March 2019 Brain HQ Posit Science
Turning our clocks ahead robbed us all of an hour – as we were sleeping. It’s an opportune time to ask one of the world’s top brain scientists how we benefit from sleep. For his third in a series of the “Brain on…” videos from Posit Science, maker of the BrainHQ brain exercise app, Dr. Michael Merzenich unravels the nearly “magical” properties of the Brain on Sleep. Dr. Merzenich is a world-renowned neuroscientist. Thirty years ago, he discovered the brain remains plastic – capable of chemical, structural, and functional change based on sensory and other inputs – throughout life. What you do affects your brain health, so you should do the right things. Getting a good night’s sleep is one of them. Dr. Merzenich also was the first to harness plasticity for human benefit – co-inventing the cochlear implant to restore hearing to people with deafness. Then, he pioneered the creation of plasticity-based computerised brain training, shown to have broad benefits in hundreds of studies.
In his video chat about sleep, Dr. Merzenich explains that the brain is actually working hard while you sleep. During deep REM (rapid eye movement) sleep, the brain is very busy cleaning out irrelevant material from the day. If not removed, he notes, “the trash piles up and creates a lot of background noise that impairs thinking.” In the “slow wave” period of moderately-deep sleep, the brain does more heavy lifting – consolidating learning from the day. Important information, which is in a temporary record, gets engraved into a more persistent form. In fact, if there are unresolved issues from the day, your brain works on them during this consolidation period. That’s a reason you may have a great idea during that morning shower. If you are working hard at learning something – perhaps doing your brain exercises – the consolidation actually improves your performance, so you are better at it the next morning, than you were immediately after you finished the hard work.
The third critical job of sleep is that the brain resources – brain chemicals – you’ve expended during the day get replenished. “If you don’t get a good night’s sleep, there are piles of trash in there, which no one has taken out, and the important things are fleeting, because there’s no consolidation,” Dr. Merzenich observes. “And there’s no rejuvenation. So, you wake up unprepared to live your life the next day.”
Sleep affects every aspect of your thinking, and your attention control, and how bright you feel.
“You can ruin the next day, just by having a ruinous night of sleep,” Dr. Merzenich points out. So, get a good night’s sleep. And, know that when you’re grappling with something, it’s not only okay to sleep on it — that’s actually a good idea.