DR MICHAEL MOSLEY: Why you have dreams about being naked in public… and how to stop them

Dreaming occupies a surprisingly large amount of our night. A study by the University of Wisconsin-Madison – where they measured the brain waves of people as they slept – concluded that we spend up to 70 per cent of our nights dreaming.

Yet we never remember most of our dreams. So why do we have them?

Well, scientists are now beginning to understand why we have certain dreams — and what they mean.

Dreams have long fascinated us. The Ancient Greeks decided there were two types: most were unimportant, triggered by everyday hopes and fears. But some were prophetic, a form of divine intervention allowing the gods to communicate with ‘chosen’ individuals and help them see into the future.

As far as I know I’ve never had a prophetic dream – and the ones I remember are fairly straightforward, like trying to get my bags packed in time to get to the airport but struggling to find the last few socks or underpants I need.

This sort of dream is very common, one of several classic ‘anxiety’ dreams.

But while most of us have anxiety dreams, in fact a lot of what we dream about is, as the Ancient Greeks claimed, simply a reflection of the events of that day and which your brain is busy processing.

This was strikingly demonstrated in a recent study by the University of Freiburg in Germany, where 20 people were asked to listen to four audiobooks before bed. These included The Mystery Of The Blue Train by Agatha Christie and Inkheart by Cornelia Funke.

The volunteers were asked to wear an EEG cap, to record their brain waves, and then left alone in the sleep lab to drift into the land of nod.

Ninety minutes after they’d gone to sleep, the volunteers were woken and asked if they had been dreaming and, if so, about what. The researchers did this to the unfortunate volunteers several more times during the night.

The next morning independent researchers (who didn’t know anything about the experiment), read the accounts of what each volunteer had been dreaming about and were asked to guess which audiobook they had listened to. They got it right with impressive accuracy. They could also tell, based on looking at their brain waves, which of the volunteers had been listening to the same audiobooks.

In other words, their dreams reflected the things that happened to them earlier in the day.

Most dreams occur during a stage of sleep called rapid eye movement (REM), particularly our anxiety dreams, which paradoxically serve an important purpose: helping us feel less stressed when we are awake.

During REM sleep most of our muscles are paralysed. We still breathe, but apart from that, the only part of us that is obviously moving is our eyes. (If you look at someone in REM sleep, underneath their eyelids, their eyes will be flickering madly.) It’s thought this ‘sleep paralysis’ is to ensure we don’t act out our dreams.

REM sleep is also the only time, day or night, when links to stress-inducing chemicals in the brain are switched off. This means that, while the dreams we have might be scary, they’re nothing like as bad as they would be if you were having them while you were awake.

Having a stress dream while in REM sleep is a form of psychotherapy – you revisit unpleasant memories and events but remain calm. This allows you to process your emotions and defuse them.

So the more REM sleep you can get, the better for your emotional wellbeing. We get REM sleep throughout the night, but more of it towards morning, so try not to cut your sleep short.

There are lots of different ways people express anxiety in their dreams, but here are six of the most common:

1. Running late

For me, this takes the form of trying to pack in order to catch a plane, but failing. Or sometimes I’m late for a meeting and unable to find my way there.

These types of dreams are thought to be your subconscious mind telling you that you’re cramming too much into your life.

2. Chasing someone

I often dream about chasing someone, but I’m never quite able to catch up.

The most plausible explanation is that this is a subconscious fear I have that however hard I try, I am never going to achieve my goals.

3. Falling off a cliff

Dreams of falling – perhaps off a cliff or building – are interpreted as a fear about loss of control; that you don’t feel as in charge of your life as you’d like.

4. Unprepared for a test

Like falling off a cliff, this is about feeling out of control and ill-prepared for challenges ahead.

5. Teeth falling out

This seems to happen more commonly after the loss of a loved one and may reflect a fear of growing old and dying.

6. Being naked in public

This is not one I experience (and so don’t have to inflict it on your imagination), but if you do, it may suggest you harbour feelings of guilt or inferiority.

If you have anxiety dreams then it can be reassuring to know that they are common and are really just a sign that you are stressed.

Pinpointing what is causing the stress may help, as can writing down the dream during the day – and then changing the ending.

I know someone who was haunted by dreams of spiders, but who found that writing about them, and then imagining them fleeing in terror from her, made a big difference. The spider dreams gradually faded away.