My Plastic Brain

by Caroline Williams

  Steve Marchette, who is a spectacularly nice guy, tried to make me feel better about the graph, showing how I compared to other volunteers. “You’re still on the normal distribution [curve], but you’re on the tail….” Russell jumps in to correct him: “She's pretty far out on the tail….” And he's right—all the evidence points toward me being terrible at mentally shifting perspective.

  The results from the three virtual-reality tasks also make a very clear case that I am fine at knowing where I’m going as long as I follow a route dotted with familiar landmarks. At no point in the maze task did I risk a shortcut; instead, I stuck to the exact routes I had learned previously. An example: from the traffic barrier turn right, and right again, and there is the bin. From there, go left, then left, and there is the chair. If I was told to collect the chair, I’d always take the long route, rather than risk getting lost by skipping from the barrier to the chair.

  In the open-arena game, where there was no route to learn, only mountains around the outside and a small landmark (a ball) inside, I still used the one and only landmark rather than the huge, unchanging mountains all around me. I was aware while I was doing it that it would make much more sense to use the mountains, but I just couldn’t seem to remember where they were in relation to each other and hold that information in my mind. Again, my head kept spinning whenever I tried.

  Using information about a large-scale scene rather than smaller landmarks is a hippocampal strategy, Russell tells me, and I’m clearly not very good at it. Which makes me wonder how my hippocampus is working—or not, as seems more likely.

  I don’t have to wait long to find out. The next slide shows the results of my brain scans, with the hippocampus outlined in red. Steve reassures me it's very shapely, which is nice to know. Then he hits me with the detail: if you break it down into different areas of the hippocampus, which are known to do different jobs, it starts to look more interesting. In fact, my brain is almost the exact opposite of what Eleanor Maguire found in the London taxi drivers.

  In a 2000 study, Maguire found that taxi drivers who had been learning their trade for longer developed a larger posterior (back) section of the hippocampus, while the anterior (front) part of it got smaller.7 In my case, this size pattern is reversed: the posterior part is in the bottom 10 percent of size compared to other women they had measured, while the front is slightly larger than average. In Russell's studies, too, he tells me, people with a bigger posterior hippocampus on the right side of their brain tend to be better at forming cognitive maps. So if mine is small, it might explain why I am not so good at mental mapmaking.

  Interestingly, while the posterior hippocampus is largely tied up with spatial memory, the anterior part has a role in processing anxiety,8 and trait neuroticism has been linked to a generally smaller hippocampus. A study by Giuseppe Iaria's team at Calgary University showed that the higher trait anxiety is, the worse a person's performance on spatial cognition tests.9 So perhaps it makes sense that the emotional bit of the hippocampus would be larger than average in neurotic old me and that I am bad at navigating. In that regard, I’m still doing the meditation and happy-faces clicking and feel like it's improving—but it's definitely a work in progress. Hopefully, this is all in the process of balancing out.

  Later, when I send these results to Klaus Gramann back in Berlin, he is curious to find out if his results with small hippocampus and larger caudate nucleus apply to me as a user of landmarks rather than cognitive maps. I ask Steve if he’ll measure it on my scan, which he very kindly does. Sadly, though, it turns out that I’m not particularly well endowed in that area either, particularly on the right side, which, like my right hippocampus, is way below average.

  What does it mean? I ask Klaus. “I have no idea what this actually implies without further information about your scans and performance in other tests, but definitely nothing that should make you value your orientation abilities less,” he says, in an email. “That's the reason I don’t look at my brain scans.”

  In case I needed any more evidence for a below-par navigational system, I get some from my functional MRI scan, which measures not size but activity in key navigational areas. The good news is that of the three areas of the brain known to specifically care about scenes rather than anything else, two of them look pretty normal. The parahippocampal place area, which is Russell's baby, looks fine—as does the retrosplenial complex. The occipital place area, though…not so much. “We couldn’t identify a very strong OPA for you,” Steve tells me, slightly apologetically.

  But I’m delighted—at last, some evidence that my brain isn’t working as it should. But what does it mean? Which piece of the puzzle am I lacking? “The OPA's function is not super well known, but Josh can say something about that,” says Steve.

  Josh, a PhD student in the lab, isn’t telling though. “I don’t really want to speculate on it at this point….” “Right, but we have some reason to think that it might be specific for coding locations to boundaries?” Steve chips back in. Josh nods. “Large-scale spatial information,” he confirms. Which, unsurprisingly, I’m not terribly good at. It looks to me like the reason it feels like I can’t compute a large scene while I’m in it is because I physically can’t—the bit of the brain that should be doing it is sleeping on the job. It's quite a relief, a bit like finding out that the reason I can’t see without my glasses is because the lenses in my eyes are the wrong shape. Not my fault, just one of those things.

