THE advent of 鈥渃yborgs鈥� has been brought a step closer by the creation of a
strange hybrid creature with a mechanical body controlled by the brain of a
fish. As ghoulish as this chimera sounds, it may one day allow people to be
fitted with prosthetic devices that are controlled directly by their brain.
Light sensors housed in the mechanical body feed the brain sensory
information. The brain tissue processes this information to generate command
signals which tell the robot鈥檚 motors which way to turn in response to its
environment. Steve Grand, an expert in artificial life with Cyberlife Research in
Somerset, describes the work as 鈥渓audably perverse鈥� and likely to bring the
world of cyborgs one step closer.
The robot possesses only a few neurons borrowed from the sea lamprey
Petromyzon marinus, a primitive eel-like vertebrate. Yet it still displays
apparently 鈥渃omplex鈥� behaviours in response to simple light stimuli. Ferdinando
Mussa-Ivaldi of Northwestern University in Chicago and his colleagues at the
University of Illinois also in Chicago and the University of Genoa, Italy,
describe it as an 鈥渁rtificial animal鈥�.
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To create the hybrid, the team extracted a lamprey鈥檚 brainstem and part of
its spinal cord under total anaesthetic, and maintained it in an oxygenated and
refrigerated salt solution. The researchers then located a group of a few very
large nerve cells known as M眉ller cells. These cells, which are easy to
access and have been extensively studied, are responsible for integrating
command and sensory signals directed to the motor nerves, helping the lamprey
orient itelf.
Mussa-Ivaldi and his colleagues then attached electrodes to stimulate the
M眉ller cells with the sorts of frequencies they would normally receive.
Other electrodes monitored the activity at the axons, the output part of the
neurons.
The robot itself is a commercially available module called a Khepera and
couldn鈥檛 look less like a lamprey. With two wheels and a body made up of a
couple of circular circuit boards it looks more like a wired-up Oreo biscuit
than a cyborg. The researchers didn鈥檛 mount the brain tissue on the robot, but
connected it by wire.
When the robot was presented with a number of light stimuli, its lamprey
brain responded with a variety of behaviours, such as following the light,
avoiding the light and moving in a circle.
The research was originally intended to explore how brain cells adapt to
changing stimuli. But Mussa-Ivaldi hopes that learning how neurons can
communicate with artificial machines will have other benefits. 鈥淲e will be able
to build better prosthetic limbs and devices for disabled people,鈥� he says.
Team member Vittorio Sanguineti of the University of Genoa says the work can
also reveal the principles of how the brain learns and how memory works. The
work will be presented at Artificial Life 7 in Portland, Oregon, in August.
Kevin Warwick, a cyberneticist at Reading University, believes that it may
even one day be possible to have your brain transferred to a robot when your
body dies. It would be extremely difficult, 鈥渂ut mapping the entire brain to a
robot can鈥檛 be ruled out鈥�, he says. More realistic, he says, is connecting
electronic devices such as mobile phones directly into our brains.