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Being an entrepreneur comes with benefits - a big one being job satisfaction. This makes sense as business owners tend to start their companies around topics they enjoy. Being successful in your role is dependent on how you handle situations - but also, how you learn. Learning how to learn is important in every facet, whether it's learning new marketing techniques, learning about product development methodologies or negotiation skills. The more skills you master and the more you learn about everything, the more confidence you'll have when inevitable problems arise.

Today we're going to walk you through the ways you might be hindering your full learning potential. In other words, how you could be operating under a common 'learning illusion' -illusion of competence- and how to overcome it.

Basically, the illusions of competence encompass the idea that you think you know more than you actually do. Sounds simple but you'd be surprised how easy it is for this to fall under our radar. Essentially, this could be happening to you over and over again without you even realizing it. In this post I'm going to be explaining the illusion of competence in learning by covering four of the most common learning misconceptions.

Illusion of repetition

Illusion of confidence

Illusion of simplicity

Illusion of difficulty

After reading this article you will have the tools to determine when you are truly learning and when you're falling victim to this illusion. This post is based off of established academic research. Our team of psychology and neuroscience PhDs have sifted through hundreds of papers to ensure you have the fullest confidence in all our recommendations.

Illusion of repetition
Going over material multiple times doesn't necessarily help learning.
Seems strange right? You would think that repeating and re-reading material would lead to a solid memory of those events - unfortunately this is a common misconception. Repetition has actually been shown to interfere with the ability to learn new information, especially if that information is similar to knowledge you already have. In other words, these findings suggest that it's your ability to recognize information that increases after repeated exposure. So, repetition can actually provide a false belief that we've learned something when we really haven't.

How to overcome the illusion of repetition:

The 2-minute rule

What to do.
Say you just read up on some new product development methodology and you're thinking of trying it out. Instead of re-reading that information later on - which we now know will give us a false sense that we 'know' that information - take 2 minutes to regenerate that information.

How to do it.
Pretend as if you need to explain this new concept to a colleague in 2 minutes. By doing this, you'll be forced to regenerate the information rather than just recognize it, you'll be forced to summarize the key, important findings and you'll have to explain the information in laymen for someone with no prior background.

Why it works

Take away: Repeated exposure to information gives you the illusion that you know the material very well because you have no problem recognizing the information, when in fact there are many gaps in what you have actually learned.

Overestimating our knowledge brings us into our next illusion...

Illusion of confidence
Predicted learning doesn't reflect actual learning.
We've all run into those people who think their work and their capabilities are amazing but their output says otherwise. For example, Bob is the programmer you hired for your new business. On paper he looks like a great programmer but you come to realise he isn't producing up to your standards. As soon as he joins, he suggests you should change some of your tech stack and he takes longer than he should for a simple feature release. You decide to have a conversation with him about his performance but all you're met with is resistance. Bob truly believes he is an excellent programmer with skills that cannot be matched by anyone else.

If you've ever been in a situation like this one, where someone's capabilities are far less than their predicted capabilities, you have come across what is known as the 'illusion of confidence' or the ' Dunning-Kruger effect '. This effect describes the cognitive bias to inflate self-assessment whether that's of your capabilities or information you have recently learned. In other words, we tend to overestimate how much we've learned from newly acquired information.

This illusion extends from classroom to everyday life. Researchers completed a study where they visited a local gun range to quiz gun hobbyists about gun safety. They found that those those who scored the lowest on their knowledge about gun safety, grossly overestimated their knowledge about firearms.

When it comes to learning new information, this ties in nicely with illusion of repetition because when we go over material multiple times, we incorrectly predict that we have learned that material. We overestimate our predicted learning and capability of retaining information. These illusions are no fault of the person but rather due to ineffective learning strategies.

How to help employees overcome the illusion of confidence:

Give more feedback!

But not just any feedback! Generally, when people hear constructive criticism they try to use the most expedient avenue to reject the feedback. Instead, you will want to close off avenues for this type of avoidant behaviour without creating any hostility and anger.

Start off your conversation with questions and then go into ways in which they can meet your expectations.

Example:

Let's look at our example with Bob from above. We could start by asking him, What skills do you think are required to be the best programmer possible?

Once Bob is thinking about the various attributes required for a successful programmer, you could ask, If you discovered that your performance on one of those attributes was lacking, what are some steps you may take to correct that? Do you both agree on these steps? Suggest some others that would help meet your expectations.

