Boxed

Things I learned after lying in an MRI machine for 30 hours

Marco Giancotti,

Photo by Vladimir Kramer, Unsplash

Last year a researcher from a Japanese lab asked me if he could borrow my aphantasic brain for an experiment. Neuroscientists have been studying the weird capacity most people have of "visualizing", or mentally conjuring pictures of things that aren't there, for a long time. The problem is that the brain is such a wild tangle of interconnections that it's hard to tell which of its parts are involved in visualization and which are unrelated, or downstream of it. Comparing people who visualize with aphantasics who don't is a very convenient way to partially work around that problem.

I agreed to participate in the experiment. That decision led to me spending an inordinate amount of time deep inside an MRI, looking at pictures or trying (and failing) to imagine pictures. The machine, worth half a dozen Lamborghinis, is hidden somewhere in a basement on the University of Tokyo campus.

Click to play the animation. Source: Fastfission, CC BY-SA 3.0.

Essentially, an MRI is a big pipe you climb into, which happens to be capable of seeing right through you. Wrapped around the pipe is a hidden network of metal coils cooled to 9 degrees Celsius above absolute zero, constantly switching very large currents to fill the hollow inside with a strong magnetic field and shooting (harmless) radio waves at some corner of your body—the brain, in this case.

In neuroscience, MRI is used to detect microscopic changes in blood flow inside the brain, allowing the researchers to obtain a 3D video map of which neural networks are active at each instant.

In my experiments, the researchers record what goes on in my head when I look at a picture of a fire hydrant, then a camel, then a piece of wood, and so on, covering thousands of pictures over the months. Other times they asked me to imagine various things, or to remember images that I had been shown earlier.

The scientific side of these experiments is very interesting, but there are many other places to read about it in depth. Here, instead, I want to leave some notes on my subjective observations of this experience. I've found that lying down in a cramped space for hours at a time, fully awake and with only very weird kinds of pastimes, leads to some unusual reflections.

These are a few of those reflections, in approximate order of decreasing banality.

1 - It's noisy

Anyone who has spent more than two seconds in an MRI knows this, but if you're thinking of trying for the first time, be warned: those things are LOUD.

The high-frequency current switching causes the metal coils around you to expand and contract and vibrate like a jackhammer. You feel like a rescue team is trying all they can to get you out of an unbreakable iron coffin. If you're sensitive to loud noises, you might want to avoid it.

Usually they give you foam earplugs before you go in, and those make the experience bearable for me. Still, there are risks. The other day I mis-inserted one of the earplugs and got a taste of the unabridged experience: I tried to continue like that for a while, but I was so worried for my eardrum that eventually I had to stop the experiment early. When I got out I felt like the left side of my head had been in the front row at a rock concert. Not healthy.

Even with properly-inserted earplugs, the racket echoing all around you is the most unpleasant part of the experiment. It's surprisingly draining. If it weren't for that, I think I could keep going just fine for much longer.

2 - It's very good at putting you to sleep

Remaining horizontal in a semi-dark space for a while doesn't help you stay awake. This shouldn't come as a surprise to most people, but it surprised me. I usually have the opposite problem, because I never nap or sleep during daytime (as in, maybe once a year), and not for lack of trying. There is something about the infinite possible activities that I could be doing instead of sleeping that excites my brain during the day, even when I'm very tired.

Yet, looking at long sequences of unrelated pictures or—much worse—the same set of pictures over and over has an almost magical power to induce slumber. I haven't succumbed to it yet, but I've come close a few times. I should try something similar for my next napping attempt.

A gray surface with a gray stripe running through it.
The scenery as seen from inside the machine.

3 - My brain craves novelty

Aside from the problem of sleepiness, I was shocked at how the lack of new stimuli can strain my grasp on my mental faculties.

Some experiments consist of seeing the same images hundreds of times, or repeating the same task over and over with only minor variations. Since an MRI pipe is essentially an isolation chamber, those tasks and images (and the noise) are the only sensory input you're going to get. After a while, my brain started rejecting them.

At first, it wasn't a big deal, but after a few weeks of those repetitive tasks, even the simple act of paying attention to what was in front of my eyes began to take a tremendous effort of concentration. I came out in shambles every time, depleted of life force, and I even thought of the word torture once or twice. But hey, someone's gotta do this.

Luckily that repetitive series of experiments ended just before I reached my breaking point. I wonder if this is something that can be trained, but I'm not sure I'd want to do that either.

4 - Novel, random images are great for creativity

Most of the experiments involve looking at non-repeating images, meaning that I see each one only once and never again. My brain is apparently fine with this and, with a good infusion of caffeine, it's actually happy to go on the ride.

This is an experience you don't usually have in your daily life. Normally you know, more or less, what to expect to see next. Even when you can't predict what's coming—when you're watching a movie, for example—things have some kind of connection to each other, some theme or context that ties them together. With random images in a lab, none of that exists. Now you're seeing a picture of a man blowing smoke from his mouth in the Grand Canyon, next it could be a close-up on a smudged corner of a book, or a group of penguins near an ice cliff, or a pile of broken CRT monitors, or something else altogether.

Every four seconds or so, you see something new that you would never have guessed from the previous pictures. Each time it's a different cascade of activations in your brain, evoking random memories, creating unexpected connections, and stimulating thoughts that would never have occurred to you.

Something strange happens: even though it's all purely random, the brain tries to make sense of it all, tries to find patterns and associations. With no time to establish conventional framings, it has to improvise, take in the images in a partly-unconscious way, without thorough processing. This, I think, is a great way to stimulate creativity.

