Hi there, it's Matt here and welcome back to the podcast and welcome back to another of our AMA episodes.

Ask Me Anything episodes.

We've got a long list of questions, so we're just going to dive straight in.

But as always, I am joined by the unparallel, the unmatched brilliance. That is Dr. Ety

Ben-Simon. Eity, welcome back. Great to be here, Matt. Okay, Etie. So with all of that said,

why don't we just jump in and start with the first question? The first question is a very

intriguing one. Someone is saying,

since moving to Finland for work, my sleep has completely changed. Does latitude really affect

sleep that dramatically? Yes, for some period of time until which your system will acclimate

at least. So I guess there's two things.

The first is the initial move there, and that's all the jet lag and the circadian disruption.

But that's not, I think, what this person is talking about.

Latitude can significantly influence sleep due to differences in the amount of daylight exposure,

the timing of the sun, and the seasonality of that light, all of which basically impacts both your circadian rhythms and in part by way

through melatonin signaling. There has been some work done looking at Nordic countries,

including Finland, that showed that during midnight sun or polar twilight periods, individuals often report later sleep onsets, lower sleep efficiency, and an increased phase delay, essentially in the summer months. So not really a big surprise there,

but if you are at the equator, you're getting really nice, usually very consistent sinusoidal

waves of light and dark, light and dark. And that happens day after day, month after month,

irrespective of the month of the year, with some minor modifications. But once you get in the

high latitude areas, then all of a sudden, if you're in Finland during the summer,

you're going to have light at almost all times of day. So no wonder

your brain gets confused. And that's why you really have to be so careful to ensconce yourself

...