PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

EECoG may finally allow enduring control of a prosthetic or a paralyzed arm by thought alone

Mind over matter

2011-02-20
(Press-News.org) VIDEO: In 2006 a teenager played Space Invaders with the help of an electrocorticography (ECoG) grid that used signals from the area of his motor cortex that normally controlled his right...
Click here for more information.

Daniel Moran has dedicated his career to developing the best brain-computer interface, or BCI, he possibly can. His motivation is simple but compelling. "My sophomore year in high school," Moran says, "a good friend and I were on the varsity baseball team. I broke my arm and was out for the season. I was feeling sorry for myself when he slide into home plate head first and broke his neck.

"So I knew what I wanted to do when I was 15 years old, and all my career is just based on that."

Moran, PhD, associate professor of biomedical engineering and neurobiology in the School of Engineering & Applied Science at Washington University in St. Louis, is young enough that his career has coincided with the rapid development of the field of brain interfaces. When he began, scientists struggled to achieve lasting control over the movement of a cursor in two dimensions. These days, his aspirational goal is mind control of the nerves and muscles in a paralyzed arm.

A typical primate arm uses 38 independent muscles to control the positions of the shoulder and elbow joints, the forearm and the wrist. To fully control the arm, a BCI system would need 38 independent control channels.

The latest from Moran's lab There are four types of brain-computer interfaces: EEGs, where the electrodes are outside the skull; microelectrodes, where the electrodes are inserted in the brain; ECoGs, grids of disk-like electrodes that lie directly on the brain, and, Moran's choice, EECoGs, grids of disk-like electrodes that lie inside the skull but outside the dura mater, a membrane that covers and protects the brain.

Moran has just completed a set of experiments with MD/PhD student Adam Rouse to define the minimum spacing between the EECoG electrodes that preserves the independence of control channels. Together with Justin Williams at the University of Wisconsin, he has built a 32-channel EECoG grid small enough to fit within the boundaries of the sensorimotor cortex of the brain.

His next step is to slip the thin, flexible grid under a macaque's skull and to train the monkey to control — strictly by thinking about it — a computational model of a macaque arm that he published in the Journal of Neural Engineering in 2006.

This might sound like science fiction, but in 2006, Moran and his long-time collaborator Eric Leuthardt, MD, a Washington University neurosurgeon at Barnes-Jewish Hospital, had demonstrated that a young patient, in the hospital for surgery to treat intractable epilepsy, could play the video game Space Invaders just by thinking about it.

VIDEO: In this real-time movie, a monkey tries to move a cursor over the colored section of a circle with the help of an epidural electrocographic (EECoG) grid picking up signals...
Click here for more information.

Of course the virtual arm is a much more ambitious project. Only two degrees of freedom (two independent control channels) are required to move the Space Invaders' cursor in a two-dimensional plane.

The arm, on the other hand, will have seven degrees of freedom, including rotation about the shoulder joint, flexion and extension of the elbow, pronation and supination of the lower forelimb, and flexion, extension, abduction and adduction of the wrist.

(The monkey will not be harmed in this experiment, but instead will be persuaded by a virtual reality simulator into treating the virtual arm as though it were its own.)

Using the virtual arm, Moran showed that the classic task that has been used to study motor control for 20 years, called center-out reaching, does not adequately separate out the control signals that add up to an arm motion, making it difficult to determine which part of the brain is controlling which element of the motion.

So the monkey will instead be asked to trace with its virtual hand three circles that intersect in space at 45 degrees to one another, like interlocked embroidery hoops. Because this task better separates degrees of freedom, it will make it easier for the scientists to map cortical activity to details of movement, such as joint angular velocity or hand velocity.

Should this experiment be successful, and Moran fully expects it will be, he would like eventually connect his EECoG BCI to a new peripheral nerve-stimulating electrode he is developing together with MD/PhD student Matthew R. MacEwan. By connecting these two devices they will create a neuroprosthetic arm: that is, a paralyzed arm that can move again because the mind is sending signals to peripheral nerves that stimulate muscles to expand or contract.

Neuroprosthestics like the one Moran and colleagues are designing may one day help people suffering from spinal cord injury, brainstem stroke or amyotrophic lateral sclerosis, which paralyzes the body while leaving the mind intact.

The background BCI has been slow to develop in part because early scientists worked with two "platforms" that have turned out to have serious limitations: EEG systems that measure brain signals through the skull and arrays of microelectrodes inserted directly into the brain.

EEG systems have a series of drawbacks related to the distance between the electrodes and the scene of the action. They have poor spatial resolution, the signals do not contain detailed information, and the signals are weak.

