REM sleep respiratory behaviours match mental content in narcoleptic lucid dreamers

Abstract

Breathing is irregular during rapid eye-movement (REM) sleep, whereas it is stable during non-REM sleep. Why this is so remains a mystery. We propose that irregular breathing has a cortical origin and reflects the mental content of dreams, which often accompany REM sleep. We tested 21 patients with narcolepsy who had the exceptional ability to lucid dream in REM sleep, a condition in which one is conscious of dreaming during the dream and can signal lucidity with an ocular code. Sleep and respiration were monitored during multiple naps. Participants were instructed to modify their dream scenario so that it involved vocalizations or an apnoea, -two behaviours that require a cortical control of ventilation when executed during wakefulness. Most participants (86%) were able to signal lucidity in at least one nap. In 50% of the lucid naps, we found a clear congruence between the dream report (e.g., diving under water) and the observed respiratory behaviour (e.g., central apnoea) and, in several cases, a preparatory breath before the respiratory behaviour. This suggests that the cortico-subcortical networks involved in voluntary respiratory movements are preserved during REM sleep and that breathing irregularities during this stage have a cortical/subcortical origin that reflects dream content.

The cognitive neuroscience of lucid dreaming

“…Furthermore, lucid dreamers can not only signal to indicate that they are aware that they are dreaming, but they can also make the eye movement signals to time-stamp the start and end of experimental tasks performed during lucid dreams (LaBerge, 1990). By providing objective temporal markers, this technique has opened up a new method for studying the psychophysiology of REM sleep, allowing, for example, investigations into the neural correlates of dreamed behaviors (e.g., Dresler et al, 2011;Erlacher, Schredl and LaBerge, 2003;LaBerge, 1990;Oudiette et al, 2018). Lucid dreaming thus provides a way to establish precise psychophysiological correlations between the contents of consciousness during sleep and physiological measures, as well as enables experimental control over the content of dreams, and therefore provides a potentially highly useful experimental methodology.…”

Dream engineering: Simulating worlds through sensory stimulation

“…Since then, lucid dreaming and other dream phenomena such as somnambulism and REM behavior disorder (RDB) have revealed further correspondences between the sleeping and the dreaming body. For instance, lucid dreamers can induce muscular twitches in the actual forearm through dream movements ( LaBerge et al, 1981 ) and can actively influence respiration, abdominal and thoracic muscle movements ( Oudiette et al, 2018 ). The authors of the latter study suggest that even in nonlucid dreams the content of dream experience may physically manifest in the sleeping body, which may in part explain the erratic respiration, changes in heart rate, and muscular activity exhibited particularly during REM sleep.…”

Smooth tracking of visual targets distinguishes lucid REM sleep dreaming and waking perception from imagination

“…9 , 13 ; for recent implementations see, e.g., refs. 10 , 15 ). The instructions provided to participants were as follows: “When making an eye movement signal, we would like you to look all the way to the left then all the way to the right two times consecutively, as if you are looking at each of your ears.…”