Just think about for a moment: learning something new, or remembering something old has something in common –it involves activation of
neurons. Yes, this is quite a broad statement. After all, the motor area of the brain doesn’t get stimulated when we learn; only specific cells in specific areas get stimulated. So what if could specifically stimulate those cells? Could we become math whizzes without the numbingly long hours of homework? The answer, as always is, it depends. Let me explain.

Electricity and the brain

The invention of electricity is a bit contested. My favorite inventors are the Greeks of about 600 BC. They discovered that by rubbing a piece of amber, which in classical Greek is called electron, against a fur coat, it attracts straw. (Which raises the counter-historical speculation: would electricity have been discovered had the Greek version of PETA existed then?). But even these ingenious people’s imagination did not lead them to speculate that everything that is happening in their head is based on electricity as well. Today we know that nerve conduction is an electrical phenomenon. So when we solve a problem in math, or form a sentence, or recall a memory, the neurons in charge are buzzing with electricity.

So now let’s push the envelope a bit. If these activities are electric, what would happen if we enhanced the electric activity of the neurons involved?

This indeed is the question that Roi Cohen Kadosh of Oxford University investigated. Is known that the math center resides in the parietal lobe (right under the crown of the head) in the right hemisphere. So he and his colleagues attached electrodes to the scalps of 15 volunteers—over the
right side of the parietal lobe—and applied a weak electrical current. Each day, five volunteers received a positive current for 20 minutes; five
volunteers received a negative current for 20 minutes; and five volunteers received a positive current for 30 seconds. Now, don’t worry, this is not one of those hair-raising scientific experiments that make us want to storm the labs; the volunteers usually reported just a “tingling sensation” around the electrodes on the scalp, and Dr. Cohen Kadosh, says that he tried out the procedure on himself before subjecting anyone else to it.

As reported in Science Now, 4 November 2010, “the volunteers were trained to learn the value of nine made-up symbols, including shapes that looked like triangles and staples (see picture, adapted from Kadosh et al. Current Biology 23 November, 2010).

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.

Each training day ended with a type of test known as a numerical Stroop task. In the classic version of the test, volunteers are shown, say, the word “blue” written in red ink and asked to state the color of the ink. Most of us hesitate for a second because we have good reading skills and want to say what we’ve read—i.e., “blue.”  In Cohen Kadosh’s version of the test, the volunteers were asked to look at the symbols they had learned—except this time, some of the low-value symbols were written larger than the high-value symbols—and say which of the symbols was larger in size. Students who hesitated were judged to have learned the symbols better than those who did not hesitate.

And the results…

Volunteers who had received 20 minutes of positive electric current to their brains per day performed best on the test. Specifically, they hesitated
about twice as long as the group that received only 30 seconds of positive current. Students in the group that received 20 minutes of negative current per day were unable to recognize the symbols at all and didn’t respond. The effects of the electrical treatment were retained even 6 months later”.

This is truly amazing, and I must admit –I was surprised. The concept is so simple that you must wonder if it would make any impact on such a complex system as the brain. But then, we always do reach for complex answers to complex problems, don’t we?

Can you imagine students sitting in algebra or creative writing class all wired up? I can.

Dov Michaeli, MD, PhD
Dov Michaeli, MD, PhD loves to write about the brain and human behavior as well as translate complicated basic science concepts into entertainment for the rest of us. He was a professor at the University of California San Francisco before leaving to enter the world of biotech. He served as the Chief Medical Officer of biotech companies, including Aphton Corporation. He also founded and served as the CEO of Madah Medica, an early stage biotech company developing products to improve post-surgical pain control. He is now retired and enjoys working out, following the stock market, travelling the world, and, of course, writing for TDWI.


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