Building on previous studies showing that electromagnetic stimulation of the brain can improve the memory, researchers at Northwestern University have demonstrated that the process can be specifically targeted to improve precise memories, such as specific shapes and colors of objects.
Non-invasive, painless transcranial magnetic stimulation (TMS) can not only boost memory function, but has shown promise as a treatment for migraines, as a learning aid, and could even allow people to play games and send messages using just their brains. But in these cases, that stimulation was applied fairly broadly to the brain, described by the authors of the current study as like taking a hammer to it.
In this instance the team focused the stimulation like a scalpel, identifying and targeting the brain network responsible for spatial memory. The specific aim was to improve precise memory – the kind of memory is what allows you to recall particular details about something, such as its size, shape and color, in this case related to locations.
After the researchers stimulated the area with electromagnets, participants took a memory test where they had to study around 100 objects scattered around a grid on a screen, and after a delay, recall where those objects had been.
Compared to a control group who took the same test without TMS, those who had the treatment showed improved ability to remember the locations of the objects up to 24 hours after the stimulation. EEG scans showed that these better scores corresponded with improved function of the brain network.
"We improved people's memory in a very specific and important way a full day after we stimulated their brains," says Joel Voss, lead author of the study.
According to the researchers this is the first time TMS has been used to target a very specific ability, like precise memory.
"We show that it is possible to target the portion of the brain responsible for this type of memory and to improve it," says Voss. "People with brain injuries have problems with precise memory as do individuals with dementia, and so our findings could be useful in developing new treatments for these conditions."
The research was published in the journal Current Biology.