Each thought you have creates a harmony of electrical waves that ripple through the brain in coordinated bursts. It's thought these pulses of electricity become more disjointed and unsynced as we age, like a slightly out of tune instrument. This is why our working memory gets hazier as we get older. However, a new study suggests it might be possible to temporarily reverse that.
New research by neuroscientists from Boston University has shown how stimulating the brain with a soft electrical current can help to improve the working memory – the ability to hold information for a short period while we make decisions, including recognizing faces and being able to navigate new environments – of older people by reharmonizing the lost brain rhythm between the brain’s prefrontal cortex and temporal lobe.
It’s thought that our working memory gets worse as we age because these two brain networks fail to communicate with each other as seamlessly as when we're young, they get out of sync. By applying currents to these regions, the networks are encouraged to resync, allowing better communication to resume. The study found that a mild electric current allowed older brains' working memory to perform like a person in their 20s. Although the benefits were only temporary – nearly an hour – and the researchers don’t yet know how long they could last, they hope this work may someday be used to treat people with age-related memory problems.
Reporting in the journal Nature Neuroscience, the researchers gathered 42 young adults, aged 20 to 29, and 42 older adults, aged 60 to 76, then asked them to carry out a short term memory test. It involved viewing an image on a computer screen, then a blank screen for three seconds, followed by a second image that was either identical to the first or very slightly modified. The participants were asked whether the image was the same or different.
They subjected each group to 25 minutes of a noninvasive form of electrostimulation, as well as a sham version with no electrostimulation. In an attempt to remove the placebo effect from the results, it was a double-blind test, meaning neither participants nor researchers knew when the participants were receiving brain stimulation or not.
As you would guess, the older participants performed worse in the control round. Following the stimulation treatment, both groups scored about the same on the test. However, improved results were seen in both young and old people who performed badly in the first round of tests. The team noted that the positive benefits were seen for at least 50 minutes following the stimulation, after which they stopped testing. This meant that for a brief period, the older brains performed as well as the younger ones.
“We showed that the poor performers who were much younger, in their 20s, could also benefit from the same exact kind of stimulation,” Rob Reinhart, an assistant professor of psychological and brain sciences at Boston University, said in a statement. “We could boost their working memory even though they weren’t in their 60s or 70s.”
Their recordings of the participants' brainwaves revealed an "increase in neural synchronization patterns and the return of sender-receiver relationships of information flow within and between frontotemporal regions."
“It’s opening up a whole new avenue of potential research and treatment options – and we’re super excited about it,” Reinhart said.