Working memory: The master of attention?

Words falling off a page

How does it feel like to have a problem with working memory? How does it feel to read while having a working memory deficit? Consider this analogy:

Imagine using scissors and a piece of paper to cut out a small hole in the shape of a rectangle so that you have a paper with a hollowed out window, or a viewfinder, to look through. Now imagine placing the paper over a textbook, and reading the text through the little window. In situations of distress, as I shift the window to accommodate more text, the previous text I just read is no longer in my memory. In other words, as I am processing new information, old information somehow gets lost. Ideally, if the perimeter of our little paper viewfinder – our metaphorical representation of working memory – is expanded then one is able to process more information at a time.

What exactly is working memory?

Most people already know about the concept of “working memory” but refer to it as “short term memory” instead. While this is in fact true, working memory is specific term used by experts to refer to a special kind of short term memory that involves not just holding information in mind, but also being able to mentally manipulate that information. Being able to repeat the number 867-5309 back is an example of short term memory while repeating that number backwards is a closer example of using working memory. (However, if you are familiar with the song “Jenny” by Tommy Tutone you might actually be exercising your retrieval of long term memory for that number.)

Looking at ADD and working memory in different ways

ADD has been parodied in pop culture as an “Oh look, there’s a chicken” disorder. I have heard this comment or some incarnation of it many, many times. The person with the disorder cannot focus because of internal, or in case of the chicken, external distractions. While it is a silly characterization of AD(H)D, there is some truth to it. I believe the reason for this madness can be explained by poor working memory. Let me explain this further:

To understand the importance of working memory, I am going to consider someone I know very well who I believe has superior working memory abilities, specifically my dad. I would consider my dad a living, breathing “math whiz” and he finds high level mathematics extremely exciting, almost like a form of entertainment. I suspect it is his strong ability to hold and manipulate abstract concepts and numbers in his mind which allows him to excel at mathematics, and it is that task itself that he finds stimulating.

Further evidence as to why I believe my dad is so great at math due to strong working memory is because some people have reported such effects after doing mental training that may improve working memory.

After one forum member negatron completed working memory exercises, he commented on his enhanced abilities:

“I developed an odd curiosity for what I previously considered unpleasant material, such as advanced mathematics. Never imagined I’d consider the thought of advanced calculus exciting. I began reading up on such subjects far more frequently than I used to”

astriaos comments on his drastic school improvements after working memory training:

“in physics class I went from vaguely understanding most of the concepts covered in class to a mastery thorough enough that now my questions usually transcend the scope of the in-class and textbook material, routinely stupefying my physics teacher into longer-than-average pauses….”

He also adds: “I can pay attention longer; my problem solving skills are significantly better… Really, it’s amazing how much cognition depends on attention!” (Of course, being as smart and initiated as he is, he does question the possibility of a placebo effect, but says if that’s a case then it’s “a damn good placebo.”)

When attention is high, it is the task itself that provides enough excitement so that individuals feel satisfied enough by what they are doing so that they no longer go looking for distractions to keep them occupied.

The neurotransmitter dopamine is a feel good chemical that has been known to be involved in working memory. Some studies (e.g here and here) have shown that doing working memory exercises actually results in physical chemical changes in the brain such as in dopamine receptors. It is this same chemical that research has shown people with ADD and ADHD seem to have an imbalance of.

Because of a problem with working memory, people with AD(H)D may not see a difficult problem as an interesting academic puzzle (like my dad’s love for math) but rather an incomprehensible and boring task. To remedy a bored and under-aroused state of mind, people with ADD start thinking about irrelevant, but perhaps more interesting things. Or they may go looking for external distractions such as looking through the classroom window at the duck, bird, plane, chicken, bunny rabbit, or whatever else which may have contributed to the “I have ADD but look there’s a X” stereotype that is often propagated.

Working memory as the master skill of all skills

I have often thought of working memory as “the master skill that helps you with all the other skills.” It is hard for me to think of a task that would NOT be helped by improved working memory. There have even been informal reports that improving working memory improves sleep and dream recall. (The reason why I describe working memory as a “skill” rather than some innate ability here is because there may be some ways to increase working memory through practice and training; I will talk about this in a bit.)

