Lucid dreaming is the ability of someone to be aware that they are dreaming and even exert voluntary control over their experience in dreams. Metacognition is defined as “cognition about cognition”. In general terms, it is being extremely introspective. In metacognitive monitoring, someone is in tune to their mental state and potentially able to modify this state through thought and training. During sleep, metacognitive awareness is essentially unavailable, except in the case of lucid dreaming. The subset of people who report lucid dreaming are able to communicate through volitional eye movements while their bodies remained locked in the atonia of REM sleep, suggesting that they can access cognitive processing that is off limit the larger population during sleep.



Metacognition is linked to the brain regions within the prefrontal cortex, including the dorsolateral prefrontal cortex and the frontal polar cortex. For example, activation in these regions is associated with self-reflection, working memory organization, action planning, multitasking and theory of mind. During REM sleep, activity is reduced in these regions but not in lucid dreamers. Therefore, a relationship between this brain region, metacognition and lucid dreaming seems intuitive, but until now it was not directly tested. Recently, researchers evaluated groups of subjects within a spectrum of lucid dreaming ability which they reported on a questionnaire. The researchers had these subjects perform a thought monitoring task while awake in a magnetic resonance imaging (MRI) machine and evaluated reaction time. During the task, researchers measured gray matter volume (essentially collections of neuron cell bodies) in the prefrontal cortex and blood flow to the region (a measure of neuronal activity).



The results, published in a recent issue of the Journal of Neuroscience, found that gray matter volume was higher in the prefrontal cortex of people who reported being lucid dreamers. They also found that blood flow was increased in this region when subjects were actively thought monitoring compared to simply resting with visual stimuli, and that the difference in blood flow between resting and thought monitoring was even greater in the lucid dreamers than control participants. Therefore, the authors conclude, this provides evidence that lucid dreaming and metacognition are anatomically connected through neuronal processes that are seated in the frontal pole.