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Conflicting Advice: Mind-Wandering Is Bad, or Just Fine
Andrew Watson
Andrew Watson

The Harvard Gazette recently posted a soothing headline: “When Wandering Minds are Just Fine.”

mind wandering advice

The subhead offers even more encouraging news: “The practice has no detrimental effects in some situations, study says.”

No detrimental effects. That sounds kind of great.

It also sounds a bit confusing. Here’s the title of another recent journal article:

Mindwandering While Reading Not Only Reduces Science Learning But Also Increases Content Misunderstandings.”

So: which is it? Mind wandering is just fine? Or, mind wandering hampers learning and creates misunderstandings?

Mind Wandering Advice, Part 1: Consider the Paradigm

These two studies arrived at dramatically different conclusions because they studied dramatically different situations.

In the language of psychology, they used different research paradigms.

One study had students read a science passage, and then write about the information and concepts they had learned.

The other study had participants look at a clock and press the space bar whenever it showed exactly 12:00. The clock was designed to show 12:00 every twenty seconds.

Now: which one of those two studies sounds more like the work you do every day?

Mind Wandering Advice, Part 2: Focus on Your Students

Given that these two studies consider such different activities, we can easily decide which one applies to us. Focus on the study that resembles your students’ work.

For the most part — I suspect — we’re interested in the research about students who read the science passage. After all, that study looks a lot like school.

In that study, researchers found that students who spent more time mind-wandering learned less science.

They also held on to more misconceptions about the science that they studied.

In brief: mind wandering harms much of the work that students do in school.

MWA, Part 3: Don’t Panic

At the same time, the 20-second-clock study can also give us some useful parameters.

That study makes a simple point. Sometimes — when the clock is approaching 12:00 — we need to focus clearly. Other times — when we’ve got 10-15 seconds to go — it’s just fine to mind wander a bit.

So: if your students can confidently predict when they’ll need to refocus, you don’t need to worry if they take some mental time off.

 

To explore this question further, you might look at Kevin Kent’s article called Drifting Away. In it, he explores the settings where mind-wandering just might benefit learning.

Just Not a Useful Debate: Learning Styles Theory [Updated]
Andrew Watson
Andrew Watson

At one of the first Learning and the Brain conferences I attended, a speaker briefly mentioned that learning styles theory doesn’t have much good evidence to support it.

learning styles

That comment turned into a heated debate. Several attendees asked vexed, unhappy questions. The speaker held her ground.

When I got in the elevator at the end of that session, I heard one attendee curtly dismiss the speaker’s objection: “well, it’s all just statistics.”

It’s All Just Statistics

Well, it IS all statistics.

In the worlds of neuroscience and psychology, researchers rely on statistical methods to ensure their recommendations aren’t simply hunches.

Anyone can stand behind a microphone and have an opinion. But: if you’re going to do scientific research, your numbers have to add up.

And, as researchers look at valid statistical models, they just don’t find good support for the idea that — for instance — some people are visual learners and others are auditory learners.

The numbers just don’t add up. Or, in this case: if you teach “visual learners” “visually,” they don’t learn any more than if you had taught them “auditorily” or “kinesthetically.”

Multiple Entry Points

Instead, the content itself often offers guidance on the best way to teach. If you’re teaching a French or Spanish or Japanese accent, that content is — by its nature — auditory.

If you’re teaching geography, that content is visual.

Free throws? Kinesthetic.

Most content, however, can be taught in multiple ways.

For example: I’m thinking of an actress. She’s Australian. She played Virginia Woolf in that movie. And, she was married to Tom Cruise.

If you’re shouting NICOLE KIDMAN, you’re right. Notice that I gave you three entry points to the neural network that encodes this memory: her country of origin, a role she played, and her marriage.

So: “teaching to learning styles” helps because you probably teach your content in different ways — auditorily, visually, and kinesthetically. Those three different approaches give distinct connections to the memory you want your students to form.

This approach to teaching helps not because of a student’s learning style, but because all your students now have multiple ways to access that memory.

In other words, the theory helps students learn — but not for the reason it claims to.

“Learning Styles”: Today’s News

Daniel Willingham — one of the early debunkers of learning styles myths — has recently posted his current thoughts on learning styles. The short version:

Nope. Learning Styles still don’t exist. Really.

Learners should “tune their thinking to the task.” That is: learn about geography visually — even if you think you’re not a “visual learner.”

More than many researchers, Willingham gets teachers and teaching. So: if you’re still a learning-styles believer, I encourage you to check out his article.

 

In related news: Greg Ashman argues that, no, rejecting learning styles theory isn’t sexist. After all, LOTS of thoughtful female researchers reject the theory.

