From: Michael M. Butler (butler@comp-lib.org)
Date: Wed May 01 2002 - 22:48:26 MDT
Scientists unveil the Ratbot, a robot with whiskers
Rodent with newly developed brain implants and radio backpack could be used to
find earthquake victims or detect land mines
By Steve Connor Science Editor
http://news.independent.co.uk/world/science_medical/story.jsp?story=291019
02 May 2002
The age of the robotic rodent is upon us. A study has shown the movements of a
live rat can be controlled by using a laptop computer, a radio and a set of
microelectrodes implanted into the animal's brain.
"Ratbot", as the creature has been named, could one day be used to rescue
earthquake victims buried under rubble, seek out land mines or even, with the
help of miniature video cameras, spy inside secret installations.
Scientists used brain implants and tiny radio "backpacks" to guide five rats
through a complex maze, composed of ladders, steps, hoops and ramps, from a
distance of more than 500 yards.
Human operators were able to steer the Ratbots through the obstacle course as
if they were guiding intelligent robots, said Sanjiv Talwar, a researcher at
the State University of New York, who helped to run the study, published in
the journal Nature.
"One can think of the guided rat as a very good robot platform capable of
traversing terrain that modern robots are unable to do," Dr Talwar said
yesterday.
The experiment involved exploiting the principle that an animal can be trained
to do tasks by stimulating "reward" regions of the brain that normally respond
to food, drink and sex.
Professor Patrick Bateson, an expert on animal behaviour at Cambridge
University, said: "It's been known for a long time that animals will work like
anything to get these rewards."
In conventional animal training, a morsel of food can be used as a reward "re-
inforcement". In laboratory tests going back 40 years scientists have shown
that direct electrical stimulation of the brain's pleasure centres is just as
good or even better.
In this latest experiment, microelectrodes implanted directly into the reward
centre of the rat's brain – a region called the medial forebrain bundle – were
stimulated each time the rat made a move in the "correct" direction.
At the same time, the scientists implanted another set of electrodes into the
brain regions receiving nerve impulses from the right and left set of
whiskers. The rats were trained to move to each side depending on which set of
whiskers was stimulated. If they did it correctly they were given a "reward"
to the medial forebrain bundle.
The rats also quickly learnt to associate the stimulation of their brains'
reward centres with simply walking forwards, even if this involved climbing or
descending ladders or steps, or moving into the centre of a brightly lit room
– something that most rats would avoid.
Dr Talwar said, however, that there were clear limits to what each rat could
be made to do. "The rats worked within their instincts. They appeared to
finely calibrate their awareness of a difficult obstacle versus the pleasure
they would receive if they overcame it," he said.
Nevertheless, the rats were easily guided through pipes and across elevated
runways and ledges, and could be instructed to climb, or jump from, any
surface with a good foothold, such as a tree, the scientists write in Nature.
"We were also able to guide rats in systematically exploring large, collapsed
piles of concrete rubble, and to direct them through environments that they
would normally avoid, such as brightly lit, open areas," they say.
John Chapin, the leader of the research team and professor of physiology and
pharmacology at the State University of New York, said that the rats could be
made to "search" for an hour without showing any signs of getting tired or
bored. "A search-and-rescue dog costs $60,000 [£43,000] to maintain and you
cannot use them in very tight spaces," Dr Chapin said. "Nor could you use a
dog to discover land mines, since the weight of the animal would detonate the
explosive. A rat, however, being small and light, could sit on the mine
without exploding it.
"In addition, rats are more mobile than mechanical robots, which are often
stymied by obstacles such as fences, rocks and debris. While robots would be
useful in environments where a living thing could not survive, such as where
there are fires or poisonous gases, the rat has rather sophisticated
navigational skills developed over 200 million years of evolution. It makes
sense to make good use of the animal's abilities," Dr Chapin said.
The Chapin team published work in 1999 showing that rats could be trained to
operate a robotic arm using the power of thought alone.
In this experiment, each rat had microelectrodes implanted into the region of
the brain that controlled the movement of its limbs. The animals were then
trained to operate a lever with a foot to release food.
After a period of time, the operation of the lever was taken over by a
mechanical arm and each rat quickly learnt that the mere thought of using its
limbs to operate the lever still resulted in access to the food.
Another set of experiments a year later on monkeys showed that the same
principle could be applied to primates. In this test the scientists even
managed to get the monkeys to use mind control to operate robotic arms over
the internet some 600 miles away.
One aim of the research is to develop a means whereby severely paralysed
patients could control the movements of robot arms and other devices by the
power of thought alone.
According to Dr Talwar, the latest work on Ratbot could lead to a way of
controlling a robotic arm with the extra help of the sense of touch.
"The larger idea behind the study was to continue our research in
neurorobotics," Dr Talwar said. "We wanted to get an idea about how
effectively can animals sense brain- stimulation cues. This would enable us to
evaluate the feasibility of a 'sensory' prosthesis, which could enable
paralysed patients to experience sensations such as touch and so be able to
better control an artificial limb through a suitable brain-machine interface,"
he said.
If this research continues to advance, the age of Ratbot could be a prelude to
the day when paralysed humans could operate artificial limbs, just like the
half-human cyborgs of science fiction.
Animal Magic: From dogs to dolphins
Search-and-rescue dogs
The St Bernard is thought to be the oldest working dog specifically bred for
search-and-rescue missions. Its origin is inextricably linked to the Great St
Bernard Pass which provides a snow-bound route between Switzerland and Italy.
Guide dogs for the blind
Dogs were trained as guides for the blind as early as 1819 in Vienna but it
took a further 100 years for the movement to take hold internationally,
boosted by the number of blinded soldiers returning from the First World War.
Workhorse elephants
Training of elephants begins when they are three years old and is carried out
by a "mahout" and his apprentice who will bond with the animal for life. A
mature elephant can lift 1,500lb (700kg) and haul a log for more than half a
mile.
Cormorant fishing
Cormorants are first-rate fishing birds and are easily able to seek out and
capture their prey. Chinese fishermen train their cormorants to fish off
boats, tying their necks with string to prevent the birds swallowing their
catch.
Military dolphins
At the height of the Cold War both the US and the USSR had secret programmes
involving dolphins. The Soviet navy had a stable of about 70 dolphins
stationed in the Black Sea, trained to hunt down divers in military ports.
Also from the Science/Medical section.
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