Previously, we learned sleep is necessary before learning to prepare the brain to learn effectively. But sleep is also needed after learning to cement new information in your brain. This discovery happened in 1924 when two German researchers pitted sleep and wake against each other to see which would win out in memory-savings benefit. Their findings suggested that time spent awake can be hazardous to new memories while time spent asleep has fixating benefits.

Researchers have also put REM sleep head-to-head with non-REM to see which is more effective at saving memories. When it comes to memory, it is deep non-REM that helps hit the save button on new memories. These results led Matt to conduct experiments where we causally enhance the memory using electrical or auditory brain stimulation methods, and as a result, boosting the next day retention of memories. Indeed, with some of these sleep-stimulating methods, researchers have been able to double the amount of memory-savings benefit from sleep.

The results of these studies have real pragmatic and clinical implications, including in the context of aging and dementia. It’s no secret our learning and memory abilities begin to decline as we get older, but it’s also been discovered that a physiological signature of aging is that your sleep gets worse, especially the amount of deep, non-REM sleep. Recent evidence indicates that these two processes aren’t simply co-occurring but significantly interrelated.

The potential silver lining of this is that sleep is something we may be able to do something about. Matt and other researchers are exploring the use of direct current brain stimulation to restore some healthy quality of deep sleep in older adults and those with dementia, thereby salvaging aspects of the learning and memory function. And the tentative answer so far is that this could work, although it will take some years before we can even start to entertain real hope in this regard.

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.

Those fine people at Athletic Greens are one of the sponsors of this week’s episode. and they are generously offering three benefits for anyone who uses the above link for their first order: 1) a discount on your order; 2) a one-year free supply of vitamin D; 3) five free travel packs. Athletic Greens is a nutrition drink that combines a full complement of antioxidants, minerals and biotics, together with essential vitamins. Matt’s been using it for several years now because he’s serious about his health and because he did his research on the science and ingredients in Athletic Greens and thinks its science and scientific data that can be taken as ground truth.

Another sponsor this week is the good people at InsideTracker, and they are generously offering a special 25% off any one of their programs for anyone who uses the above link. InsideTracker is a personalized biometric platform that analyzes your blood and your DNA to better understand what's happening inside of you and also offers suggestions regarding things that you can do to better try and adjust some of those numbers, optimize them, and, as a result, optimize you.

So, make your way over to Athletic Greens and InsideTracker 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.

#36: Sleep and Memory - Part 2

The Matt Walker Podcast