By Tom Henderson
Small Times Senior Writer
CHICAGO – It sounds like something out of one of those black-and-white B movies from the 1950s: A brain is cut out of its host, kept alive in a lab and used to control a robot.
But this is no fiction.
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| At top, a contraption that includes Legos and fishing line houses the robot’s track. Above, the robot, running on lamprey power, takes aim at a light bulb. |
Dr. Ferdinando Mussa-Ivaldi and his fellow researchers at Northwestern University, the University of Illinois at Chicago and the University of Genoa in Italy use the brain stem and part of the spinal cord of a lamprey to control a wheeled robot. It is research they hope will allow people to be fitted with prosthetics wired to a variety of small-tech sensors that are directly controlled by the brain.
Those debilitated by Lou Gehrig’s disease or stroke, for example, might again be able to interact with the world, and those now paralyzed with spinal-cord injuries could relearn to walk.
“This will help us establish better communications between the brain and machines,” says Mussa-Ivaldi, who holds dual posts in Northwestern’s department of physiology and the medical school’s department of physical medicine and rehabilitation. He also works at the Rehabilitation Institute of Chicago.
“To effectively connect areas of patients’ brains to robotic devices, you have to better understand how brains and machines can talk to each other, and how the brain can be better patterned by sensory information.”
FISHING LINE AND LEGOS
The lamprey is a primitive eel-like predator fish that can be found attached to, and sucking fluids from, its host fish in nearby Lake Michigan, just a block from Mussa-Ivaldi’s lab on Northwestern’s downtown Chicago campus. All that remains of the fish in the lab is a thin slice of neural matter a little more than a centimeter long, kept alive in a solution rich in sodium, potassium, magnesium and glucose.
The robot looks like a hockey puck that has been glued atop a cylinder containing an array of photo sensors, a bundle of wires leading to a nearby computer and two small wheels that zip it around.
The puck rolls atop a black poster-board circle two feet in diameter, surrounded by a short sidewall. A series of small lights flash on and off under the lip.
As one lights, the robot turns slowly, then picks up speed and crashes into the lip. Researchers dim that light, and then flash another. The robot turns, picks up speed and crashes again.
The wires lead into a computer, then out to the lamprey brain, which was surgically removed from the body of the fish by a post-doctoral researcher, Karen Fleming.
Two electrodes are stuck into large, easy-to-access nerve cells known as Muller cells at the front of the brain. Muller cells are well understood and extensively studied, says Mussa-Ivaldi, and are responsible for integrating command and sensory signals directed to the motor nerves. Two other electrodes are attached at the rear, in the spinal cord, which would normally control the fish’s wiggling action in water.
Eyeless, the brain and spinal cord see the light. Incapable of motion, themselves, they send the robot careening and crashing. One array of photosensors on the right half of the robot connects through the computer and then on to the fish, which relays a message back to the right wheel. The left array of sensors controls the left wheel.
This is high tech done on the cheap. Pointing to the light sensors, the computer, the motion-dampened table, the electrodes going in and out of the fish brain, Mussa-Ivaldi says: “These are all off-the-shelf components.”
The components are also out of the toy box, and out of the fishing-tackle box.
The robot is stabilized by several pieces of fishing line attached to it from above, strung through pulleys made of Legos that are attached to what looks like pieces of an Erector Set. Dangling from the lines are washers, nuts and bolts added for extra weight and tension.
Rube Goldberg had nothing on this.
FISH TO GO
Fleming orders a year’s worth of lampreys at a time, about 200 or so, from a Michigan company called Nuisance Animal Control. Lampreys are native to the Atlantic Ocean and moved into the Great Lakes in the ballast of merchant ships.
A biomedical engineer, Fleming has become an accomplished lamprey surgeon as well, personally removing the brains from the anesthetized fish as they are needed. She says the record for keeping one brain alive is three days.
The lamprey was chosen because Mussa-Ivaldi’s original collaborator, Simon Alford, now at the nearby University of Illinois-Chicago, was familiar with them
“The lamprey turned out to be a very good choice for several reasons,” he says. It’s relatively easy to keep its brain tissue alive; its brain cells are very large and easy to work with; it has been well studied and “has a well-mapped nervous system.”
The project was funded in its first three years by a grant from the Office of Naval Research. A second three-year Navy grant has just begun.
According to a spokesperson for the Office of Naval Research, the two grants for the lamprey project have totaled $660,000.
The office funded the project, said the spokesperson, “because it is in the forefront of technologies related to the development of intelligent robots. The research is an early step towards adaptive robotic systems of the future.”
Mussa-Ivaldi didn’t want to speculate on how long his research might take to result in real applications but says it is all part of the momentum that is building in related research. “The interest in this area, neuroengineering, is becoming very big.
“The basic goal of this project is to extract knowledge. What we’re trying to note is if we can induce a change in the brain, to see if we have an adaptive response,” he says. And in fact, they get one, he says. Though each brain is only used briefly, the brains exhibit what Mussa-Ivaldi calls “plasticity.” After being hooked up to both right and left arrays of sensors, for example, the fish adapts when one of the arrays is covered up and can no longer send signals.
“You can see changes in the brain in a period of half an hour,” he says.
CYBORGS AROUND THE WORLD
Animal-machine cyborgs are becoming reality at research institutions around the world. Some noteworthy examples:
- Researchers at Emory University and Georgia Institute of Technology have collaborated to use neurons from leeches to solve simple addition problems, through an interaction with a PC.
- Also at Atlanta’s Emory University, Phillip Kennedy and Roy Bakay, both with the department of neurosurgery, have implanted electrodes into the motor cortex of patients who are “locked in” – that is, those suffering from Lou Gehrig’s disease or severe stroke who are aware of their surroundings but no longer able to communicate. With cortex implants, patients have been able, through the power of thought, to control a cursor on a computer screen and, as a result of a corresponding computer program, produce audible sounds.
- This summer, Kevin Warwick, a professor who heads up the Cybernetics Department at the University of Reading in the United Kingdom, plans to implant a silicon chip in his own body, which will interact with his brain. Surgeons will connect the chip to nerve fibers in his left arm, and the chip is supposed to exchange signals between his brain and a computer. It is hoped that as Warwick makes various motions, the computer will eventually be able to replicate the signals to his arm, too, and control motion when asked to.
- Miguel Nicolelis, a bioneurologist at Duke University, published an article in Nature last November detailing his work on owl monkeys that operate a robot arm using only their brain signals. Eventually, he theorizes, amputees could use what he calls a hybrid brain-machine interface to control artificial arms or legs, or those paralyzed by spinal-cord injuries could transmit signals back and forth between body parts and brain. “The brain is still the best computer around,” says Mussa-Ivaldi. “The more we understand it, the better we can emulate it in an artificial situation.”
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CONTACT THE AUTHOR:
Tom Henderson at [email protected] or call 734-994-1106, ext. 233.