My Plastic Brain

by Caroline Williams

  Then there is the possibility that stimulation gets the brain waves going in a particular frequency that allows for concentrated thought. Setting the stimulator to the gamma frequency of 40Hz, for example, might encourage natural brain waves to follow suit. Gamma waves are at work when we are concentrating hard and pouring all of our mental energies into a taxing mental puzzle.

  Whatever is happening exactly, the basic theory is that it makes the region under the electrode more active than it was before. Given that the region being targeted in this experiment—the dorso-lateral prefrontal cortex—is involved in regulating negative emotions, it could be helping to do the job more effectively. This would explain why stimulating the prefrontal cortex helps math-anxious types. If they are slower because they are processing an emotional reaction at the same time as trying to work out whether 8 + 6 = 12, a bit of extra brainpower is bound to help—adding more juice just helps the whole process along.

  In this case, the key thing is how well you can dampen down the “aaaargh” reaction to get your thinking brain into gear. If you can get rid of that obstacle, it frees up some mental capacity that you can then use to do sums. Unlike most of the hype about brain training and stimulation, it isn’t always about adding capacity—it's about releasing the capacity that you already have, or removing a block that has no business being there.

  Brain stimulation, then, might not be strictly necessary, but new evidence suggests that it does seem to make a difference. In a recent study, Cohen Kadosh's team (this time not including Amar) found that doing mathematical training improved scores in all of their healthy volunteers, but adding tDCS gave one group a significant boost over the other, who received sham stimulation instead.7

  Having had a fair amount of brain stimulation now, I can kind of see why braver people than me think that this is something they could use at home. When you see a scientist dip a sponge into salt water, measure roughly where the right bit of brain is inside your head, pop a toweling headband on top, and then turn on the current, it doesn’t seem out of the realms of possibility to do the same thing at home. It's certainly easy enough to get hold of a tDCS machine, if you have access to the internet and a couple of hundred dollars. So what's the problem with it?

  Well, for a start, Amar's study suggests that sometimes stimulation can make things worse. In his experiment, only the people who hate math got any benefit from stimulation, in terms of their reaction time and cortisol level. People who were confident about their ability got worse after a zap to the prefrontal cortex: they slowed down and were less able to keep their cortisol levels at a nice, low, unstressed-by-math kind of level. Both groups, the confident and angst-ridden volunteers, performed worse at standardized tests of attentional control. So you can easily strap a battery to your head, but you might just make yourself slower and more stressed, not lightning fast and confident. “It's not a free lunch,” says Amar. “If you enhance one process, it might come at the cost of another.”

  Because most studies are done on large groups of people, and the data all put together, these subtle differences often go unnoticed, says Roi. As a result it has barely been raised as an issue, in science or in the burgeoning home-tDCS market.

  It is also possible that the bit of the brain that needs stimulation will change as the learning process happens—something that scientists haven’t even gotten a handle on yet, let alone home users. Roi and his team are looking at whether stimulating the prefrontal cortex is good at early stages of learning—it helps with the control needed to make a deliberate effort to learn, but when a person gets better at the task, and is mostly retrieving information from memory, areas farther back in the parietal lobes might benefit from a boost instead.8

  More importantly, Roi says, there is no evidence that using tDCS, or any other form of brain stimulation, every day for months on end is good for you, or even safe. To know that for sure would involve stimulating a group of people every day for months and keeping a very close eye on them.

  “I would not run this study,” he says with a wry laugh. “I would not feel good about stimulating my own brain for three months. I am not going to do that for anyone else!”

  All in all, there are too many reasons to be cautious, he concludes. “We don’t know who it fits, who is going to benefit from it the most; we don’t know if it is safe to use it for an extended amount of time. Stimulation by itself doesn’t seem to be effective—you need to combine it with cognitive training if you want to induce long-term changes rather than just improving on the task you are doing at the moment. All of these together doesn’t make me say, ‘Hey, you know what? Let's go and do this!’”

  I trust his judgment on this—particularly as he says he has been offered lucrative opportunities to put his name to home tDCS but has so far resisted the temptation. “I think that this is not, at the moment, the right approach. We need to know more.”

  Instead, Roi lobbies for the regulation of commercially available brain-zapping headsets, which currently don’t come under legislation for medical devices. In the same way that dietary supplements don’t come under drugs regulations as long as the manufacturers don’t make any specific medical claims for them, home-tDCS kits are outside the current regulation. Which means that there is an experiment going on in heads all over the world but one that is not being safety checked or monitored in any way.

  And, as a final point on brain stimulation—which also relates to everything I have done to change my brain—there is this basic fact: no one gets to be superhuman. It may be fun for the likes of me to think, “Great, we have this neuroplasticity thing, let's use it,” but the evidence for “cognitive enhancement” is more about ironing out individual differences stemming from genetic differences or what we have learned along the way. It is not going to turn any one of us into a supercomputer (or as it says in one of Roi's papers, it's not going to take us “beyond the species-typical level normal range of functioning”9). In the same way that no matter how much protein I ate as a child, I was never likely to grow to more than five feet tall (the genetic limit for women in my family, it seems), the brain is plastic, but there are limits.

