Sleep
April 11, 2022
Benjamin Baird, Giulio Tononi, Stephen LaBerge
41 citations
Lucid dreaming is not a hybrid state mixing sleep and wakefulness, as previously claimed based on increased 40 Hz brain activity. The apparent rise in frontolateral 40 Hz power during lucid REM sleep is actually an artifact caused by saccadic spike potentials from heightened eye movement density. In a reanalysis of 14 signal-verified lucid dreams from six participants, lucid REM sleep showed higher REM density than baseline REM sleep, but no difference in 40 Hz power after removing the spike potential artifact. Lucid REM also showed small reductions in low-frequency and beta band power and increased signal complexity, all within normal REM sleep variation. Lucid dreams involve higher physiological activation, including subcortical and cortical measures.
Sleep
May 14, 2021
Laura Sophie Imperatori, Jacinthe Cataldi, Monica Betta et al.
30 citations
Functional connectivity metrics, which describe how brain regions interact, can reveal differences across stages of sleep and wakefulness that power-based analyses alone may miss. Analyzing overnight sleep and resting-state wakefulness recordings from 24 healthy adults, the study found that combining power features with two connectivity measures—weighted Phase Lag Index (wPLI) and weighted Symbolic Mutual Information (wSMI)—improved the accuracy of classifying four vigilance stages (wakefulness, NREM-N2, NREM-N3, and REM sleep) compared to using any single feature type. Delta-band connectivity (0.5–4 Hz) was most important across all classifications, suggesting slow waves play a role in consciousness and sensory disconnection.
Sleep
February 10, 2025
Yannis Idir, Régis Lopez, Amélie Barbier et al.
5 citations
Disorders of arousal (DoA) episodes, such as sleepwalking, are not a uniform state but involve varying levels of consciousness and responsiveness. In a retrospective questionnaire, 81% of 61 adult patients reported occasional conversations during episodes. Auditory stimulation during N3 sleep triggered episodes in only 7 of 157 trials, and only one patient indirectly responded to verbal prompts. Analysis of 364 home video-recorded episodes from 19 patients found 37 instances of discussion with a bed partner. Patients' ongoing mental content influenced their responses and perception of the outside world. These findings highlight limitations in current diagnostic criteria for DoA.
Sleep
July 11, 2022
Claudia Picard-Deland, Max-Antoine Allaire, Tore Nielsen
5 citations
Frequent lucid dreamers show better static balance, as measured by lower center of pressure velocity on a force plate, compared to other participants, partially supporting a vestibular contribution to lucid dreaming. In a study of 131 adults who kept dream logs and performed balance tasks, lucid dreaming frequency correlated globally with better balance. Flying sensations in men's dreams and greater dream control in women's dreams were also linked to better balance. However, body height and sleepiness confounded some effects. The findings support the view that the vestibular system underlies basic aspects of bodily self-consciousness, such as self-agency and self-location, during both wakefulness and dreaming.
Sleep
May 26, 2025
Alejandra Mondino, Amir Jadidian, Brandon A Toth et al.
4 citations
The preoptic area of the hypothalamus, long thought to only promote sleep, contains glutamatergic neurons (MLPO_VGLUT2) that actually drive wakefulness and suppress REM sleep. Using fiber photometry in mice, these neurons were highly active during REM sleep, wakefulness, and brief arousals, but minimally active during non-REM sleep. Chemogenetic stimulation of MLPO_VGLUT2 inhibited REM sleep onset, independent of non-REM fragmentation caused by hypothermia, and blocked the REM sleep rebound normally seen after total sleep deprivation. Chemogenetic inhibition increased REM sleep time only during the light phase. Mapping showed these neurons project to brain regions that promote wakefulness and inhibit REM sleep. The authors conclude that MLPO_VGLUT2 powerfully suppress REM sleep, and their overactivation disrupts REM recovery.
Sleep
October 11, 2024
Jennifer M Mundt, Phyllis C Zee, Matthew D Schuiling et al.
3 citations
A remote mindfulness-based intervention adapted for narcolepsy was tested in three program lengths: brief (4 weeks), standard (8 weeks), and extended (12 weeks) among 60 adults with narcolepsy. Attendance, meditation practice, and data completeness benchmarks were met by 71.7%, 61.7%, and 78.3% of participants, respectively. All groups showed clinically meaningful improvements in mindfulness, self-compassion, self-efficacy for managing emotions, positive psychosocial impact, global mental health, and fatigue. Standard and extended groups also improved anxiety and depression; the extended group additionally improved social and cognitive functioning, daytime sleepiness, hypersomnia symptoms, and hypersomnia-related functioning. The extended program appears to offer the most clinical benefit while maintaining engagement.