This will then give you the opportunity to explain where your expectations lie and where you think he could improve. From there, you can go over some of the steps he said he would take and schedule a follow-up meeting for some time in the future to review.

Approaching a situation like this will deter an unwilling employee from getting defensive. Remember, people overestimate their abilities because they don't know how they could be doing better or what great performance looks like. In fact, people are willing to criticize their own previous poor performance once they were given feedback and shown an example of great performance.

How to help yourself overcome the illusion of confidence:

Learn how to be abstract

As we will discuss in the next section, practicing easy/familiar material will give you a false expectation of knowing.

It is more important that you focus on difficult material within a topic to enhance your learning.

You can also try making material more difficult by asking yourself abstract questions.

If you're trying to see what's capable on each marketing channel (eg, Facebook/LinkedIn, Email, your blog... etc), step back and see what your strategy is and how the channels will help each other.

For example, you might decide that you'll write a detailed and thorough blog post (let's say 2000+ words), break it down into smaller emails and sequence them into a email nurturing campaign. Furthermore, you're going to extract the pieces of information from the blog and schedule them on a daily cadence on your LinkedIn and Facebook accounts. Now you have a strategy and a more abstract understanding of your strategy.

How could you apply that knowledge to new situations?
Using the same example, say you decide to put some efforts into your public relations traction. Here you choose an industry related topic for your your rich blog article, and from there you check this topic against unique statistics that you have assembled from multiple sources - to ensure it will gain traction. Finally, you find the perfect infographic for the article and now you have a story for the media.

These strategies will give both you and your employees a framework for testing whether you're falling under the illusion of confidence. In the next section we're going to talk about the importance of solving problems on your own.

Illusion of simplicity
Solve problems yourself - just because you see someone solve it, doesn't mean you'll understand it
Most of us have had experiences where we watch a demonstration by another professional and gotten the feeling that it is really easy (e.g. watching someone figure skate). This gives way to the illusion that we actually know how to do the task since we just watched another person do it. In psychology, this is something called cognitive fluency. It turns out, we actually prefer things that are easy to think about to those that are hard. This seems rather intuitive but there is a surprising extent to which fluency guides our thinking and also situations where we have no idea it is at play. So when it comes to learning, it is something to watch out for.

How does it guide our thinking? Well, a good example of this comes from a psychological study where shares in a company with names that are easy to pronounce, significantly outperform those with names that are hard to pronounce. This also extends to what we believe! Other studies have shown that individuals presented with factual statements, that are easier to mentally process will be more likely to believe that information. This can be done just by making the font easier to read, making the statement rhyme or simply repeating the information.

Since it guides our thinking in many ways, it is also implicated in most areas we weigh information such as the products we buy, what/who we find attractive and while learning.
How can we get caught up in the illusion of simplicity? While reading
Remember from above? When we read or rehearse information multiple times, the processing fluency of those words gets easier. Because of this, we tend to judge the information that we are re-reading as "learned material". This can be dangerous because it doesn't necessarily mean that you have that information in memory but rather you are simply getting good at recognizing that information.

How to overcome the illusion of simplicity while reading:

What to do:

How to do it:

After you have read something for the first time. Take a step back and try to think of the information as a whole. Ask yourself questions.

For example:

As an entrepreneur you tend to wear many hats. Sometimes this requires you to understand a topic you might know little about. Say you need to understand financial projections for your business but you don't have a strong background in this. You pour through research on how to interpret the data.

Take a step back, what were the key concepts and ideas?

Why should you look at your monthly/quarterly growth?

What is the importance of understanding your funnel's performance?

What does it all mean collectively? Try to think about the information before going back to it.

How it works:
When someone shows you the solution to a problem rather than solving it yourself
This is a big no no when it comes to learning and one of the many reasons we think we have learned information when in fact we haven't. Scientists believe that when we study any material we have both the 'question' and the 'answer' whereas when we need to retrieve the information later on, we only have the question - this is what causes a bias of 'knowing' the information. A more relevant example here is if you're stuck on a problem at work and then you're given the answer by a colleague, you won't encode that information as well in your brain than if you came the conclusion yourself.

How to overcome the illusion of simplicity while solving problems:

What to do:

If you're stuck on a problem, try to solve it yourself before asking for help

How to do it:

Identify the problem

This is really important, make sure you are clear on what you are trying to solve.