  Taking all of that on board, has it been worth the effort of putting myself through these extra math classes when I have a perfectly good calculator on my phone? For me, yes. It has been a huge confidence boost to find out that I have plenty of capacity there, waiting to be used, if only I can get past the initial aversion and start to enjoy the puzzle.

  Which brings me to logical reasoning—a skill related to, but not the same as, mathematical reasoning. Like math, and indeed nearly everything I’ve been working on, this is not something that comes particularly easily to the human brain. It relies on executive functions (particularly working memory) to keep a deliberate train of thought going long enough to come to a logical answer.

  As far as math goes, it was a surprise and relief to find that I didn’t exactly need to change my brain at all—I just needed to realize it was in there somewhere, buried under a layer of brain-sapping low confidence. I am now wondering if this lets me off the hook about improving my logical reasoning skills, too—not only because if my math skills are fine then my reasoning skills probably are, too.

  There is no denying that I have always been something of an emotional person (see chapter two). This basic feature of my personality often brought me into conflict with my stepdad when I was a kid because, to him, logic is everything. I’ve lost count of the number of times he told me that there's absolutely no need to get all het up and emotional about stuff—just think it through slowly and logically. If the answer to your problem makes logical sense, then it must be right. It might have something to do with him being brought up by a sergeant major in the military police. Or maybe he's part Vulcan. Either way, it's fair to say that we don’t entirely see eye to eye on the role of emotions versus logic in deciding how to live.

  Actually, there is some pretty good evidence that I am at least partly right about the importance of emo
tions. A particular region of the brain's prefrontal cortex seems to be important for combining emotional information with more logical information, when we make decisions. Studies of people with damage to this part of the brain have shown that, when they are given a choice between two options, and there is no logical advantage to either of them, they struggle to choose at all. When there is no logical reason to choose, it seems, we rely entirely on our emotions to guide us. Without our illogical gut feelings and emotions, we would be lost.10

  On the other hand, studies have shown that, when it comes to making rational decisions about the people or issues we love, emotions are no help whatsoever, often leading us to conclusions that are just plain bad for us. I’m reminded of the experiments I did with Amar, in Oxford, where my terror of math left me unable to think about the problem in hand. Allowing your emotions to get in the way can be disastrous for mathematical thinking and probably logical thinking, too. So, it seems that there is no easy answer to the “logic versus emotions” question. Ideally, we all need a bit of both.

  Then there are the unconscious biases, which influence even our most logical decisions, whether we like it or not. Researchers at Harvard University's Project Implicit are trying to measure these biases via a series of online tests on their website: projectimplicit.com. These short tests provide you with immediate results on how your unconscious biases might be coloring your decision-making. In my experience, they are quite revealing.

  I have always thought myself to be immune to the idea that high-fat foods are inherently bad—logically, I know that a bit of everything is fine in moderation, and I try to make my food choices accordingly. I can’t see anything wrong with eating chips or chocolate if that's what I fancy. According to the Project Implicit test about attitudes to foods, though, I strongly associate words like “shameful,” “disgusting,” and “unacceptable” with high-fat foods like cakes and biscuits, and positive words like “healthy” and “success” with low-fat foods like fruit and vegetables. And while, consciously, I am equally unimpressed by all organized religions, according to the Project Implicit test on feelings about religion, I feel most positive about Buddhism, then Christianity, then way further down the scale are Judaism and Islam. This makes me wonder how much this is feeding into my daily life without me being consciously aware of it. Am I a closet Islamophobe? Have all the headlines gotten to me despite my lefty liberal leanings? And has a combination of my Christian schooling and recent love affair with yoga and meditation pushed Christianity and Buddhism to the top of the list?

  Not all of my implicit assumptions are so much of a shock, though. I am pleased to find that I associate women and men equally with the home and the workplace, and have no bias against women in science (this might be because I talk to a lot of psychology researchers, where women are better represented than in other areas of science). And when I took the “attitudes to homosexuality” test I was slightly more likely to associate words like “joyful” and “lovely” to gay people than to heterosexual people.

  How much these implicit biases impact on day-to-day thought processes isn’t clear, but research does suggest that, when our beliefs contradict the evidence before us, our minds do backflips to try to make our beliefs stand up. This is why people are susceptible to conspiracy theories even when the evidence is right in front of them. The only way to align the two is to get them out in the open and take a long, hard look at the assumptions you don’t know you are making. I recommend giving it a go—it's fascinating.

  “Know thyself” is a theme that has come up time and again as I have been trying to improve my brain skills. If you know what your limits are and why, then you stand a much better chance at tackling any problems at the source.

