Have you ever wondered why you remember some dreams but forget others? Or why some people seem to remember their dreams all the time, while others hardly ever do? Scientists have been curious about this too, and recent studies are starting to give us some answers.
Dream Recall: A Matter of Brain Activity
A study published in 2015 highlighted that 1 in every 250 people rarely remembers their dreams, leading some to believe they don’t dream at all. However, the issue isn’t the act of dreaming; it’s the recall that’s elusive. Research from the past decade has provided insights, suggesting that dream recall is linked to how our brains respond to external stimuli during sleep.
The Lyon Neuroscience Research Center conducted a study in 2014 involving 41 participants. Those who frequently remembered their dreams reported recalling an average of 5.2 dreams per week, while others remembered about 2 dreams per month. The study utilized positron emission tomography (PET) scans, revealing that individuals with higher dream recall exhibited increased activity in the temporo-parietal junction, a brain region associated with processing external stimuli and maintaining alertness. So, people with more activity there might not sleep as deeply and could be more likely to remember their dreams.
Furthermore, a 2017 study supported these findings, indicating that individuals who described lighter sleep were more likely to remember their dreams. This is corroborated by additional research showing that people with higher dream recall also exhibit more activity in the brain’s default mode network, a brain area that springs to life when we’re at rest but not fully asleep.
Fragility of Memory Consolidation
Upon waking, our memory consolidation is particularly vulnerable. Any distraction can prevent the retention of recent memories. Thus, if we fall back asleep quickly or remain drowsy, recalling dreams becomes less likely. Conversely, those who are more alert upon waking and attuned to their surroundings have an easier time remembering their dreams.
Question of Dream Frequency
Some researchers hypothesize that individuals with higher dream recall simply dream more often, increasing the likelihood of remembering at least one dream. While definitive proof remains elusive, intriguing evidence suggests a correlation between dream recall and a higher concentration of white matter in the medial prefrontal cortex, a region involved in self-referential processing.
White matter, primarily composed of neuronal connections called axones, differs from gray matter, which consists of neuron somas. Interestingly, individuals with white matter lesions, particularly in the aforementioned brain region, often lose the ability to dream.
In essence, those who remember more dreams might do so because they dream more frequently or because they remain partially connected to their dream experiences even when awake, whether delightful or nightmarish.
Other studies also suggest that external factors such as alarm clocks, irregular sleep schedules, and health conditions can lead to abrupt awakenings during REM sleep, enhancing dream recall. Moreover, individuals who respond more strongly to hearing their name when awake, as observed in a study using electroencephalography, may also exhibit heightened dream recall.
While the exact causes of dream recall remain a subject of ongoing research, the current understanding points to a combination of neurological activity, sleep patterns, and external stimuli.