It happens all too often for some people. A sudden fall. A loud growl. An ominous-looking character.
There are many different things that can wake us up from dreams. Chances are, that in those few seconds after, you’ll be able to remember your dream. Fall asleep again though, and it’s forgotten — unless you’ve taken notes.
Very little is understood about why we dream. In an effort to get closer to that answer, however, researchers have discovered the parts of the brain responsible for remembering dreams, and why some people don’t.
The researchers, from the Lyon Neuroscience Research Center in France, had previously found that people who were likely to remember their dreams, so-called “high dream recallers,” had twice as many moments of wakefulness and were more reactive to auditory stimuli during sleep than those who rarely remembered dreams, called “low dream recallers.” At the time, the researchers said that these dreamers’ higher levels of neural activity could lead to an easier time remembering what happened.
Why Some People Remember Their Dreams
They went a step further in their new study, looking for dream-related regions of the brain that activated during sleep and wakefulness in both groups of dreamers. Out of 41 people, 21 identified themselves as “high dream recallers” — remembering them about 5.2 mornings per week — while the remaining 20 said that they were “low dream recallers,” who remembered their dreams only two times each month.
Using positron emission tomography (PET) to look at their brains’ activity, the researchers found that “high dream recallers” showed stronger spontaneous activity in two regions of the brain. One of them, the medial prefrontal cortex, is responsible for making associations between context, locations, events, and adaptive responses like emotions.
The second area, called the temporoparietal junction, is responsible for imitation, and forming pictures of oneself and other people in the brain. Hence, the two together could not only help in creating dreams, but also remembering them, too.
“This may explain why high dream recallers are more reactive to environmental stimuli, awaken more during sleep, and thus better encode dreams in memory than low dream recallers,” Perrine Ruby, a researcher at the Center, said in a statement. “Indeed, the sleeping brain is not capable of memorizing new information; it needs to awaken to be able to do that.”
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