When you're working or studying, what do you have on in the background? Perhaps a podcast, music of some kind, or maybe complete silence? Evidence suggests that certain types of music might help or indeed hinder our attempts to learn. But in the future, there might be a better way.
A new study reviewing past research makes the case that random, artificially generated noise has the potential to help the brain learn better.
How so? It's thought that random noise aids learning by increasing the brain's plasticity, or ability to take on new information – essentially, helping the brain form new paths and connections.
Specifically, we're talking here about a relatively new technique called transcranial random noise stimulation, or tRNS, not some carefully curated chill-out playlist.
tRNS involves placing electrodes on a person's scalp and passing weak electrical currents through specific parts of the brain.
"The effect on learning is promising," says neurologist Onno van der Groen, from Edith Cowan University in Australia. "It can speed up learning and help people with neurological conditions."
"So, people with learning difficulties [could] use it to enhance learning rate, for example. It's also been trialed on people with visual deficits, such as after stroke and traumatic brain injury."
The newly published paper doesn't involve any new research but summarizes a host of previous studies on tRNS. Overall, adding brain stimulation during periods of study can improve learning and helps with attention after the treatment, too.
Based on past research, tRNS can have two effects: an 'acute' effect where learning is enhanced while tRNS is applied, and a longer-term, modulating effect where cognitive performance can be improved in the future, even after tRNS has stopped being used.
Studies have shown that tRNS can boost visual perception, help us to learn new information more efficiently, and improve our ability to focus, the researchers report. That's useful in areas where the brain might be damaged or recovering from damage.
However, the review also notes that tRNS isn't a tool that works in all situations; it can't keep on leveling up our brains indefinitely.
In some scenarios and some age groups, the application of electrical noise doesn't seem to affect the brain at all.
"There's a case study where they tried to enhance the mathematical skills of a super mathematician," says van der Groen. "With him, it didn't have much of an impact on his performance, presumably because he is already a top performer in that area."
"But it could be used if you're learning something new."
Despite all of these past experiments, the exact mechanisms at play inside the brain during tRNS remain unclear.
It's thought that the noise might help certain neurons to stay in sync better, or that it might affect levels of a key neurotransmitter called gamma-aminobutyric acid (GABA) – although no one is sure yet.
What's clear from this study review is that this random noise stimulation can have some positive effects as far as learning goes, at least some of the time in some people. That means there's plenty of potential in terms of future research.
Another advantage of tRNS is that it doesn't necessarily need a complicated laboratory setup to operate. In the future, it might be possible to develop kits that people can use themselves without any assistance, the researchers say.
Eventually, it might even replace the soundtrack to your working day.
"The concept is relatively simple," says van der Groen. "It's like a battery: the current runs from plus to minus, but it goes through your head as well."
"We're working on a study where we send the equipment to people, and they apply everything themselves remotely. So in that regard, it's quite easy to use."
The research has been published in Neuroscience & Biobehavioral Reviews.