And: the Learning Scientists have a great take on this debate. We shouldn’t focus simply on rejecting learning styles theory. Instead, we should replace it with a better theory. They have thoughts on how to do so

[Update, 6/25/18]

Finally, Scientific American has a recent article showing that most students don’t use the learning styles that they believe would benefit them. And, when they do, those strategies don’t help them learn.

Capture Intergalactic Criminals; Feel the Mental Burn
Andrew Watson
Andrew Watson

I’ve posted a good bit recently about the dangers of working memory overload. (For instance: here and here.)

Teachers can understand the dangers of WM overload. However, we rarely experience WM overload in school. Because we’re in charge of the lesson, we keep it comfortably within our own mental limits.

(Of course, faculty meetings can tax our working memory. As well as our patience.)

I think it’s occasionally helpful for teachers to feel WM overload, so we can recognize what our students experience all too often.

For that reason, I’m linking to the Ted Ed video below.

Take six minutes. When you try to solve the riddle, you’ll abruptly recognize that baffled-and-stunned look you see on your students.

You might even feel that way when you listen to the solution.

Enjoy!

https://www.youtube.com/watch?v=dh4nEuhZBgg

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Andrew Watson
Andrew Watson

Unless you’ve been napping under a LatB rock, you’ve heard about the importance of research-based study habits.

study habits

In particular, you know that students should spread practice out over time rather than bunching practice all together. (The benefits are called the spacing effect.)

And, you know that students should not simply look over what they already know. Instead, they should quiz themselves to see what they can actively retrieve from memory. (That’s called retrieval practice.)

Here’s a little secret you might not know: most of the research about the spacing effect and retrieval practice takes place in psychology labs.

What happens in the real world? Do students who use these techniques actually learn more than those who don’t?

Asking Students about their Study Habits

In a recent study, Fernando Rodriguez and colleagues surveyed students about their study practices.

Do these students space practice over time? Do they do all of their studying all in one session?

Perhaps they quiz themselves on what they know? Or, perhaps they reread the textbook?

Rodriguez & Co. then compared these answers to the students’ grade in the class. By this method, they could tease out the effects of spacing and retrieval practice on actual learning.

So: did these research-endorsed study habits translate into classroom learning?

No. And, Yes.

Rodriguez found mixed results.

Study habits that spaced practice out didn’t make any difference. Students who crammed and students who studied material in several brief sessions got the same final grade.

(I’ll propose an explanation for this finding below.)

However, retrieval practice made a clearly measurable difference. Students who reviewed material averaged a B-. Those who self-tested averaged a B.

Given that both study techniques take the same amount of time, it obviously makes sense to self-test. Students who do so learn more. Retrieval practice just works.

Spacing Doesn’t Help? Or, Spacing Already Helped?

If we’ve got so much research showing the benefits of spacing, why didn’t it help students in this class?

We don’t know for sure, but one answer stands out as very probable: the professor already did the spacing for the students.

That is: the syllabus included frequent review sessions. It had several cumulative tests. The class structure itself required students to think about the material several times over the semester.

Even if students wanted to cram, they couldn’t wait until the last moment to review. The test schedule alone required them to review multiple times.

So: the students’ own additional spacing study habits didn’t help.

However, in a class where the professor hadn’t required spacing, it most likely would have done so.

The Bigger Picture

This possibility, in my view, underlines a bigger point about spacing and retrieval practice:

For the most part, students have primary responsibility for retrieval practice, whereas teachers have primary responsibility for spacing.

That is: students — especially older students — should learn to review by using retrieval practice strategies. (Of course, especially with younger students, teachers should teach RP strategies. And, offer frequent reminders.)

Teachers — in our turn — should design our courses to space practice out. (Of course, students should do what they can to space practice as well.)

In other words: retrieval practice is largely a study habit. Spacing is largely a teaching habit.

Students will get the most benefit from this research when we divide up responsibility this way.

A Hidden Adolescent Struggle: Identifying Complex Emotions
Andrew Watson
Andrew Watson

Teenagers often baffle adults.

adolescent emotionThe moody sulkiness that erupts into warmth and affection. The impressive academic accomplishment that precedes an idiotic, immature decision.

(How often have you had this conversation:

YOU: What on earth were you thinking?

TEEN: That’s just it. I wasn’t thinking.)

Of course, teenagers often baffle themselves. And according to recent research, some of that confusion may result from difficulty understanding their own emotions.

Emotion Differentiation

Researchers who study emotions often focus on our ability to distinguish among them.

For instance: when I see a picture of rotting food, I might be disgusted and upset. However, I’m not angry or scared.

