The U.S. Department of Defense is spending $40 million to develop implantable devices to restore memories in people suffering from trauma and neurological disorders.
More than 270,000 military servicemembers have been diagnosed with traumatic brain injury since 2000, and 1.7 million U.S. civilians are affected every year. The goal is to develop wireless neuroprosthetics to bridge the gaps that interfere with the ability to form new memories or retrieve old ones, the Defense Advanced Research Projects Agency (DARPA) announced this week.
To that end, teams from the University of California, Los Angeles, and the University of Pennsylvania were selected to begin leading the agency’s Restoring Active Memory (RAM) program, part of President Obama’s BRAIN Initiative. They’ll receive up to $15 million and $22.5 million, respectively, over four years to develop and test electronic interfaces that not only sense memory deficient but also restore normal function. Lawrence Livermore National Laboratory will receive $2.5 million to develop a device for UCLA’s effort.
Both teams will start with the basics: explore new ways to decode neural signals to understand what sorts of stimulation could help reestablish the brain’s ability to process new memories after an injury. They’ll also design computer models that describe how neurons encode memories. Building on that foundation, the teams will work with volunteers who suffer from memory deficits, along with patients undergoing neurosurgery for conditions such as epilepsy and Parkinson’s.
UCLA researchers previously demonstrated that memory could be facilitated by stimulating a brain region called the entorhinal. It’s known as the entrance to the hippocampus, our memory forming and storing area. “The entorhinal cortex is the 'golden gate' to the brain's memory mainframe,” UCLA’s Itzhak Fried says in a university statement. “Every visual and sensory experience that we eventually commit to memory funnels through that doorway to the hippocampus. Our brain cells send signals through this hub in order to form memories that we can later consciously recall.”
The team will collect data from patients already implanted with brain electrodes for their epilepsy treatment. The data will help them develop a model of the hippocampal-entorhinal system, which will be used to test memory restoration in patients.
The Penn team's approach is based on an understanding that memory is a result of complex interactions among widespread brain regions. The team will record neural activity from electrodes already implanted in patients as they play memory games, and they'll measure “biomarkers” of successful memory function -- patterns of activity that accompany the successful formation of new memories and retrieval of old ones.
“Biomarkers of good memory function will guide our ability to stimulate the brain to synthesize patterns of neural activity conducive to proper memory function,” Penn’s Michael Kahana says in a news release. “By deciphering the unique spatiotemporal maps of good memory function in each participant, we can determine how to use brain stimulation to gently coax brain activity out of dysfunctional states and towards optimal ones.”
UCLA’s device will be implanted into the entorhinal and hippocampal areas of patients with traumatic brain injury. Penn’s device will modulate many different brain regions involved with memory.