Write down all the questions you have and I mean ALL the questions. Some of the best solutions come from the silliest ones. For example, the co-founder of Nike, Bill Bowerman asked, "What would happen if I pour rubber over a waffle iron?" This rubber mold inspired Nike's first shoe, the waffle trainer, which debuted in 1974.

Develop strategies

For example, break down your problem into smaller pieces.

Come up with as many solutions to the problem as possible.

Use heuristics: what have other people done to solve similar problems and could it work for mine?

Evaluate and refine solutions

Apply solutions to the problem(s) and evaluate their effectiveness.

Did this solution lead to a question being solved? If it did, move onto the next piece. If not, refine your solution. Can you alter it in any way? What part of the solution didn't work?

If all else fails, ask for guidance
If you don't have time to go through all these steps or don't really care about learning the topic, ask for help. Instead of getting someone to give you the full solution, ask them to guide you or give you the next step.

How it works:

This process albeit tedious and time consuming can be of huge benefit.

Not only will you develop great problem solving skills, but you will also find that you will be able to keep that information in memory for longer.

You will expand your overall knowledge base for that topic which you can use as shortcuts to solving complex problems in that domain later on.

This provides us with a nice segway into our last misconception of learning: the illusion of difficulty.

Illusion of difficulty
It gets easier when you're overwhelmed; know your mental library builds on itself.
Learning something new, especially if it is complex, can be stressful and/or uncomfortable. This can activate an area associated with pain in the brain. Your brain will force you to look for ways to avoid this negative feeling by switching your attention to something more engaging. This is why we find it so difficult getting started with things!

Some examples of this:

1. Learning a new language

2. Learning how to cook

3. Learning a new instrument

4. Learning a new programming language

How to overcome the illusion of difficulty:

Don't procrastinate

Procrastinating will simply fuel this cycle of feeling negative toward a particular task, shifting your mind to something more pleasant to feeling terrible about having to cram in all the work later on.

Researchers have found that one way to minimize this effect is through practice. Basically, the best way is to work through the discomfort, not long after this initial step the "pain" signals to your brain disappear.

Practice learning hard and abstract things

The more abstract a problem (meaning it is difficult to understand or grasp), the more important it is to work through the information in order to fully understand it. Human memory is better able to remember concrete information rather than abstract information. To solidify abstract or hard to grasp concepts, create examples of that information in your mind that are specific.

Here's an example:

Think of the word 'scarcity'. It can be described as the more rare something becomes, the more valuable it becomes. This definition contains a lot of vague elements such as, when does something become rare? and what determines it's value? How can we make this idea more concrete in order to make it stick? Let's try to use a specific example to illustrate this idea.

Think of coffee beans. Let's say a major exporter of coffee beans, such as Colombia, produces very low yields of beans one year due to drought or blight. There will be a shortage of coffee beans in the world. This scarcity then drives up the price (value) of the beans.

This is a concrete example of scarcity, an abstract idea, which you will encode better.
Recap
Together, these common misconceptions of learning fall under the illusions of competence. These occur everyday without us even realizing and can contribute to ineffective learning. Understanding how these work will help you avoid falling under their constraint and lead you in the direction of effectively building your knowledge base. Let's take a look at what we've covered:

Illusion of repetition

Going over material multiple times doesn't necessarily help learning.

Instead, use the 2 minute rule! Every time you finish a key concept, give yourself a little walkthrough of what you just learned. By doing this, you're also breaking the material into chunks which has the potential to keep you motivated. Remember, try not to use any learning materials while doing this.

Illusion of confidence

We tend to overestimate our abilities

Give your employees feedback so they know where they lie within your expectations

Practice abstract thinking and applying information to different contexts.

Illusion of simplicity

Solve problems yourself, just because you see it, doesn't mean you'll understand it.

Identify the problem

Develop strategies

Evaluate and refine the solution

If all else fails, ask for guidance

Illusion of difficulty

It gets easier, when you're overwhelmed, know your mental library builds on itself.
Avoid procrastination because your brain WILL get over the initial learning discomfort and practice abstract and difficult ideas more than easier concept.

Put these suggestions into action right now and watch how much more information you retain! Hopefully these four illusions will get you on your way to being an effective learner.

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How to overcome the illusion of learning

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Being an entrepreneur comes with benefits - a big one being job satisfaction. This makes sense as business owners tend to start their companies around topics they enjoy. Being successful in your role is dependent on how you handle situations - but also, how you learn.