Researchers call this ability “emotion differentiation.” Unsurprisingly, individuals who succeed at emotion differentiation see other kinds of success. They’re good at coping with difficult emotional situations. They’re less likely to rely on alcohol to get through tough times.

To understand adolescent emotion, we might ask: how good are teens at emotion differentiation?

Are they better at it than children? Than adults? In other words, how does this capacity develop over time?

Adolescent Emotion: Seeming Weakness

Erik Nook recently investigated this question, and came up with an intriguing answer.

He and his colleagues showed people (age range 5 to 24) pictures, and asked them to rate their emotional responses to them. Focusing on negative emotions, Nook asked participants how “angry, upset, sad, disgusted, and scared” each picture made them.

For example: if a participant gave the highest rating to all five emotions, that response pattern showed little emotional differentiation. All five emotions were experienced equally.

If, however, he gave a high rating to “scared,” a medium rating to “disgusted,” and a low rating to the other three, that pattern showed high emotional differentiation.

What did they find?

Children and adults distinguish among emotions better than adolescents do.

That is: children and adults can say “I’m feeling upset, but not scared.” Adolescents, however, have a harder time drawing those distinctions. Their negative emotions swirl together in a chaotic muddle.

Adolescent Emotion: Hidden Strength

But why is this so?

Nook & Co. investigated several competing hypotheses. Their answer reveals a hidden strength in adolescent emotion processing.

It turns out that children are good at distinguishing among emotions because they don’t really understand it’s possible to experience more than one emotion at a time.

In other words: young children report that they’re feeling disgusted but not sad because they don’t recognize it’s possible to feel both disgusted and sad.

Adolescents, however, DO recognize the possibility of feeling multiple emotions. And yet, because this understanding arrives freshly with adolescence, teens don’t yet have much practice differentiating among them.

As Nook and colleagues write:

children have high emotion differentiation because they experience emotions one at a time, whereas adults have high emotion differentiation potentially because of increased ability to specifically identify co-experienced emotions.

Adolescents, however, fall between these two stools. They do recognize the possibility of experience multiple emotions, but don’t yet have enough practice at sorting out which is which.

Teaching Implications

As so often happens, this research guides us in two directions. Teachers should both think this way and do this thing.

Think this way. With this clearer understanding of adolescent emotion, we can clear our own heads when we cross paths with a teen in an emotional tasmanian-devil vortex.

Rather than say to ourselves “why is this 17-year-old melting down like a child?,” we can say “Aha! He’s aware that he’s experiencing multiple emotions, but he’s not sure which is which. That confusion has led to an atypical emotional outburst.”

This simple understanding may help us stay calm despite adolescent angst.

Do this thing. Adolescents know that they’re feeling many things, but they don’t yet have much experience naming them simultaneously. We can help them.

In the emotional moment itself, we can ask guiding questions and offer potential labels. As always, teacherly guidance can show teens the way in difficult moments.

Also, in our teaching, we can highlight moments of emotional complexity. In Their Eyes Were Watching God, does Janie admire Jody Starks, or hate him? Fear him, or pity him? Perhaps, all at the same time?

In this way, the curriculum that we teach can help adolescents develop emotion differentiation.

 

 

Two final notes.

First: we’ve written about work from Leah Somerville’s lab before. If you want to know more about adolescence, look here or here.

Second: one of the co-authors of this study is Stephanie Sasse, one-time editor of this blog. Congratulations!

The Best Way to Take Notes: More Feisty Debate
Andrew Watson
Andrew Watson

Over at The Learning Scientists, Carolina Kuepper-Tetzel asks: is it better to take longhand notes? Or to annotate slides provided by the speaker? Or, perhaps, simply to listen attentively?

longhand notes

(Notice, by the way, that she’s not exploring the vexed question of longhand notes vs. laptop notes.)

Before we get to her answer, it’s helpful to ask a framing question: how do brain scientists approach that topic in the first place? What lenses might they use to examine it?

Lens #1: The Right Level of Difficulty

Cognitive scientists often focus on desirable difficulties.

Students might want their learning to be as easy as possible. But, we’ve got lots of research to show that easy learning doesn’t stick.

For instance: reviewing notes makes students feel good about their learning, because they recognize a great deal of what they wrote down. “I remember that! I must have learned it!”

However, that easy recognition doesn’t improve learning. Instead, self-testing is MUCH more helpful. (Check out retrievalpractice.org for a survey of this research, and lots of helpful strategies.)

Of course, we need to find the right level of difficulty. Like Goldilocks, we seek out a teaching strategy that’s neither too tough nor too easy.

