by John B. Carnett: The quest to restore damaged cognitive functions with electronic parts begins with a small dish of living rat brains [above], located inside a lab at the University of Southern California. Photo by John B. Carnett

In wet lab 412C on the University of Southern California´s Los Angeles campus, Vijay Srinivasan is poking a long, evil-looking needle at a slice of rat brain about half the size of a fingernail. All around him, coils of cable are piled near hulking microscopes. Glass vials and fluid-filled plastic dishes compete for space with spare keyboards and computer chips. The place looks more like a computer-repair shop than a world-class laboratory.

â€Watch this,†says Srinivasan, a design engineer working with USC´s Center for Neural Engineering. A thin wire runs between the needle and a tiny silicon chip hooked up to a boxy signal transmitter. He flips a switch, and a series of small waves shimmers across a nearby screen-waves that mean exactly zilch to me. Watch what? I wonder.

Srinivasan explains that the chip is sending electric pulses through the needle into the brain slice, which is passing them on to the screen we´re watching. â€The difference in the waves´ modulation reflects the signals sent out by the brain slice,†he says. â€And they´re almost identical in frequency and pattern to the pulses sent by the chip.†Put more simply, this iron-gray wafer about a millimeter square is talking to living brain cells as though it were an actual body part.

Ted Berger, Srinivasan´s boss and the mastermind behind the tangle of coils and electrodes, has arranged this demonstration to provide a small but profound glimpse into the future of brain science. The chip´s ability to converse with live cells is a dramatic first step, he believes, toward an implantable machine that fluently speaks the language of the brain-a machine that could restore memories in people with brain damage or help them make new ones.

Remedying Alzheimer´s disease would, if Berger´s grand vision plays out, be as simple as upgrading a bit of hardware. No more complicated drug regimens with their frustrating side effects. A surgeon simply implants a few computerized brain cells, and the problem is solved.

Down the hall, Berger rises to greet me in his office. An imposing man with a shock of gray hair, Berger, 56, has the thick build of an aging athlete and the no-nonsense manner of a CEO. Can a chunk of silicon really stand in for brain cells? I ask. â€I don´t need a grand theory of the mind to fix what is essentially a signal-processing problem,†he says. â€A repairman doesn´t need to understand music to fix your broken CD player.â€