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Chunking is a method of facilitating short-term memory by grouping individual pieces of information into larger, more familiar (and therefore, more easily remembered) groups.

If you're looking to improve your memory or remember several important things, try chunking. Grouping small bits of information into a whole leverages the brain's natural tendency to recall large chunks better than it does those bits. This article discusses how chunking works, along with examples, uses, and techniques.

How Chunking Works

Separating disparate individual elements into larger blocks makes them easier to recall. This is mainly because of how limited our short-term memory can be. While some research suggests people are capable of storing between five and nine units of information, more recent research posits that short-term memory has a capacity for about four chunks of information.

According to neuroscientist Daniel Bor, author of The Ravenous Brain, chunking represents our ability to "hack" the limits of our memory. Bor argues that our natural tendency to see patterns and make connections is not just important for memory, but that it is also the source of creativity. As Steve Jobs once famously suggested, "Creativity is just connecting things."

Examples of Chunking

You're probably already using chunking in your daily life. For example, when you leave the house, you might think of the group of items you need to bring--phone, wallet, keys, jacket--and thinking of them together helps you remember each. Entities such as businesses and institutions use chunking to help organize vast amounts of data, too.

More examples include:

Bank account numbers. The numbers on your checks are chunked into groups--more than likely, the check, routing, and account numbers.

Credit card numbers. They're always shown in groups of four (e.g., 5555 5555 5555 5555).

Phone numbers. A phone number sequence of 8-8-8-5-5-5-1-2-3-4 is chunked into 888-555-1234.

Paired items. Knife and fork, earrings and necklace, phone and charger--if you remember one, you're likely to remember the other.

Acronyms, acrostics, and mnemonics. If you use a sentence or a set of letters to remember something, you're chunking. For example, you might use "homes" to remember the names of the Great Lakes (Huron, Ontario, Michigan etc.) or "My very educated mother just sent us nine pizzas" for the names of the planets.

Chunking allows people to take smaller bits of information and combine them into more meaningful, and therefore more memorable, wholes.

How to Use Chunking

The next time you are trying to remember items from a list, start by forming them into groups. If you are working with a list of vocabulary words, for example, you might create small groups of words that are similar or related to one another. A shopping list might be broken down into a smaller grouping based on whether the items on the list are vegetables, fruits, dairy, or grains.

Chunking can be used as an everyday memory enhancer, but researchers have also found that you can improve your ability to effectively chunk information.

Bor relates the story of one participant in a memory experiment who challenged himself to improve the number of items he could remember. He was initially able to remember seven items, but he increased this to 80 units of information over the course of 20 months. He devoted an hour a day, approximately four days a week to this task.

Although you might not be able to devote such intense concentration to improving your memory, you can make the most of your brain's natural tendency to seek patterns and group information.

Practice Chunking

Challenge yourself to remember a series of items, whether it's your grocery list, vocabulary words, or important dates. As you become better at remembering larger chunks of information, challenge yourself to remember even more.

Look for Connections

As you are creating groupings, look for ways to relate units to each other in meaningful ways. What do the items share in common? You might group items together because they are each spelled with four letters, because they start with the same letter, or because they share a similar purpose.

Make Associations

Linking groups of items to things from your memory can also help make them more memorable. You might be more likely to remember that you need eggs, baking soda, and chocolate chips if you associate the items with the delicious cookies that your mother used to make.

Combine Other Memory Strategies With Chunking

You might use mnemonics, acronyms, acrostics, and other strategies as ways to chunk different units of information-whatever works best for you. For example, if you're going to the grocery store and need bananas, eggs, nectarines, and tea, you can create a word out of the first letters of each item you need: BENT. Once you remember the keyword, you will then be better able to recall the items represented by each letter of the acronym.

A Word From Verywell

Chunking is not a cure-all for memory problems, but it can be an effective tool in your memory improvement arsenal. By practicing chunking methods regularly and incorporating this technique in your study habits, you might find that you are able to remember more.

Additional Reading

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How the Chunking Technique Can Help Improve Your Memory

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Learn about how the chunking technique, which involves taking small units of info and grouping them into larger units, can improve your memory.,

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Dr. Richard Felder in 1999 wrote an interesting "Memo To Students Who Are Disapponted With Their Last Test Grade". It was originally aimed to his engineering students, but it's actually of general applicability, so it's well worth reporting here. A link to the PDF of the original memo.
The gist of the following checklist is that if you answer (honestly) "Yes" to most of the questions, you should be confident enough to get a good grade. If you answer "No" to many questions, than a bad grade should not be suprising...

