researchers began testing the brain-machine interface for real-time synthetic speech production. The system is “telemetric” – it requires no wires or connectors passing through the skin, eliminating the risk of infection. Instead, the electrode amplifies and converts neural signals into frequency modulated (FM) radio signals. These signals are wirelessly transmitted across the scalp to two coils, which are attached to the volunteer’s head using a water-soluble paste. The coils act as receiving antenna for the RF signals. The implanted electrode is powered by an induction power supply via a power coil, which is also attached to the head.
The signals are then routed to an electrophysiological recording system that digitizes and sorts them. The sorted spikes, which contain the relevant data, are sent to a neural decoder that runs on a desktop computer. The neural decoder’s output becomes the input to a speech synthesizer, also running on the computer. Finally, the speech synthesizer generates synthetic speech (in the current study, only three vowel sounds were tested). The entire process takes an average of 50 milliseconds.
The tests on the first patient are quite promising.
To confirm that the neurons in the implanted area were able to carry speech information in the form of formant frequency trajectories, the researchers asked the volunteer to attempt to speak in synchrony with a vowel sequence that was presented auditorily. In later experiments, the volunteer received real-time auditory feedback from the speech synthesizer. During 25 sessions over a five-month period, the volunteer significantly improved the thought-to-speech accuracy. His average hit rate increased from 45% to 70% across sessions, reaching a high of 89% in the last session.
Although the current study focused only on producing a small set of vowels, the researchers think that consonant sounds could be achieved with improvements to the system.
Link -via J-Walk Blog
The story of Rom Houben was posted earlier today on Neatorama, and is being carried on every major online news site – a Belgian man paralyzed for 23 years and diagnosed as being in a vegetative state has been found through new technology to be alert but “locked in.” With an assistant helping him communicate by means of a keyboard, he is now reportedly describing what this experience has been like. The case adds fuel to the fiery controversy regarding end-of-life planning and the right to die.
Every site that I have encountered has taken the story at face value. The one exception has come from the James Randi, who has written an essay entitled “This Cruel Farce Has to Stop!“ He notes that the communications from the subject all occur via a “facilitator” who “supports” the patient’s hand as it traverses the keyboard…
The “facilitated communication” process consists of the “facilitator” actually holding the hand of the subject over the keyboard, moving the hand to the key, then drawing the hand back from the keyboard! This very intimate participatory action lends itself very easily to transferring the intended information to the computer screen. In the video you have just viewed, it is very evident that (a) the “facilitator” is looking directly at the keyboard and the screen, and (b) is moving the subject’s hand. The video editing is also biased, giving angles that line up the head of the subject with the screen, as if the subject were watching the screen.
At the essay, Randi states that he has previously investigated “facilitated communication” when it was used to communicate with severely autistic children; he found the technique to be faulty and subject to observer bias in the manner of the “clever Hans” effect.
This patient is clearly severely impaired but is clearly not brain dead. Brain imaging studies have shown evidence of consciousness and awareness, which is fully compatible with his impairment. The controversy is whether the communications are valid representations of his thoughts, or whether they are (consciously or subconsciously) creations of the facilitator.
The video embedded above is a brief excerpt from the MSNBC video. Several other videos are available at the BBC, Telegraph, and other news sites.
Addendum: Subsequent controlled trials failed to show any validity for “facilitated communication.”
