We often live our lives with the advice to “follow our dreams” — to always do that which we can aspire to do. While dreams in reality are often less flattering than that, and almost always less coherent, we’ve attached value to what they mean for centuries.
The ancient Talmud suggests that an unexamined dream is like an unopened letter. The advance of modern psychology urges us to describe our dreams in detail. How often do we wake up in the middle of the night, wildly inspired, and attempt to write down what incredible dream we had? How often too, do we fail to describe the essence of what we dreamt, as the day draws on and our recollection of it quickly fades?
While some days you might at least remember at least a few seconds of a beautiful dream or a terrifying nightmare, other times you might swear you passed the night with no dreams at all. Now, science may soon be able to determine what allows us to remember our dreams at night.
A study conducted at the Lyon Neuroscience Research Center of France used 36 participants. Half of them reported recalling and even writing down their dreams in detail, while the other half, described by the study as low recallers, only remembered one or two dreams they had over the course of a month. Even while we sleep, the mind remains incredibly active, with the brain generating many of the same waves as when we are awake. Consequently, the periods of wakefulness during rapid-eye-movement (REM) sleep may be a discerning factor when it comes to recalling our dreams.
For the study, an EEG monitoring system was attached to the participants while they slept, while a recording was played, calling their names in a voice that wasn’t quite loud enough to wake them up. A brain wave originating in the occipital lobe, known as the alpha wave, decreased in high recallers while they were awake and heard their names being called. The same was true of low recallers, but the duration of the decrease was noticeably longer in high recallers — indicating that they experienced more bouts of wakefulness throughout the night, being much more sensitive to ambient noises in the room than their deep-sleeping counterparts.
A later study conducted by the same researcher, Perrine Ruby, was published in Nature, which showed increased activity in the medial prefrontal cortex of high recallers during REM, the stage of sleep at which dreams occur — the same region associated with moderating social behavior and decision-making — which could even suggest that the area of our brain which defines and maintains our personality also deals with the obstacles presented by the subconscious.
At the same time, however, the regions of your brain used in learning and long-term memory are not as active during sleep, and so forming distinct memories of dreams is a considerably difficult task. Using positron electron tomography (PET) scans, Ruby’s team was able to chart blood flow through the brains of the participants, another factor associated with wakefulness and more likely to happen in high recallers.
It stands to reason then that the common advice of writing down your dreams immediately after you wake up, and being woken up abruptly by an alarm placed close to your bed, might have some truth to them.