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<nettime> hybrid robot (NYT)
Ana Viseu on Fri, 16 May 2003 01:23:55 +0200 (CEST)


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<nettime> hybrid robot (NYT)


[A very interesting article from the NYT describing a hybrid robot that is 
operated by the brain cells of a rat. In my research on wearable computers 
I often come accross projects, products and ideas that use technology to 
augment the human. This research stream tends to come out of AI research 
(paradoxically) and aims at the creation of the so-called cyborgs or 
man-machines.  The robot described here is an intriguing example of the 
opposite: physically using biology to augment technology. Both kinds of 
augmentation or experimentation pose questions about the ability to discuss 
'essences' and boundaries (and the more obvious questions of control, 
privacy, etc). ana]


http://www.nytimes.com/2003/05/15/technology/circuits/15next.html
The New York Times
May 15, 2003
By ANNE EISENBERG

Wired to the Brain of a Rat, a Robot Takes On the World

The nerve center of a conventional robot is a microprocessor of silicon and 
metal. But for a robot under development at Georgia Tech, commands are 
relayed by 2,000 or so cells from a rat's brain.

A group led by a university researcher has created a part mechanical, part 
biological robot that operates on the basis of the neural activity of rat 
brain cells grown in a dish. The neural signals are analyzed by a computer 
that looks for patterns emitted by the brain cells and then translates 
those patterns into robotic movement. If the neurons fire a certain way, 
for example, the robot's right wheel rotates once.

The leader of the group, Steve M. Potter, a professor in the Laboratory for 
Neuroengineering at Georgia Tech, calls his creation a Hybrot, short for 
hybrid robot.

"It's very much a symbiosis," he said, "a digital computer and a living 
neural network working together."

Dr. Potter has been building the system of hardware, software, incubators 
and rat neurons that constitute the Hybrot since 1993, when he was a 
postdoctoral student at the California Institute of Technology. He and his 
group have not only introduced the neurons to the world outside their dish; 
the team has also closely monitored minute changes that take place in the 
shape and connections of the neurons as they are stimulated, using 
techniques like time-lapse photography and laser imaging.

Dr. Potter hopes that close observation of how brain cells behave as they 
are exposed to a world of sensation will help researchers understand the 
way small groups of neurons go about learning. "If the network begins to 
get better at a job," he said, "we will watch what changed within the 
network to allow it to do that."

Dr. Jonathan Wolpaw, laboratory chief and professor of neuroscience at the 
Wadsworth Center of the New York State Department of Health and the State 
University of New York at Albany, said that Dr. Potter's research could 
yield a simple system for exploring the capacity of neurons and circuits to 
change based on incoming activity.

"These changes could be analogues of what happens in learning," Dr. Wolpaw 
said. "You are dealing with neurons, the same tissue as in a brain," 
although in a different setting and with different circuitry. "Some things 
presumably are in common, for example, the neuron's capacity for 
plasticity," he said.

In Dr. Potter's hybrid system, the layer of rat neurons is grown over an 
array of electrodes that pick up the neurons' electrical activity. A 
computer analyzes the activity of the several thousand brain cells in real 
time to detect spikes produced by neurons firing near an electrode.

A silver three-wheeled model of the robot is commercially available through 
the Swiss robotics maker K-Team (www.k-team.com) for about $3,000 and is 
about the size of a hockey puck. It trundles along at a top speed of one 
meter per second.

"We assign a direction of movement, say, a step forward, that is 
automatically triggered by a pattern of spikes," said Thomas DeMarse, a 
former member of Dr. Potter's group who is an assistant professor in the 
department of biomedical engineering at the University of Florida. "Twenty 
of these patterns, for instance, means 20 rotations of the wheel."

As the robot moves, it functions as a sensory system, delivering feedback 
to the neurons through the electrodes. For example, Mr. DeMarse said, the 
robot has sensors for light and feeds electrical signals proportional to 
the light back to the electrodes. "We return information to the dish on the 
intensity of light as the robot gets closer and the light gets brighter."

The researchers monitor the activity of the neurons for new signals and new 
connections. Dr. Potter said that the feedback mechanism was crucial to the 
functioning of the neural network. In traditional, isolated cultured 
networks, he said, in which neurons are not connected to a body, the 
activity patterns of the neurons are largely pathological. "They behave in 
an aberrant way," he said. "It's a symptom of sensory deprivation, because 
the neurons are not receiving the input they usually get."

He decided to provide a body for the neurons early in his research, first 
in computer simulation and then in reality, so that neurons would have 
feedback. In that way, if the cells learned, he and his group might observe 
the changes that came about in the network. "People say learning is a 
change in behavior that comes from experience," he said. "For a cultured 
network to learn, it must first be able to behave."

There is an analogy to the human nervous system in the feedback loop 
developed by Dr. Potter, said Nicholas Hatsopoulos, an assistant professor 
in the department of organismal biology and anatomy at the University of 
Chicago.

Dr. Hatsopoulos also works on brain-machine interfaces, including ways that 
brain signals may one day be used to move prosthetic devices.

"Potter's device has sensors that pick up information, and then the signals 
go back to the dish and stimulate the cells," he said. Similarly, he said, 
"signals out of the brain control the arm, but there are also sensors in 
the muscles and skin that send information back, too."

Such feedback loops are necessary to basic research in brain-machine 
interactions, he said. Researchers need not only to record signals that 
drive a device but also take signals from sensors and stimulate the nervous 
system. "Closing the loop will be a key issue in moving this field to the 
next level, for the feedback presumably helps learning," he said.

Miguel A. L. Nicolelis, a neuroscientist at Duke University, has identified 
signals generated by a monkey's brain as it gets ready to move, and then 
used the signals to move a robotic arm. "We are discovering that when 
animals learn to operate a robotic device, the operation changes the 
sensory and motor maps of the animal," he said. "Steve is looking for the 
same thing at the cellular level."

Dr. Potter has not yet demonstrated learning in his network but said he 
might be able to do so within six months. In experiments, Dr. Potter said 
he hoped to observe the Hybrot following an object at a certain distance.

"The next step is to watch it to see if it becomes better at following this 
object," he said. "That would become exciting."






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