A few times during those experiments, I came up with so many ideas—things to write about, better ways to explain things, new intriguing questions about the world, etc.—that my biggest worry was trying to remember them all for the 20 or 30 minutes left until the end of the session. In the short pauses between bursts of images, I tried to rehearse the list of ideas with shortened mnemonics, but found that I could only keep around five in my head before I forgot some of them.

This is an amazing state to have my brain in, and I wish I could induce it at will. Social media feeds look similar on the surface, but they don't give you truly random stimuli. Their contents are highly edited to appeal to the viewer, and come with lots of cultural baggage and trend-following. They don't work to unhinge my creativity—rather, they trap it.

What I need is an app that does nothing but show you truly random pictures, with no curation and no memetic aspirations. If you know of one, please let me know.

An athlete's hand being wrapped in tape by someone.
A random picture. I bet you didn't see that coming. Source: Dylan Nolte, Unsplash

5 - Our sense of time is non-linear even at the shortest scales

Everybody has experienced the subjective relativity of time. When you have fun, it flies. When you're waiting anxiously, it never budges. But, before these experiments, I had never realized just how warpy my perception of time can be even on the scale of a couple of seconds.

These tasks with pictures require me to stay focused on what's shown on the screen. To ensure that I'm not distracted, the screen will show certain cues at random intervals, to which I have to react by pressing a button. Usually, the cue is the repetition of the same image twice in a row: normally each image stays there only four seconds, but sometimes it will flash back to itself instead of being replaced by a different image. This sounds like an easy thing to spot, and most of the time it is. But when I'm not in an optimal shape, it can become fiendishly difficult.

I find myself asking, have I seen this same picture two seconds ago or not? Is this still the first four seconds?

This is so strange and almost disconcerting. In the highly controlled environment of the lab, I can easily notice these lapses in my perception of time, but what about all the other times? Does my sense of time ebb and flow like that every few seconds of my waking life?

6 - Having your thoughts monitored feels... weird

Sometimes, during the experiments, I wonder about things like:

  • Is it enough to just watch, or should I think intensely about the subject?
  • I was asked to imagine the picture of a duck, but I imagined a moving duck, beating its wings quickly. Will this taint the results?

In order to protect the objectivity of the experiments, the researchers don't tell me exactly how they're analyzing the fMRI data, or what their hypotheses are. Still, I know that they happen to have the closest thing ever to mind-reading technology, which has interesting implications.

In previous studies, they have successfully trained generative AI to read fMRI scans and replicate the images people were thinking about, or to add captions describing those mental images. Considering the amount of data they're taking of my brain, it would be possible for them to train an AI for my specific brain patterns.

I don't think many people have experienced this situation before. People have had tyrants and Big Brothers spying on their actions and words for millennia, but has anyone ever had their thoughts monitored? In a sense, I feel naked.

For now, this is not a big problem. At worst, I might worry that they would know it when I'm distracted, and I might try not to think about kinky stuff (usually a big mistake). Not the end of the world. But I can't help imagining about the dystopian societies that could emerge if the same technology was somehow scaled to portable sizes and affordable prices.

7 - We are usually oblivious to what our brains are doing

I've only ever tried short-ish sessions of mindfulness-like meditation, where the goal is to free your mind of thoughts, focus on your breathing, or something along those lines. I don't know about other types of meditation, but I would guess that most of them are about relaxing or at least not thinking very hard. All of these may help you, in one way or another, to feel better and more centered and even, in some cases, to know your body and mind better.

But I doubt there is a kind of meditation that prompts the level of introspection that long hours in an MRI machine doing simple but focused tasks can give you.

Inside the machine, I have to remain very still with no phone to check, nothing to read, no tossing and turning just for the sake of it, nothing to fiddle with, and—given that the tasks all require a moderate but constant level of attention, no opportunity to get really lost in thought. I did this for over 30 hours now, and counting.

In other words, I got to spend a lot of time in the peaceful, forced company of myself, not too cognitively busy but neither focusing on breathing or clearing my head. It's a sort of Goldilocks zone not only for creativity (point 4), but also for the observation of how my mind works.

In this process, I've learned more about myself than I had in the previous two decades. For example, it's how I uncovered the details of how my non-visual imagination works—something I had never noticed before. One day, right after a session in the MRI, I ran to a cafe and wrote a Twitter thread explaining exactly what that is like for me. The thread had a surprising success, attracting the keen interest of lots of other people (you can read a copy of the thread here). Apparently it's a kind of description that is usually hard to come by, yet it came easily to me with all that time of confinement.

This unexpected success at discovering new things about myself has encouraged me to try this introspection outside the lab, too. That's how I first realized I have time-space synesthesia, something that I hadn't even heard of before. It's also how I realized that wearing special earplugs in noisy places helps me understand what the people around me are saying, mitigating a mild auditory processing disorder that I had never thought much about. And so on, with a new quirk or peculiarity coming to my attention every now and then as I do other things.

Somehow the mere fact of staying still in a state halfway between emptying my mind and filling it to the brim has helped me become more attuned to myself. I feel a bit more centered in the moment, so to speak. Much more than before, I now consider the brain to be an organ that you can observe and study, a black box you can tinker with (carefully) to better understand it. This kind of exploration can be very fruitful, showing you what works best for you, what to avoid, how to be kind to yourself, and generally how to "use" your brain more expertly. ●

Cover image:

Photo by Vladimir Kramer, Unsplash