Why do some people remember their dreams and others do not?

Longer answer

Dreaming versus remembering. We spend a third of our life asleep, during which we experience many fantastical and sometimes bizarre dreams. Researchers can only access dreams by asking people what they dreamt about after waking up. We can ask people to keep a dream diary, meaning they write down (or record audio) every morning which dreams they remember. Or, we can ask them in questionnaires how much and which dreams they remember. From this data, we can estimate the dream recall frequency: how many mornings someone remembers a dream. This differs from person to person but can also change for an individual over time. When someone remembers a dream, this is a good indicator that they actually did dream. However, when a person does not report a dream, we don’t know whether they did not have a dream or whether they had a dream but cannot remember it.

Some methods and settings increase the chance of remembering a dream. For example, you will remember more dreams if you fill out a dream questionnaire or dream diary or even because a researcher asked you to remember your dreams. We can increase dream recall even more by having people sleep in the sleep laboratory and waking them up several times a night to ask about their dreams. Scientists hypothesize that the memory traces of dreams are fragile. If you don’t focus on your dreams immediately after waking up (thus strengthening your memory), it disappears quickly, leaving you to feel like you did not dream.  

During a night of sleep, we cycle through two alternating sleep stages called REM and NREM. When you initially fall asleep, you go through three different ‘non-rapid eye movement’ (NREM) stages as you sink into a deeper slumber. This occurs because the brain activity, breathing rhythm and heartbeat decrease in these stages. The last stage is the ‘rapid eye movement’ (REM) sleep, where the brain activity sems to increase, similar to a brain that is awake. During the rapid eye movement (REM) sleep stage, our muscles are relaxed, except for the eye muscles, which move in bursts. While initially researchers thought that people only dream in REM sleep (80 – 95% of awakenings lead to dream reports), we now know that more than half of the time, people also report a dream when woken up from NREM sleep. Still, you are more likely to remember a dream when woken up from REM sleep. It is possible we dream less in NREM sleep, or the memory trace is even weaker when waking up from NREM.

Does this mean that everyone dreams? Most people who do not remember any dreams at home, do remember dreams if woken up in a laboratory. But some people with damage to specific brain regions never report any dreams, even when researchers repeatedly wake them up. Potentially these brain injuries affect areas necessary for us to dream. Therefore, overall studies suggest that most people experience dreams for most of the night nearly every night.

So why do some people naturally remember more of their dreams than others? Researchers have identified several factors associated with higher dream recall frequency: age (younger people recall dreams more frequently), gender (women have higher dream recall frequency), personality factors (more open-minded people remember more dreams), and the amount of sleep we get (people remember more dreams during the weekend). Some of these factors likely lead to better dream recall because they are associated with better memory in general (e.g., age), for others, we do not yet know why they are associated with higher dream recall. Interestingly, people remembered more dreams during the pandemic, likely because they got more sleep due to working from home.

In conclusion, most people likely dream most of the night, but several factors influence how often we remember our dreams.