Shared EEG correlates between non-REM parasomnia experiences and dreams.

Incomplete awakenings from non-rapid eye movement sleep can produce sleepwalking and related behaviors, which sometimes involve conscious experience and later recall. Using high-density EEG and immediate interviews, the authors found that conscious experiences during these episodes (56% of cases) were preceded by high-amplitude slow waves in anterior brain regions and activation in posterior regions, patterns similar to those seen in dreaming. Recall of the experience (56% of cases) was linked to higher EEG activation in the right medial temporal area before movement. No conscious experience occurred in 19% of episodes, and no recall in 25%. These findings suggest that the brain activity underlying parasomnia experiences resembles that of dreams, pointing to core processes for sleep consciousness.

Study at a glance

Abstract

Sleepwalking and related parasomnias result from incomplete awakenings out of non-rapid eye movement sleep. Behavioral episodes can occur without consciousness or recollection, or in relation to dream-like experiences. To understand what accounts for these differences in consciousness and recall, here we recorded parasomnia episodes with high-density electroencephalography (EEG) and interviewed participants immediately afterward about their experiences. Compared to reports of no experience (19%), reports of conscious experience (56%) were preceded by high-amplitude EEG slow waves in anterior cortical regions and activation of posterior cortical regions, similar to previously described EEG correlates of dreaming. Recall of the content of the experience (56%), compared to no recall (25%), was associated with higher EEG activation in the right medial temporal region before movement onset. Our work suggests that the EEG correlates of parasomnia experiences are similar to those reported for dreams and may thus reflect core physiological processes involved in sleep consciousness.