Newspapers have reported on a prosthetic brain implant with the potential to help treat people with memory loss. This device is being developed with funding from DARPA (the US Defence Advanced Research Projects Agency) to help soldiers with memory loss, but the news reports say that it could also be used to treat people with dementia. Here we look at the research behind the headlines in more detail.
What is this brain implant and how could it work?
People with Alzheimer’s disease and other forms of dementia often have problems with their short-term memory. While they may be able to recall events from long ago, they can struggle to remember things that happened yesterday. This is because they have damage to an area of the brain called the hippocampus, which plays an essential role in the creation of new memories.
When we make a memory, our senses such as sight, sound and touch generate electrical signals which are processed in the hippocampus and passed out into other areas of the brain for long-term storage. In theory, this implant would work by allowing the signals to bypass the damaged hippocampus and be processed artificially into a signal that can be committed to memory.
What research has been done?
Over the last decade, researchers in the US have made electrical recordings from the animal hippocampus and used it to model the complex processes that occur when a new memory is formed. They were then able to deliver electrical signals generated by the model back in to the brain of primates and found it could enhance their memory performance.
Human memories are much more complicated than those of rodents and primates. In their latest work the researchers have recorded from the brains of 9 people and used it to develop a computer model of how the human hippocampus forms memories. The next steps will be to design an implant device that can send electrical signals into the human brain and test it in people with a damaged hippocampus.
What does it mean for people with dementia?
In recent years there has been much interest in brain implants for people with paralysis to help them to regain movement, but this is the first time we’ve heard about implants being developed to help restore memory. Whilst it is exciting that such cutting edge techniques are being applied to the problem of memory loss, it is important to realise that this research is still in its infancy and there is still a great deal that we don’t understand about memory formation.
It will take at least a decade or more for these implants to be further developed and tested in people with damage to their hippocampus. If the implants were found to work for people with dementia, they would only treat memory symptoms and not other symptoms of dementia such as visual disturbances or changes in behaviour, which are caused by damage to other areas of the brain. The implants would not cure dementia nor would they stop the condition from progressing.