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The Great Homework Debate: Working Memory Disadvantage?
Andrew Watson
Andrew Watson

Here at Learning and the Brain, we think a lot about the great homework debate.

homework debate

Some scholars rail against homework. Some schools are doing away with it. However, other researchers champion its benefits.

What can brain researchers contribute to this discussion? Knowing what we know about brains and minds, how can we reconsider this argument?

Working Memory in Schools

All academic learning depends on a crucial cognitive capacity: working memory — often abbreviated as WM.

WM allows students to hold pieces of information in mind, while simultaneously reorganizing or combining them.

Clearly, students use WM all the time. For example:

Performing mathematical operations.

Following instructions.

Applying literary terminology.

Combining letters into new words.

Comparing famous figures.

Using scientific principles in new situations.

All these mental operations — and many, many more — require students to hold and process information simultaneously. Whenever students hold and process, they use WM.

Unfortunately, we just don’t have very much of this essential cognitive capacity. As a simple test: you can probably alphabetize the five days of the work week in your head. (Go ahead — try it!)

But, you probably can’t alphabetize the twelve months of the year. Why? You just don’t have enough WM. (Don’t worry: almost nobody does.)

Working Memory and the Homework Debate

A just-published study by Ashley Miller and Nash Unsworth points to a possible connection between WM and our views on homework.

Imagine, for instance, I give my students a list of random words to learn. Later, I ask them to recall words from that list. As you can imagine, the longer the list, the harder that task will be.

As it turns out, a student’s WM influences her performance on that task. The lower her WM, the more she will struggle to recall all those words.

The Miller and Unsworth study adds a crucial twist. As students see the same word list more and more often, the difference between high-WM students and low-WM students gets smaller.

In some ways of measuring, in fact, it simply goes away.

Put simply: repetitive practice can eliminate this functional difference between high-WM and low-WM students.

What’s another name for “repetitive practice”? Homework.

In other words, homework designed in a particular way might help students who traditionally struggle in school. Although a relatively low WM typically makes learning very difficult, a well-structured assignment might ease some of those difficulties.

If teachers could make cognitive life easier for low-WM students, we’d be going a long way to making school more fair and beneficial.

Caveats (Of Course)

First: this argument says that the right kind of homework can help some students. Of course, the wrong kind of homework won’t. In fact, it might be a detriment to most students.

Second: Miller and Unsworth’s study suggests that repetitive practice can reduce the effect of WM differences. However, teachers might struggle to make “repetitive practice” anything other than really, really dull. We’ll need to be insightful and imaginative to ensure that the solution to one problem doesn’t create a new problem.

Third: To be clear: Miller & Unsworth don’t say that their research has implications for assigning homework. However, as I thought over their findings, it seemed the most direct application of this study in a school setting.

Finally: Teachers might object: we rarely ask students to recall random words. This research paradigm simply doesn’t apply to our work.

And yet, we face an awkward truth.

The words that our students learn might not seem random to us, but they nonetheless often seem random to our students.

We know why the words “chlorophyll,” “stomata,” and “Calvin Cycle” are related to each other. However, until our students understand photosynthesis, even that brief list might feel quite random to them.

Words and ideas that live comfortably in teachers’ long-term memory systems must be processed in our students’ WM systems. The right kind of homework just might make that processing easier.

Pro Tips: How To Think Like A Cognitive Scientist
Andrew Watson
Andrew Watson

Here’s an enthusiastic article from down under.

cognitive science principles

The Sydney Morning Herald reports that Victoria University has introduced an “intensive” course model. Students don’t take multiple courses over many weeks. Instead, they take one course for four weeks. Students absorb a full term of learning in one zealous month.

The students interviewed by the paper were enthusiastic. 19-year-old Alice Growden says:

I am learning a lot more; I feel like the information is easier to understand this way. It’s easier to do better. You are not slammed by four different assignments at once. It is much more balanced.

The Morning Herald’s tone (and my Twitter feed) insist on the benefits of these intensive courses. Seemingly only grouchy professors — who fret that they won’t have enough time for research — object.

Cognitive Science Principles, Take 1: The Spacing Effect

Despite this article’s enthusiastic tone, cognitive scientists will quickly doubt the benefits of this “intensive” course schedule.

After all, we have lots of research showing that spreading practice out over time creates more learning than bunching that practice all together.

For instance, Doug Rohrer looks at shorter and longer lengths of time that courses cover topics. His conclusion — in the modest language of research:

Long-term learning is best achieved when the exposures to a concept are distributed over time periods that are longer rather than shorter.

