Dr. Aarti Jagannath

A lot of animals do do that.

They compress the hours that they're active in and they expand when they're sleeping.

But as humans, what matters to us is the 24-hour regularity, not necessarily how much of that is sunlight.

But our start of the day, which will be in the dark, is no longer really aligned with the solar day.

Normally, we would space out our waking hours evenly to span across the limited sunshine that there is.

When you bias that more towards the afternoon and evening, that lack of morning light becomes really problematic.

Our bodies would say, well, this is still nighttime.

The brain shouldn't be awake just yet.

That instinct that we have to hunker down in the winter, it's a real biological one, but we're just going to be pushing ourselves further in towards being crumpy, disgruntled, disoriented in the morning.

Biologically, what's happening is that our eyes are picking up this light-dark cycle signal and sending it to our brains to estimate time and to make sure that the whole body is coordinated and doing the right thing at the right time of day.

When to up the dopamine and serotonin secretion and therefore when to elevate mood, when to elevate alertness.

When you have constant sleep and circadian rhythm disruption, all of these go out of sync.

And almost every mental health condition you can think of, depression, bipolar disease, schizophrenia, you do see significant changes.

sleep and circadian rhythm disruption co-occurring with them.

Well, the flip side of that is a darker morning and schoolchildren going to school in the dark in the winter.

Chasing light is an entirely natural way of living.

In the lab you can see fungi growing towards the light and of course lemurs and they're known as sun worshippers because they get up in the morning and they keep this pose where they're meditating facing the sun.

This is something that is universal to all life.

But if we do decide to live with summertime, there are ways of tailoring the light exposure in a way that would work.

So we would be able to use bright artificial lights to give us that healthy dose of morning light.