5 ms·

The measurements were performed at time points relative to the natural rhythms of the subjects i.e. respectively 1h30 and 10h30 after waking up according to the

• scotch_drinker 17y ago
  That's not what the article says. The article seems to draw its conclusions entirely on this statement: "After 10 hours of being awake, the early birds showed reduced activity in brain areas linked to attention span, compared with the night owls." I saw from your comments above that measurements were taken at two different times. However, the article, not the study, is linked prominently on the front page of HN and that's what I'm taking exception with. I have no doubt that the study is rigorous and careful but the conclusions drawn and the tone taken by the author of the article are sketchy at best. On top of that, as you mention in a previous comment, the study is comparing what the two groups can do in "their relative evenings". Again, this seems like apples to oranges to me. Of course morning people are going to be less effective in their evenings because, well, they are MORNING people. I guess I would be interested in understanding what we hope to get from a study like this. The article says people who are extreme in either direction are genetically predisposed to their own personal direction. If we identify that one group of people is better than the other based on their genetics, what does this do for us, long term? That's something I'd be interested in hearing about.
  • pygy 17y ago
    "After 10 hours of being awake" is correct actually. For the behavioral part of the study, "In their relative evening, late risers are more alert and can outperform early birds in a reaction time test assuming they're allowed follow their natural sleep rhythm, whereas there are no such differences in the morning" would be more accurate. For the imaging one: "Ten hours after waking up early birds show patterns of activation similar to those of sleep deprived people (1 night skipped). Late owls show patterns associated with optimal concentration". The sleep pressure in EB is also greater as demonstrated by the amount on slow wave sleep in the first part of the night. > Of course morning people are going to be less effective in their evenings because, well, they are MORNING people. Not necessarily. In absolute time, it's obvious it will be the case, but why, beforehand, would it be when you adjust the measurements to the sleep cycle? At least it's not obvious for me. Read the detailed methods in my post above. Furthermore, evening people are as performant as early people in their relative morning. The only difference is in the relative evening where late types are better. I'm not sure it has much impact in terms of eugenics. The paper shows that late people, who tend to be seen as slackers in general, actually perform better (at some tasks) if they are free to follow their natural rhythm (up at 10+am, go to sleep at 2+ am), which is impossible to do for most of them in the current socio-proffesionnal environment.