Early Birds versus Night Owls

Early Birds versus Night Owls

         Which are you? Do you get up at the crack of dawn raring to go? Or do you like to sleep in and then stay up until all hours of the night? Who do you suppose has the best attention level?

         Researchers at the University of Liege in Belgium recently attempted to answer this very question. Using volunteer participants from both groups and magnetic resonance imaging, they monitored the volunteers’ brains for focus of attention, peaks and troughs of alertness, and cognitive performance throughout the day. Working in a sleep clinic where participants were allowed to follow their normal sleep schedule, after awaking, at 1.5 hours and 10.5 hours, they were asked to perform tasks requiring sustained attention.

         At 1.5 hours the attention levels of the two groups were found to be no different, but after 10.5 hours of being awake, the night owl group was found to be much more focused than the early birds.

         Two mechanisms controlling alertness were determined to be responsible for the difference in the shift between the two groups. Our built-in circadian clock triggered by light, and part of the homeostatic process, specifically the one that says “you need to go to sleep after being awake a certain number of hours”, pressured the early birds to think more about sleep than their task at hand. It had been thought prior to this study the two mechanisms operated independently, but upon observing the mri’s, it is now known they are always interacting together.

         Most importantly, this study tells us a night job would definitely be inappropriate for an early bird, but, conversely, a day job would not be inappropriate for a night owl. Finally, let’s hear it for the night owls!

This study is detailed in the April 24th issue of Science  .

An apple a day....