Neural correlates of dream lucidity obtained from contrasting lucid versus non-lucid REM sleep: a combined EEG/fMRI case study.

STUDY OBJECTIVES To investigate the neural correlates of lucid dreaming. DESIGN Parallel EEG/fMRI recordings of night sleep. SETTING Sleep laboratory and fMRI facilities. PARTICIPANTS Four experienced lucid dreamers. INTERVENTIONS N/A. MEASUREMENTS AND RESULTS Out of 4 participants, one subject had 2 episodes of verified lucid REM sleep of sufficient length to be analyzed by fMRI. During lucid dreaming the bilateral precuneus, cuneus, parietal lobules, and prefrontal and occipito-temporal cortices activated strongly as compared with non-lucid REM sleep. CONCLUSIONS In line with recent EEG data, lucid dreaming was associated with a reactivation of areas which are normally deactivated during REM sleep. This pattern of activity can explain the recovery of reflective cognitive capabilities that are the hallmark of lucid dreaming.