Why Do Some People Remember More of Their Dreams?
Some people seem to recall their dreams every night, while others rarely remember them at all. What accounts for these differences? A study by a group of French neuroscientists provides some clues.
The researchers compared two groups of participants — those who remembered their dreams often and those who rarely remembered any.
They used a brain imaging technique called positron emission tomography (PET) to look at these participants’ brain activity while they were awake and during sleep.
In those who tended to remember their dreams, two brain areas were more active during rapid eye movement (REM) sleep: the temporoparietal junction (where the temporal and parietal lobes meet) and the medial prefrontal cortex in the frontal lobes.
These findings were intriguing given that our most vivid and memorable dreams occur during REM. So what does it mean that there was greater activity in these areas?
The authors offered some possible interpretations:
- These brain differences reflect something about the nature of the dreams. In particular, they might show that people who generally remember their dreams have more exciting dreams.
- People who remember their dreams more often are more likely to wake up during the night. The processes that store memories are generally “turned off” during sleep. Waking up after a dream would allow the brain to encode it into memory.
These explanations aren’t mutually exclusive, of course. It could be that a person is more likely to wake up from a more interesting dream, which would make their dreams all the more likely to be recalled the next day.
These explanations are consistent with the fact that we’re more likely to remember REM dreams than those that happen during non-REM deep sleep.
While we usually think of dreams as happening only during REM sleep, in fact we can dream in any sleep stage. What distinguishes REM dreams is their tendency to be vivid, gripping, and bizarre.
Dreams during other sleep stages typically are more mundane (like dreaming you’re making coffee or checking your email). We’re more likely to remember REM dreams not only because they’re weird and exciting but also because we’re more likely to wake up briefly after a REM stage than after a stage of deep sleep.
So if you’re someone who wishes for more exciting or memorable dreams, consider the consolation prize: Perhaps you’re sleeping better.