Working memory and its effect on reading

Reading is one of many tasks that stress working memory. In The Language Instinct, Steven Pinker said that “sentences are held together by a mental tree.” However, I think that if the sentence tree becomes too big then there won’t be enough memory to hold all the branches.

Consider this sentence which I borrowed from Wikipedia’s entry on working memory:

“If the cake is from France, then it has more sugar if it is made with chocolate than if it is made with cream, but if the cake is from Italy, then it has more sugar if it is made with cream than if it is made of chocolate”

I have to admit that I had to reread this sentence more than a few times to truly understand it due most likely to problems with working memory. But I did finally understand it, and I can show the sentence relationships by creating a flowchart. Then to test your understanding, you can answer this question:

If you visit Europe and want to eat chocolate cake but are on a diet, do you order cake from France or Italy? (Click on the footnote for the answer. 1)

In all honesty though, drawing a picture is most likely a way around having to hold the information in your head so it is a handy strategy to overcome difficulties with memory.

In the very introduction of this article, I described how it feels like to have problem with working memory and its relationship to reading comprehension difficulties If I had a severe problem every single time I read, it would be a pretty unfortunate situation and people would wonder how I can even graduate from college with such a reading difficulty. However, my ability to read and understand texts is highly variable (attention variability disorder?) and depends on multiple factors such as the specific reading topic and genre, interest and previous knowledge about the topic I am reading, drugs and supplements I may be currently on, my amount of sleep the previous night and so on.

There are different flavors of working memory and there is not just one big attribute called “working memory.” Working memory involves processing of both visual and auditory information. There is still much to be learned about working memory and the research is current and ongoing.

Dual-n-back: a “game” to help improve working memory

Dual-n-back is a game that has been scientifically proven in some studies to improve working memory. There is one catch however. The game was designed to be difficult. If it were easy, then it wouldn’t work. (Try it for yourself and download Brain Workshop, which is a free version of the game.)

I use the word “game” loosely here because it is not the type of game that people with AD(H)D would get addicted to, but interestingly there have been some reports of people being addicted to dual-n-back.

Dual-n-back is perhaps a bit more special than many other “brain games” out there, because there is some evidence that the game transfers to actual real life benefits. A big complaint about the brain training software market is that the games may look educational, but some claim that such games have any far reaching benefits are based on false science. So for example, it has been argued that playing Nintendo’s Brain Age game only makes you better at playing Nintendo’s Brain Age game and does nothing else such as improving memory or concentration outside the game.

When I first tried dual-n-back (and the easier version, single n-back) I have to admit I was a little frustrated and a little disturbed by my poor results, so much that I told my therapist about my concerns with the game. She simply accused me of “thinking too much.” However, I bet anyone who tries to explain dual-n-back to someone who is unfamiliar with it would also get accused of thinking too much.

The concept is deceivingly simple at first: If given a string of letters, say G, P, G K, K, the object of the game at the easiest level, level n=1, is to press a button every time two letters are presented in a row. So in the example I gave, the player will hit a button after the fifth letter K because the letter before it was also a K.

It gets harder at the second level, level = 2, because then the player needs to hold more information in memory. Instead of looking for a pattern like K, K or P, P the player hits a button when a matching letter is one more step away. The player is then on the lookout for patterns like K, P, K, or G, B, G. So in a longer string of letters like G, P, R, P, K, K, J the only time a user is to hit a key is on the fourth letter which is a P because two letters earlier there was a P as well.

At the next highest level, n=3, the player needs to look out for gaps such as P, G, A, P. Notice how the fourth P is three letters away from the first P. This pattern would require the user to hit a key. As the level increases so does the gap between the target letters, stressing the user to keep more and more information at on time. The level can always be made more difficult by adding 1. There is no such thing as beating the game.

So far I have only described part of the game which involves the audio portion. The visual part of the game follows the same exact concept as the letter matching portion but instead of letters, the player should be on the lookout for matching squares on a grid position.

The difficulty lies in being able to do both the visual and audio portions at the same time, hence the name “dual”-n-back. If it sounds confusing, check out this video here.

For a more detailed and perhaps theoretical discussion about the game, I highly recommend reading Gwern Bradwen’s gigantic introduction, analysis, and dual-n-back FAQ.