In the world of note-taking, the desirable-difficulty lens offers some hypotheses.

On the one hand, taking longhand notes might require just the right level of difficulty. Students struggle — a bit, but not too much — to distinguish the key ideas from the supporting examples. They worry — but not a lot — about defining all the key terms just right.

In this case, handwritten notes will benefit learning.

On the other hand, taking longhand notes might tax students’ cognitive capacities too much.  They might not be able to sort ideas from examples, or to recall definitions long enough to write them down.

In this case, handing out the slides to annotate will reduce undesirable levels of difficulty.

Lens #2: Working Memory Overload

Academic learning requires students to

focus on particular bits of information,

hold them in mind,

reorganize and combine them into some new mental pattern.

We’ve got a particular cognitive capacity that allows us to do that. It’s called working memory. (Here’s a recent post about WM, if you’d like a refresher.)

Alas, people need WM to learn in schools, but we don’t have very much of it. All too frequently, working memory overload prevents students from learning.

Here’s a key problem with taking longhand notes: to do so, I use my working memory to

focus on the speaker

understand her ideas

decide which ones merit writing down

reword those ideas into simpler form (because I can’t write as fast as she speaks)

write

(at the same time that I’m deciding, rewording, and writing) continue understanding the ideas in the lecture

(at the same time that I’m rewording, writing, and continuing) continue deciding what’s worth writing down.

That’s a HUGE working memory load.

Clearly, longhand notes keep a high WM load. Providing slides to annotate reduces that load.

Drum Roll, Please…

What does recent research tell us about longhand notes vs. slide annotation? Kuepper-Tetzel, summarizing a recent conference presentation, writes:

participants performed best … when they took longhand notes during the lecture compared to [annotating slides or passively listening].

More intriguing, the group who just passively viewed the lecture performed as well as the group who were given the slides and made annotations.

Whether the lecture was slow- or fast-paced did not change this result.

Longhand notetaking was always more beneficial for long-term retention of knowledge than both annotated slides and passive viewing.

By the way: in the second half of the study, researchers tested students eight weeks later. They found that longhand note-takers did as well as annotators even though they studied less.

It seems that the desirable difficulty of handwriting notes yielded stronger neural networks. Those networks required less reactivation — that is, less study time — to produce equally good test results.

Keep In Mind…

Note that Kuepper-Tetzel is summarizing as-of-yet unpublished research. The peer-review process certainly has its flaws, but it also can provide some degree of confidence. So far, this research hasn’t cleared that bar.

Also note: this research used lectures with a particular level of working memory demand. Some of our students, however, fall below the average in our particular teaching context. They might need more WM support.

We might also be covering especially complicated material on a particular day. That is: the WM challenges in our classes vary from day to day. On the more challenging days, all students might need more WM support.

In these cases, slides to annotate — not longhand notes — might provide the best level of desirable difficulty.

As is always the case, use your best professional judgment as you apply psychology research in your classroom.

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.

The Neuroscience of Intelligence: “Slim” Neural Networks
Andrew Watson
Andrew Watson

We’re a “more is better” culture, and so we’re quick to assume that more brain stuff is better.

slim neural networks

Presumably, we want to have more neurons. We want to have more synapses. We want to have higher brain volumes in essential brain regions.

However, recent research suggests an alternate theory.

Slim Neural Networks

According to a recent study by Erhan Genç, published in Nature Communications,

the neuronal circuitry associated with higher intelligence is organized in a sparse and efficient manner, fostering more directed information processing and less cortical activity during reasoning.

Or, as Genç writes:

Intelligent brains are characterized by a slim but efficient network of their neurons. This makes it possible to achieve a high level of thinking with the least possible neural activity.

So: despite our cultural preferences, more isn’t necessarily better. Sometimes, a “slimmer” neural network works better than a more complex one.

Slim Neural Networks: “Blooming and Pruning”

When neuroscientists talk about the neural network development, they often talk with gardening terminology: “blooming” and “pruning.”

Networks “bloom” when neurons join together to create a memory or facilitate a particular function.

The “prune” when the brain simplifies those networks.

Sometimes pruning happens because of disuse. If you learned to juggle when you were younger, you have to keep practicing. If not, that network will start to thin.

Sometimes pruning happens because of expertise. If you keep practicing your juggling, you’ll use fewer neurons than when you started.

As teachers, therefore, we’re working to help brains simultaneously bloom and prune.

We want our students to develop new skills and acquire new information.

And, as they develop their expertise, we want those networks to prune.

The best teaching/gardening, in other words, requires both seeds and clippers.

 

For more thoughts on the relative size of brain regions, click here.