Early Birds Have Different Brains Than Night Owls

By Breanna Draxler | October 1, 2013 1:21 pm

morning person versus night owl chronotypeIf the early bird gets the worm, what does the night owl get? According to a recent study, “sleep disturbances, vulnerability to depression and higher consumption of nicotine and alcohol.” The study is the first to hint at what brain differences might underlie a person’s so-called chronotype—their natural tendencies toward sleeping and waking.

Chronotypes fall into three categories—early, late or intermediate. About 10 percent of people have early chronotypes; 20 percent are naturally late risers, and the rest fall somewhere in the middle. But chronotypes indicate more than just when a person rolls out of bed. Studies have shown chronotype-related differences in hormones, lifestyles and brain functions between individuals. But are there differences in the brains themselves?

To find out, researchers in Germany hooked up 16 early birds, 23 night owls and 20 middle-of-the-roaders to a diffusion MRI machine to see what was going on inside their heads.

Turns out the night owls’ white matter was in worse condition than their earlier-rising counterparts, especially in areas associated with sadness and depression, according to the results published in Science Direct. One of the researchers told New Scientist,

“We think this could be caused by the fact that late chronotypes suffer from this permanent jet lag.”

The misery of jet lag without the joy of travel? Sounds like a pretty bad deal. But identifying the brain mechanism responsible may help scientists understand, at a molecular level, what makes mornings so miserable for some—and midnights abhorrent for others—and therefore find ways for us to behaviorally or chemically make our days a little better.

Image credit: Aleshyn_Andrei/Shutterstock

MORE ABOUT: brain, chronotype, jet lag, sleep
  • Ferdinand Marcos 2.0

    So what defines a “natural” tendency then? Genetics? Environment? Culture?

    • Rus Archer

      in this case, it means habits not dictated by work, culture, alarm clocks, etc

  • Rus Archer

    what about those of us who stay up late AND wake up early?
    what do you call that?

    • Forever DED

      Screwed. :)

  • Helen Azar

    “We think this could be caused by the fact that late chronotypes suffer from this permanent jet lag.” Great.

  • Trium Shockwave

    Couple things:

    1. I find the idea that there are 3 kinds of “chronotypes” highly dubious. It seems each person is rather unique and sleep patterns defy such categories. An earlier commenter already pointed out how theirs does not seem to fit. So, problems right there with the premise.

    2. “Night Owls” seem to have these problems, but that is merely correlation. What is the causal relationship? Is there something physical that causes both late sleep patterns AND depression? Or are the problems simply because our culture requires people to obey a “typical” sleep cycle regardless of what their nature tells them? Or are these different symptoms caused by completely separate things, and the correlation is just coincidence?

    • BayAreaGuy

      You do know that science doesn’t work like this, right? Your experiences, or whether you find something “dubious” really doesn’t matter at all. I’m sure these researchers didn’t wake up one day and decide that people fall into three categories of chronotypes. This conclusion came about from years of hard work in sleep labs, and in vivo research. Unlike you, they didn’t just do a quick mental checklist from their Facebook friends and decide what was most convenient to them.

      Also, YES, part of this research is correlative. But since they found brain differences, it could lead to a causal explanation.. At this stage, even the brain scans are correlative, but they show that something biological is happening. That’s important since it shows that the sleep patterns aren’t just behavioral but are also linked to physiological differences. The next step is to determine the direction of causality. Simply screaming out that it’s a correlation is a freshman reaction to research whose results you simply don’t like.

  • Forever DED

    If us night owls were to move west, would our bodies retain the same wake-sleep cycle and thus fit in with normals or would our bodies slowly resort to becoming night owls in the new time zone?

    • Olga Starcher

      You keep your sleep cycle as you move from time zone to time zone. In fact, when you move west, it is far easier to adjust to time change than when you move east.

    • Gabe

      I spend several months a year in Europe. I’m an “early bird” in the U.S. When I get to Europe I’m, of course, jet lagged, and stay out at night till late and sleep until 10 or 11 am on the days I don’t work. However, after week or so, I slowly get back into my old routine and after two weeks or so, I’m back to being a natural early bird, despite the time change. So, I assume, early bird or night owl, when you change time zones, eventually you’re back to your old routine.
      I must be a true early bird. I have been like this all my life, even as a kid and adolescent. I just can’t sleep in past 8 am, even if I stay up late. Ideally, I am asleep at 11 and am up around 6. With this schedule I feel most rested during the day.
      I had to work shift in my early 20s and it was killing me. I quit the job after a year, even though I liked it, just because I am so set in my sleep patterns and couldn’t adjust. I was always tired and got sick a lot.

  • Monica Mallow

    I can reset my “chronotype” depending upon what my schedule requires. Give me 3 days and I can become whatever type you need me to be (without an alarm clock). Currently I rise at 6am so that I can be at work at 7:30am. When I was on the afternoon shift, I didn’t rise until about 9:30am or sometimes a bit later. No alarm clock necessary after 3 days, as long as I go to bed at the appropriate time the night before.
    Soooooo, I suspect there’s a bit more to this story than is being tested. Too many variables not mentioned that might influence sleep patterns and brain matter – like culture, nutrition, exercise, genetics, stress factors…
    Sounds like a “which came first, the chicken or the egg” theory to me.

