What is a chronotype?
Where an individual falls on the spectrum of day or night preference, is widely determined by their “chronotype” or “sleep phenotype.” This term describes a person and their disposition regarding the timing of daily routines. It explains their timing preference and their potential for mental alertness at different times of the day.
The Early Riser Chronotype
That new lawn mower sparked up at sunrise may make some of us cringe, yet for the early riser, this urge to mow the lawn is motivating and invigorating. Much like the early morning jogger who is beaming with focus and energy at 6 are, many of us are still in deep slumber, or playing hit the snooze button (a daily ritual).
The Night Owl Chronotype
The Night Owl detests mornings and the chirpy “Rise and Shine” does nothing to hasten their awakening.
The Intermediate Chronotype
There is a third preference which falls within the middle of both the early riser and the night owl chronotype. Named the “Intermediate” preference., this person is flexible and can have mental alertness where needed and necessary.
Studies show that night owl, and early riser tendencies are most likely driven by biological and genetic forces.
Recent research has discovered that there is a physical difference in the brains of different chronotypes. Researchers at Germany’s Aachen University investigated the brains of early birds, night owls, & “intermediate” chronotypes. What they pinpointed was some structural differences in the brains of people with varying sleep-wake tendencies.
A group of fifty-nine men & women in different chronotypes were observed within this study. Sixteen were self-professed early birds, twenty were between the two chronotypes, & twenty-three were night owls. Researchers found when comparing the early birds & intermediates; night owls appeared to have a decreased integrity of white matter. This was apparent in multiple areas of the brain.
White matter is the fatty tissue found in the brain. It gives us the ability to efficiently communicate with nerve cells. Reduced integrity of the brain’s white matter has been linked to depression in many cases and disruptions in healthy cognitive function.
The reason for this difference in the quality of white matter among night owls compared to those falling in between the spectrum isn’t entirely clear. People that are placed on late nights & sleeping late are often at odds with the general schedule in their life., especially work & school schedules that require early morning starts. They experience fatigue & daytime insomnia, difficulty concentrating, physical pain & discomfort., much like that of travel-induced jet lag.