Hello and Happy Friday,
We hope the week has treated you well and that you’re settling into a slower end to the day. It might be a good time to turn inward a little, and allow for some rest.

In Part 1, we met REM sleep as your brain’s emotional editor: it keeps the memory but gently turns the volume down. In Part 2, we saw how hard experiences can overload that editing room so feelings stay stuck on high.

Now for the uncomfortable part: many of us often sabotage that editor every night – with our phones.

Picture a familiar scene.
You are tired. You mean to sleep. But you open one app, then another. A breaking news alert, a reel that pulls you in, a message that stings a bit. Suddenly it’s late, your chest feels tight, and you’re more awake than you were half an hour ago.

If REM is supposed to be a low‑adrenaline replay of emotional memories, doomscrolling is like handing your night‑shift editor a last‑minute pile of chaotic, alarming footage and spiking the stress chemistry right before work starts. Studies on evening screen use show later sleep onset, shorter and more fragmented sleep, and less time in the deeper stages that support emotional processing (Harbard et al., 2016; Exelmans & Van den Bulck, 2017).

It’s not just the blue light. It’s the red alert content. Stress and mental overdrive before bed keep noradrenaline and cortisol higher – exactly the chemicals REM usually turns down so it can safely replay emotional memories (Yoo et al., 2007; Walker & van der Helm, 2009). The more keyed‑up you are going into the night, the harder it is for your brain to slide into that calm internal theatre where emotional editing happens.

Phones aren’t the enemy; timing and emotional load are.
The question is: what are you feeding your emotional system in the last 30–60 minutes before sleep?

Small experiments for a more “REM‑friendly” night shift:

Across this series, the thread is simple: sleep is your emotional maintenance shift. Hard days load the system; sleep edits; your habits decide whether that editor ever gets a fair chance.

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