Put aside the crossword puzzles and push the ginkgo biloba pills to the back of the shelf. The key to better memory may lie in three letters: ERC.
That stands for entorhinal cortex, a region that lies deep in the brain. In the first study of its kind, scientists at University of California Los Angeles (UCLA) showed that when they activated the ERC with electrodes, people’s spatial memory — the kind that helps you orient yourself or find your car in a parking lot — improved.
The small but intriguing study involved seven patients with epilepsy who had electrodes inserted in various parts of their brain to identify the source of their seizures. Alzheimer’s researchers saw an opportunity to test a controversial idea — that zapping certain parts of the brain might enhance recall in patients with memory disorders.
Previous studies of deep-brain stimulation have shown that the treatment holds promise for conditions such as Parkinson’s, Alzheimer’s and depression. And scientists have also been able to improve learning in animals by stimulating the brain. But human data on the effects of stimulation of the hippocampus, the part of the brain that receives information and consolidates it into memories, have suggested that the procedure actually disrupts normal memory-making.
Dr. Itzhak Fried, a neurosurgeon at UCLA, and his colleagues decided to test the idea anyway, focusing on the ERC, a region that neighbors the hippocampus. This region is thought to channel to the hippocampus continuous information from our daily experiences for processing and encoding into memory.
The researchers asked the seven patients to play a video game in which they acted as taxi drivers, responsible for taking passengers to six different stores in a virtual world. During trips to half the destinations, the researchers stimulated various parts of the patients’ brains, including the ERC (it didn’t hurt), while the drivers learned where the stores were located.
When fares to all six stores were repeated, patients chose shorter routes and arrived sooner at the locations they had learned while receiving stimulation to the ERC than to the stores they had learned without electrical stimulation.
The study is the first to hint that it’s possible to tweak parts of the human brain to enhance memory. The fact that the patients were able to find short cuts and get to their destinations faster suggested that they were remembering the layout of the virtual city better — in other words, that their spatial memory had improved. “This is an important step in understanding memory, but it’s a first step,” says Fried.
How well the findings will translate to Alzheimer’s patients with memory deficits isn’t clear, but Fried is encouraged by the fact that some of the epilepsy patients had memory problems, and that all of them, regardless of their recall abilities at the start of the study, had improved by the end. “We have to interpret the results cautiously — this is a preliminary study in a small group of patients — and obviously we need more studies to answer some big issues,” he says.
Those include the question of whether other types of memory, such as recall of words or more complex series of events, can be enhanced in similar ways, and if so, which parts of the brain’s memory hub are critical to creating those memories.
If the results hold up, Fried says it may be possible to develop some way of selectively activating the ERC to give failing memory systems a boost, such as with a device that can be switched on when people are trying to learn specific tasks.
The new study was published in the New England Journal of Medicine.