No one knows exactly why we dream, or whether our dreams hold any meaning. A new study, though, takes one step closer to understanding the peculiarities of dreaming. It explains why some people seem always to remember their dreams, while others are left completely in the dark.
Researchers recruited 41 people to take part in a study in which the participants' brains were monitored while they dreamed, the International Business Times reports. About half the participants considered themselves dream-rememberers. After waking, the 41 subjects were asked whether they recalled their dreams. On average, the self-identified rememberers said they recalled their dreams about five times per week, while the non-rememberers reported knowing what they had dreamed just twice per month.
The brain imaging revealed a difference, too. The part of the brain invovled in information processing was more active in the dream-rememberers. IBT explains:
"High dream recallers" have more activity in the temporo-parietal junction, which the researchers believe may allow the dreamer to focus more attention on external stimuli, promoting intrasleep wakefulness, which means dreams are better embedded into the sleeper's memory.
Previously, the researchers found high dream recallers have twice as much time of wakefulness during sleep as their low recalling counterparts. Low dream recallers are also far less reactive to auditory stimuli during sleep and wakefulness, suggesting time awake may facilitate the ability to remember dreams.
Whether wakefulness and sensitivity to outside stimuli are responsible for the differences between people, however, is not clear. It could be that people who frequently remember their dreams also tend to have more dreams, IBT points out. When one of the scientific mysteries surrounding dreams closes, it seems, another opens.