

Tuesday, June 21, 2011

Memory chips and brain signal transmitters

In the movie Eternal Sunshine of the Spotless Mind, a technique has been developed which allows your memories to be selectively erased.  If you want to forget an unpleasant breakup, erase the pain of a traumatic event, or just have the opportunity to experience again reading your favorite book for the first time, you can go in and have Lacuna, Inc. selectively delete those memories.

We have just taken a step closer to being able to do that.

A team of scientists from Wake Forest University and the University of Southern California have developed a "neural prosthesis" which, when installed into the brain of a rat, allowed the scientists to delete and retrieve a specific memory.  Rats were trained to press one of two levers for food, but had been given a drug which inhibited a part of the hippocampus that allows the processing of short-term memory into long-term memory.  With the prosthesis in place, electrodes inserted into the hippocampus, the scientists were able to trigger them to remember what they'd forgotten.

“Flip the switch on, and the rats remember.  Flip it off, and the rats forget,” team leader Dr. Theodore Berger said.

The application of this technology to individuals with memory loss from Alzheimer's, dementia, or stroke is obvious.  There needs to be a memory trace there to amplify -- so the idea of using it in cases of severe brain damage is probably going to be limited, at least for the reasonable future.  But the ability of doctors to enhance memory selectively is heady stuff.  Couple that with more information about how memory is encoded in the first place -- a hot area of research at the moment -- and we'll be that much closer to creating prosthetic memory interfaces for the human brain.

Also in the news is a story about a different sort of brain implant -- one which might eventually help the paralyzed to walk again.

Developed at the University of Michigan - Ann Arbor, the BioBolt implant allows the brain to use the skin as a conductor, and send wireless signals.  This could allow a quadriplegic to, for example, operate a computer.  Ultimately, the interface could allow the brain to send signals to muscles, effectively routing motor impulses around the sites of damage that are preventing a person from walking.

"The ultimate goal is to be able to reactivate paralyzed limbs, by picking the neural signals from the brain cortex and transmitting those signals directly to muscles," said Dr. Kensall Wise, who is also founding director of the NSF Engineering Research Center for Wireless Integrated MicroSystems.  Wise did state that scientists are years away from these applications in humans, but just having a low-energy brain interface that can be installed in a minimally invasive fashion is a tremendous advance.   Previous incarnations of the the device had to be implanted through a hole in the skull; the BioBolt is implanted under the skin of the skull, and acts like a "microphone" to pick up, amplify, and transmit signals from the neurons.

Advances such as these never fail to awe me.  I know we're still a long way from restoring memory in individuals with brain damage (or enhancing memory in people who are normal), or seeing the paralyzed walk.  But just the fact that the scientists have accomplished this much is positively stunning, and my sense is that this is only the beginning.  It makes me think of the quote from Napoleon Hill:  "What the mind can conceive, it can achieve."

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