Science of Chess: Playing blindfold and seeing chess in your dreams

I've been reading a lot about blindfold chess recently, mostly because I'm fascinated by the accomplishments of great blindfold players. I consider myself to be downright mediocre in terms of my ability to visualize positions and calculate, so finding out more about how skilled players pull off not just one blindfold game, but simultaneous exhibitions with dozens of competitors playing against them for hours is inspiring. Blindfold play also appeals to me because of the many questions it raises in terms of visual cognition and neuroscience. I think visual imagery is a fascinating topic for research that forces you to reckon with arguably the key challenge facing all cognitive science studies: How do you measure what's going on inside someone's head?

A few weeks ago, I finally found the time to sit down with the book "Blindfold Chess" by Eliot Hearst and John Knott, which I'd seen referred to several times as the best resource for learning more about the history of blindfold play and the techniques blindfold players use to manage multiple games in their mind's eye. It's a wonderful book with tons of little asides about noteworthy blindfold players and their approach to playing simultaneous exhibitions that could easily keep me busy in the lab for a while. For example, many players relied on imposing a sort of spatial organization on their games during a large exhibition by blocking out games opened with 1. d4 and 1.e4, sometimes with "anchor" games separating these with an opening like 1. f4 or c4. A few players throughout the history of blindfold play have also noted that having an empty physical board in front of them during a blindfold match was hugely disruptive! This is consistent with some standard interference paradigms for measuring visual imagery in the lab, and made me think of modern players who are known for looking up and away from the board while calculating.

Blindfold exhibitions give no rest for the weary

For this post, there is another item that came up several times throughout the book may seem less interesting from a scientific perspective, but stood out to me right away. It turns out that many players who have attempted large blindfold simuls over the years have reported an unfortunate side-effect of all this mental effort: Terrible, terrible insomnia. Harry Pilsbury, for example, noted that "his mind was so occupied with unplayed variations" that sleep was impossible for several hours. Miguel Najdorf claimed that after his famed 45-game blindfold exhibition it was days before he could really sleep, finally nodding off during a movie. While not all of the blindfold players in the book reported such aftereffects, it appears that persistent and intrusive chess imagery - seeing positions in your mind's eye and feeling stuck in loops of calculation - is fairly common. Some players found ways to mitigate these symptoms with other activities (card games, for Pilsbury) while others either toughed it out or used various sleep aids to overcome the problem.

On one hand, you might chalk this post-game sleeplessness as nothing more than a bit of leftover adrenaline from an intense experience. Keep in mind that we're talking about players who are juggling dozens of games for 8-12 hours in public, often in attempts to break world records, or at least to impress people with their prowess. Maybe that just means sleep is tough to come by because you've been pushing yourself to your limits for such a long time. I think it's a little more interesting than that, though. These observations about blindfold play and insomnia reminded me of a few different phenomena that are all related to the important role that sleep plays in learning and memory. Here, instead of walking you through a specific research study in depth, I’ll highlight these various effects in an effort to make some connections between blindfold play, sleep, and learning. Our first stop is another game that's known to lead to similar outcomes, but that has been studied by cognitive scientists and neuroscientists more thoroughly.

The Tetris Effect: Clearing lines in hypnagogic images

First of all, my guess is that you've very likely experienced visual imagery when you are just on the edge of sleep. Something like 3 out of 4 people report seeing things ranging from simple phosphenes of greenish or violet light to full-fledged visions of natural scenes with people moving around. These visual phenomena are referred to as hypnagogic images, and the first thing that came to mind when I read about blindfold players seeing the pieces and squares as they were trying to sleep was a well-known hypnagogic experience called the Tetris Effect. I'm usually more of a phosphene guy myself at day's end, but I have fallen victim to the Tetris Effect many, many times over the years as well.

I’ve mentioned in other posts that I wasn’t the most diligent chess player when I was a kid, but I more than made up for it in video games. I loved going to the arcade, my Sega Genesis still sees a fair amount of use, but the real gaming console of my childhood was my Game Boy. *A sad personal note: I managed to lose my Game Boy and all of my games during our move from Boston to Fargo, and I still have days where I consider going back to that apartment on the off-chance that it’s still sitting in the basement. Surely there’s a chance, right?

The original Game Boy came bundled with Tetris and I think in some ways the game and the console were made for each other. Tetris is addictive in any format, and the Game Boy version seemed especially so. I played for hours, eventually rewarded with the full-size shuttle launch you could only see by getting past level 25. If you played the game as much as I did, you may have seen the same things I did on the edge of sleep after long sessions: Visions of blocks falling through space, or sometimes just sort of floating there, crying out to be rotated and fit together into rows and rows of perfect rectangles.

