Ever wondered why someone is able to remember their dreams so vividly while another person cannot? Well, researchers have discovered how we store dreams and why some people can never remember them the morning after, UK MailOnline reported.
Two types of dreamer have been identified - but only one is able to remember them, a French team said.
A region in the brain, which remembers dreams, has been discovered. It allows dreams to be encoded in our memory while we sleep.
According to UK MailOnline, the team was puzzled by the fact that some people recall a dream every morning, whereas others rarely recall one.
In order to understand the differences between the dreamers, the team, led by Perrine Ruby, an Inserm Research Fellow at the Lyon Neuroscience Research Center, studied the brain activity of the two types.
"The researchers found the temporoparietal junction, an information-processing hub in the brain, is more active in high dream recallers," UK MailOnline reported. "Increased activity in this brain region might facilitate the encoding of dreams in memory, they believe."
In a study published in the journal Neuropsychopharmacology, the team found that "high dream recallers" have twice as many times of wakefulness during sleep as "low dream recallers" and their brains are more reactive to auditory stimuli during sleep and wakefulness, UK MailOnline reported.
This increased brain reactivity may promote awakenings during the night, and may thus facilitate memorization of dreams during brief periods of 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. Indeed the sleeping brain is not capable of memorizing new information; it needs to awaken to be able to do that," said Perrine Ruby, who led the study.
In earlier studies, the South African neuropsychologist Mark Solms had observed that lesions in these two brain areas led to a cessation of dream recall.
According to UK MailOnline, the originality of the French team's results is to show brain activity differences between high and low dream recallers during sleep and also during wakefulness.
"Our results suggest that high and low dream recallers differ in dream memorization, but do not exclude that they also differ in dream production. Indeed, it is possible that high dream recallers produce a larger amount of dreaming than low dream recallers," concludes the research team.
In this new study, the research team sought to identify which areas of the brain differentiate high and low dream recallers. To measure the spontaneous brain activity of 41 volunteers during wakefulness and sleep, they used Positron Emission Tomography.
"The volunteers were classified into 2 groups: 21 'high dream recallers' who recalled dreams 5.2 mornings per week in average, and 20 'low dream recallers,' who reported 2 dreams per month in average," UK MailOnline reported.
High dream recallers, both while awake and while asleep, showed stronger spontaneous brain activity in the medial prefrontal cortex (mPFC) and in the temporoparietal junction (TPJ), an area of the brain involved in attention orienting toward external stimuli, UK MailOnline reported.