    • msbadger

      Lucky you. Few people are able to do what you describe. You cannot judge everyone by your own experiences. Thanks.

      • Monica Mallow

        Oh I absolutely agree! A study on an individual certainly cannot be applied to a group. My point was that the study failed to include or perhaps mention other factors that might influence chronotypes. I’m not sure based on what was presented, if the correlation between brain and chronotypes had to do with precisely that, or perhaps other lifestyle choices that may have gone along with the types. In my observation, night owls also seem to have a poorer diet and exercise regimen than do early risers. That may be more of an influence on brain development and health than the time of day one actually sleeps. I’m being hypothetical here. I just don’t see where this was a good study. Too many ifs and not good control.

  • Gary

    I actually thought this article was going to be about birds. As in the difference between birds that are active in the mornings as opposed to nocturnal birds. I think that would have been more interesting.

  • http://blogs.discovermagazine.com David Center

    All of my life my natural cycle has been to stay up late and get up late. I have two adult sons and that has been their natural cycle also. My wife is just the opposite. The problem for my sons and I has always been the “conspiracy” by early birds to configure the world to their preferences and thereby imposing an unnatural schedule on night owls.

    No intervention is needed for night owls other than a social intervention to make flex scheduling of work hours standard. Fat chance of that happening. Thus, the next best solution is for night owls to find employment or start businesses that can accommodate their natural cycle.

    I solved my problem by becoming a professor in an urban university where I taught in a graduate program that held most of its classes at night. With an evening teaching schedule no one much cared what time I came to work in the mornings. I am now retired and have even more flexibility!

  • Lee Riffee

    I’ve been a night owl (not sure which “type” I’d be, but I naturally stay up until 3:30-4 am and tend to get up around noon, not sure if that is moderate or total night owl) most all of my life. It started when I hit puberty (before that, I was up at dawn everyday and had to wait until my parents got up so I could go and play outside) and I’ve been like that ever since.

    However, I’m not at all depressed (have had a few bouts in my life, but they were unrelated to my sleep schedule – that I’m sure of), and I’m essentially a life-long teetotaler with regards to substances.
    But, what has made me quite annoyed is that certain other people would always expect me to conform to their rooster-like morning schedules. The way I see it is would they like to be forced to stay up way past their bedtimes? I think not.

    People have this “early to bed and early to rise” notion which is total bunk for the owls among us. It only makes us miserable.

    I worked a job where I had to get up just before 5 am every working day to get to work at 7. Well, the only thing that kept me going was a ton of coffee. My body did everything it could to tell me I should still be in bed, and I swear every day I didn’t fully enter a waking pattern until around 11:30 am. I fought sleep until that time came just like a morning person would fight sleep if he or she had to work a 2nd or 3rd shift.
    It can be hell being an owl in a lark’s world, but I think any link to substance abuse and depression is due to something else other than the person being a night owl (perhaps it may have to do with availability of alcohol and such – bars are almost never open at 9 am but they are surely open at 11pm and later).

  • BayAreaGuy

    Wow. I really thought the comments section for Discover would be filled with science-minded people, discussing the research in articles like adults. Instead, what I find is a cesspool of comments that I’d expect from high school students, ranting on and on about their own experiences, and decrying the research findings as “irrelevant” because it doesn’t fit with their desires, experiences, and expectations. Perhaps this is yet another professional publication that needs to eliminate their comments section, like Scientific American recently did?

    • simon

      You pretend to be a brainy Scientific American-reading spokesman for science and rationality, but your rhetoric reveals scorn and anger that’s curiously inappropriate. I see that several comments above, you chided some fellow commenter (at excessive length) for “screaming out” something you deemed “a freshman reaction” (screaming out? hardly); no doubt you were pleased with your little lecture, but it came off as pompous finger-wagging. Then, apparently disappointed at the lack of applause, you piped up again, criticizing commenters en masse for “ranting on and on” (they’re not the ones who are “ranting”) about their personal experiences, just like “high school students” (freshmen, I assume). Me, I found the comments interesting — but for those who don’t, there’s an obvious solution, and it isn’t shutting down the entire section. Try taking an anger-management class, you pathetic twit!

    • Nick

      I like to think of myself as a scientific mind, but have you considered that the way in which their scientific method was conducted was possibly based off of social norms rather than true circadian rhythm? All I am saying is we are one species in which our sleep cycle is variable. “Variable” the one thing they seemed to forget and is essential to scientific method. Social norm is the constant but what causes the difference in variable and are those differences correlated to the constant.

      This is really a matter of sociology. Each person in society is a variable, making no “true” constant from a biological standpoint. Now if the study was based on social standards this all holds true. I think some of these people are simply pointing out that the standards are unfair and biased.

  • Jenna Bilbrey

    Science Direct is a search engine for scientific papers. Saying something is published there is like saying something was published on Google.

  • Hank Rearden

    interesting study, but I would offer the hypothesis that causality at least for depression may flow in the opposite direction – not depressed because up late, but up late because depressed – Winston Churchill, for instance, used to stay up until 2 or 3 AM.

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