  And so I decided not to pursue logic training. When I started this project, I thought that my emotional circuits were quite strong enough and that what I needed to do was to strengthen the logical circuits to balance them out. Now, though, I’m not so sure. I keep remembering what John Kounios, the creativity researcher I met in Philadelphia, told me about creativity. His research has divided people into two broad groups depending on the way they tend to solve problems. Some people fall into the category of “analytical” problem solvers, who tackle a problem by slowly and steadily working through the options. These people, Kounios found, have relatively more activity in their left hemisphere (it seems there is a smidgen of truth in the “left brain = logic” idea, even if there is way more to it than that). Other people, who Kounios calls “insightfuls,” tend to solve problems by insight and have relatively more right-hemisphere activity at rest. This method of problem-solving is a bit hit-and-miss because they tend to have nothing to show for their efforts until a solution pops into their heads in an “aha” moment. According to Kounios, there is some tentative evidence that these tendencies might be inherited and are quite stable over time, suggesting that we come set up to either be logical or creative types and tend to stay that way throughout life.

  In Kansas, I did lots of tests of creativity, and several insight tests, with Lila Chrysikou. Without wanting to blow my own trumpet too much, I came out way above average on all of them. We didn’t measure which side of my brain had more activity at rest, but all the other results point toward me being more of an insightful type than a logical Vulcan.

  Do I really want to push myself away from that and toward a more logical mind? That seems like a step too far away from the person I naturally am. There have been parts of my natural state that I have been happy to change (anxiety and distractibility being two of the most obvious), but even though it's probably possible to override my creative bent to get more logical, I’m not sure I want to; I quite like being a writer….

  For those wanting to boost their logic skills, though, there is evidence that if you spend a lot of time practicing logic problems (and get the answers right), it will have a physical effect on the structure of your brain. In studies at the University of California in Berkeley, when prospective law students took a crash course in logical reasoning as part of their preparation for their Law School Admission Test (LSAT), their brains gained connections between the frontal and parietal lobes—two regions thought to be important for logical trains of thought—after just ten weeks.11

  The volunteers were given logic puzzles every day for ten weeks, which is quite an investment of time in something you are not even sure you want to do—and anyway, when I asked her about it, the lead researcher in this study, Silvia Bunge, wasn’t able to have me in her lab to do the experiments anyway. So I can’t offer any specific advice on whether this works, but anyone who wants to take the challenge can find LSAT revision papers freely available online.

  Instead, I found some online tests of logical reasoning of the type that prospective employers use to torture well-meaning graduates, and gave them a go.12 My score came out as middle of the road, average—fine, but not stellar. And you know what? I’m okay with that.

  Interestingly, when talking to a friend about my decision to leave my powers of logic well alone, I realized something. If I’m choosing not to train my brain in a given direction for fear of it working too well, it must mean that I am starting to believe that brain override is possible. I started off imagining that I’d find at least some things that couldn’t be changed, no matter what you do, but I have to admit that the brain's adaptability has come through every time. Some of the changes I have made came down to simply changing my mind-set, others to practice, some to embracing what is already there, and some to tackling unconscious biases that I wasn’t previously aware of. But for all the different routes to changing my mental workings, one thing seems to be coming through loud and clear: work on what you want to change, and after a few weeks things will start to happen.

  OVERRIDE YOUR RUSTY MATH BRAIN IN FOUR EASY STEPS

  Do some easy math—use pencil and paper; take your time

  Do some slightly harder math—on paper; take your time

  Realize you can do it if you put your mind t
o it

  Repeat steps 1 to 3 as necessary

  INTERVIEWS/CONVERSATIONS:

  Amar Sarkar, conversations and interview during lab visit, February 15–19, 2016, and email conversation, March 23, 2016.

  Roi Cohen Kadosh, Skype interview, March 4, 2016.

  Override: to interrupt the action of (an automatic device), typically in order to take manual control.

  —Google definition

  It's time to tackle the million-dollar question: do I think I have changed my brain? Or—given that everything changes your brain and that none of us are sitting here today with the same brain we had a year ago—have I made any useful, deliberate changes that have moved it toward the kind of brain and mind that I was aiming for at the start of this experiment?

  Yes, I think I have.

  But before I get to what I think has changed, how I plan to keep it going, and how anyone could do something similar, I want to raise the possibility that we have been thinking about brain change all wrong. The reason I say this is because the way that I think my brain has changed is not at all what I was expecting.

  When I started this project I, like most people outside of working neuroscience labs, thought that what I needed to do was to tone up a few brain areas and improve on a few key circuits in my brain—a mechanistic approach, if you like, that thinks of the kilo or so of mush in my head as an engine that needs a bit of work: upgrade a component here, insulate a wire there, and get the whole thing running more smoothly.

  When I tried to turn this idea into practical action, though, it became obvious that this view of the brain is missing an important part of the picture. While there are definitely areas of the brain that specialize in certain skills, anything worth doing requires the activity of many, many different brain areas. With that in mind, what is most important is not activity in certain areas, or even the thickness of the wiring between them, but the way that the brain puts these different streams of activity together to create something that is greater than the sum of its parts.