Neural Computers

A microscopic view of the “brain in a dish,” or rat neurons growing on a multi-electrode array in a petri dish. (Tom DeMarse)

An array of rat brain cells has successfully flown a virtual F-22 fighter jet.… Enzymes were used to extract neurons from the motor cortex of mature rat embryos and cells were then seeded onto a grid of [60] gold electrodes patterned on a glass Petri dish.¹ When [Thomas DeMarse (pic), a biomedical engineer at the University of Florida in Gainesville,] first puts the neurons in the dish, they look like little more than grains of sand sprinkled in water. However, individual neurons soon begin to extend microscopic lines toward each other, making connections that represent neural processes. “You see one extend a process, pull it back, extend it out – and it may do that a couple of times, just sampling who's next to it, until over time the connectivity starts to establish itself,” he said. “(The brain is) getting its network to the point where it’s a live computation device.”²

Steven Potter, a biomedical engineer at the University of Georgia,…and DeMarse’s former supervisor, created in 2002 the Hybrot — or “hybrid robot” — a cup-sized robot controlled by an array of rat neurons grafted to silicon electrodes. The robot moves around in response to infrared signals that it converts into movement using a combination of its sensors and its “living” brain.

But until now, no one had written algorithms that harnessed neuronal responses to fly a plane. The ultimate aim is to put arrays of neurons into unmanned planes — or other dangerous situations — where only living brain cells can be relied upon to make the right decisions.

DeMarse’s array of 25,000 interconnected neurons were able to convert signals that indicated whether the simulated plane is experiencing stable conditions or hurricanes into a measurement of whether the plane is flying straight or tilted and then correct the flight path by transmitting signals to the airplane’s controls.³

When the system is first engaged, the neurones don’t know how to control the aeroplane; they don’t have any experience. “[But] over time, these stimulations modify the network’s response such that the neurones slowly [over the course of 15 minutes] learn to control the aircraft,” he said. “The end result is a neural network that can fly the plane to produce relatively stable straight and level flight.”⁴

The research is another step in one of the hottest areas of science these days. Computer wizards and biologists and neurologists around the world are trying to fabricate artificial brains, or neural networks, that can function on a human scale, taking over such tasks as piloting rescue aircraft into enemy territory.

There have been various reports of partial success. A team of Russian scientists claimed recently to have created an artificial brain that functions on a human level, although that claim has been met with broad skepticism in the west.

Most claims are far more modest, although it is clear that a marriage between neurology, or the study of the human brain, and high speed computers is leading into territory that sounds more like science fiction than fact. Some experts have warned that incredibly smart machines might someday leave the rest of us in the dust, usurping our self-appointed role as the most important creatures on the planet, if not the universe.⁵

Endnotes

¹ Jennifer Viegas (Discovery News), “Brain cells in a dish fly fighter plane,” NewScientist.com, 26 Oct 2004 (retrieved: 17 July 2010, quote from previous version).

² “UF scientist: ‘Brain’ in a dish acts as autopilot, living computer,” University of Florida press release, 21 Oct 2004, at http://www.eurekalert.org/pub_releases/2004-10/uof-us102104.php; Original news release can be found at http://www.napa.ufl.edu/2004news/braindish.htm.

³ “Brain cells,” NewScientist.com.

⁴ Jennifer Viegas (Discovery News), “Brain-in-a-dish flies plane,” Australian Broadcasting Company, 26 Oct 2004.

⁵ Lee Dye, “Scientist Build a ‘Brain’ From Rat Cells,” ABC News, 30 Oct 2004.

Neural Computers

Endnotes

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