Working memory (or "WM") is the system we use to keep information immediately available. We use it when we perform calculations in our heads, track the meaning of a conversation, and remember what we're supposed to do next.
As I explain elsewhere, the capacity of a child's WM affects his or her ability to follow directions, learn to read, excel in mathematics, and achieve in school.
Can we help kids expand this capacity?
Researchers have tested computer-based memory games to see if intense, repetitive practice can boost children's WM skills. These computer games are effective, insofar as they help kids perform better on very similar, computer-based tasks.
But the improvements don't seem to generalize to WM challenges in the real world. After training, kids experience little or no improvement in academic performance (Sala and Gobet 2017; Shiphead et al 2012).
The same may be said for adults (Melby-Lervåg et al 2013), and the lackluster findings apply not only to real-world working memory function, but also to fluid intelligence.
Despite early hopes that working memory games could boost I.Q. scores (Jaeggi et al 2008), the best-designed studies have failed to replicate this effect (Melby-Lervåg et al 2016).
So the computer-based memory game solution hasn't panned out. But that doesn't mean it's a dead-end. Future research may discover new ways to train WM skills -- ways that transfer to specific academic tasks, like decoding a text, or doing arithmetic.
Meanwhile, there is still a lot that adults can do to help children improve WM performance.
This includes supportive strategies in the classroom, which I discuss at the end of the article, "Working memory: What every parent needs to know".
And it includes becoming more savvy about the things that affect everyday performance. Here are seven evidence-based tips for helping children reach their full potential.
We don't use WM in a vacuum. There is always something going on in the background, and that background affects us. Internal sensations and environmental distractions compete for our attention, and we use some of our working memory resources to monitor this stream of information.
This may explain why people experience dips in WM performance when they are uncomfortable, ill, or in pain (Smith et al 2012; Hood et al 2013; Sellaro et al 2015).
People also experience temporary deficits when they detect an unpleasant odor, or notice another person's direct gaze (Martin and Chaudry 2014; Wang and Apperly 2017).
Even something as simple as walking across a crossing a threshold -- into a new room -- can make you forget your purpose. Why did I come here? Was I going to fetch something? Or close a window? The change of scene seems to wipe out the information we were trying to keep in our consciousness. The temporary contents of our mental workspace are lost (Horner et al 2016).
Such are the findings of experiments on adults. What must it be like for young children? Their brains haven't yet developed the attention skills of older people. It's harder for them to filter out irrelevancies, and focus.
So if we want kids to perform demanding WM tasks, we need reduce distractions to a minimum, and make allowances when they aren't feeling well.
When we worry, we use up precious working memory. It's as if information related to our worries creeps into our limited mental workspace, leaving less room for us to think about other things.
The effects are more pronounced if you are particularly prone to worrying, or suffer from an anxiety condition (Sari 2017; Stout et al 2015; Vytal et al 2016), and even young children are not immune.
Anxiety symptoms have been linked with poorer WM performance in preschoolers (Visu-Petra et al 2014).
Moreover, individuals have anxieties that affect their working memory for specific tasks, like solving mathematical problems (Shi and Liu 2016). In fact, poor WM performance can itself be a trigger for worries, creating a snowball effect (Tresize and Reeve 2016).
Can we improve WM performance by treating our anxieties? Research supports the idea.
One useful technique is to write candidly about your worries and anxieties, and explore the reasons for them. The therapeutic effects of this approach, called "expressive writing," has been shown to improve WM capacity -- sometimes for weeks afterward (Klein and Boals 2001; Yogo and Fujihara 2008; Park et al 2014). And it can lead to higher scores on academic exams (Ramirez and Beilock 2011).
Another approach is to train your mind to resist intrusive, distressing thoughts. This is one of the goals of mindfulness meditation, a traditional Buddhist practice. Research suggests that mindfulness meditation can reduce anxiety (Goyal et al 2014), and a recent study of middle school students hints at working memory benefits as well (Quach et al 2016).
What about anxiety in young children? Kids too young to try expressive writing, or enroll in a middle school meditation course?
Warm, responsive parenting is always helpful, and so is "emotion coaching" -- teaching children about their emotions through sensitive conversations and problem-solving sessions. But it's important to recognize that some children will need more support than others -- more reassurance, and more help learning strategies that build confidence. And we should watch out for common mistakes.
When we are dismissive or critical of children's anxieties, kids get the message that we're unsupportive. When we are overprotective, children get the message that their anxieties are justified. Either way, kids don't get the coaching they need to build skills and overcome with fears (Hurrel et al 2017).