Test Preparation Checklist
Answer "Yes" only if you usually did the things described (as opposed to occasionally or never).
Homework

Did you make a serious effort to understand the text? (Just hunting for relevant worked-out examples doesn't count.)

Did you work with classmates on homework problems, or at least check your solutions with others?

Did you attempt to outline every homework problem solution before working with classmates?

Did you participate actively in homework group discussions (contributing ideas, asking questions)?

Did you consult with the instructor or teaching assistants when you were having trouble with something?

Did you understand ALL of your homework problem solutions when they were handed in?

Did you ask in class for explanations of homework problem solutions that weren't clear to you?

Test preparation

If you had a study guide, did you carefully go through it before the test and convince yourself that you could do everything on it?

Did you attempt to outline lots of problem solutions quickly, without spending time on the algebra and calculations?

Did you go over the study guide and problems with classmates and quiz one another?

If there was a review session before the test, did you attend it and ask questions about anything you weren't sure about?

Did you get a reasonable night's sleep before the test? (If your answer is no, your answers to 1-11 may not matter.)

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Dr. Richard Felder in 1999 wrote an interesting "Memo To Students Who Are Disapponted With Their Last Test Grade". It was originally aimed to his engineering students, but it's actually of general applicability, so it's well worth reporting here. A link to the PDF of the original memo.

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Let's get a handle first on what we know about memory and recall.

There are two basic types of explicit, or declarative, memory. First, short term or working memory. Think of this as the focus of current attention, or what you are actively thinking about right now. Second, long term memory which is broken down further into semantic memory (facts) and episodic memory (specific events).

Within explicit, or declarative, memory, there are three basic stages of memory processing. Encoding is the process of forming new memories. Storage comes next, and is the process of information maintenance. And finally there is the process of gaining access to stored knowledge, referred to as retrieval. For learning to take place, as we categorize it in this sense, it requires that the information that is processed is then committed to memory and that the student can pull it back out when it's needed (let alone apply it to a novel circumstance through adaptation and abstraction).

By examining each part of memory and recall from encoding to storage to retrieval, we get a clear sense of how best to optimize this process for our students.

To make encoding a powerful process, it's necessary to recognize that memories are NOT stored as faithful recordings, like a book you can pull off a shelf to share again as needed in their exact original form. Instead, each new memory is integrated into our existing body of knowledge - coloring and being colored by other memories. Therefore, the most robust memories are formed through elaboration and organization where learners:

1. process the new information as deeply as possible,

2. maximize connections with what is already known, and

3. situate new knowledge into an existing framework.

The challenge with storage is that once something has made it into long-term memory, it tends to remain stored, but not necessarily always accessible. The challenge here is not one of capacity. In fact, our capacity for storing new memories is essentially unlimited, and more so, organized learning appears to create additional capacity. However, the ability to access a given memory typically declines over time, primarily due to interference caused by the acquisition of new, competing memories. Do not let this sour your hope of learners remembering what was learned in your class. You can markedly increase the likelihood of students being able to recall a memory at a future time by strengthening it through retrieval.

Retrieval is an active reconstruction process, not a playback of a memory of an event, fact, concept, or process. Every time a memory is accessed for retrieval, that process modifies the memory itself; essentially re-encoding the memory. The good news: Retrieval makes the memory itself more recallable in the future.

How does it work, and work best for learning? Retrieval is cue and context dependent - know this and how you can cue retrieval and provide the best context to strengthen memory. To reinforce memory through cues, we're referring to making as many connections as possible with existing memories. The more possible cues available to elicit retrieval, the better. With regard to context, the more closely matched the retrieval context is with the context in which the memory was encoded, the better. This holds true even if you can only have one context (i.e., you only have one shot at retrieval - think high-stakes exam as sole measure of learning in a course). But, multiple retrievals in multiple contexts are superior for long-term retention (think frequent, low-stakes quizzes which are cumulative). Additionally, we can enable students to do this even better by encouraging them to vary the contexts of retrieval (e.g. studying method, physical location), which results in more accessible memories.