  There might also be more to my normal-looking retrosplenial complex than meets the eye, too, Russell tells me. “The RSC is active when you do these tasks that you’re bad at, like imagining yourself in the location and figuring out where something else is. So you can say, ‘Oh, you look great on that.’ But here's the interesting thing; there was a study done on a person with [a condition called] developmental topographical disorientation who gets totally lost all the time. And if you do this test, their RSC looks normal. But if you take it a step further and do more probing of function of this region, it starts to look a bit abnormal. And that's something that we didn’t do with you.”

  In other words, my RSC might react normally when it sees a picture of a place, but if you looked at how the RSC reacts when I imagine standing at one place I know well and point to another, it might not respond as much. “Normally, the RSC would respond even more on that task—perhaps it wouldn’t in you,” Russell suggests. The team did discuss doing this experiment with me but decided that it would require several more hour-long sessions in the scanner, and even then the results wouldn’t be that reliable. It's the same problem I keep coming up against: scientists never do what I am trying to do and understand how minds work one brain at a time. There are too many other factors that might explain the results on just one person, but if you scan tens or hundreds, you can notice patterns. Brain-size measurements don’t actually predict anything, statistically speaking, which is why we are nowhere near being able to scan a person's brain and use it to understand or predict that person's behavior. On the other hand, like everything I have tried so far, the results do seem to line up remarkably well with my own experience. It might not be scientific-paper worthy, but it's fascinating nonetheless.

  So the million-dollar question is, if some of my circuitry isn’t working properly, can I improve it with practice or do I need the navigational equivalent of contact lenses? Russell answers quickly, because I’ve been asking him this a lot over the past couple of days. “We have no idea!” Steve is more hopeful but gives more or less the same message. “It's not that an argument from all the evidence says you can’t get better; it's more that there is no evidence,” he says.

  But what about the taxi drivers? They managed to grow their posterior hippocampus and become superhuman expert navigators. Can’t I do something similar? Russell surprises me by saying that he isn’t convinced that what the taxi drivers are learning are actually navigation skills. They are certainly getting better at learning routes around London streets, but is that im
proving their navigation ability or memory? It's a new one on me—I thought navigation was a done deal as far as brain changes go. I see what he means though: improving navigation would mean that London cabbies would be better at learning to navigate New York, LA, or anywhere else in the world, better than the average person. And that, he says, we don’t know. “That's an important question that we don’t know the answer to.”

  Yet again, the question of whether you can “change your brain”—in the sense of rewiring circuits to make them work better—is actually an open question for many scientists. The folklore surrounding neuroplasticity might make it seem possible, but in some cases it might not be. If my OPA doesn’t respond properly to scenes, for example, that might make it physically difficult to make a mental map. If that's the case, where do I even start in trying to train my mental-mapmaking skills? It’d be like trying to learn a language underwater, from the other end of the pool—the right messages just wouldn’t get through no matter how hard I listened.

  Another possibility, of course, is that if I practice navigating by calculating my distance from boundaries I might start to find it easier. One possibility is to start taking an interest in my son's computer games. Recent research found that novice gamers gained gray matter in their right hippocampus after two months of playing Super Mario Bros. for thirty minutes a day.10 Not only that, but they started to favor an allocentric strategy over an egocentric one as they became more expert at the game. Computer gaming has also been linked to improved ability to focus attention, which does make me wonder if a quick stint on Lego Star Wars every evening with my son could cure a multitude of ills.

  The only catch is that I have always hated playing computer games (probably because I am so bad at them), and in the Super Mario study, the degree of improvement, and gray matter increase, depended on how much the volunteers wanted to play video games. It's the same old problem—you need to pay attention to something to get better at it. You can’t expect any brain change if you don’t focus on the task at hand. I’m in two minds: the working-memory training made it very clear that life is too short to force yourself to do something you hate in the hope that it might improve your brain skills, but on the other hand the face clicking has proven to be useful and worth the daily investment of time.

  I ask Russell whether he thinks I should start playing video games to improve my spatial navigation skills. He answers, “That depends if you want to play more video games!” Which is a good point. Maybe I should skip the games and find a way to add what support I need from elsewhere. A much better use of my time, and indeed brainpower, seems, to me anyway, to be to practice the actual skill that I want to improve—navigating in the real world—using very specific tools to support me while I learn. After all, I don’t berate myself for not being able to reach a high shelf and try to train my body to get taller: I just grab the nearest chair and stand on it.

  This is where the feelSpace comes in. My plan is to wear the belt for the prescribed six weeks, get out in the countryside, and see if it turns my random wanderings into a mental map of my hometown.

  FEEL YOUR WAY….

  Back at home, I treat my dog to six weeks’ worth of long, rambling walks in the countryside. Surprisingly, considering how self-conscious I feel, not that many people seemed to notice the belt, even though I decided early on that trying to hide it under clothes looks both ugly and dodgy, and I have been wearing it loud and proud on the outside. Those who noticed and expressed an opinion guessed that it was either a) a bum bag for storing dog treats, b) one of those waist-toning devices, c) a TENS machine to relieve back pain, or d) some kind of colostomy bag. Only one person picked up on the subtle buzzing and said something like, “You sound like you’re having a nice time there,” with a wink. Only once did someone shout, “Oi ya bomber!” out of a passing car, and it turned out to be someone I knew.

