James Meek, science correspondent
The Guardian
Researchers
in Chicago have built a cyborg, a half-living, half-robot creature
which connects the brain of an eel-like fish to a computer and
is capable of moving towards lights.
The device,
developed at a research centre owned by Evanston's Northwestern
University, consists of the brain stem from the larva of a lamprey,
a bloodsucking fish, attached by electrodes to an off-the-shelf
Swiss robot.
In an arrangement
reminiscent of the genesis of the Daleks, the living brain floats
in a container of cool, oxygenated salt fluid.
Placed in
the middle of a ring of lights, the robot's sensors detect when
a light is switched on. It sends signals to the lamprey brain,
which returns impulses instructing the robot to move on its wheels
towards the light.
When all the
lights are off, the robot stays still. When one of the robot's
eyes is masked, the disembodied brain is temporarily confused,
but learns to compensate.
One of the
researchers, Sandro Mussa-Ivaldi, said the work was a step forward
in neural engineering. "There's an element of uniqueness
in what we've done, particularly in the fact we've created a closed
loop system, where the lamprey brain and the robot are exchanging
information," he told the Guardian.
Scientists
are exploiting the immature lamprey's instinct to keep itself
oriented the right way up in the water. In a cyborg arrangement,
that translates into seeking light.
The marriage
of baby bloodsucker and Swiss engineering has little chance of
conquering the universe as yet. Scientists can only keep the brains
alive for a few days and are unable to stabilise them long enough
to see whether they can remember anything.
But they hope
their work will ultimately lead to the creation of advanced, brain-controlled
prostheses for people whose normal ability to control their limbs
has been disrupted by a stroke or Parkinson's disease.
"The
focus of our work is not so much to create a cyborg as to create
a tool for investigating the organisation of the brain,"
said Dr Mussa-Ivaldi.
Other scientists
are already moving towards the practical application of microelectronics
to help the disabled.
In Atlanta,
scientists have implanted a tiny glass electrode in the cerebral
cortex of a quadriplegic patient and coaxed neurons to grow inside.
By attaching a transmitter, the patient was able to move a cursor
on a computer screen by thought alone.
The creation
of the cyborg brings closer the advent of machines with animal
parts. Advances in miniaturised electronics have inspired other
scientists to try to develop devices with living biological components.
The Washington
Post reported that an Iowan entomologist, Tom Baker, has attached
moth antennae, capable of detecting the smell of high explosives,
to an electronic device which reads variations in the nerve signals
sent out by the antennae when they pick something up.
But the electronics
are not sophisticated enough to distinguish one smell from another
- so as yet the half-moth, half-chip machine isn't much use for
its intended purpose, sniffing out land mines.
Dr Mussa-Ivaldi
said cyborgs were, in a sense, already all around us. "People
wearing prostheses could be considered cyborgs," he said.
"Some think that when we're attached to our internet connections,
we're cyborgs."
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