A Moment of Science

How Time Passes In Dreams

So how many minutes or hours pass during a dream? Find out on this Moment of Science.

Trippy dreamscape

Photo: h.koppdelaney (flickr)

Although sometimes people think their dreams seem to last a long time, one scientist concluded that "dream time" is similar in length to real time

Many people believe that hours worth of events and activities can be dreamed about in a matter of seconds. Despite this common belief about how we dream, time in dreams actually is not compressed. If you dream of an activity that would take five minutes in waking life, you probably dream about it for a full five minutes.

Dream Time Vs. Real Time

Dream and sleep researcher William Dement conducted two studies that demonstrated that dream time was similar to real time. Because dreamers’ eyes move under their eyelids very rapidly while they are dreaming, Dement was able to monitor sleepers and record the length of their dreams by observing their rapid eye movement.

After recording this information, Dement would wake dreamers and have them write down a description of their most recent dream. He assumed that longer dreams would take more words to describe than shorter ones.

Word Count

When he compared the number of words in each dream report with the number of minutes the dream had occurred, he found that the longer the dream, the more words the dreamer used to describe it.

In another related experiment, Dement woke sleepers while they were dreaming and asked them how long they perceived their most recent dream had taken. Eighty-three percent of the time they perceived correctly whether their dreams had been going on for a long time or for a short time.

With these experiments, Dement concluded that time in dreams is nearly identical to time in waking life. So the next time in your dreams you slay a dragon or fly from your house to your workplace, the amount of time it seemed to take is probably just about how long it actually took to dream it.

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  • KYousuf1400

    No offense to William Dement but I cannot see how these experiments have established anything other then that dreamers know the difference between a long dream and a shorter one in real time. Jumping to the conclusion that this somehow proves that dream time and real time are the same or even similar sounds silly. 

    For example, he asks the dreamers in the second experiment how long did their dream seem to last. He then comes across the astonishing fact that they perceive a longer dream as….. A longer dream (wow).
    No mention is made of the actual estimations that the dreamers made for their dream . I would like a mention made of a estimation of a dreamer vs the actual period of the REM cycle of a dream.

    I would just check the raw data of his study but I can’t seem to find it. As the results of his studies are presented here, I maintain that this does not suggest anything but a positive relationship between subjective length and objective length in dreams.

  • Simone Schwendimann

    Hi there! Could you please indicate the exact title of Mr. Dement’s research paper summarised in this passage. Thank you! :)

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