A small new study published in Current Biology involved electrical stimulation of the parietal lobe, a part of the brain involved in math learning and understanding. When this area was stimulated, students performed better on a math problem test. Said study leader Cohen Kadosh:
“We’ve shown before that we can induce discalculia [an inability to do math], and now it seems we might be able to make someone better at maths, so we really want to see if we can help people with dyscalculia…. Electrical stimulation is unlikely to turn you into the next Einstein, but if we’re lucky it might be able to help some people to cope better with maths.” [BBC News]
Dyscalculia is a learning disability similar to dyslexia, in which a person has an innate difficulty with learning or understanding math. People with this condition can have trouble with daily arithmetic, telling left from right, and telling time on analog clocks. Some studies estimate up to five percent of the population suffers from dyscalculia, and about 20 percent have less severe troubles with math.
For the experiment, 15 students were hooked up to a transcranial direct current stimulation (tDCS) machine, which stimulates the brain through the skull with 1 milliamp of electricity, and were given either a positive (right to left) zap to their parietal lobe for 20 minutes, a positive zap for 30 seconds, or a negative (left to right) zap for 20 minutes (five students per group). The current produced a tingling sensation in the scalp, but it didn’t hurt. Then the students were trained to learn the assigned number values of made-up symbols.
To replicate what children go through when they first learn numbers, the researchers presented the volunteers with two symbols at a time and asked them which one had a higher value. At first, the volunteers had to guess, because they had never seen the symbols before. But as the training progressed, those volunteers who remembered their correct guesses began to learn the relative value of all nine symbols. [ScienceNOW]
The students got hundreds of guesses each training day, which the researchers predicted would allow the students to gain an understanding of how the nine symbols ranked.
Each day they were also given a type of mathematical Stroop test: The students were shown two of the symbols where one shape was large and the other small, and were then asked which was bigger in size. The test can be confusing when the higher figure numerically is the smaller figure spatially, but students only have this difficulty if they’ve really learned the sequence of the figures. The researchers judged that students who hesitated in confusion longer had learned the sequence better.
The students who had the 20 minutes of “positive” stimulation at the beginning of each session showed that they’d learned the numbers better than those who were stimulated for only 30 seconds. Both groups did much better than those with the 20 minutes of “negative” stimulation, whose mathematical function was on par with that of a six-year-old. Even six months later, when the students were re-tested, those that received the positive stimulation performed better on the symbols test.
“It is already known that tDCS affects neurotransmitters involved in learning, memory and plasticity, so we presume that these are being manipulated in this study to cause long-term changes in the brain,” says Cohen Kadosh. [New Scientist]
But there are a lot of caveats to the results. A 15-person study is quite small. And though the electrical stimulation seemed to improve the students’ number processing abilities, it didn’t change their other math skills. It’s possible that this type of stimulation could be used to help students learn math better in school, but wouldn’t necessarily help them understand calculus.
Dr Cohen Kadosh, who led the study, said: “We are not advising people to go around giving themselves electric shocks, but we are extremely excited by the potential of our findings and are now looking into the underlying brain changes.” [BBC News]
Some other researchers who weren’t involved in the study say the data looks interesting, but note that the test wasn’t compared with a non-computational task. That makes it hard to tell if the effect is purely mathematical, or if the electrical current was having other effects on memory, learning, or the brain.
80beats: Magnetic Zaps to the Brain Can Alter People’s Moral Judgments
80beats: Female Teachers’ Math Anxiety May Give Girls the Arithmetic Jitters
Discoblog: Is There Such a Thing as Dyslexia for Math?
Not Exactly Rocket Science: When learning maths, abstract symbols work better than real-world examples
DISCOVER: Brain Damage Can Make You Brilliant
DISCOVER: 5 Ways Scientists Are Hacking the Brain to Cure Disease, Improve Memory & Increase Libido