  Figure 4.1. Me, my dog, and my best innocent face.

  Incidentally, as we enter the woods on the first day, I’m reminded of a study I read about a while ago that said that dogs align themselves north to south when they poo.11 This is the perfect opportunity to test that on my dog, Jango. And sure enough, more often than not, if I face the same way as him while he does a poo, the belt buzzes at my back. Actually, his compass seems to be a bit off—most of the time he seems to face either southeast or northwest. There must be a snappy way to describe this: bum to the sun? No, that isn’t right…. Poo to the pole? I will keep an eye on this; since most of the navigating I am going to do will involve taking the dog out, there is plenty of opportunity to gather data.

  The other thing I discover is that the path we enter the woods on faces roughly north-south. The loop I normally do is more or less square, with a few different paths heading off to the sides; I have walked there so often over the years I have a pretty good mental map of it. The belt backs this up: the paths that I always assumed are going in the same direction as the first path into the woods actually are. Over time, I begin to put this information together for different areas: this path heads north, and my house faces north, so it must be over…there.

  As the weeks pass, I find that more and more landmarks in my town start to line up like this. I’m surprised to find that looking across the river in town I was facing north, the same direction as my house faces. If you’d asked me before, I would have guessed that my house faces in the same direction as the river flows, not looking across it. Over time, I can almost see familiar landmarks swivel and slide around in my mind's eye and click into place, all lining up to north. As a result, the whole layout of my hometown starts to make sense to me for the first time. I know that the nearest big town is northeast of here, and when I find myself driving into the sunset one evening I have a navigational “aha” moment: “The sun sets in the west—yep, that makes sense, because town is northeast of here, and it's behind me and over there.” I’ve even started noticing how the sun moves through the sky during the day, something that seemed like black magic before. “Oh, look, the sun is in the south at midday.” It suddenly seems like a skill that might come in handy if I was ever lost in the wilderness.

  I also discover when I get home that my wanderings with the belt in Berlin after I left Klaus's lab have left me with a pretty accurate mental map of central Berlin. One afternoon, my son is watching Go Jetters—a kids’ TV program about major landmarks. Today's episode is about the Brandenburg Gate (an evil baddie has stolen the horse and chariot on top of it). As soon as I see the Brandenburg Gate, I think, Ah, that's looking west. The Reichstag is north of there, and I walked right to get to it. I never, ever think like that, normally. I couldn’t tell you which direction Buckingham Palace is in relation to Piccadilly Circus in a million years, and I lived, and cycled, in London for years (I did a test of my mental map of London while I was in Philadelphia; you can see how London looks in my head below). Back in cartoon Berlin, when the Go Jetters’ boss says that the baddie is heading east, I think about it for a second, watch the action, and think—actually, that's right! Checkpoint Charlie is sort of…that way. I spent one day in Berlin with the belt, and it has cemented the landmarks in my head in relation to their compass positions. That's pretty amazing.

  It's not perfect, though, and in unfamiliar territory, knowing the position of north isn’t enough, even with a prominent landmark for guidance. On one day, I decide to try walking on a huge area of heathland about fifteen minutes from home. I start the walk by a large war memorial that is easy to see from large swathes of the heath and set off north. My plan is to go south a bit, then right (west), and do a loop. Fast-forward an hour or so, and by my calculations, any minute now I should see the memorial to the left (southeast). And…. it turns up to my right.

  Figure 4.2. The map of London in my head as measured by the iJRD app. At least I know that the Tower of London is in the east….

  It would appear I’ve been walking in the right direction, but I have gone too far. A compass is only useful if you also know how far you have gone
in each direction, and landmarks are only useful if you know where they are in space. A line from one of Russell's research papers seems relevant here: “Identification and localization/orientation are conceptually distinct operations: a tourist in Paris might be able to identify the Eiffel Tower and Arc De Triomphe without being able to use that information to figure out where they were in the city or which direction they were facing.”12

  One thing is for sure. If the war memorial wasn’t there, I’d be lost—belt or no belt. In the end, I trudge back to the memorial and turn around until I recognize my surroundings. I spend a while trying to figure out where I went wrong, fail to make sense of it, and then, disappointed, retrace my steps back to the car. When I get there, I spot this sign, which seems strangely appropriate:

  After seven weeks with the belt, I reluctantly send it home to Germany. I’ve enjoyed playing with it, but has it changed anything about my brain's navigation circuitry? I have to be honest: I’m not sure. My brain scan in Philadelphia took place after my feelSpace adventure, and studies where brains were scanned before and after an intervention show that two months is long enough to start to see changes. I had the belt for seven weeks, in the end. So, by one token, if my brain was going to start looking as if it could navigate properly, it probably would have by then. On the other hand, it has definitely changed the way I perceive my hometown, and now that I have the mental map in order, I have begun to use it to get around. Having the belt, and now a compass, also helped me to learn new navigational cues, like the position of the sun through the day, and this is something I can now use to navigate in a way I never would have before.