The researchers attached electrodes to 177 cells in an anesthetized
cat's thalamus, a region of the brain falling about half-way in the
visual processing pathway.

Having recorded patterns of firing as various scenes were flashed
before the cat's eyes, the team was able to reconstruct very
closely what the animal saw, which varied from people's faces to
scenes of a dark forest.

The research was applauded by other neuroscientists.

"The demonstration that you can reconstruct a movie from the
multiple cells in the thalamus is an important step in our
understanding of how signals are represented in the activity of
populations of cells," said Fred Rieke, an assistant professor of
physiology and biophysics at the University of Washington.

Stanley, an assistant professor of biomedical engineering, said the
research provides clues about how prosthetics may one day be wired
into the mammalian nervous system. By understanding the language of
the brain, scientists will be able to create devices that talk to
it, he said.

"Trying to understand how the brain codes information leads to the
possibility of replacing parts of the nervous system with an
artificial device," he said.

Stanley predicted that in the next couple of decades, as more and
more of the neural code is decoded, brain interfaces may start to
appear.

But he cautioned it may take a lot longer. He noted that the team
also recorded the activity of cells higher up in the cat's visual
pathway -- in the visual cortex -- but the results were not as
startling because of the greater complexity of the cells.

"So little is understood about thoughts, perceptions, dreams, it's
impossible to predict how much progress we'll make in understanding
them," he said.

However, Ken Miller, as associate professor at the University of
California, San Francisco, said researchers around the world are
using similar techniques to decode higher brain functions.

"These methods could be applied to further up the visual pathway,"
he said. "It will become more difficult ... but it's a promising
direction."

The experiments were reported in the September 99 issue of the Journal
of Neuroscience.
                             -118-