As today is the shortest day of the year in the Northern Hemisphere (and the longest in the Southern Hemisphere), it seems appropriate to talk about how the seasons change our bodies’ rhythms. Many things change with the seasons, but the main seasonal variation that I will consider here is the variation in day length. …
Tis the Season: Seasonal Effects and Circadian Rhythms Read More »
Why do you go to sleep when you do? Sure, there’s a big part of it that’s physical: You go to sleep because you’re sleepy. But you might also stay awake, even when you’re on the verge of collapsing from fatigue because you have work to get done. Or because your neighbor is practicing a …
Meme #1 Here we see Squidward staying up and reading instead of going to sleep. Squidward himself might smugly point out that he’s reading a book, not looking at a light-emitting screen, and use that as an excuse to feel superior. If so, he would be tragically mistaken. There are clearly lights on in the …
Here’s a fun fact: You probably get way less light exposure during a normal work day than you would if you were out camping. “Sure,” you say. “That’s no surprise. At home, I have walls around me to block the sun. If I’m camping, I presumably have fewer walls.” “You don’t understand,” I say, leaning …
Rods, cones, and…ipRGCs? For almost a century and a half, it was thought that the mammalian retina had just two types of photoreceptors: rods and cones. That assumption was not proven to be false until studies in the late 1990s proved the existence of a third kind of mammalian photoreceptor that differed greatly from rods …
inTRO to ipRGCs ( Intrinsically Photosensitive Retinal Ganglion Cells) Read More »
I recently got some blackout curtains for my bedroom. This was pretty long overdue: about thirty feet from my bedroom window is a cheerfully bright, energy-efficient street lamp, which—while great when I’m taking the dog out for a nighttime stroll—is the photic equivalent of somebody standing in my azaleas and playing “Seventy-Six Trombones” while I’m …
I love my Apple Watch. The ability to track my exercise, heart rate, activity levels, and sleep has enabled a real awareness of how my physical and mental health changes over time. The ability to track personal health data over long time periods outside of laboratories is one of the most exciting developments of the …
I have always been a good eater. Before I knew about time-restricted eating, back when I was in college—waking up at 4:50 am for crew practice, staying up until 1:00 am working on problem sets, and sleeping in until noon on my days off—I could eat pretty much any food in any amount at any …
What is sleep regularity and why is it important? Sleep regularity is a gauge of how consistent a person’s sleep patterns are, based on the day-to-day variability in their sleep–wake times. In general, having poorer sleep regularity, or irregular sleep patterns, has been shown to lead to many adverse outcomes in metabolism, mental health, and …
In this blog post, I want to point to some common symptoms of circadian disruption. The role of circadian rhythms in sleep is subtle, and many times issues that are attributed to other sources really have circadian factors as the root cause. The two process model: To understand the interaction between sleep and circadian rhythms …
