Brain implant may restore memory

Guardian 13:03:03
Tim Radford Science editor
US researchers are poised to test an artificial aid to the brain. They have made a mathematical model of a memory store called the hippocampus, and programmed it on to a silicon chip. This could one day be fitted to a human with brain damage from stroke, epilepsy or dementia.

Futurologists have talked for more than a decade about "downloading" human memory on to a chip and preserving it as an implant. But for the first time, some scientists think they can see a way to do it.

The hippocampus is one of the most studied parts of the brain. It processes experiences so that they can be stored as memories. Last year, a US researcher "eavesdropped" on nerve cell firings in a sleeping rat's hippocampus and claimed to read its dreams. Three years ago psychiatrists revealed that London taxi drivers - famous for their encyclopaedic knowledge of London - had, on average, hippocampuses that were bigger than those of a comparable group of ordinary motorists.

New Scientist reports today that a team at the University of Southern California in Los Angeles will soon test their artificial hippocampus by linking it with live tissue taken from rat brains. They could then fit the silicon memory aid to live rats and monkeys trained to perform memory tasks.

"If you lose your hippocampus, you only lose the ability to store new memories," Theodore Berger, a biomedical s engineer and leader of the team, told the magazine. Eventually, researchers will test the hypothesis by stopping a monkey's hippocampus and by-passing it with the chip. If the animal regains the ability to store new memories, then the chip must have worked.

Professor Berger promised five years ago that mathematics might one day help engineers "speak to the brain in its own language" and help researchers understand the basis of thought.

Although an artificial brain device could help people with memory damage, it does raise ethical problems. "If someone can't form new memories, then to what extent can they give consent to have this implant?" asked Joel Anderson, a bio-ethics expert at Washington University in St Louis, Missouri.