Magnetic stimulation of the brain improves working memory, according to a study that may lead to a new therapy for individuals living with Alzheimer's disease and other forms of dementia.
The study, published in the journal PLoS One, found that healthy younger and older adults who received repetitive transcranial magnetic stimulation (rTMS) therapy performed better on a memory task than those who received placebo.
Working memory is the process of recalling and then using relevant information while performing a task.
It is a key component of day-to-day tasks like driving to a new location, making a recipe, or following instructions.
"This study relies on highly individualised parameters, from the selection of the stimulated target, based on fMRI activation, to the selection of the difficulty, titrated according to subjects' performance," said Lysianne Beynel, a postdoctoral associate at Duke University in the US.
Functional magnetic resonance imaging or functional MRI (fMRI) measures brain activity by detecting changes associated with blood flow.
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"Now that we have shown that these specific parameters can improve performance in healthy subjects, we will be able to extend it to populations with memory deficits," said Beynel.
Individuals with Alzheimer's disease, which will more than double by 2050, and other forms of dementia, experience progressive loss of working memory and other forms of cognition, researchers said.
This leads to a greater risk of injury or death and reduces their ability to function without home care, they said.
Twenty-nine young adults and 18 older adults completed the study, which involved trying to remember and then reproduce a series of letters in alphabetical order.
The researchers applied either online high-frequency (5Hz) rTMS, or a placebo-like sham over the left prefrontal cortex, an area on the brain responsible for higher executive function.
Participants of all ages who received rTMS performed better than those who received the rTMS-like placebo.
"Interestingly, we only saw this effect during when participants were trying their hardest, suggesting a real use-it-or-lose it principle at work here," said Simon W Davis from Duke University.
"Contrary to much of what we hear, ageing brains have a remarkable capability to remember past events and to use that information in a flexible manner.
"The brain stimulation applied in our study shows that older adults benefited just as much as the young," Davis said.