Here's the thing: Playing Tetris requires that you make use of a broad range of cognitive processes that depend on coordination of multiple parts of the brain: Mental rotation (pre-motor cortex and parietal lobe), working memory (frontal lobe and sub-cortical structures like the hippocampus), and basic visual processing (occipital lobe) are all required to be good at the game, and continued play can strengthen connections between these areas. As you play more Tetris, the increased efficiency of communication between these different parts of the brain helps you recognize key spatial forms more accurately and more quickly and also helps you work out how shapes can be transformed by rotation to fill critical gaps in the playing field. That part probably seems intuitive, but where does sleep and hypnagogic imagery fit into all of this?

The replay of waking activity Tetris players experience just before sleep or during dreaming is more than just a quirk of focusing pre-adolescent attention on a tiny screen for hours. Instead, there is substantial evidence that “playing through” recent experience while you’re sleeping is a reflection of important processes that help ensure learned information sticks around in the mind and brain and strengthen your ability to carry out these tasks later. That is, forming those connections that make you a better Tetris player appears to depend in part on what's happening in your dreams. When I was an undergraduate, a particularly exciting result in this area came from electrophysiological recordings n rodents trained to navigate mazes, which is our next stop on this brief tour of hypnagogic imagery and learning.

Replaying maze navigation in hippocampal "place cells."

To tell you about a particularly cool connection between sleep, dreaming, and learning, we need to dive into the brain a bit. Specifically, we need to spend sometime in a subcortical structure called the hippocampus - so named because it supposedly looks like a sea-horse, at least if you look at it from the right angle and don't quite remember what a sea-horse looks like (maybe it's just me). Anyway, the hippocampus (pictured below) plays a critical role in memory across species. Bilateral loss of the hippocampus in human leads to the so-called amnesic syndrome, in which the ability to form new memories is disrupted, and the left and right halves of the hippocampus appear to support verbal and spatial memory respectively. This makes it a key target of many, many studies designed to understand the basis of learning and memory in the brain.

In rodents, the hippocampus helps to encode information about spatial navigation through neurons called “place cells.” These cells got this name because they are sensitive to an animal’s location, becoming active for example when a rat enters a specific part of a maze that is has learned to navigate to get some reward. These place cells offered an opportunity to examine how learning to traverse a maze during the day (an experience experiments could control) might have implications for activity in the hippocampus during memory consolidation processes researchers thought may happen during sleep. The remarkable result I learned about in class years ago was that recording activity from these place cells while a rat slept led to sequences of activity that were consistent with the rodent replaying their journey through the maze. As one place cell after another became active in sequence, researchers could see how they corresponded to the correct path from the beginning of the learned maze to the end.

By itself, this is really neat - rats are dreaming and we can see what they're dreaming of! There are subsequent studies replicating this result and demonstrating that place cell activity can even reveal a sort of wish-fulfillment in rodent dreaming: Rats that knew a food reward was in a part of the maze they couldn't get to will show place cell activity for the location of the food while asleep. If you can't get there while you're awake, at least you can get to the reward in your dreams! More interesting though is research showing that interrupting this replay of the path through the maze disrupts performance the next day. This suggests that working through waking experiences again and again either hypnagogically or during sleep isn't just about the imagery, it may help you consolidate what you learned so you'll be better at the task later.

Targeted Memory Reactivation - Nudging the sleeping brain towards learning

So rats dream of the mazes they learned to run during the day and that seems to be a crucial part of them retaining what they've learned. How sure are we that the persistent and intrusive visions our Tetris players (and maybe our blindfold masters) experience also have something to do with learning and memory, too? The last phenomenon I want to highlight is one I was fortunate enough to hear about a few weeks ago from Dr. Michael Scullin, a faculty member at Baylor who visited NDSU to give the keynote address at our annual Red River Psychology Conference. During his talk, Dr. Scullin told us about a bunch of exciting work his lab has done examining sleep and cognition, some of it using a technique called Targeted Memory Reactivation (or TRM). The results from his lab and other research groups that have used this technique help connect memory, dreaming, and learning in a way that I think helps make a compelling case that blindfold chess insomnia may be more of a feature than a bug.

The gist of Targeted Memory Reactivation goes something like this: If I really think that replaying waking experiences during sleep is an important way to consolidate memory and reinforce learning, it would be great if I had a way to promote dreams about tasks and other learned material that I wanted to retain. That is, I'd like to be able to sort of nudge the sleeping brain into dreaming of the content I really want my learner to hang on to. One way I could try to do that is by pairing the activity they do during their waking hours with some sort of cue (let's say a sound) that I know I can deliver to them while they're asleep. If the association between that cue and the activity is strong enough, playing the cue to them while they're asleep may provide the nudge I need to persuade their brain to replay their memories of the activity I want them to learn. That, in a nutshell, is how Targeted Memory Reactivation is supposed to work.