"Here's the deal," says Moran. "The brain is about an inch below the surface of your scalp, which in recording terms is a long, long way away. When you're on the surface of the scalp, it's kind of like being five blocks from Busch Stadium. You can't hear anything unless someone hits a home run and all 60,000 fans scream simultaneously.

"For an EEG, you need the neurons in a chunk of cortex about the size of a quarter screaming at the same time in order to record anything. And the primary motor cortex, the thin strip of the brain that controls the skeletal muscles, is so small you're only going to get a few control channels up there."

VIDEO: The goal of brain-computer interfaces is to control muscles directly from the brain's cortex, skipping the intervening spinal cord. In this movie each yellow line represents the instantaneous firing rate...
Click here for more information.

There are other drawbacks to EEG as well. For example, it takes many training sessions (roughly 20 to 50 half-hour sessions) to learn to control an EEG BCI.

Still, Moran and colleagues write in a review article in Neurosurgical Focus, EEG BCIs perform better than is sometimes supposed. They allow accurate control of a computer cursor in two or three dimensions and so far they are the only systems that have achieved clinical use (in patients with amyotrophic lateral sclerosis and spinal cord injury).

Microelectrode arrays The traditional alternative to an EEG platform has been an array of microelectrodes whose tiny tips are implanted a few millimeters into the motor cortex.

Microelectrodes were implanted in both monkeys (in the 1970s) and in humans (in 1998), and were very successful -- but only for a short time.

They suffer from what is probably a fatal drawback: The insertion of the electrodes initiates a reactive cell response that promotes the formation of a sheath around the electrode that electrically isolates it from the surrounding neural tissue.

Some labs are investigating biomaterial coatings for electrodes or drug delivery systems that would prevent this foreign body response, but these efforts are still preliminary.

No needles In working with penetrating microelectrodes scientists made several discoveries that had interesting implications.

The first systems recorded the action potentials in single neurons, but in the 1980s, scientists discovered that populations of neurons in the motor cortex could be used to control the direction and speed of movements in three-dimensional space.

These small assembles of cortical cells synchronize their activity to produce high-frequency local field potentials, called gamma waves, that resemble signals from nearby single-unit microelectrodes.

In short, the gamma waves from neuronal populations can substitute for the action potentials from individual neurons. This meant it wasn't necessary to poke anything into the brain to get a useful signal. Instead, a sheet of disc like electrodes could be laid on the surface of the brain.

Moran was able to piggyback his first ECoG experiments on human epilepsy monitoring taking place at Barnes-Jewish Hospital.

"Our first ECoG experiments in 2004 were done with people," he says. "Patients with focal (localized) seizures that cannot be controlled with medication are regularly implanted with ECoG grids so that surgeons can pinpoint damaged portions of the brain for removal without disturbing healthy tissue. "

In 2006, Moran and Leuthardt attached an ECoG grid that had been implanted in a 15-year-old boy to monitor seizures to a computer running the game Space Invaders.

In order to move the cannon right, the subject thought about wiggling his fingers and to make it move left he thought about wiggling his tongue. "He could duck and dive and had pretty elegant control of the video game," Moran says, "and he made it to level three on the first day."

In the video the subject can be seen wiggling his fingers, but this behavior soon drops away, Moran says. The brain adapts and instead of imagining "wiggle fingers" the boy imagines "cursor right."

Intuitively you would think that signals from the motor cortex would provide the best control for tasks involving movement. But even this turned out not to be true. In 2007, scientists at the University of Wisconsin-Madison reported that patients were able to teach themselves to modulate gamma band activity either by imagining hand, foot or tongue movements, or by imagining a phone ring tone, a song or the voice of a relative. In other words, they were able to train neurons in the auditory as well as the motor cortex to control movement.

A thin sheet slipped under the skull All of this was very exciting. What if, Moran wondered, the brain was completely plastic and populations of neurons could arbitrarily be reassigned to control movement in different directions in space?

If neuronal populations could be reassigned, maybe more electrodes could be crowded into a grid without losing independent control of movement along different axes in space.

If the electrodes were shrunk as well as moved closer together, he wondered, how far could you go? How many degrees of freedom could you bring under the brain's control?

And why not make the implants safer as well? Instead of laying the electrode grids on the brain's surface, why not lay them on the dura mater, the outermost of the three membranes surrounding and protecting the brain and spinal cord.

