Why are some people always able to remember their dreams, while others have trouble remembering any at all? A new study suggests activity in a certain part of the brain could have something to do with it.
The study, published in the journal Neuropsychopharmacology, shows that a part of the brain called the temporo-parietal junction has more spontaneous activity among people who regularly recall their dreams, compared with people who rarely recall their dreams.
The study included 41 people who had their spontaneous brain activity measured with Positron Emission Tomography as they were sleeping and as they were awake. Half the volunteers were considered "high dream recallers," and remembered their dreams about five mornings a week, on average. The other half of the volunteers were "low dream recallers," and only remembered about two dreams a month, on average.
Researchers found that the spontaneous activity of the brain's medial prefrontal cortex and the temporo-parietal junction was higher during both sleep and wakefulness in the "high dream recallers." The temporo-parietal junction is known to play a role in processing information from both within the body and from the external environment.
The new findings come on the heels of research published last year in the journal Cerebral Cortex and conducted by the same Inserm researcher, Perrine Ruby of the Lyon Neuroscience Research Center, which showed that people who regularly recall their dreams have more wakefulness and their brains have higher levels of reactivity to sounds during sleep and wakefulness.
"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," Ruby 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."