A new study used a one milliamp current to stimulate the parietal lobe of a small number of students. The current could not be felt, and had no measurable effect on other brain functions. The volunteers tried to learn a puzzle which involved substituting numbers for symbols. Those given the current from right to left across the parietal lobe did significantly better when given, compared to those who were given no electrical stimulation. The direction of the current was important – those given stimulation running in the opposite direction, left to right, did markedly worse at these puzzles than those given no current, with their ability matching that of an average six-year-old.
The effects were not short-lived, either. When the volunteers whose performance improved was re-tested six months later, the benefits appear to have persisted. There was no wider effect on general maths ability in either group, just on the ability to complete the puzzles learned as the current was applied.
Dr Christopher Chambers, from the School of Psychology at Cardiff University, said that the results were “intriguing”, and offered the prospect not just of improving numerical skills, but having an impact on a wider range of conditions.
He said: “The ability to tweak activity in parts of the brain, turning it slightly ‘up’ or ‘down’ at will, opens the door to treating a range of psychiatric and neurological problems, like compulsive gambling or visual impairments following stroke.”
However, he said that the study did not prove that the learning of maths skills was improved, just that the volunteers were better at linking arbitrary numbers and symbols, and he warned that researchers needed to make sure other parts of the brain were unaffected.