* content on this page was adapted from the Teaching Excellence Colloquium workshop "How Students Learn", by Chelan Huddleston (College of Letters and Science)

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Let's get a handle first on what we know about memory and recall. There are two basic types of explicit, or declarative, memory. First, short term or working memory. Think of this as the focus of current attention, or what you are actively thinking about right now.

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Before we dive into understanding the relevant science behind the learning process, let's ground ourselves in a definition of learning that is drawn from research.

Learning is a process that:

1. is active - process of engaging and manipulating objects, experiences, and conversations in order to build mental models of the world (Dewey, 1938; Piaget, 1964; Vygotsky, 1986). Learners build knowledge as they explore the world around them, observe and interact with phenomena, converse and engage with others, and make connections between new ideas and prior understandings.

2. builds on prior knowledge - and involves enriching, building on, and changing existing understanding, where "one's knowledge base is a scaffold that supports the construction of all future learning" (Alexander, 1996, p. 89).

3. occurs in a complex social environment - and thus should not be limited to being examined or perceived as something that happens on an individual level. Instead, it is necessary to think of learning as a social activity involving people, the things they use, the words they speak, the cultural context they're in, and the actions they take (Bransford, et al., 2006; Rogoff, 1998), and that knowledge is built by members in the activity (Scardamalia & Bereiter, 2006).

4. is situated in an authentic context - provides learners with the opportunity to engage with specific ideas and concepts on a need-to-know or want-to-know basis (Greeno, 2006; Kolodner, 2006).

5. requires learners' motivation and cognitive engagement to be sustained when learning complex ideas, because considerable mental effort and persistence are necessary.

The conditions for inputs to learning are clear, but the process is incomplete without making sense of what outputs constitute learning has taken place. At the core, learning is a process that results in a change in knowledge or behavior as a result of experience. Understanding what it takes to get that knowledge in and out (or promote behavioral change of a specific kind) can help optimize learning.

* content on this page is drawn from the Lawrence Hall of Science/UC Berkeley NSF-WIDER Grant: Faculty Learning Program

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Before we dive into understanding the relevant science behind the learning process, let's ground ourselves in a definition of learning that is drawn from research. Learning is a process that: is active - process of engaging and manipulating objects, experiences, and conversations in order to build mental models of the world (Dewey, 1938; Piaget, 1964; Vygotsky, 1986).

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"Sleep, it turns out, may play a crucial role in our brain’s physiological maintenance. As your body sleeps, your brain is quite actively playing the part of mental janitor: It’s clearing out all of the junk that has accumulated as a result of your daily thinking."

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Opinion

Credit... Eiko Ojala

SLEEP seems like a perfectly fine waste of time. Why would our bodies evolve to spend close to one-third of our lives completely out of it, when we could instead be doing something useful or exciting? Something that would, as an added bonus, be less likely to get us killed back when we were sleeping on the savanna?

"Sleep is such a dangerous thing to do, when you're out in the wild," Maiken Nedergaard, a Danish biologist who has been leading research into sleep function at the University of Rochester's medical school, told me. "It has to have a basic evolutional function. Otherwise it would have been eliminated."

We've known for some time that sleep is essential for forming and consolidating memories and that it plays a central role in the formation of new neuronal connections and the pruning of old ones. But that hardly seems enough to risk death-by-leopard-in-the-night. "If sleep was just to remember what you did yesterday, that wouldn't be important enough," Dr. Nedergaard explains.

In a series of new studies, published this fall in the journal Science, the Nedergaard lab may at last be shedding light on just what it is that would be important enough. Sleep, it turns out, may play a crucial role in our brain's physiological maintenance. As your body sleeps, your brain is quite actively playing the part of mental janitor: It's clearing out all of the junk that has accumulated as a result of your daily thinking.

Recall what happens to your body during exercise. You start off full of energy, but soon enough your breathing turns uneven, your muscles tire, and your stamina runs its course. What's happening internally is that your body isn't able to deliver oxygen quickly enough to each muscle that needs it and instead creates needed energy anaerobically. And while that process allows you to keep on going, a side effect is the accumulation of toxic byproducts in your muscle cells. Those byproducts are cleared out by the body's lymphatic system, allowing you to resume normal function without any permanent damage.

The lymphatic system serves as the body's custodian: Whenever waste is formed, it sweeps it clean. The brain, however, is outside its reach - despite the fact that your brain uses up about 20 percent of your body's energy. How, then, does its waste - like beta-amyloid, a protein associated with Alzheimer's disease - get cleared? What happens to all the wrappers and leftovers that litter the room after any mental workout?

