Friday, February 8, 2013

The Brain on Tetris

What happened to that hour?  That other hour?  The one after that?  Where did they go?

My son's best friend from childhood, whom I haven't seen in ten years, sent me a message with this link to a BBC story, The Psychology of Tetris.  When he saw it, did he remember that I used to ask my son to hide the Gameboy?


The Zeigarnik Effect

It is the heart's desire of every psychologist, psychiatrist, even physicist to get one's own name attached to some phenomenon.  They don't have to explain it.  They just get to name it.  Then they put everybody else to work for a couple decades trying to explain it.  But whoever cracks that nut will not go down in history   The person who named it will.

So some day we will know what part of the brain itches when presented with an uncompleted task, and will not rest until it is finished.  That is the Zeigarnik Effect, named after Bluma Zeigarnik who noticed in some Russian cafe that waiters remember what you ordered until you are served, and then they forget.  The brain holds the task in short-term memory, and does a memory wipe when it is completed.  From my own experience with memory games at lumosity.com, I absolutely know this to be true.  I have no idea what Elvis ordered, once Patricia takes his place at the counter.

Tom Stafford, author of the linked article, suggests an explanation of the Zeigarnik Effect, that the mind is designed to reorganize around the pursuit of goals.  That's great, Tom.  But where in the brain?  Where is that fMRI machine now that I need it?  Once again, I need that fMRI machine.

Tetris in the Brain

So there are those blocks lying around at the base of the puzzle, and another falling from above.  You use your thumbs on the controls to turn the falling block so it fits up against the ones already settled.  When horizontal lines of blocks fill in with no gaps, they disappear.  You tidy up the screen.

It's a puzzle in motion.  You can figure out which way you want the block to fall and then turn it so that it will.  Or you can turn it until you can see it will fall the way you want.  People who play this game a lot tend to use the second strategy.  The thumb is faster than the mind.

Until your thumbs wear out and you have to ask your ten-year-old to hide the game so they can heal.

I am thinking, maybe a channel between the parietal lobe (in yellow -- spatial orientation) and the occipital lobe (pink -- visual processing) with a check moving forward to the anterior cingulate cortex (dotted red and blue lines -- pattern seeking).

It is faster to [rotate the blocks and then check] than it is to [figure it out and then execute], because the parietal and occipital are right next to each other and can communicate quickly, whereas the ACC is farther forward and the neurological impulses have too far to travel to get a decision made before the next block starts falling on top of the pile.

You kinda just have to do it.

An fMRI machine could confirm my hypothesis about which lobes are doing what to accomplish the task.  Anybody out there who has one -- there is your next project.  Give me a footnote, will you?

The Zeigarnik Effect and Tetris

So as the lines fill in and disappear, the screen gets tidier.  That must shoot out some endorphines, a little reward for task accomplished, and you never think of those disappeared lines again -- the Zeigarnik Effect.

But the blocks keep falling!!  On to the next falling block, which demands your brain's total attention until it has found its proper resting place.  Thus the game continuously gives you the next little task, the next little itch that has to be scratched by continuing to play, and is satisfied only to have another itch appear.  There we have habit formation, really bad, time-evaporating habit formation.


[I explain the graphic above in a different context over here.  It's a little detour I'm taking to show off this graphic I made last year, because I love to create graphics.  Now back to the post...]

If things are not going well, if your attention strays or you get a spasm in your thumb, the blocks pile up faster than you can arrange them.  Then they fill the screen, and the game is over.

It is very difficult to stop when the game is over, because you know you can empty that screen if you try again.

It is impossible to stop in the middle of the game.  Don't bother trying.  Unless you are short on dopamine, which condition will suck the motivation right out of you and interrupt that habit-formation cycle up there, not to mention your game.

PTSD and Tetris

I first reported research regarding PTSD and Tetris three years ago.  Since then Emily Holmes and colleagues at the University of Oxford have continued their work.

The theory is that the visiospatial cognitive stimulation of Tetris makes such intense demands on the brain's processing powers that when the game is played after an experience that could induce flashbacks, it interferes with memory consolidation of the trauma, and thus protects the player from PTSD.

Okay, I understand that sentence.  But I wrote it.  Let me break it down.

