Israeli research may help severely paralyzed speak
Almost completely paralyzed people such as theoretical physicist Hawking might one day benefit from Israeli and US research.
By JUDY SIEGEL-ITZKOVICHStephen Hawking 370(photo credit: Sheryl Nadler/Reuters)
Almost completely paralyzed people such as British theoretical physicist Prof. Stephen Hawking might one day benefit from Israeli and US research that identified a structured neurological code for syllables and could let them “speak” virtually by connecting the brain to a computer.The work, just published in the prestigious Nature Communications online journal, was conducted by Prof. Shy Shoham and Dr. Ariel Tankus of the biomedical engineering faculty at Haifa’s Technion- Israel Institute of Technology and Prof. Itzhak Fried of Tel Aviv Sourasky Medical Center and the neurosurgery department at the University of California at Los Angeles.The team experimented on 11 US patients at UCLA who suffered from severe epilepsy that could not be controlled with medications. They were thus candidates for an electrical implant that could locate the damaged part of the brain that caused their seizures.Unlike patients who receive electrical implants for controlling Parkinson’s disease in one procedure, epileptics have to undergo surgery to determine where the electrodes would best be located, with testing over two weeks, and then another operation to surgically remove the misfiring neural tissue.“It was during this two-week period that we tested the patients, who were aged 19 to 53, to test their brain reactions when they spoke,” Shoham told The Jerusalem Post on Wednesday.Human speech sounds are produced through a coordinated movement of structures along a vocal tract, the researchers wrote. “Here we show highly structured neuronal encoding of vowel articulation.”They studied nerve cells in the anterior cingulate cortex region of the brain and how these reacted when the epileptics spoke. When they voiced different vowels, mathematical algorithms were used to see how the section of the brain reacted.At present, people with “locked-in syndrome” who are unable to speak or operate most of their muscles are able to communicate by batting their eyelids when a light passes over letters in the alphabet and reaches the one they want.They are thus laboriously able to put the letters together into words and sentences, as Hawking – who has suffered from Lou Gehrig’s disease since early adulthood – does today five decades later. It takes minutes to complete a sentence.There was research at the Weizmann Institute of Science that found controlled breathing into a tube could be used to select letters or syllables.
“We performed both sharp and gradual tuning. We found neurons that react to specific vowels,” said Shoham. If the brain’s language center/computer interface is successfully developed further and the whole range of vowels and consonants can be recognized as a structured code, he continued, the patient might be able to communication merely by trying to speak but being unable to produce sounds.“This is the first step but an important one,” Shoham said.Fried, a veteran neurosurgeon who shuttles between Tel Aviv and Los Angeles – he performs neurosurgery at both hospitals – performed the electrode implants, while Tankus recorded the data and analyzed it together with Shoham.A wireless connection between the brain and any computer could then “translate” what he intended to say into artificial speech. “It is so far very promising,” said Shoham, “but I can’t say how long it would take. There are only a handful of Israelis with the need for such a device but thousands around the world. There are many more people who suffer from less serious paralysis and speech difficulty who could benefit.”Shoham did his doctorate on brain/machine interfaces 11 years ago, and since then has worked with a lab team to develop devices for neural engineering, including a retina implant to help the blind to see.“For the speech interface, we would need electrodes only to record and not to stimulate – unlike an electrode to permanently stimulate a part of the brain for Parkinson’s disease. Thus our device would require less power and could be wireless,” Shoham explained.
