If you've ever woken up from a dream only to have it instantly wiped from your memory, you're not alone. French scientists have been looking into the phenomenon, uncovering vital information that could explain why some people remember their dreams more vividly - and more readily - than others.
The temporo-parietal junction, or the information processing center of the brain, tended to be more stimulated, and thus active, in people who frequently remembered their dreams. It's thought that external auditory stimuli and a higher incidence of waking up throughout the night leads to 'high dream recall,' while heavier sleepers ('low dream recall') who didn't respond to such stimuli were less likely to remember their dreams. High dream recallers were defined by an average of five memorized dreams per week, while on the other end of the spectrum, low dream recallers only remembered an average of two dreams per month.
Why? Because the process of waking up and being intermittently alert keeps the brain active, thus leading to a stronger memory of dream scenarios. "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 the study's leader Perrine Ruby of the Lyon Neuroscience Research Center. Ruby is also a research fellow at the French National Institute of Health and Medical Research (INSERM), where this study was conducted.
Published in medical journal Neuropsychopharmacology, the study looked at 41 people whose brain activity was quantified and interpreted by Positron Emission Tomography. The process saw higher instances of spontaneous activity not just in the temporo-parietal junction, but also in the medial prefrontal cortex, in those who were quicker to recall their dreams.
This field of research is not new to Ruby, who just last year (also with INSERM) published similar findings in the journal Cerebral Cortex. Ruby's earlier research found that people with higher dream recall respond more readily to sounds and stimuli while both sleeping and awake.