If I could give a few pieces of advice first don’t give up. Susanne Jaeggi, the lead researcher and designer of dual-n-back, has said that the biggest challenge with the task is “to get people engaged and motivated to play our working memory game and to really stick with it. Some people say it’s hard and really frustrating and really challenging and tiring.” (I also recommend reading the New York Times article about working memory training in which Jaeggi makes this comment.)

I have literally done the task a few thousand times on and off for the last couple of years and I can reach a score of 4.5 which is considered average, but it took me an extremely long time to get there compared to the average time it takes people to get to reach that level. People with ADD and ADHD have been known to take longer to advance in the game.

Second, on the opposite extreme of giving up and abandoning the task altogether, some people obsessively start freaking out and worrying about their innate cognitive quirks.

Here is member KD Jones’ reflections of dual-n-back:

“I’ve generally been viewed by people with considerable horsepower as being very intelligent in a broad sense. BUT only if I have been sampled in given circumstances… because though I’ve apparently got what I have understood to be a very “asociative” brain, I also have the working memory of a gerbil. When attempting any task that meaningfully loads working memory, I can actually FEEL the holes in my thinking, as though it is a concrete, physical attribute. Like mad cow swiss cheese. (Really not kidding here.)”

Obviously, one should not take their worrying to an extreme as in the case of KD Jones.

Working memory is important, but it is not everything

Strong working memory can be an advantage, but having difficulties with working memory is not an absolute recipe for failure either. One can still have relatively poor working memory but still achieve high marks in school. One study found that “Associative learning predicts intelligence above and beyond working memory and processing speed.” I would assume many people with ADHD, ADD, and SCT would fall under this category.

Working memory and the relationship to long term memory

Some people with SCT, myself included, have reported problems not only with working memory but also with problems with retrieval of long term memory. True, “childhood-onset dysexecutive syndrome” might as well be called “CRS syndrome” after all. I have to say that one of the most curious and intelligent people I have found online who can relate to SCT is ADDForums member Jshect and he has posed a very interesting and important question of “Do those with Sluggish Cognitive Tempo have problems with long term memory?

No two brain regions work in isolation. For this reason, probing the relationship between long and short term memory is a step closer in the right direction. Long term memory will need an entire article of its own, but I will briefly mention a few points.

Spaced repetition is an exercise for long term memory in the same way that dual-n-back is an exercise for working memory. I recommend checking out Gwern’s detailed analysis of how one can improve recall from long term memory. (I really, really do like Gwern and I appreciate all of his benevolent efforts in having such intriguing discussions on his website available for all.)

I had an idea at first regarding different types of memory retrieval. Could poor retrieval of long term memory really just a sign of a severe working memory problem? At first glance, it seems to me that improving working memory will provide better access to retrieval of long memory. To me this seems ever so clear when one thinks about how a computer’s memory works. For example, when one first boots a computer its RAM or hardware analog of short term memory is required to access the data from its hard drive (i.e. long term memory). The higher the RAM, the more data that can be accessed from its hard drive at a given time.

But of course humans are not computers, and computers are not humans. (Tech optimists like Ray Kurzweil may argue otherwise though.) There is a dissociation between working memory and long term memory so it is not that easy to jump to those conclusions. For example, I remember reading about one individual with Asperger’s syndrome who was reported to have severe working memory (bottom 2 percentile) but very superior retrieval of long term memory (top 98 percentile). Another member on an Asperger’s support forum makes a comment on his paradoxical abilities and disabilities: “Throughout my entire life, the only thing I have really had to hold on to is the fact that I know I have a phenomenal mind but it is phenomenal and extremely flawed at the same time.” And if I research the scholarly papers long enough, I may even find individuals with the opposite profile – that is, strong working memory but poor long term memory.

In short, working memory is important and improving working memory is a worthwhile task to partake in. But I do believe if I had to make the difficult ultimatum of choosing between strong working memory and strong long term memory, I would choose long term memory.

Final words

Even after all this detailed talk about working memory, I would consider my working memory relatively poor (and I have evidence for this). But if anybody ever happens to ask me about what working memory exactly is, I am fully armed and prepared with a large arsenal of information on the topic. See I told you that AD(H)D is really a problem of “doing what you know, not knowing what to do.”


  1. The answer is Italy.