Brain Implant Lets One Monkey Control Another

[Buster's Uncle]

Brain Implant Lets One Monkey Control Another
LiveScience.com
By Charles Q. Choi, LiveScience Contributor  2 hours ago



A schematic of the experimental setup in which brain activity from one monkey was used to control the hand of another, sedated monkey.



In work inspired partly by the movie "Avatar," one monkey could control the body of another monkey using thought alone by connecting the brain of the puppet-master monkey to the spine of the other through a prosthesis, researchers say.

These findings could help lead to implants that help patients overcome paralysis, scientists added.

Paralysis due to nerve or spinal cord damage remains a challenge for current surgical techniques. Scientists are now attempting to restore movement to such patients with brain-machine interfaces that allow people to operate computers or control robotic limbs.

"However, we were interested in seeing whether one could use brain activity to help control one's own paralyzed limb," said study author Ziv Williams, a neuroscientist and neurosurgeon at Massachusetts General Hospital of Harvard Medical School in Boston. "The benefit there is that you are using your own body as opposed to a mechanical device, which can need a lot of support and is not always practical to carry around with you."

Ultimately, "the hope is to create a functional bypass for the damaged spinal cord or brainstem so that patients can control their own bodies," Williams told Live Science.

The researchers developed a brain-to-spinal-cord prosthesis that connected two adult male rhesus monkeys.

"I was inspired a little by the movie 'Avatar,'" Williams said. The main character in the 2009 sci-fi film is a paraplegic, and connects his brain to a computer that helps him control an artificial body.

The monkey that served as the master had electrodes wired into his brain, while the monkey that served as the avatar had electrodes wired into his spine. The avatar's hand was placed onto a joystick that controlled a cursor displayed on the master's screen.

The avatar monkey was sedated so that he had no control over his own body. Computers decoded the brain activity of the master monkey and relayed those signals to the spinal cord and muscles of the avatar monkey. This allowed the master to control the cursor by moving the hand of the avatar. The master received a reward of juice if he successfully moved the cursor onto a target.

"Probably the biggest challenge we had was having this happen in real-time," Williams said. "In theory, you can record neuronal activity any time, analyze it offline, and use those signals to stimulate the spinal cord or muscles. The trick is being able to figure out what the monkey is intending in real-time and then stimulating the spinal cord or muscles to create the desired movements."

Controlling every single muscle in a limb to carry out a desired motion would be very complex. The researchers simplified this problem "by focusing on the target of the movement as opposed to which muscles and joints are used for the movement," Williams said.

The scientists emphasize the goal of this research is not for one person to control the body of another. Rather, when it comes to treating patients with spinal cord injuries, such as quadriplegics, "we envision putting a microchip into the brain to record the activity behind the intent for movement and putting another microchip in the spinal cord below the site of injury to stimulate limb movements, and then connecting the microchips," Williams said.

"This is just a proof-of-concept," Williams said. "We only had the monkeys aim for a few targets at a time — to be clinically useful, we'd have to be able to cause many different movements in space for fine motor control. Still, we think in principle that is possible."

Williams and his colleagues Maryam Shanechi and Rollin Hu detailed their findings online today (Feb. 18) in the journal Nature Communications.


http://news.yahoo.com/brain-implant-lets-one-monkey-control-another-160433698.html

[Buster's Uncle]

Monkey experiment 'could lead to paralysis cure'
AFP
By Mariette Le Roux  5 hours ago



A file picture of a paralysis victim (AFP Photo/Justin Sullivan)



Paris (AFP) - Scientists working on a paralysis cure said on Tuesday they had demonstrated how a monkey can use only its thoughts, transferred by electrodes, to manipulate a sleeping fellow primate's arm to do its bidding.

The lab experiment, in which a fully sedated Rhesus monkey's hand moved a joystick to perform tasks at the other monkey's command, was designed to simulate full paralysis -- the brain completely disconnected from the muscle it seeks to control.

"We demonstrate that a subject can control a paralysed limb purely with its thoughts," co-author Maryam Shanechi of Cornell University's School of Electrical and Computer Engineering told AFP of the study in the journal Nature Communications.

The discovery "could have the potential to help paralysed patients regain control of their own limbs."

In lab tests, a team of engineers and neuroscientists used electrodes to connect the brain of one monkey to the spinal cord of another via a computer that decoded and relayed the neural signals.

The first monkey, dubbed the "master", was placed in a special chair before a computer screen that showed a cursor and a green circle that alternated between two spots. The monkey's head was restrained.

The second animal, or "avatar", was fully sedated in a separate enclosure -- its arm strapped to a 360-degree joystick with which to move the cursor and chase the circular target on the "master's" screen.

As the master thought of moving the cursor, its brain signals were decoded to determine which of the two targets it had in mind, and the data was relayed in real-time to the spinal cord of the sleeping avatar, whose arm manipulated the joystick accordingly.

Every time the cursor hit its target, the master received a squirt of juice as reward.


- Proof of concept -

Previous research into so-called brain-machine interfaces (BMI) had shown people move computer cursors or even robotic arms using their thoughts.

Shanechi and her team claim they are the first to give an animal control over the actual limb of another animal.

The findings "provide a proof of concept that just by thinking, subjects can move an arm in two dimensions" even with no physiological connection between the brain and the muscle, she said.

Paralysis can be caused by damage to the central nervous system, especially the spinal cord, by stroke or diseases like Parkinson's or an accident.

Scientists are keen to find a way for paralysed people to move their own limbs in a natural way, but have found it difficult to read the brain signals that control the complex functioning of the muscles.

Previous BMI research has allowed only repeated movements to the same target over and over again, or on a single line, said the study authors.

What is different this time: Shanechi and her team decoded the brain signals the monkey directed at his on-screen target rather than trying to decipher the detailed step-by-step processes required to achieve the movement.


- High precision -

The primate pair, interchangeably master and avatar, hit the target in about 84 percent of cases, the researchers said.

Also new was the use of separate monkeys, which "more closely mimics true quadriplegia", said co-author Ziv Williams of the Harvard Medical School's Center for Nervous System Repair.

In connecting the brain and muscles of a singular animal, scientists can never be sure how much of the movement achieved is "confounded by possible sensory feedback of preserved muscle contractions", he explained.

Bernard Conway, head of biomedical engineering at the University of Strathclyde in Glasgow, commented that the research was "a key step forward" in identifying a paralysed subject's intention or desire to perform a specific movement and translating that into action.

University of Warwick biomedical engineering professor Christopher James added the findings had "profound implications... for controlling limbs in spinal cord injury, or controlling prosthetic limbs with limb amputees."

It was not clear how well the findings in sedated monkeys could be replicated in truly paralysed patients whose muscles have become weak with disuse.


http://news.yahoo.com/monkey-experiment-39-could-lead-paralysis-cure-39-165725117.html