Performance Hacking Sleep

What is the evolutionary purpose of sleep? Doesn’t it seem like a huge concession to spend a third of your life inactive? Or is it an amazing strategic adaptation from the days before indoor lighting, when productivity went down once the sun set, and danger came in the form of fast and powerful predatory animals?

Jerome Siegel, a UCLA neuroscientist, suggests the latter. He says that for our ancestors, staying awake and mobile during the evening hours would actually have been evolutionarily maladaptive. We are not the brown bat, who can avoid predators by sleeping 20 hours a day and still manage to hunt blind at night via sonar.

It’s been argued that the way our bodies recharge during our evening REM cycles—not just regaining energy but rebalancing the immune system and performing brain maintenance—is just another example of evolution piggybacking on an existing adaptation and making the most of it. We aren’t equipped for echolocation, so this is what we got instead.

Of course, there is no way to know if Siegel’s theory is correct, but it’s an interesting idea. What’s not in question is that something like 80% of adults are sleep deprived. And a lack of sleep is unquestionably maladaptive.

Sleep deprivation increases your chances of cancer, obesity, heart disease, Alzheimer’s disease, dementia, high blood pressure, stress and depression. If that weren’t enough, we now know it compromises your ability to pick up and store new information—to learn, in other words.

It appears that your brain assimilates and consolidates semantic memory—facts, figures and bits of specific data—during the first stage of deep sleep. This means that if you’re studying for a test on the periodic table, it’s not in your best interest to stay up cramming. You’re just putting off one of the most key parts of the process.

During the last stage of sleep, which happens right before you wake up in the morning, your brain builds out episodic memory of physical activities, like learning dance steps or banjo licks, or any other form of performance-based learning. If your goal is to master the latest position from your yoga class, you’ll want to make sure you don’t wake up earlier than usual and cheat yourself.

So getting up extra early for marching band practice to run through drills is, by definition, self-defeating. And staying up late plays havoc with memorizing the state capitol of Pennsylvania (Harrisburg).

In his book How we Learn, Benedict Carey makes the point that ‘sleep is learning’. And for maximum learning to take place, there’s no way around needing those eight hours a night for those sleep cycles to play out. Based on the latest research, it appears that Carey is correct. At the very least, it’s something to sleep on.

Forgetting to Learn, or, The Paradox of Memory

Memory is a fickle thing. There are times when the important information you need, like an email password, remains just out of your grasp.  But you’re equally likely to recall a jingle for a product that’s been obsolete for decades, a product you never even purchased or liked.

Forgetting: the older we get, the scarier it seems, what with the threat of Alzheimer’s and dementia hovering out there like the ghosts of senility future.

But what if the act of forgetting wasn’t just part of the normal degradation of memory but actually intrinsic to the act of remembering?  What if in order to remember something, you had to forget a little of it?

It flies in the face of how we conceptualize memory, as stored information slowly disappearing like cookies from the cookie jar.

But University of California scientists Robert and Elizabeth Bjork have helped alter our perception of how memory and learning work.

In one experiment, people were given a series of poetry lines to learn. Once the lines were studied and memorized, subjects were immediately tested on their recall. They did pretty well.

This is the principle behind pulling an all-nighter to cram for a test. The downside, apart from a lost night of sleep, is that you will retain very little of the material in a few days. In other words, we might say you never really imprinted it into your long-term memory.

If your goal is actually increasing your knowledge, there is a much better way to go, says Benedict Carey in How We Learn. It has to do with capitalizing on forgetting. In the act of losing and then subsequently retrieving the information again (either through the act of remembering or reinforcement), you create a stronger set of neural connections.

The Bjorks’ “forget to learn” theory states that forgetting is a “desirable difficulty.” The harder your brain has to work to retrieve stored information, the more hierarchical importance it gives that information for later retrieval.

A good analogy is weight lifting. When you do biceps curls with heavy weights, you break down your arms’ muscle fibers. After about 48 hours, your body has rebuilt those fibers—and strengthened them in anticipation of more lifting.

Forgetting is like breaking down the muscle fibers. When you struggle to recall something, you create an imprint more powerful then the original one. Those moments of racking your brain and feeling like an idiot are simply a part of the cycle.

The 30-day memory rule

If you really want to take advantage of this process, how should you space your “reps”, so to speak?

From facts to poetry, the time between taking in the information and forcing yourself to recall and review it should ideally be about a month.

This puts you right on the memory’s edge of forgetting. Following this process with a 30 day window has shown to significantly increase your chances of holding on to that original information, moving it permanently into long-term memory, where that irritating TV jingle has pitched a tent.

The next time you need to retain something important, make a date with yourself to recall and review it again in 30 days.

Forgetting: it’s not necessarily a bad thing—and that’s probably worth remembering.

How to Not Eat a Marshmallow (Willpower Part II)

In last week’s post, we learned how Walter Mischel’s famous marshmallow test demonstrated that preschoolers with a willpower strategy fared much better later in life across a wide spectrum of circumstances than their counterparts who “ate the marshmallow.”

So are the marshmallow eaters among us doomed to a life of constantly giving into our temptations?

Not necessarily, says Mischel. Willpower, or more accurately, a strategy for maintaining one’s willpower, is a skill that can be developed and practiced at virtually any age.

The clues to building your own willpower system can be found in Stanford’s Bing Nursery preschoolers, who tested and proved many methods during the original marshmallow experiment. The next time you need to reach for some self-control, you might consider using one of the following as a template.

Out of sight, out of mind

Among the marshmallow resistors, pushing the marshmallow to the far end of the table and/or closing their eyes was a popular way to ramp down the emotional brain’s impulses. Our brains register all information through our senses; fewer sensory inputs means a reduction in cravings.

If you’re trying to eat healthier, stop the waiter before he even brings you the basket of freshly baked tortilla chips or wheels out the dessert cart. Make things easy on yourself.


Children in the experiment had a much better shot of holding out if the researcher asked them to use their hands to frame the marshmallow like a picture, rendering it unreal in their minds.

One child was quoted as saying, “Well, you can’t eat a picture.” As silly as this may sound, he has a point.

The craving is taking place, not in objective reality, but inside the confines of the emotional brain. Reframing can actually lower the potency of the chemical surge in the amygdala that urges one towards grabbing that marshmallow.


Here is a little more mental jujitsu at work.

Our brains are designed to make snap judgements by storing a huge number of subconscious links between ideas or images. You can leverage this natural predisposition by imagining that a cockroach has, only moments before, been living inside the marshmallow, or that piece of chocolate cake was dropped on the bakery floor before it landed on the plate. Creating this false association can put a real damper on emotional desire.

The same principle explains why many college freshmen swear off of a particular food they happened to have consumed the first time they were sick from alcohol indulgence. You probably know someone who will readily testify how these associations can leave an indelible mark on food decisions for the rest of one’s life.


In Mischel’s marshmallow test, some of the children made up clever games to distract themselves from eating the treat.

What does not appear to work is to simply tell yourself that you’re not going to think about the marshmallow. It’s like that old joke, “Whatever you do, don’t think about a pink elephant.” Fixating on the order puts the image more firmly in your mind. The key is to get your mind on something else entirely.

In the end, the one thing that the two-marshmallow kids demonstrated was a strategy of some kind. Simple or goofy as they might seem, these same skills led to real-world benefits for the rest of their lives.

So the real question is, what’s your strategy for not eating the marshmallow?