If you think your child suffers from anxiety problems, discuss your concerns with your medical provider, and ask about programs for improving symptoms. Researchers have developed a number of programs for parents struggling with anxious children (e.g., Fox et al 2012; Chronis-Tuscano et al 2015; Creswell et al 2017; Morgan et al 2017). They draw on principles of cognitive behavioral therapy -- which has a good track record in improving anxiety symptoms in kids -- and typically take only 6-8 weeks to complete.
What happens when we feel we are being unfairly judged? Snubbed? Targeted for social discrimination? These situations are stressful, and they can impair WM performance.
You might wonder if stress hormones are directly responsible, but that doesn't seem to be the problem. Instead, it appears that our minds become partially preoccupied with the job of restraining our negative emotional responses. And that uses up precious WM (van Ast et al 2016).
For example, experiments show that being reminded of a derogatory stereotype -- concerning one's own race, sex, or other group membership -- can cause immediate, measurable reductions in WM capacity (Pennington et al 2016).
People naturally want to prove the stereotype wrong, and to succeed, they know they will need to control their negative emotions. It's hard to be at the top of your game if you're feeling anxious, defensive, or outraged.
So people end up diverting valuable working memory resources to keeping these emotions under control, leaving less WM capacity for performing the task at hand (Johns et al 2008).
How early in life are children affected by "stereotype threat"? That's not entirely clear, but experiments in the United States suggest that boys as young as 7 years perform more poorly on tests of reading, writing, and mathematics when they are reminded of the "girls are better students" stereotype (Hartley and Sutton 2013).
And recent research conducted by Kate Wegmann suggests that kids between the ages of 7 and 11 years have no trouble identifying the threats posed by derogatory ethnic stereotypes about academic ability (Wegmann 2017).
This might sound discouraging, but researchers have identified effective strategies for countering stereotype threat, which you can read about here.
When you don't get enough, WM performance suffers.
It's not surprising that performance on working memory tasks would deteriorate when we're tired or sleepy. If we're physically uncomfortable, that's a distraction. If we're sleepy enough, we might also suffer from spontaneous lapses of consciousness, called microsleeps. Experiments show that one night of sleep deprivation results in immediate impairments in working memory (e.g., Kopasz et al 2010; deBruin et al 2017).
What's more interesting -- and disturbing -- is the idea that chronic sleep troubles might interfere with the development of WM capacity.
When researchers have administered WM tests to different populations, they've found links between an individual's test scores and his or her habitual patterns of sleep (Sciberras et al 2015; Kopasz et al 2010).
For instance, when researchers tested WM in more than 1700 Australian first graders, they found strong links between verbal working memory difficulties and parent-reported poor sleep (Cho et al 2015).
Is it possible that we could boost a child's WM capacity -- and academic performance -- by making sure he or she is getting enough sleep?
I haven't found any experimental research on the topic. But in a recent study of college undergraduates, students randomly assigned to add an afternoon nap to their schedule experienced better WM performance immediately afterwards (Lau et al 2015).
For help troubleshooting sleep problems in children, see these tips.
What happens when somebody tells you a new telephone number? Until you can make a record of it, you keep the memory alive by repeating the information back to yourself. You might speak out loud, or repeat the numbers silently in your head. But either way, you're talking to yourself, and that repetition is called "verbal rehearsal."
Rehearsal is essential for some WM tasks (Lucidi et al 2016), and kids discover its value early in life. Young children often talk to themselves in ways that help them stay on task (Alderson-Day and Fernyhough 2015), and they may use verbal rehearsal to keep information active in working memory (Fatzer and Roebers 2012).
Yet children don't always take full advantage of this strategy, which might explain some individual differences. Among 5- and 6-year-olds, researchers have found that the use of self-regulatory speech is linked with better problem-solving (Fernyhough and Fradley 2005; Winsler and Naglieri 2003).
And research suggests that many kids -- including young children, and those with low working memory capacity for their age -- may benefit from being encouraged to voice, or repeat back, key information (Müller et al 2009; Gatherole and Alloway).
So it makes sense to encourage kids to make use of verbal rehearsal, and be mindful of what happens when we do the opposite. Asking kids to suppress their self-regulatory speech (e.g., "work silently at your desk") could have a negative impact on performance. When researchers asked school kids to solve a visual-spatial puzzle that required planning ahead, they found that children performed worse when they were instructed not to speak aloud (Lidstone et al 2010).
Many people find it natural to gesture as they speak. Is this just a lot of hand waving, or does it serve a purpose?