"Think about a fish tank," says Dr. Nedergaard. "If you have a tank and no filter, the fish will eventually die. So, how do the brain cells get rid of their waste? Where is their filter?"

UNTIL a few years ago, the prevailing model was based on recycling: The brain got rid of its own waste, not only beta-amyloid but other metabolites, by breaking it down and recycling it at an individual cell level. When that process eventually failed, the buildup would result in age-related cognitive decline and diseases like Alzheimer's. That "didn't make sense" to Dr. Nedergaard, who says that "the brain is too busy to recycle" all of its energy. Instead, she proposed a brain equivalent of the lymphatic system, a network of channels that cleared out toxins with watery cerebrospinal fluid. She called it the glymphatic system, a nod to its dependence on glial cells (the supportive cells in the brain that work largely to maintain homeostasis and protect neurons) and its function as a sort of parallel lymphatic system.

She was hardly the first to think in those terms. "It had been proposed about one hundred years ago, but they didn't have the tools to study it properly," she says. Now, however, with advanced microscopes and dyeing techniques, her team discovered that the brain's interstitial space - the fluid-filled area between tissue cells that takes up about 20 percent of the brain's total volume - was mainly dedicated to physically removing the cells' daily waste.

When members of Dr. Nedergaard's team injected small fluorescent tracers into the cerebrospinal fluid of anesthetized mice, they found that the tracers quickly entered the brain - and, eventually, exited it - via specific, predictable routes.

The next step was to see how and when, exactly, the glymphatic system did its work. "We thought this cleaning process would require tremendous energy," Dr. Nedergaard says. "And so we asked, maybe this is something we do when we're sleeping, when the brain is really not processing information."

In a series of new studies on mice, her team discovered exactly that: When the mouse brain is sleeping or under anesthesia, it's busy cleaning out the waste that accumulated while it was awake.

In a mouse brain, the interstitial space takes up less room than it does in ours, approximately 14 percent of the total volume. Dr. Nedergaard found that when the mice slept, it swelled to over 20 percent. As a result, the cerebrospinal fluid could not only flow more freely but it could also reach further into the brain. In an awake brain, it would flow only along the brain's surface. Indeed, the awake flow was a mere 5 percent of the sleep flow. In a sleeping brain, waste was being cleared two times faster. "We saw almost no inflow of cerebrospinal fluid into the brain when the mice were awake, but then when we anesthetized them, it started flowing. It's such a big difference I kept being afraid something was wrong," says Dr. Nedergaard.

Similar work in humans is still in the future. Dr. Nedergaard is currently awaiting board approval to begin the equivalent study in adult brains in collaboration with the anesthesiologist Helene Benveniste at Stony Brook University.

So far the glymphatic system has been identified as the neural housekeeper in baboons, dogs and goats. "If anything," Dr. Nedergaard says, "it's more needed in a bigger brain."

MODERN society is increasingly ill equipped to provide our brains with the requisite cleaning time. The figures are stark. Some 80 percent of working adults suffer to some extent from sleep deprivation. According to the National Sleep Foundation, adults should sleep seven to nine hours. On average, we're getting one to two hours less sleep a night than we did 50 to 100 years ago and 38 minutes less on weeknights than we did as little as 10 years ago. Between 50 and 70 million people in the United States suffer from some form of chronic sleep disorder. When our sleep is disturbed, whatever the cause, our cleaning system breaks down. At the University of Pennsylvania's Center for Sleep and Circadian Neurobiology, Sigrid Veasey has been focusing on precisely how restless nights disturb the brain's normal metabolism. What happens to our cognitive function when the trash piles up?

At the extreme end, the result could be the acceleration of neurodegenerative diseases like Alzheimer's and Parkinson's. While we don't know whether sleep loss causes the disease, or the disease itself leads to sleep loss - what Dr. Veasey calls a "classic chicken-and-egg" problem - we do know that the two are closely connected. Along with the sleep disturbances that characterize neurodegenerative diseases, there is a buildup of the types of proteins that the glymphatic system normally clears out during regular sleep, like beta-amyloids and tau, both associated with Alzheimer's and other types of dementia.

"To me," says Dr. Veasey, "that's the most compelling part of the Nedergaard research. That the clearance for these is dramatically reduced from prolonged wakefulness." If we don't sleep well, we may be allowing the very things that cause neural degeneration to pile up unchecked.

