If you’ve read any of my previous work here on HELIX Magazine, you know that I’m fascinated by noninvasive brain stimulation, or as I like to call it, brain zapping. And, why not? It’s amazing that we have a tool that can temporarily change how our brains function without any medication or surgery.
Though brain zapping might strike some as scary, it has been getting more positive attention from the mainstream media. A recent study published in the journal Science may help further erode that stigma.
Researchers here at Northwestern, led by principal investigator Joel Voss in the department of Medical Social Science, recently demonstrated that memory can be improved in healthy adults using nothing but noninvasive brain stimulation.
In the study, participants first had their brains scanned with fMRI in order to identify the parts of their brains that were part of the memory network. Specifically, the researchers were interested in finding places on the outside of the brain that were connected to the hippocampus, a structure located deep in the brain.
Then the participants took a baseline memory test, where they needed to learn associations between faces and specific words. Next, they had their brains zapped using repetitive transcranial magnetic stimulation (rTMS) every day for a week. The zapping was administered over those parts of the brain that were identified earlier as being connected to the hippocampus.
After a week of zapping, the participants were tested on how well they remembered the face-word associations. Amazingly, their scores improved significantly over baseline. In order to verify that it was the zapping to specific locations that led to this improved performance, the researchers also employed a sham rTMS condition, where they pretended to stimulate participants’ brains, as well as a control condition, where a different set of participants were zapped in a part of the brain that wasn’t part of their memory networks. Scores on the memory test didn’t improve from baseline in the sham or control conditions.
There are a couple of interesting takeaways from this study. First, it provides clear evidence that noninvasive stimulation can improve cognitive functioning in healthy people. There are lots of studies showing that rTMS can help people recover function after stroke, or improve the symptoms of depression when other treatments aren’t working, but there’s not as much evidence that it can enhance skills in people who are otherwise unimpaired (though there are a few). This study supports the idea that cognitive skills can be improved using brain stimulation even in people who don’t have specific deficits. I don’t think this means we’re close to giving people super powers, but it is certainly a step in the right direction!
Second, this study demonstrates the importance of connections inside our brains. Unfortunately, we don’t have any tools that can safely stimulate deep parts of the brain, like the hippocampus. But, the researchers were able to take advantage of the fact that there are many parts of the brain connected to the hippocampus, including parts of the parietal lobe that can be easily stimulated with rTMS. It’s a little bit like taking a detour on a road trip: because the direct route to the destination wasn’t available, the researchers took advantage of the connectivity in the brain to devise a detour.
I’ll be honest – I actually first heard about this study on the Today Show. It’s a little embarrassing to admit that I wasn’t up to speed on a major project happening right under my nose using my research tool of choice. But, at the same time, I think it’s great that major news outlets are covering this topic. Since I first learned of this study on TV, I’ve heard people talking about it on the train, at the grocery store, and even had a few friends and family ask about it. There may still be some stigma surrounding noninvasive brain stimulation, but projects like this can help fix that, and cultivate excitement and optimism instead of fear.