Alzheimer’s memories could be switched back on with implant

Alzheimer’s sufferers could once again remember the faces of loved ones, or find their way back home, after scientists developed a way to boost memories.

In a groundbreaking pilot study, US researchers recorded memories as they were being formed and then later played them back into the brains of 10 patients.

They found that it increased memory performance by up to 37 per cent.

The study was funded by US Department of Defense's military research department, (Darpa), and focused on improving episodic memory, which is the most common type of memory loss in people with Alzheimer's disease, stroke and head injury.

Episodic memory is information that is new and useful for a short period of time, such as where you parked your car or left your keys.

Patients had implants placed in their heads then were asked to look at images as their brainwaves were recorded  - Credit: Wake Forest Baptist 
Patients had implants placed in their heads then were asked to look at images as their brainwaves were recorded Credit: Wake Forest Baptist

“This is the first time scientists have been able to identify a patient's own brain cell code or pattern for memory and, in essence, write in that code to make existing memory work better, an important first step in potentially restoring memory loss,” said Dr Robert Hampson, professor of physiology/pharmacology and neurology at Wake Forest Baptist.

“In the future, we hope to be able to help people hold onto specific memories, such as where they live or what their grandkids look like, when their overall memory begins to fail.”

"We envision this system being made into an implant to provide continuous support to a person’s ability to encode and store new memories.

Scientists replayed memories back into patients brains and boosted their performance  - Credit: Wake Forest Baptist
Scientists replayed memories back into patients brains and boosted their performance Credit: Wake Forest Baptist

"A patient would visit with a clinician periodically to ensure the system is working properly, but the closed-loop system is being designed to continuously read, analyze, and support the patient’s innate memory function." 

Around 850,000 people are suffering from dementia in Britain, and around two thirds have Alzheimer’s disease, in which sticky amyloid plaques build up in the brain, preventing brain cells from communicating, and wiping out memory.

For the new study, researchers enrolled 10 epilepsy patients who were already participating in an separate experiment mapping their brains, and so already had electrodes implanted in their heads.

The participants were asked to study a simple image - such as a coloured block - while their brain activity was recorded. Scientists then blanked the screen and asked them to choose the correct image from five options.

The electrodes monitored brain activity while patients were involved in memory tasks then fed it back later  - Credit: Wake Forest Baptist 
The electrodes monitored brain activity while patients were involved in memory tasks then fed it back later Credit: Wake Forest Baptist

They found that when they asked people to remember, while playing back the recorded memory into the hippocampus region of their brains, their performance improved by 37 per cent. The hippocampus is responsible for forming memories, and spatial recognition and is one of the first areas to be damaged in Alzheimer’s disease.

In a second test, participants were shown a highly distinctive photographic image, followed by a short delay, and asked to identify the photo out of four or five others on the screen 75 minutes later. They found that playing back the recorded memories boosted recall by 35 per cent.

“We showed that we could tap into a patient's own memory content, reinforce it and feed it back to the patient,” added Dr Hampson.

"Even when a person's memory is impaired, it is possible to identify the neural firing patterns that indicate correct memory formation and separate them from the patterns that are incorrect.

“We can then feed in the correct patterns to assist the patient's brain in accurately forming new memories, not as a replacement for innate memory function, but as a boost to it.”

Commenting on the research, British experts said the study provided important ‘stepping stones’ into understanding how memories form, which could one day lead to new treatments for Alzheimer’s disease.

Dr James Pickett, Head of Research at Alzheimer’s Society, says: “Future tests using this method in people with Alzheimer’s could represent a vitally needed new form of treatment for dementia.

“With no new drug for dementia in the past 15 years, and one person developing the condition every three minutes, it’s more urgent than ever to find new ways to treat the condition.

“These kind of ‘first-in-human’ studies are important stepping stones to understanding how we make memories.”

Dr David Reynold’s, Chief Scientific Officer at Alzheimer’s Research UK, added: “People with Alzheimer’s disease often have difficulty recalling recent events, even while still being able to remember things that happened decades earlier.

"Techniques that boost a person’s ability to lay down new memories could potentially help tackle one of the most common symptoms affecting people with dementia.

“Complex technologies like this take years of research to hone, but improving life changing symptoms like memory loss is an urgent goal for dementia research. To accelerate progress towards new treatments we must see continued investment in research.”

The research was published in the Journal of Neural Engineering.