Stickgold, an associate professor of psychiatry at Harvard Medical School and Beth Israel Deaconess Medical Center, is a sleep expert and a leader in the field of dream research.
Q. We’re always told to get eight hours of sleep, but that seems unrealistic for most adults.
A. We know now that sleep plays critical roles in our immune function, in our endocrine function, we know it has a massive amount to do with memory processing and emotional stability. It might actually turn out that how much sleep you “need” to optimally carry out those different functions might not be the same.
Q. How can someone tell if they’re getting enough sleep?
A. If you sleep more on the weekend than you do during the week, it’s because you aren’t getting enough sleep during the week. If you’re using coffee before 10 a.m., you’re self medicating. Think about what would happen if you threw away your alarm clock. If the answer is ‘I’d be fired,’ you’re not getting enough sleep.
Q. Are you a role model in your own sleep habits?
A. I actually average eight hours time in bed every night. I nap every chance I get, which is never. If I drop down to seven hours a night, I just can’t function any more.
Q. What happens to us if we don’t get enough sleep?
A. We never ask the flip side of that, which is: What happens during a 90-minute nap that can turn a psychotic dwarf into a delightful 2-year-old? That so dramatically alters the waking behavior of that child’s brain that they go from being unbearable to totally delightful? I suspect that the same thing happens to adults, but we’re so much trained and equipped to suppress our crankiness that it’s less evident.
Q. You’ve said that our understanding of the role of sleep in learning has advanced dramatically over the last decade. What do we know now?
A. I can now say with confidence that sleep allows the brain to stabilize memories from the day before, so you don’t forget them — it actually strengthens them. Whether to keep the details or whether to extract the gist also seems to be a calculus that’s made during sleep. What you do when you’re awake is you record. Without that record, you couldn’t do anything, but that’s just the start of the job.
Q. So sleep helps us remember what we might need again?
A. Memory is all about helping us perform better in the future based on what we’ve learned in the past.
Q. So, it’s more important to get a good night’s sleep on Friday than on Sunday?
A. The sleep that comes after you learn is at least as important if not more important than the sleep that comes before you learn.
Q. So, should we be trying to increase one type of sleep versus another?
A. The different types of sleep seem to be involved in different types of memory processing. People ask me, should I be increasing my slow-wave sleep if I can or increasing my REM sleep? The good news is that all of this is elegantly, homeostatically regulated, which means, if you just let your body do what it wants to, you’ll get the sleep that you need. And you’ll get the kind of sleep that you need. That’s putting aside sleep disorders.
Q. Can we use this new understanding to improve our learning while we sleep?
A. If you think you’re smarter than your brain, you might be able to get your brain to pay more attention to certain topics while you’re sleeping, but it might be that your brain is much smarter than you are.
This interview has been edited and condensed. Karen Weintraub can be reached at Karen@KarenWeintraub.com.