- A computer made of neurons taken from
leeches has been created by US scientists. Bill Ditto: "They will
not get up and attack anyone"At the moment, the device can perform
simple sums - the team calls the novel calculator the "leech-ulator".
- But their aim is to devise a new generation
of fast and flexible computers that can work out for themselves how to
solve a problem, rather than having to be told exactly what to do.
- Professor Bill Ditto, at the Georgia
Institute of Technology, is leading the project and says he is amazed that
today's computers are still so dumb.
- Bill Ditto views his computer wetware"Ordinary
computers need absolutely correct information every time to come to the
right answer," he says. "We hope a biological computer will come
to the correct answer based on partial information, by filling in the gaps
- Well connected
- The device the team has built can "think
for itself" because the leech neurons are able to form their own connections
from one to another. Normal silicon computers only make the connections
they are told to by the programmer.
- This flexibility means the biological
computer works out it own way of solving the problem. "With the neurons,
we only have to direct them towards the answer and they get it themselves,"
says Professor Ditto.
- This approach to computing is particularly
suited to pattern recognition tasks like reading handwriting, which would
take enormous amounts of power to do well on a conventional computer.
- Each neuron's electrical activity corresponds
to a numberThe neurons are harnessed in a petri dish by inserting micro-electrodes
into them. Each neuron has its own electrical activity and responds in
its own way to an electrical stimulus.
- These features can be used to make each
neuron represent a number. Calculations are then performed by linking up
the individual neurons.
- Leech neurons are used because they have
been extensively studied and are well understood.
- Though much simpler, the neuron computer
works in a similar way to the human brain. Professor Ditto says a robot
brain is his long-term aim, noting that conventional supercomputers are
far too big for a robot to carry around.
Ditto: "We want to make a robot brain""We want to be able
to integrate robotics, electronics and these type of computers so that
we can create more sentient robots," he says.
- However, in the immediate future, the
team from Georgia Tech and Emory University are working on enabling their
computer to do multiplication.
- The biological computer is featured on
BBC One's Tomorrow's World at 1930 BST on Wednesday 2 June 1999.