He finds this conclusion to hold even for intensive language courses, where teachers most often champion the strategy.

Many other scholars have reached this same conclusion. Nicholas Cepeda (along with Doug Rohrer, Hal Pasher, and others) worked with more than 1300 students, and retested them up to a year later.

Their conclusion? Spread learning out over time.

This idea holds even for flashcard study strategies.

Pro Tip #1: If you want to think like a cognitive scientist, beware teaching strategies that promote lots of learning in a relatively short time.

Cognitive Science Principles, Take 2: The Illusion of Knowing

As quoted above, student Alice Growden emphasizes the ease with which she learns:

“I am learning a lot more; I feel like the information is easier to understand this way. It’s easier to do better.”

Yet here again, cognitive scientists will be skeptical.

Remember this principle: easy learning doesn’t stick. Instead, teachers should foster a desirable level of difficulty.

In fact, this principle helps explain the principle above. Spreading practice out over time helps students learn better because it creates additional cognitive challenges.

The extra mental work that students do, in turn, creates more enduring neural networks to encode new memories.

Another example: rereading the textbook.

Students LOVE rereading the book, because it’s relatively easy. This study strategy gives them the illusion of knowing. They say to themselves: “I recognize that passage! I must know this!”

Alas, this illusion comforts students, but isn’t helping them learn more.

I frequently cite Nick Soderstrom’s comprehensive article distinguishing between two results of study: performance vs. learning.

Students often believe that if they “perform” well — say, they recognized everything in their notes — then they have studied effectively. Alas, higher early performance often results in less learning.

Pro Tip #2: If you want to think like a cognitive scientist, beware teaching strategies that emphasize how easy new learning will be. Easy learning doesn’t stick.

 

Is Dopamine For Motivation or Learning?
Andrew Watson
Andrew Watson

Neuroscientists talk a lot about neurotransmitters. These chemicals move from one neuron to another at synapses, and in this way help brain cells communicate with each other.

dopamine, motivation, and learning

We’ve got several dozen different kinds of neurotransmitters.

Some you never hear about. When was the last time you heard about tyramine? Or, octopamine? (I really hope it has eight legs.)

Others you hear about all the time. Serotonin. Glutamate. Oxytocin.

And dopamine.

Dopamine, Motivation, and Learning

Teachers hear a lot about dopamine, because it’s an essential ingredient in neural networks central to both learning and motivation.

Of course, we care deeply about both of those topics, and so we naturally want to know more.

However, learning and motivation aren’t the same thing.

They interact, of course. I might learn something that, in turn, motivates me. Or, my general academic motivation might help me learn. But, each is possible without the other.

How, then, do we make sense of dopamine’s role in our world?

In his recent article What Does Dopamine Mean, John Burke sums up the question this way:

Dopamine is a critical modulator of both learning and motivation. This presents a problem: how can target cells know whether increased dopamine is a signal to learn or to move?

Speed Counts. Or, Not.

Often, different rates of dopamine change have been held up as explanations to answer this question.

According to this theory: slow dopamine change = motivation. Fast dopamine change = error detection and learning.

Burke, however, has a different theory:

Dopamine release related to motivation is rapidly and locally sculpted by receptors on dopamine terminals, independently from dopamine cell firing. Target neurons abruptly switch between learning and performance modes, with striatal cholinergic interneurons providing one candidate switch mechanism.

Got that? It’s all about the striatal cholinergic interneurons.

Implications for Teaching

About a year ago, I wrote this:

I encourage you to be wary when someone frames teaching advice within a simple framework about neurotransmitters. If you read teaching advice saying “your goal is to increase dopamine flow,” it’s highly likely that the person giving that advice doesn’t know enough about dopamine.

BTW: it’s possible that the author’s teaching advice is sound, and that this teaching advice will result in more dopamine. But, dopamine is a result of the teaching practice–and of a thousand other variables–but not the goal of the teaching practice. The goal of the teaching is more learning. Adding the word “dopamine” to the advice doesn’t make it any better.

In brief: if teaching advice comes to you dressed in the language of neurotransmitters, you’ll get a real dopamine rush by walking away…

Burke’s article, I believe, underlines that point. At present, scientists don’t know the answer to very basic questions about dopamine’s effect on students’ learning and motivation.

As teachers, we can be curious about dopamine and serotonin and oxytocin. But we should focus on teaching and learning…not on the dimly-understood neurotransmitters that make them possible.