The latest news and information about what's going on with SCI science and research. Brought to you by Sam Maddox, author of the Christopher & Dana Reeve Foundation Paralysis Resource Guide.

Mind Reading Robot News: Man Grabs His Own Beer

You have to applaud Erik Sorto for letting these engineers monkey around with his posterior parietal cortex (PPC). I might let them mess with mine but not if they have to attach those huge electrical portals on my skull the way the did with Erik. 

Photo courtesy of Caltech, Keck USC, Rancho Los Amigos Team.

In case you missed it, this story from Los Angeles made the gee whiz grade, probably not because of the title of the research paper in Science – “Decoding motor imagery from the posterior parietal cortex of a tetraplegic human.” That’s downright tedious sounding. Instead, you get this, from the Washington Post, one that people can latch on to: “After years of paralysis, man drinks a beer with the help of a mind-reading robot.”
 
Yep, Erik, 34, hoisted a mind-controlled cold one for the first time since he lost all upper extremity function below the neck after a spinal cord injury by gunshot wound when he 21. They say he can play “rock-paper-scissors” and shake hands, too. Erik was the first human subject to have what’s called a neural prosthesis implanted in a part of the brain that controls intent, not motor function.
 
A team from Caltech, the University of Southern California and Rancho Los Amigos National Rehabilitation Center fitted Erik’s PPC with two small, precisely placed electrode arrays, one for reach, one for grasp, each with 96 active electrodes. The five-hour surgery took place in April 2013. The arrays are output to rather gruesome headgear implants. These cranial applicances are connected by cable to a computer system that decodes the signals so he can control output devices, such as a computer cursor or robotic arm. What’s more, the movement Erik makes are fluid and smooth, unlike some of the jerkier motions we've seen from pervious neural implants.
 
From a press release:
 
Designed to test the safety and effectiveness of this new approach, the clinical trial was led by principal investigator Richard Andersen, the James G. Boswell Professor of Neuroscience at Caltech, neurosurgeon Charles Y. Liu, professor of neurological surgery, neurology, and biomedical engineering at USC, and neurologist Mindy Aisen, chief medical officer at Rancho Los Amigos.

Andersen and his colleagues wanted to improve the versatility of movement that a neuroprosthetic can offer to patients by recording signals from a different brain region other than the motor cortex, i.e., the posterior parietal cortex (PPC), a high-level cognitive area. In earlier animal studies, the Andersen lab found that it is here, in the PPC, that the initial intent to make a movement is formed. These intentions are then transmitted to the motor cortex, through the spinal cord, and on to the arms and legs where the movement is executed.

"The PPC is earlier in the pathway, so signals there are more related to movement planning--what you actually intend to do--rather than the details of the movement execution," Andersen says. "When you move your arm, you really don't think about which muscles to activate and the details of the movement--such as lift the arm, extend the arm, grasp the cup, close the hand around the cup, and so on. Instead, you think about the goal of the movement, for example, 'I want to pick up that cup of water.' So in this trial, we were successfully able to decode these actual intents, by asking the subject to simply imagine the movement as a whole, rather than breaking it down into a myriad of components. We expected that the signals from the PPC would be easier for patients to use, ultimately making the movement process more fluid."
 
Erik is digging his mind-reading robotic capabilities. "I was surprised at how easy it was to control the robotic arm," he says. "I remember just having this out-of-body experience, and I wanted to just run around and high-five everybody."
 
Though he had to train, starting 16 days after his implant surgery, Erik was able to work his brain chips right away. "It was a big surprise that the patient was able to control the limb on day one -- the very first day he tried," Andersen says. "This attests to how intuitive the control is when using PPC activity."
 
Erik says he’s happy to be a neural guinea pig. "As much as the project needed me, I needed the project. It gives me great pleasure to be part of the solution for improving paralyzed patients' lives. I joke around with the guys that I want to be able to drink my own beer -- to be able to take a drink at my own pace, when I want to take a sip out of my beer and to not have to ask somebody to give it to me. I really miss that independence. I think that if it were safe enough, I would really enjoy grooming myself--shaving, brushing my own teeth. That would be fantastic."
 
What it all mean? The engineers are still way ahead of the biologists. Let your imagination run a little. I see lightweight, noiseless exoskeletons donned by quads who operate them by thought; I see these prancing down the street and into offices or homes, or sitting down unassisted to have a beer and play rock-paper-scissors. Or maybe the piano. These are the same folks today who’d otherwise be waiting for their PCA to give them a sip. I know, a lot of people don’t want to hear about any spinal cord research that has an on-off switch. But this is a remarkable study with potential to add function and quality of life to guys like Erik.
 
Somebody asked him about the beer. It tasted “like a little piece of heaven,” says Erik. 
 
Posted by Sam Maddox on May 26, 2015 10:39 PM America/New_York

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