In 2009, Moran published the first studies of epidural electrocortiocography (EECoG -- not to be confused with ECoG). Recording sites over the motor cortex of monkeys were arbitrarily assigned to control a cursor's motion in the horizontal and vertical directions as the monkey traced circles on a computer screen.

In the latest set of experiments, Moran sought to define the minimal separation between electrodes that preserved independence of control. Once a monkey gained control of the cursor, the initial electrodes were abandoned and control was given to two electrodes that were closer together. The next week, the control electrodes were closer still.

Moran found that the electrodes, which were initially a centimeter apart, maintained their independence until they were only a few millimeters apart. "So now that we know how many electrodes we can pack into an area, we have some idea how many degrees of freedom we'll be able to control," he says.

Together with Williams, he designed a 32-channel EECoG supported on a sheet of plastic thinner than Saran Wrap that sucks down to the dura and sticks like glue. He can hardly wait to test it with the virtual arm.

"I like doing basic research and I want to continue to do basic research," Moran says, "but I also really want to solve the problem and help people. Someone's got to get the technology translated to the marketplace, so we're trying to do that as well.

"Eventually," he says, "we'll have a little piece of Saran Wrap with telemetry. We'll drill a small hole in the skull, pop the bone out, drop the device in, replace the bone, sew up the scalp and you'll have what amounts to Bluetooth in your head that translates your thoughts into actions.

"My passion is for paralyzed individuals," he says, "but you can see down the road that a lot of people will want one of these devices."

### END


ELSE PRESS RELEASES FROM THIS DATE:

Physicists build bigger 'bottles' of antimatter to unlock nature's secrets

Physicists build bigger bottles of antimatter to unlock natures secrets
2011-02-20
Once regarded as the stuff of science fiction, antimatter—the mirror image of the ordinary matter in our observable universe—is now the focus of laboratory studies around the world. While physicists routinely produce antimatter with radioisotopes and particle colliders, cooling these antiparticles and containing them for any length of time is another story. Once antimatter comes into contact with ordinary matter it "annihilates"—or disappears in a flash of gamma radiation. Clifford Surko, a professor of physics at UC San Diego who is constructing what he hopes will ...

'Telecoupling' explains why it's a small (and fast) world, after all

2011-02-20
WASHINGTON, D.C. -- Understanding and managing how humans and nature sustainably coexist is now so sweeping and lightning fast that it's spawned a concept to be unveiled at a major scientific conference today. Meet "telecoupling." Joining its popular cousins telecommuting and television, telecoupling is the way Jack Liu, director of the Human-Nature Lab/Center for Systems Integration and Sustainability at Michigan State University, is describing how distance is shrinking and connections are strengthening between nature and humans. The "Telecoupling of Human and Natural ...

Juggling languages can build better brains

2011-02-20
Once likened to a confusing tower of Babel, speaking more than one language can actually bolster brain function by serving as a mental gymnasium, according to researchers. Recent research indicates that bilingual speakers can outperform monolinguals--people who speak only one language--in certain mental abilities, such as editing out irrelevant information and focusing on important information, said Judith Kroll, Distinguished Professor of Psychology, Penn State. These skills make bilinguals better at prioritizing tasks and working on multiple projects at one time. "We ...

BU's Kunz to introduce new discipline of aeroecology at AAAS symposium

2011-02-20
BOSTON—A team of research biologists headed by Thomas H. Kunz, professor of biology and director of the Center of Ecology and Conservation Biology at Boston University, will conduct a symposium on the emerging scientific discipline of aeroecology at this year's American Association for the Advancement of Science (AAAS) annual meeting. Aeroecology is a new discipline whose unifying concept is a focus on the aerosphere and the myriad organisms that inhabit and depend on this aerial environment for their existence. The symposium is scheduled from 3:00-4:30 PM, Saturday, February ...

US will no longer dominate science and research

2011-02-20
A shift in the global research landscape will reposition the United States as a major partner, but not the dominant leader, in science and technology research in the coming decade, according to a Penn State researcher. However, the U.S. could benefit from this research shift if it adopts a policy of knowledge sharing with the growing global community of researchers. "What is emerging is a global science system in which the U.S. will be one player among many," said Caroline Wagner, associate professor of international affairs, who presented her findings today (Feb. 18) ...

Syracuse University scientist to speak on evolution and Islam at AAAS Annual Meeting

Syracuse University scientist to speak on evolution and Islam at AAAS Annual Meeting
2011-02-20
Fierce debate over teaching evolution in public schools has raged across the United States since the epic courtroom battle between William Jennings Bryan and Clarence Darrow during the 1925 Scopes Monkey Trial (State of Tennessee v. John Scopes). Science education researchers are now turning their attention to the Islamic world to determine whether teaching of evolution in schools spawns similar social controversy and what that means for the future of scientific thought across the globe. Jason Wiles, assistant professor of biology in Syracuse University's College of ...

