# 35: Sleep and Memory - Part 1

It is a fundamental truth that sleep is far more than the absence of wakefulness. It is an incredibly active state, demonstrated by the fact that numerous functions of the brain and body are restored by and depend on sufficient sleep. One of the most impressive and best-understood of these is sleep’s beneficial role in boosting learning and memory abilities. Sleep is necessary both before and after learning and it intelligently associates and interconnects new memories together, offering the ability for creativity and ingenuity.

The first of these benefits starts while we’re awake, as the brain acquires novel information, and different types of memories are imprinted in different parts of it. Fact-based memories depend on an area of the brain called the hippocampus, which is almost like a USB stick. Some years ago, Matt and his team conducted a study on the hippocampus and found a 40% deficit in the ability of the brain to make new memories without sleep. In addition, scientists working with rats have found that depriving the brain of sleep stops the cells within the hippocampus’ memory structure from forming strong connections. Notably, it doesn’t take an entire night of sleep deprivation to produce these types of impediments—selective deprivation of deep, non-REM sleep in humans can produce the same effects.

Research has shown that during the deepest stage of deep, non-REM sleep, powerful brainwaves combine to act like a transfer mechanism. Wanting to know even more about how learning capacity and ability change across a waking day and how sleep modifies or restores that, Matt and his team designed a new study on daytime naps. They found that staying awake throughout the day resulted in a progressive decline in learning capacity, while those who took a ninety-minute nap showed no such decline. In fact, their capacity to memorize facts increased after that nap, showing a 20% learning advantage. This illustrates further that, without sufficient sleep, the brain is like a waterlogged sponge, our memory circuits saturated with memories so that we can no longer absorb new information and make new memories effectively.

Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.

Today’s podcast is supported by MasterClass - the online streaming platform where anyone can learn from the world's best about a variety of topics such as cooking, business, art, entertainment, writing, sports, science, health, and, of course, technology. When you sign up, you get access to all of the classes taught by such masters as Martin Scorsese, Neil deGrasse Tyson, Ron Howard, and Bill Clinton to name just a few of Matt’s favorites. You may even find a masterclass from a familiar sleep scientist! And for this Holiday season, if you give one annual membership you'll get a second one, free! 

Another sponsor of today's podcast is the biochemical electrolyte drink company LMNT, and they are very kindly offering eight free sample packs when you purchase any one of their orders at drinklmnt.com/mattwalker. LMNT is an electrolyte sports drink that I can fully get behind - it's created from the basis of science, and it has no sugar, no coloring, and no artificial ingredients – all qualities that are so important to maintaining your blood biochemical balance.

So, make your way over to LMNT and MasterClass to take advantage of these incredible deals. And, as always, if you have thoughts or feedback you’d like to share, please reach out to Matt on Instagram.