I've been a big David Fincher fan ever since I saw the movie Se7en in the cinema.

If you haven’t seen this 1995 movie - don’t worry - there won’t be any spoilers here. I’ll just be talking about one aspect of the movie that doesn’t give away the plot - or the twist at the end (intrigued yet?).

One of the characters - Detective Lieutenant William Somerset - is played by Morgan Freeman.

Morgan Freeman is known to help people fall asleep.

It’s true!

When we studied 13 teenagers in our sleep laboratory way back in 2008, we found one third of them fell asleep watching the documentary movie March of the Penguins - which was narrated by Morgan Freeman (Weaver et al., 2010).

I would have loved to have written in that scientific paper that Morgan Freeman was the main reason these teens fell asleep. But the reviewers would have argued it was the penguins.

That’s what happens when you conduct a research study for at least a year - some anonymous person spends a couple of hours telling you what happened in your own experiment.

And hence why writing blogs finally allows us researchers to express ourselves …

Anyway - back to Morgan Freeman …

In Se7en, Morgan Freeman’s character has a pretty regular bedtime routine. You know, dressing down into your white tshirt, throwing knives at a board, turning the bed lamp off - and starting his ticking metronome.

Clearly Morgan’s character uses the metronome because it works for him.

But is there scientific evidence for a metronome helping people fall asleep?

Those of you who actually read these blogs (rather than scanning them) know I would’ve searched Google Scholar (and I did).

The first study to test this - and one that gets cited by other studies - was done way back in 1965. With 3 people.

Time for joke?

An anxiety neurotic, a narcoleptic, and a student volunteer walk into a laboratory. One was sleep deprived, the other one was sleep deprived, and the final one was also sleep deprived. Sometimes drugs were offered and taken, sometimes not. During the click, click, clicking of a metronome, the narcoleptic and student turn to the anxiety neurotic and ask “Remind me how much we’re getting paid for this?”. The anxiety neurotic lies horizontally and says “Zzzz”.

That’s right. The scientific evidence for metronomes helping sleep comes from a single anxious person in the 1960s who reported being able to fall asleep after being classically conditioned with a metronome (conditioned stimulus) and a combo of sleep deprivation plus an anaesthetic (unconditioned stimulus).

Perhaps this is why Morgan’s character ends up throwing his metronome out of his bedroom (sorry, I guess that is a spolier!).

How Did I Come Up With This Blog?

It’s winter time here in Australia. And as my Swedish colleague Dr Serena Bauducco is discovering, Australian homes are poorly insulated.

When Serena shopped for a heater, I recommended a portable oil heater. I did my research, and they were one of the most efficient forms of heating for Australian homes (aside from blocking drafts).

We have an oil heater in our bedroom, and it has a 24-hr timer - meaning you can time the heater to come on at any time of the day or night. It seems to get really cold in our bedroom around 5 AM, so this type of heater is perfect.

Except for the fact that the timer does this gentle ticking thing.

When I woke up during the night to change positions, I heard this ticking.

I knew I shouldn’t direct my attention to it. I should let go, and drift back to sleep.

But I got thinking about Morgan Freeman and his metronome. And the science part of my brain wondered if there is any validity to back the use of metronomes?

I did eventually get back to sleep - and given what I’ve read, I doubt it was because of the metronome-like oil heater in our bedroom.

But for those of you who understand the fundamentals of learning theory - what unconditioned and conditioned stimuli are - and how they work - well, you’ll know that time will tell if my metronome will help me fall asleep - or keep me awake …

• Prof MG