Huge Breakthrough: Prosthetics to Help Memory Loss in Alzheimer's
One of the recurring themes of science fiction has been the idea of science shoring up, improving, or wholesale replacing of memories. In fact it is a major subplot of my own novel, Darkship Renegades.
Like many other things that seemed impossible, or so far-fetched as to be almost fantasy, it turns out it’s now a reality.
Scientists at Wake Forest Baptist Medical Center and the University of Southern California (USC) have managed to create and implant a prosthetic system that uses a person’s own memory patterns to facilitate the brain’s ability to create and recall memories.
In the pilot study, published in today’s Journal of Neural Engineering, participants’ short-term memory performance showed a 35 to 37 percent improvement over baseline measurements. The research was funded by the U.S. Defense Advanced Research Projects Agency (DARPA).
“This is the first time scientists have been able to identify a patient’s own brain cell code or pattern for memory and, in essence, ‘write in’ that code to make existing memory work better, an important first step in potentially restoring memory loss,” said the study’s principal investigator Robert Hampson, Ph.D., professor of physiology/pharmacology and neurology at Wake Forest Baptist (and a personal friend.)
The particular type of memory targeted was episodic memory. This memory is the one most commonly lost by people with Alzheimer’s disease, stroke and head injury. In other words, the conditions that most often rob people of their ability to function intellectually.
Episodic memory is the storing of knowledge which is new and useful within a short space of time, such as where you parked your car or exactly what your character was doing in the last chapter you wrote before going downstairs for a cup of coffee, not long-term, stored memory like what you learned in school, your social security number, or the way to your first home.
The researchers enrolled epilepsy patients at Wake Forest Baptist who were participating in a diagnostic brain-mapping procedure that used surgically implanted electrodes placed in various parts of the brain to pinpoint the origin of the patients’ seizures. Using the team’s electronic prosthetic system based on a multi-input multi-output (MIMO) nonlinear mathematical model, the researchers influenced the firing patterns of multiple neurons in the hippocampus, a part of the brain involved in making new memories in eight of those patients.
First, they recorded the neural patterns or ‘codes’ while the study participants were performing a computerized memory task. The patients were shown a simple image, such as a color block, and after a brief delay where the screen was blanked, the patients were then asked to identify the initial image out of four or five on the screen.
The USC team led by biomedical engineers Theodore Berger, Ph.D., and Dong Song, Ph.D., analyzed the recordings from the correct responses and synthesized a MIMO-based code for correct memory performance. The Wake Forest Baptist team played back that code to the patients while they performed the image recall task. In this test, the patients’ episodic memory performance showed a 37 percent improvement over baseline.