Even at the relatively more benign end - the all-nighter or the extra-stressful week when you caught only a few hours a night - sleep deprivation, as everyone who has experienced it knows, impedes our ability to concentrate, to pay attention to our environment and to analyze information creatively. "When we're sleep-deprived, we can't integrate or put together facts," as Dr. Veasey puts it.

But there is a difference between the kind of fleeting sleep loss we sometimes experience and the chronic deprivation that comes from shift work, insomnia and the like. In one set of studies, soon to be published in The Journal of Neuroscience, the Veasey lab found that while our brains can recover quite readily from short-term sleep loss, chronic prolonged wakefulness and sleep disruption stresses the brain's metabolism. The result is the degeneration of key neurons involved in alertness and proper cortical function and a buildup of proteins associated with aging and neural degeneration.

It's like the difference between a snowstorm's disrupting a single day of trash pickup and a prolonged strike. No longer quite as easy to fix, and even when the strike is over, there's likely to be some stray debris floating around for quite some time yet. "Recovery from sleep loss is slower than we'd thought," Dr. Veasey notes. "We used to think that after a bit of recovery sleep, you should be fine. But this work shows you're not."

If you put her own research together with the findings from the Nedergaard lab, Dr. Veasey says, it "very clearly shows that there's impaired clearance in the awake brain. We're really starting to realize that when we skip sleep, we may be doing irreparable damage to the brain, prematurely aging it or setting it up for heightened vulnerability to other insults."

In a society that is not only chronically sleep-deprived but also rapidly aging, that's bad news. "It's unlikely that poor sleep as a child would actually cause Alzheimer's or Parkinson's," says Dr. Veasey, "but it's more likely that you may shift one of those diseases by a decade or so. That has profound health and economic implications."

It's a pernicious cycle. We work longer hours, become more stressed, sleep less, impair our brain's ability to clean up after all that hard work, and become even less able to sleep soundly. And if we reach for a sleeping pill to help us along? While work on the effects of sleeping aids on the glymphatic system remains to be done, the sleep researchers I spoke with agree that there's no evidence that aided sleep is as effective as natural sleep.

There is, however, reason to hope. If the main function of sleep is to take out our neural trash, that insight could eventually enable a new understanding of both neurodegenerative diseases and regular, age-related cognitive decline. By developing a diagnostic test to measure how well the glymphatic system functions, we could move one step closer to predicting someone's risk of developing conditions like Alzheimer's or other forms of dementia: The faster the fluids clear the decks, the more effectively the brain's metabolism is functioning.

"Such a test could also be used in the emergency room after traumatic brain injury," Dr. Nedergaard says, "to see who is at risk of developing decline in cognitive function."

We can also focus on developing earlier, more effective interventions to prevent cognitive decline. One approach would be to enable individuals who suffer from sleep loss to sleep more soundly - but how? Dr. Nedergaard's mice were able to clear their brain's waste almost as effectively under anesthesia as under normal sleeping conditions. "That's really fascinating," says Dr. Veasey. Though current sleeping aids may not quite do the trick, and anesthetics are too dangerous for daily use, the results suggest that there may be better ways of improving sleep pharmacologically.

Now that we have a better understanding of why sleep is so important, a new generation of drug makers can work to create the best possible environment for the trash pickup to occur in the first place - to make certain that our brain's sleeping metabolism is as efficient as it can possibly be.

A second approach would take the opposite tack, by seeking to mimic the cleanup-promoting actions of sleep in the awake brain, which could make a full night of sound sleep less necessary. To date, the brain's metabolic process hasn't been targeted as such by the pharmaceutical industry. There simply wasn't enough evidence of its importance. In response to the evolving data, however, future drug interventions could focus directly on the glymphatic system, to promote the enhanced cleaning power of the sleeping brain in a brain that is fully awake. One day, scientists might be able to successfully mimic the expansion of the interstitial space that does the mental janitorial work so that we can achieve maximally efficient round-the-clock brain trash pickup.

If that day comes, they would be on their way to discovering that all-time miracle drug: one that, in Dr. Veasey's joking words, "could mean we never have to sleep at all."

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Opinion SLEEP seems like a perfectly fine waste of time. Why would our bodies evolve to spend close to one-third of our lives completely out of it, when we could instead be doing something useful or exciting? Something that would, as an added bonus, be less likely to get us killed back when we were sleeping on the savanna?