Bad news/good news

2011-02-20
A central challenge facing the planet is how to preserve forests while providing enough food to feed the world's population. It's really a "bad news/good news" story, says Eric Lambin, professor of environmental Earth system science and senior fellow at the Woods Institute for the Environment at Stanford; and professor of geography at the University of Louvain. The bad news: The world might run out of productive agricultural land by 2050, thanks to rising global demand for food, biofuels, and forest products, along with land degradation and urbanization. The good news: ...

Multiple approaches necessary to tackle world's food problems

2011-02-20
Researchers need to use all available resources in an integrated approach to put agriculture on a path to solve the world's food problems while reducing pollution, according to a Penn State biologist. Changes in national and international regulations will be necessary to achieve this goal. "Using resources more efficiently is what it will take to put agriculture on a path to feed the expected future population of nine billion people," said Nina Fedoroff, Evan Pugh Professor of Biology and Willaman Professor of Life Sciences, Penn State. "We especially need to do a better ...

Green chemistry offers route towards zero-waste production

2011-02-20
Novel green chemical technologies will play a key role helping society move towards the elimination of waste while offering a wider range of products from biorefineries, according to a University of York scientist. Professor James Clark, Director of the University's Green Chemistry Centre of Excellence, will tell a symposium at the Annual meeting of the American Association for the Advancement of Science (AAAS) that the use of low environmental impact green chemical technologies will help ensure that products are genuinely and verifiably green and sustainable. He says ...

What a rat can tell us about touch

2011-02-20
In her search to understand one of the most basic human senses – touch – Mitra Hartmann turns to what is becoming one of the best studied model systems in neuroscience: the whiskers of a rat. In her research, Hartmann, associate professor of biomedical engineering and mechanical engineering in the McCormick School of Engineering and Applied Science at Northwestern University, uses the rat whisker system as a model to understand how the brain seamlessly integrates the sense of touch with movement. Hartmann will discuss her research in a daylong seminar "Body and Machine" ...

LAST 30 PRESS RELEASES:

Call for papers: 14th Asia-Pacific Conference on Transportation and the Environment (APTE 2025)

A novel disturbance rejection optimal guidance method for enhancing precision landing performance of reusable rockets

New scan method unveils lung function secrets

Searching for hidden medieval stories from the island of the Sagas

Breakthrough study reveals bumetanide treatment restores early social communication in fragile X syndrome mouse model

Neuroscience leader reveals oxytocin's crucial role beyond the 'love hormone' label

Twelve questions to ask your doctor for better brain health in the new year

Microelectronics Science Research Centers to lead charge on next-generation designs and prototypes

Study identifies genetic cause for yellow nail syndrome

New drug to prevent migraine may start working right away

Good news for people with MS: COVID-19 infection not tied to worsening symptoms

Department of Energy announces $179 million for Microelectronics Science Research Centers

Human-related activities continue to threaten global climate and productivity

Public shows greater acceptance of RSV vaccine as vaccine hesitancy appears to have plateaued

Unraveling the power and influence of language

Gene editing tool reduces Alzheimer’s plaque precursor in mice

TNF inhibitors prevent complications in kids with Crohn's disease, recommended as first-line therapies

Twisted Edison: Bright, elliptically polarized incandescent light

Structural cell protein also directly regulates gene transcription

Breaking boundaries: Researchers isolate quantum coherence in classical light systems

Brain map clarifies neuronal connectivity behind motor function

Researchers find compromised indoor air in homes following Marshall Fire

Months after Colorado's Marshall Fire, residents of surviving homes reported health symptoms, poor air quality

Identification of chemical constituents and blood-absorbed components of Shenqi Fuzheng extract based on UPLC-triple-TOF/MS technology

'Glass fences' hinder Japanese female faculty in international research, study finds

Vector winds forecast by numerical weather prediction models still in need of optimization

New research identifies key cellular mechanism driving Alzheimer’s disease

Trends in buprenorphine dispensing among adolescents and young adults in the US

Emergency department physicians vary widely in their likelihood of hospitalizing a patient, even within the same facility

Firearm and motor vehicle pediatric deaths— intersections of age, sex, race, and ethnicity

[Press-News.org] EECoG may finally allow enduring control of a prosthetic or a paralyzed arm by thought alone
Mind over matter