Psychophysiological correlates of lucid dreaming.

In lucid dreams, where dreamers are aware they are dreaming, brain activity in the beta-1 frequency band (13–19 Hz) is higher in both parietal regions compared to nonlucid REM sleep. The ratio of frontal to parietal beta-1 activity shifts from 1 to 1.16 in nonlucid dreams to 1 to 1.77 in lucid dreams. The greatest increase tends to occur in the left parietal lobe (P3), an area linked to semantic understanding and self-awareness. Seven men and four women experienced in lucid dreaming were recorded over two nights, with lucidity confirmed by dream reports and eye-movement signals in response to light stimuli.

Study at a glance

Abstract

The main goal of the present study was to explore electrophysiologicaldifferences between lucid and nonlucid dreams in REM sleep. Seven men andfour women experienced in lucid dreaming underwent polysomnographicrecordings in the sleep laboratory on two consecutive nights. EEG signalswere subjected to spectral analysis to obtain Þve different frequency bandsbetween 1 and 20 Hz. Lucidity was determined by both subjective dreamreports and eye-movement signals made by the subjects in response to lightstimuli indicating a REM period. The main discrimination factor betweenlucid and nonlucid dreaming was found in the beta-1 frequency band (13Ð19Hz), which in lucid dreaming was increased in both parietal regions. Theratio of frontal to parietal beta-1 activity was 1 to 1.16 in nonlucid and 1to 1.77 in lucid dreaming. A tendency towards the greatest increase wasobserved in the left parietal lobe (P3), an area of the brain considered to berelated to semantic understanding and self-awareness.