And it does seem to work, by the way! If you play music while participants do some task, or maybe fill the room with a particular fragrance, playing that sound or providing that smell during sleep does lead to replay of the activity. One simple way to measure this relies on one of the most annoying experimental paradigms I can think of: Measuring sleep stages with polysomnography to work out when a participant is dreaming just so you can wake them up and ask them what was going on. Though participants are probably justifiably irritated by this, their reports (though probably a bit bleary) do suggest that delivering the cue is enough to reactivate the memory researchers are targeting.

Now for the part that I think makes all of this come together. In Dr. Scullin's lab, his team carried out a version of this paradigm in which they played classical music to students who were asked to learn quantitative material about microeconomics. Next, those students either heard that music again during slow-wave sleep or were part of a control group that heard a different auditory stimulus. Rather than try to measure replay specifically, the question they were interested in was how students fared the next day when they were tested on that microeconomics material again. You can see the outcome below - hearing the music during slow-wave sleep led to better retention of the material from the lecture.

Hearing about these results during our conference immediately put me in mind of the sleepless blindfold players I had read about in Hearst and Knott's book. The difference is that there isn't any obvious cue driving the reactivation of chess memories (and this is probably true for those Tetris players we talked about too), but this may still be a brain on the edge of sleep working on reinforcing cognitive effort so that learning sticks. Perhaps it's the sheer amount of effort that leads to such persistent replay even in the absence of a clear cue - if you've been pushing this hard on a task, perhaps the brain simply defaults to memory reactivation. Alternatively, maybe visuospatial processing is special in some way - the sleeping brain may be biased towards reinforcing activity related to space, mental rotation, and navigation. Regardless, I hope I've connected enough dots here to give you a sense that the dreams of blindfold players may be an intriguing window on how the chess player's brain learns the game both on- and off-line.

A few scattered bits to wrap up

Like so many of the topics I write about here, I think there are a ton of interesting questions to ask about this phenomenon - finding out that blindfold play consistently leads to insomnia-inducing chess visions is a starting point rather than an end. For my part, the first thing I wondered about was whether regular simultaneous exhibitions led to similar outcomes. That's still an awful lot of chess, but without the immense demands on working memory blindfold chess requires. In terms of the neural basis of hypnagogic chess visions, there are some intriguing results regarding the nature of the Tetris effect in amnesia patients that I found compelling too: Patients with damage to their hippocampi still experience Tetris-Effect dreams without explicit memory of having played the game! This work (from Dr. Robert Stickgold's lab) suggests that Tetris replay doesn't happen in the hippocampus, but may instead depend on areas in the cerebral cortex. Is this the case for chess as well?

Finally, I feel like I'd be remiss if I didn't mention that this whole body of research (of which I've only skimmed the borderlands of here) concerning sleep, memory, and learning almost universally points towards one very concrete result: Sleep matters. I try to steer away from anything that sounds like an improvement hack of any kind here, but this one is so general and supported by so much work that I feel like it's worth saying. Sleep is critical for learning and memory, so if you (like me) would like to get better at chess by learning more about the game, managing your sleep health is important. So: Practice openings if you like, solve puzzles too, but get a good night's rest.

Sweet dreams, friends - and may you dream of brilliant moves.

Chessable Research Awards - Submit your proposals by May 15th!

Some of you that read my Science of Chess posts may be scientists yourselves and may have your own interesting questions about the game that you'd like to research. The latest round of the Chessable Research Awards is now open for submissions and there is plenty of time to put together a proposal before their May 15th deadline. One of my students (the intrepid Alex Knopps) was awarded one of these grants last year and we've been excited to be able to pursue his ideas about collaboration in chess analysis with this support. If you'd like to chat about our experience with the CRA, feel free to drop me a line or check in with the Chessable Science team.

Support Science of Chess posts!

Thanks as always for reading! If you're enjoying these Science of Chess posts and would like to send a small donation my way ($1-$5), you can visit my Ko-fi page here: https://ko-fi.com/bjbalas - Never expected, but always appreciated!

References

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Gao, C., Fillmore, P., & Scullin, M. K. (2020). Classical music, educational learning, and slow wave sleep: A targeted memory reactivation experiment. Neurobiology of learning and memory, 171, 107206. https://doi.org/10.1016/j.nlm.2020.107206

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Stickgold, R., Malia, A., Maguire, D., Roddenberry, D., & O'Connor, M. (2000). Replaying the game: hypnagogic images in normals and amnesics. Science (New York, N.Y.), 290(5490), 350–353. https://doi.org/10.1126/science.290.5490.350