US researchers are banking on the hope that electrical devices implanted in the brain might one day restore memory to people who have lost it. On 9 July, the Defense Advanced Research Projects Agency (DARPA) awarded a total of $37.5 million to two research teams to study how memories are formed and retrieved and to develop devices to stimulate these processes in the brain. Here Nature offers a preview of the research to come from these awards.
Where is the money coming from?
DARPA is one of three US agencies to receive funding this year through the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative, which President Barack Obama announced in April 2013.
DARPA has said that it plans to use its share of the money — $50 million this year — to fund study of brain disorders common to soldiers and veterans, such as post-traumatic stress disorder (PTSD) and memory dysfunction caused by traumatic brain injury. In May the agency awarded $56 million to support two teams in creating brain-stimulation devices to treat disorders such as PTSD and depression, and to map the neural circuitry involved in these conditions. The latest round of grants is focused on the use of such devices to restore memory function.
How will the devices be developed?
Both teams will initially be working with people with epilepsy who have entered hospital to have electrodes temporarily implanted into their brains to help locate where their seizures originate. The researchers will ‘piggyback’ off the implants, using them to monitor other brain activity, such as the electrical patterns that occur when the brain is storing or retrieving a memory.
What will each team focus on?
One group, led by psychologist Michael Kahana at the University of Pennsylvania in Philadelphia, will map the electrical patterns (made by firing neurons) that correspond with memory formation. The researchers plan to recruit 100 people with epilepsy, many of whom tend to have mild memory problems, and record the activity in their brains while they play a computer-based memory game.
By comparing the differences in the patterns between each volunteer’s personal best and worst scores, the researchers will develop an algorithm for a personalized stimulation pattern to keep the brain performing at its optimal level. Then they will use that pattern to fire electrodes implanted in each patient’s brain, controlling the monitoring and stimulation with an external device the size of an iPhone, Kahana says.
A second team, led by neurosurgeon Itzhak Fried of the University of California in Los Angeles, plans to go a step further by creating an implant capable of recording and analyzing brain activity and stimulating the brain in real time. The researchers say that their device will be one-tenth the size of the stopwatch-sized devices now used to treat Parkinson’s disease and depression.
This article is reproduced with permission and was first published on July 10, 2014.