Earlier this year, we heard about how DARPA (the Defense Advanced Research Projects Agency) was setting up its new Biological Technologies Office. The goal of that division is to "merge biology, engineering, and computer science to harness the power of natural systems for national security." This week, the agency released details of one of the office's key projects, called Restoring Active Memory. It's aimed at using implantable "neuroprosthetics" to help army veterans and other people recover from memory deficits caused by brain injury or disease.

DARPA has already partnered with the University of California, Los Angeles and the University of Pennsylvania on the project. It will provide UCLA and Penn with research funds of up to US$15 million and $22.5 million respectively, plus it will also pay the Lawrence Livermore National Laboratory up to $2.5 million to develop UCLA's device.

The project will start with an attempt to build computer models that replicate the fashion in which neurons code declarative memories, or "parcels of knowledge that can be consciously recalled and described in words, such as events, times, and places." Additionally, the researchers will try to establish methods of electrically stimulating targeted regions of the brain, in order to help it encode new memories in cases where damage has been preventing it from doing so.

Once those goals have been achieved, the next step will involve developing actual devices that utilize the computer models to deliver the memory-forming stimulation.

The Californian approach

The UCLA scientists will be concentrating on part of the brain called the entorhinal area. Previous research has shown that the region, which is linked to the hippocampus, plays a crucial role in forming lasting memories based on daily experiences.

Using patients who already have electrodes implanted in that area for the treatment of epilepsy, the scientists plan on building a computer model of the hippocampal-entorhinal system, with an eye on its role in memory formation. They then hope to build a wireless neuromodulation device, implant it in the entorhinal area and hippocampus of test subjects suffering from traumatic brain injuries, and observe the results.

Getting a bigger picture

The University of Pennsylvania team, on the other hand, will be taking a wider approach. Going with the concept that "memory is the result of complex interactions among widespread brain regions," the researchers will be studying neurosurgical patients who have electrodes implanted in multiple parts of their brains. This will involve getting the patients to play computer-based memory games, and observing their ensuing neural activity via those electrodes.

The aim is to establish what neural activity patterns accompany the formation and retrieval of memories, and then artificially induce those patterns in brain-injured test subjects using a unique neural stimulation and monitoring system. That system is already being developed in a partnership with medical tech firm Medtronic.

The Restoring Active Memory project will be conducted over the next four years.

Source: DARPA via IEEE Spectrum