Stories about brain research can get a little boring if you just cite an endless stream of academic papers and statistics. So welcome to Healthland’s latest feature: The Lab Rat. Here, I subject myself to the same kinds of psychological and neurological testing that I’ve been writing about for two years. Then I use that personal experience to understand more fully all the papers and statistics. That’s the idea, anyway. We start this week with a memory test.
The other day, some friendly scientists in Philadelphia attached electrodes to my head — one just above and behind my right ear, and the other on my left cheekbone — and ran electricity through my brain. As they did, I took a computerized memory test. My scores on the test significantly improved from an earlier test I took without the electricity. It turns out you can tune up someone’s brain like a car battery. I felt — and looked — a bit like a Frankenstein creature, but the results were impressive.
Welcome to the promising world of transcranial direct current stimulation (tDCS), a highly refined, very safe and relatively cheap biomedical treatment that is being studied for use not only in improving memory but treating depression and epilepsy. The scientists who demonstrated tDCS for me — Ingrid Olson and David McCoy of Temple University’s psychology department; and Dr. David Wolk, a neurologist at the University of Pennsylvania — recently co-authored (along with two other researchers) an article for the November issue of Neuropsychologia about the use of tDCS to improve memory. The paper shows that just 15 minutes of tDCS can help with a common problem (especially for those of us heading into middle age): remembering people’s names.
The idea that the brain is essentially an electrical-wiring board is not new. As soon as electricity became common in the early part of the 20th century, neurologists began using electricity rather than harsh chemicals like metrazol to induce convulsions in people with severe mental illness. For centuries, inducing convulsions had been a crude but often useful way of resetting the brain’s circuitry.
Today, electroshock therapy (which psychiatrists call electroconvulsive therapy) is painless because patients are required to be put under anesthesia before they receive it. (Jack Nicholson’s character in One Flew Over the Cuckoo’s Nest, Randle McMurphy , did not receive that courtesy.) But scientists have also developed far more refined ways of using electricity in the brain: now they can stimulate certain neural regions for specific purposes without the troublesome side effect of a grand mal seizure. One method is transcranial magnetic stimulation — which pushes neurons around with a magnetic wand waved around your head.
Another is the one I received, tDCS. It uses just 1.5 milliamps of electricity, which is such a small amount that you can’t really feel it. There’s a little tingling, but it’s ephemeral.
The reason that the Philadelphia scientists attached one electrode just northwest of my right ear is that my anterior temporal lobe lies behind my skull in that spot. From brain imaging, we know that name recall originates in the anterior temporal lobes. I have always had a terrible time remembering names, which might mean that my ATLs were always a little weak, but you can also suffer ATL damage if you have a stroke or another common medical condition called “being over 40 years old.”
The electricity is thought to enhance neural firing in the ATL. After I got to the lab in Philadelphia, the scientists attached the electrodes to me and then had me take two memory tests. The tests asked me to recall the names of famous (and semi-famous) people whose photos appeared for 7 sec. on a screen in front of me. There’s Nelson Mandela — easy. Ronald Reagan — easy. But then a picture of Chuck Yeager, who has a strong historical presence but who is difficult to recognize by face if you were born after 1965 or so. And then there’s a photo of Mary Lou Retton back in her Olympic days. Remember that face? It took me the full 7 sec. to do so.
Your brain spins when you see photos of someone like Retton. You know that you know the face, but her name just sits on the tip of your tongue. What tDCS does is fire your ATL in a way that pushes the name from the tip of your tongue out of your mouth. I showed a small improvement during the tDCS session with people names — and a huge (more than double) improvement in my recall of names of landmarks like the World War II Memorial, Stonehenge, and Mount Kilimanjaro. In the first session, I often gave up on landmark names; in the second, tDCS seemed to give me a little push.
So is all this just a placebo response? In other words, did I do better because I expected to do better? That could be it, but it’s difficult for participants to tell which session is real and which one is fake because you have all that Frankenstein stuff on your head during both. There is that slight tingling during the tDCS session, but not everyone recognizes it, according to Olson, the Temple University psychologist and co-author of the paper.
Unfortunately, there aren’t immediate consumer applications for tDCS: the machine itself, which is manufactured by a U.K. company called Magstim , costs roughly $10,000. (Also, you wouldn’t want to walk around with those electrodes on your head.) But as a short-term treatment for those whose memories have been impaired by stroke or another medical condition, tDCS could be a vital way of helping them to turn a tip-of-the-tongue response into a confident answer.