Here is the experiment:  Subjects were shown The Trauma Movie, a piece of film known to induce flashbacks (the signature symptom of PTSD).  After a few hours, some subjects played Tetris, some played another video game, some sat quietly.  In the week that followed, those who played Tetris had fewer flashbacks.  The other game did not have the protective function.

Here is the deal with PTSD:  For a while after a traumatic experience, the brain is laying down memory, creating long-term memories out of short-term.  These memories encode in the hippocampus all the physical sensations that accompanied the experience and its aftermath, sights, sounds, smells, pain, hormone rushes, intense emotions.

But if the experience is too intense, the brain shuts down part of its processing.  The experience is not fully metabolized.  At a later time, when part of the memory is experienced, say, when one hears car brakes squealing, then the rest of the memory, including the disturbing emotions and the rush of hormones, gets triggered.  The person relives the trauma in the body.  That is a flashback.

It's really not that different from how the smell of hot cocoa brings back memories of Grandma and how she made you feel safe.  Except the reliving of trauma and all the things you do to avoid the triggers that make you relive the trauma -- screw up your life.

So what if you could interfere with the memory consolidation process, lower the intensity?  PTSD prevention has focussed on a variety of strategies to do this.  Holmes et al are trying Tetris.  They assume that flashbacks are largely visual.  So they are leveraging Tetris' power to engage this part of the brain, to distract the subject from the trauma.  The subject will still remember the event, but with less intensity, because the brain was absorbed by this damned game at the time of memory consolidation, and not laying down the tracks of cortisol rush, pain, fear, excitement, dread, bat shit crazy amygdala, and so on.  Triggers then would function more as reminders, not one way tickets in the time machine back to the disaster.

Evaluating the Tetris Experiment

The results are intriguing.  And pharmaceutical approaches to PTSD are so far a bust.  So it's worth a shot.  The primary problem is setting up a clinical trial.  The original experiment did not replicate a first diagnostic criterion of PTSD:

The person was exposed to the following event(s): death or threatened death, actual or threatened serious injury, or actual or threatened sexual violation.

This exposure can be by personal experience, witnessing the event happening to another, learning of it happening to a close relative or friend, or repeated or extreme exposure (such as first responders would experience.)

Side bar: I think PTSD is another one of those phenomena that has a name, but not a good explanation just yet.  But another day...

The Trauma Movie may induce flashbacks.  But it does not induce PTSD.

And I wonder about the assumption that the visual component is primary.  It is, when the flashbacks are induced by watching a film, but not necessarily in real life.  For myself, I do have a visual trigger.  But the core trauma itself was largely an auditory experience, what I heard on a lovely sunny day.  And what about traumas that happen in the dark?  Tetris may be an intervention that works for a subset of PTSD prevention.  I wonder what other games or simulations might serve the same function to address other sensory experiences.

As far as testing it goes, I can imagine a naturalistic study in a war zone, where the traumas are repeated daily, and PTSD is turned out like spent ammunition.  The US Department of Veterans Affairs estimates that 11% of Afghan war vets experience PTSD and 20% of Iraq war vets.  Researchers do not need to troll the ER and interrupt an individual's one-time experience with a consent form.

Soldiers could be divided into groups, one group allowed to play Tetris upon returning to base, another group playing whatever video games they like, for the duration of their tour.  Then do a diagnostic exam two years out.  Is there a difference in the rates of PTSD?

Preventing PTSD -- The Bigger Picture

The Tetris intervention is designed to interrupt a cognitive process that happens shortly after the trauma.  It falls under the heading of secondary prevention, coming between the cause and the development of the disorder.  Primary prevention would be preventing the cause, like, if men stopped raping women and girls.

If you are already among the ranks, sorry, no cigar.  Tetris does not address those who already have PTSD.  Still working on that one...

Meanwhile, here is a good place to start for description, treatment options and resources.  Blessings, my friend -- we're pulling for you.

Tetris screen shot in public domain
sketch of brain by Pancrat, used under Creative Commons license
photo of car crash by Dori, in the public domain
graphic by author
photo of cup of cocoa by Andre Carwath, used under Creative Commons license
photo of medical evacuation in public domain
flair from Facebook

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