Humans typically lack awareness that they are dreaming while dreaming.Maybe you remembered that vivid dream about face-planting as you ran to catch the bus because you woke up just before you hit the pavement. However, at times a remarkable exception occurs and reflective consciousness can be regained while dreaming, referred to as lucid dreaming. While most individuals experience lucid dreams rarely there is substantial variance in lucid dream frequency. The neurobiological basis of lucid dreaming is unknown, but evidence points to involvement of anterior prefrontal cortex (aPFC) and parietal cortex. This study evaluated the neuroanatomical/neurofunctional correlates of frequent lucid dreams and specifically whether functional connectivity of aPFC is associated with frequent lucid dreams. We analyzed structural and functional magnetic resonance imaging from an exceptional sample of fourteen individuals who reported ≥3 lucid dreams/week and a control group matched on age, gender and dream recall that reported ≤1 lucid dream/year. Compared to controls, the frequent lucid dream group showed significantly increased resting-state functional connectivity between left aPFC and bilateral angular gyrus, bilateral middle temporal gyrus and right inferior frontal gyrus, and higher node degree and strength in left aPFC. In contrast, no significant differences in brain structure were observed. Our results suggest that frequent lucid dreaming is associated with increased functional connectivity between aPFC and temporoparietal association areas, regions normally deactivated during sleep.įor reasons not currently understood, humans are typically unaware that they are dreaming while dreaming. At times, however, a remarkable exception occurs and we can become aware of the fact that we are dreaming, a state referred to as lucid dreaming 1. During lucid dreams, one becomes aware that one is dreaming while remaining physiologically asleep and immersed within a dream environment that often appears strikingly realistic. In addition to the metacognitive awareness of one’s state of consciousness, during lucid dreams it is also common to regain episodic memory for waking life as well as the ability to volitionally control actions within the dream (e.g. Despite initial skepticism from some scientists and philosophers, lucid dreaming has been demonstrated to be objectively verifiable through volitional eye movement signals which can be recorded in the electrooculogram during polysomnography-verified REM sleep 4 (for replications and extensions see, e.g., refs.
5– 7 for recent implementations see, e.g., refs. For most individuals lucid dreams spontaneously occur infrequently, however there is substantial variation in lucid dream frequency, ranging, by current estimates, from never (approximately 40–50%) to monthly (approximately 20%) to a small percentage of people that experience lucid dreams several times per week or in some cases every night 11, 12.
This variation invites the question of whether the frequency of lucid dreams is related to individual differences in anatomical or functional properties of the brain. The prefrontal cortex (particularly the lateral and rostrolateral regions), parietal cortex and lateral middle temporal cortex show low regional cerebral blow flow (rCBF) throughout sleep, including during REM sleep 13– 15, the stage of sleep most strongly associated with dreaming. Hypoactivity of these regions has been postulated to underlie the diminished self-awareness and volitional control during dreaming 15, 16.
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