Everyone dreams, yet the morning after brings a different reality for each of us. Some people wake up with vivid, movie-like memories of their night adventures, while others open their eyes with a blank slate, convinced they did not dream at all.
For a long time, this gap was a mystery. Now, research from the Lyon Neuroscience Research Center in France reveals that the difference is not about how much we dream, but how our brains behave while we sleep. The study shows that high dream recallers have more reactive brains that wake up briefly and frequently during the night, allowing them to capture these fleeting memories before they fade.
The difference lies in brain reactivity and wakefulness
Scientists classify people into two main groups: “high recallers,” who remember dreams almost every morning, and “low recallers,” who remember only one or two a month. By monitoring brain activity, researchers found distinct physiological differences between them.
High recallers wake up more often
The study found that high recallers experience twice as many periods of wakefulness during sleep compared to low recallers. These are not necessarily long, disruptive awakenings; they are often micro-arousals that last just long enough for the brain to switch gears.
This heightened state of alertness is driven by a brain that is more reactive to the environment. In experiments where participants heard their names called while sleeping, high recallers showed a stronger brain response than low recallers. This sensitivity to external sounds suggests their brains are constantly monitoring the environment, which triggers these frequent, brief awakenings.
The role of the temporo-parietal junction
The research team, led by Perrine Ruby, identified a specific area of the brain responsible for this difference: the temporo-parietal junction (TPJ). This region is an information-processing hub involved in orienting attention toward external stimuli.
Brain scans using Positron Emission Tomography (PET) revealed that high recallers have stronger spontaneous activity in the TPJ, as well as the medial prefrontal cortex, during both sleep and wakefulness. This higher baseline activity means their attention is more easily grabbed by sounds or sensations, pulling them out of deep sleep just enough to facilitate memory encoding. Recent work has even shown that MRI can decode simple dream content, further linking brain activity patterns to our nighttime narratives.
The brain needs to wake up to memorize
The crucial finding from this research is that the sleeping brain is generally not capable of memorizing new information. It is chemically and electrically set up to process and consolidate old memories, not to record new ones.
The arousal-retrieval model explained
This mechanism supports the “arousal-retrieval” model of dreaming. According to this theory, for a dream to be stored in long-term memory, the dreamer must wake up while the dream is still in short-term memory.
Because high recallers wake up more often, they have more opportunities to transfer the dream content from their short-term buffer into long-term storage. Low recallers, who sleep more soundly and continuously, may dream just as much but lack the waking windows required to save the files, so to speak. This understanding of how we process night-time information frames dreams as a key to brain function rather than just random noise.
Why deep sleep blocks memory formation
During deep sleep, the levels of neurotransmitters like acetylcholine and norepinephrine—which are essential for memory formation—drop significantly. Without a spike in arousal to reset these chemical levels, the memory trace of a dream vanishes almost instantly. This explains why a vivid dream can slip away seconds after waking if you are distracted immediately; the encoding process is fragile and requires that moment of conscious attention.
Personality and lifestyle also play a role
While brain structure and sleep cycles are primary drivers, psychological factors also influence dream recall. The gap between high and low recallers is not just biological; it is also behavioral.
Creativity and interest in dreams
Recent work suggests that people who value their dreams and pay attention to them are more likely to remember them. High recallers often score higher on personality traits like openness to experience and creativity.
A related study notes that people prone to mind-wandering or daydreaming during the day tend to recall more night dreams. This suggests a link between the brain’s default mode network—active during daydreaming—and the mechanisms of dreaming. Some startups are even exploring if two people can exchange a word while dreaming, hinting at how permeable and active the dreaming mind can be.
What you can do about it
If you rarely remember your dreams and want to change that, you can train your brain to improve recall.
- Keep a dream journal: Place a notebook and pen right next to your bed. The intent to remember creates a “set” in your mind.
- Move slowly: When you wake up, stay still for a few minutes. Do not jump out of bed or check your phone immediately. Let your mind drift back to the last image you saw.
- Focus on fragments: Even if you only recall a color or a feeling, write it down. This trains the brain to value these signals.
- Prioritize sleep: Longer sleep duration increases the time spent in REM sleep, the stage where the most vivid dreaming occurs.
Sources & related information
Lyon Neuroscience Research Center – Why does the brain remember dreams? – 2014
A study led by Perrine Ruby showing that the temporo-parietal junction is more active in high dream recallers, promoting intrasleep wakefulness and memory encoding.
Frontiers in Human Neuroscience – Increased Awakenings Explain Dream Recall – 2019
Research confirming that high frequency recallers spend more time awake after sleep onset and experience more awakenings, supporting the arousal-retrieval model.
Neuroscience News – Why Some People Remember Dreams and Others Don’t – 2024
A summary of recent findings linking dream recall to personality traits like mind-wandering and positive attitudes toward dreaming, alongside sleep patterns.
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