A harmless form of brain stimulation can bring about improvements in mental arithmetic skills, according to a new study.

More than 20 per cent of people struggle with such a complex, challenging task

The process, called transcranial random noise stimulation (TRNS), was still having helpful effects six months later, the research found.

The stimulation was applied to an area known to be important for ability in maths, according to the latest edition of the Cell Press journal Current Biology.

“With just five days of cognitive training and non-invasive, painless brain stimulation, we were able to bring about long-lasting improvements in cognitive and brain functions,” said Roi Cohen Kadosh of the University of Oxford.

Researchers say the evidence suggests that the process allows the brain to work more efficiently by making neurons fire more synchronously.

Cohen Kadosh and his colleagues had shown previously that another form of brain stimulation could make people better at learning and processing new numbers.

But TRNS is even less perceptible to those receiving it, and has the potential to help even more people, he said.

That is because it has been shown to improve mental arithmetic – the ability to add, subtract or multiply a string of numbers in one’s head, for example – not just new number learning. Mental arithmetic is a more complex and challenging task, which more than 20 per cent of people struggle with.

Cohen Kadosh said that with better integration of neuroscience and education, this line of study could help humans reach their cognitive potential in maths and beyond.

It might also be of particular help to those suffering with neurodegenerative illness, stroke or learning difficulties.

He added: “Maths is a highly complex cognitive faculty that is based on a myriad of different abilities.

“If we can enhance mathematics, therefore, there is a good chance that we will be able to enhance simpler cognitive functions.”