Decades of experimental research provides an answer: Gestures can help us learn and recall information. And it also appears to help people struggling with WM limitations.
Gesturing helps adults stay on track when they perform visuo-spatial tasks that tap working memory (Wu and Coulson 2014; Morsella and Krauss 2004). It also seems to help adults perform tasks that require verbal WM, especially if they have lower WM capacities to begin with (Gillespie et al 2014).
What about kids? They, too, seem to benefit from gestures.
When Susan Goldin-Meadow and her colleagues asked children to perform a working memory task, kids who spontaneous gestured during the process achieved more (Goldin-Meadow et al 2001).
Moreover, other research indicates that kids learn mathematics more readily when they are asked to perform relevant gestures during a lesson (Cook et al
2006). And the effect is passive, too: Kids learn better when their instructors include relevant gestures in their speech (e.g., Cook et al 2017).
Does this mean gesturing helps everyone? Not necessarily. But researchers suspect that gestures can reduce demands on WM. And it's clear that suppressing natural gestures can put kids at a disadvantage. When researchers prohibit children from gesturing, they perform worse on WM tests (e.g., Pine et al 2007).
To read more about how gestures help kids learn and reason, see this article.
When kids absorb more knowledge, they develop more efficient ways of juggling information.
Nobody has an objectively large WM capacity. In experiments, adults can keep only a few distinct pieces of information in focus at once -- about 3 to 5 items (Cowan 2001). In studies of 7- and 8-year-old children, the average WMC is just 1-2 items (Riggs et al 2006).
But these are the limits for information that is abstract or disconnected what we already know. When people are presented with familiar information, their performance improves.
For instance, if I briefly flashed a sequence of twelve, apparently random letters at you, and then asked you to repeat them back, you'd find that very difficult, if not impossible:
But notice how much easier it is when the letters aren't random, but instead a series of meaningful acronyms:
CIA UFO PHD IBM
Your underlying working memory capacity hasn't expanded. But your performance has.
Your prior knowledge of things like the Central Intelligence Agency helps you compress many disparate units of information into fewer, meaningful chunks.
The chunks might contain three letters each, but your working memory no longer has to keep track of all twelve letters. Instead, you probably remember each chunk as a distinct item, and rapidly retrieve information from long-term memory when I ask you to reel off the letters in the correct sequence (Cowan 2016).
So background knowledge helps you remember a sequence of letters. What else can it do? A lot.
For example, background knowledge reduces demands on working memory when we read (Miller et al 2006; Soederberg Miller 2009), allowing us to process more complex sentence structure.
And one key reason why kids perform more poorly on WM tests is because they lack the background information that adults take for granted. When researchers have created WM tests that virtually eliminate the possibility of prior knowledge, adult WM performance is sometimes reduced to what we observe in children (Cowan 2016).
Moreover, there is evidence that kids acquire better WM skills as a function of time spent in school. In a study tracking the progress of approximately 1700 first graders, researchers found that WM performance increased steadily over the course of the school year.
Was this merely because the children were getting older? Apparently not, because when researchers controlled for each student's age, they discovered it was the duration of schooling that mattered. Time spent in school, not age, predicted increases in WM performance (Roberts et al 2016). This is consistent with the idea that kids are learning things that help them organize, chunk, and encode information.
Of course, that doesn't mean that background knowledge is the only important factor. On some laboratory tests, children show dramatic gains over time -- even when the featured items are totally unfamiliar (Cowan et al 2015).
But in everyday life, you encounter a mix of information, familiar and unfamiliar. And having more background information gives you an advantage. It helps you reduce demands on working memory, so you're less likely to get overwhelmed.
It's a powerful argument for cranking up your curiosity and learning more about the world. Being an avid reader, a consumer of interesting facts, or a collector of new vocabulary may pay off in ways that go beyond the accumulation of information in long-term memory. It may actually help you repackage incoming data, freeing up crucial WM resources. You're left with more WM to think and solve problems with.
By helping kids discover intellectual passions and soak up new information, we are laying the groundwork for long-term improvements in working memory performance.
For more information on this subject, see this guide to working memory. In addition, check out these related topics:
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Image of boys playing with puzzles by US Army
Image of worried girl by Andy / flickr
Image of mother and daughter hugging my US Dept. of Education
Image of boy sleeping by Woodley Wonderworks / flickr
Image of mother and girl working at desk by AZemdega / istock
Image of toddler gesturing at father by David R Tribble /wikimediacommons
Image of girl reading magazine outdoors by Fiona Graham WorldRemitCommons / flickr
Image of kids reading on bed by Niki Duggan / wikimedia commons