The hippocampus area of the brain is known as the memory center, and this is where the researchers have focused on for their new brain implant.
Results from work with the brain implant - which was developed by researchers at the University of Southern California (USC) and the Wake Forest Baptist Medical Center in North Carolina - were recently presented at the 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society in Italy in August.
The implant includes electrodes that are placed in regions of the hippocampus, known as the memory center of the brain.
It was designed at USC and tested at Wake Forest, building on previous research by Ted Berger and utilizing a new algorithm designed by Dong Song, both from USC.
Researchers explain that when the brain receives sensory information, it forges a memory by sending complex electrical signals that travel through areas of the hippocampus. Here, the signals are re-encoded until they reach a final region, where a completely different signal is sent for long-term storage.
However, if any region has damage, it prevents the translation, resulting in a missed opportunity for long-term memory formation. This is why someone with Alzheimer's disease, for example, can recall events from the past - before brain damage occurred - but are unable to form newer long-term memories.
Algorithm predicts signals with 90% accuracy
Song and Berger built on neural data involving models and algorithms from Sam Deadwyler and Robert Hampson, of the Department of Physiology & Pharmacology at Wake Forest Baptist. As a result, the USC researchers were able to accurately imitate how a memory is translated from short-term into long-term memory.
They first did this using data from animals, but they were then able to mimic memory formation with human data.
Fast facts about Alzheimer's disease in the US
- Alzheimer's is the sixth leading cause of death
- It is the only cause of death in the top 10 that cannot be prevented, cured or slowed
- Among seniors, 1 in 3 die with Alzheimer's or another dementia.
Using patients who already had electrodes in the hippocampus region of their brains to treat chronic seizures, Deadwyler and Hampson first "read" the electrical signals that resulted from memory formation and then sent the data to Song and Berger.
The two USC researchers then put the signals into their model to read how the signals from the first hippocampal region were translated by the second region.
Results showed that, after hundreds of trials conducted with nine patients, the algorithm was able to predict how the signals would be translated with about 90% accuracy.
In effect, although there is currently no way of "reading" a memory simply by looking at its electrical signal, the researchers' prosthesis bypasses the damaged hippocampal section to give the next region the correctly translated signal.
"It's like being able to translate from Spanish to French without being able to understand either language," says Berger.
'Potential effective treatment for some symptoms of dementia'
The prospect of providing a solution for patients with memory loss is an exciting breakthrough in neural research - one that has caught the attention of Dr. Clare Walton, research manager at the Alzheimer's Society in the UK.
"Although this sounds like the stuff of science fiction stories," she says, "the researchers are addressing a major problem for people with Alzheimer's disease and other forms of dementia - the ability to lay down new memories."
Dr. Walton adds:
"If this device is developed further and successfully tested in humans, it could prove to be an effective treatment for some of the symptoms of dementia, however it will not cure or slow down the progression of the condition."
Next steps for the researchers involve attempting to send back the translated signal in the brains of patients to try to bypass the damage, allowing long-term memories to form.
In September, Medical News Today reported on a study that suggested a new brain imaging technique can show damage caused by high blood pressure before any symptoms of damage are visible.