Consciousness and Cognition
August 1, 2020
Claudia Picard-Deland, Maude Pastor, Elizaveta Solomonova et al.
25 citations
Flying dreams, though common, rarely occur. In a study with 137 participants, a virtual reality flying task followed by a morning nap increased reports of flying dreams during the nap and the following morning, compared to baseline rates and a control group. These dreams also showed greater lucid control and emotional intensity. Prior dream-flying experience and the level of VR sensory immersion influenced induction. The results support a vection-based explanation of dream-flying and could aid in developing dream flight-induction technologies.
Consciousness and Cognition
August 1, 2020
Cloé Blanchette-Carrière, Sarah-Hélène Julien, Claudia Picard-Deland et al.
20 citations
The neurophysiological basis of self-awareness during sleep (lucid dreaming) is still poorly understood. Previous work suggested that transcranial alternating current stimulation (tACS) during sleep could increase dream self-awareness, but methodological flaws in those studies motivated a new investigation. In the current study, both tACS and a sham procedure were associated with signal-verified and self-rated lucid dreams, indicating that situational factors, rather than the stimulation itself, may be critical for inducing self-awareness during sleep.
Front Psychol
January 23, 2020
Elizaveta Solomonova, Simon Dubé, Cloé Blanchette-Carrière et al.
9 citations
Vipassana meditation practitioners show different patterns of how sleep consolidates procedural memories compared to non-meditators. The study compared overnight memory retention in meditators and controls, finding that meditators exhibited distinct consolidation processes, suggesting that long-term meditation practice alters sleep-dependent memory processing.
Frontiers in Neuroscience
March 18, 2021
Louis-Philippe Marquis, Sarah-Hélène Julien, Véronique Daneault et al.
6 citations
Frequent nightmares are linked to altered brain activity in regions beyond the limbic-prefrontal circuit, including frontal, parietal, temporal, occipital, and subcortical areas. A resting-state fMRI study compared 18 frequent nightmare recallers aged 18–35 with matched controls. Nightmare recallers showed greater regional homogeneity in the left anterior cingulate cortex and right inferior parietal lobule. Positive correlation emerged between retrospective nightmare frequency and hippocampal regional homogeneity. Results suggest multiple brain regions contribute to nightmare formation, partially supporting a neurocognitive model involving medial prefrontal and anterior cingulate cortices, hippocampus, and amygdala.
Neurobiology of Learning and Memory
September 1, 2021
Claudia Picard-Deland, Tomy Aumont, Arnaud Samson-Richer et al.
Applying targeted memory reactivation (TMR) during REM sleep improves learning of a whole-body procedural task more than TMR applied during slow-wave sleep, wake, or no reactivation. Dreams that incorporate kinesthetic elements of the task, such as flying or accelerating, are associated with greater performance gains than dreams with visual elements or no task-related content. TMR does not directly alter dream content, but its performance benefits are larger when task-related dream reactivations also occur in REM sleep. These results suggest that dream imagery may reflect memory reactivation processes that support skill consolidation during sleep.
Sleep Medicine
April 1, 2019
T. Nielsen, M. Carr, C. Picard-Deland et al.
People who frequently have nightmares report more childhood adversity—including both traumatic and nontraumatic forms—than healthy controls, with effects visible as early as ages 0–6. Nontraumatic adversity in early childhood is linked to nightmares independently of trauma. Separation adversity at ages 0–6 correlates with lower slow sleep spindle density, an anomaly tied to psychopathology and early nightmare onset. Group differences in adversity are only partly explained by current anxiety or depression and relate more to nightmare distress than to nightmare frequency. The findings suggest that early adversity contributes to nightmares through mechanisms that may overlap with those in posttraumatic stress disorder.
Sleep Medicine
October 1, 2018
Claudia Picard-Deland, Michelle Carr, Tyna Paquette et al.
Frequent nightmare recallers show abnormalities in non-REM (NREM) sleep, specifically in sleep spindles—brain oscillations linked to memory consolidation and psychopathology. Compared to controls, the nightmare group had lower density of slow spindles across most EEG sites, higher density of fast spindles in frontal regions, and elevated fast spindle frequency in central regions. These differences remained after controlling for depression. Correlational analyses revealed that higher psychopathology scores were associated with higher slow spindle densities and slower spindle frequencies only in the nightmare group.
March 1, 2017
T. Nielsen, M. Carr, C. Blanchette-Carrière et al.
Fast sleep spindle density during NREM sleep is positively correlated with dream recall, especially bad dreams and the length of REM dream reports. In 53 healthy adults, fast spindles were most robustly linked to bad dream recall and the number of words in REM dream narratives. The associations varied by sleep cycle: bad dream recall correlated with spindles in cycles 2 and 3, while word count correlated with cycles 1, 4, and 5. Slow spindle density showed an opposite pattern of correlations.
Journal of Sleep Research
August 1, 2015
Gaëlle Dumel, Michelle Carr, Louis-Philippe Marquis et al.
People who habitually recall few dreams performed worse on a visuomotor task (mirror tracing) before sleep but showed greater overnight improvement than those who recall many dreams. The improvement in low recallers was linked to Stage 2 sleep rather than rapid eye movement sleep. The findings suggest that dreaming relates to visuomotor processes and that different levels of visuomotor skill engage distinct sleep-related consolidation mechanisms.
Elizaveta Solomonova, Simon Dubé, Arnaud Samson-Richer et al.
Meditators have longer dreams with friendlier, more compassionate interactions and slightly more references to the body, but their dreams are no more lucid than those of non-meditators. Meditators did not incorporate a procedural learning task or the laboratory into their dreams more often than controls. Among control participants, incorporating the task or laboratory into REM/N2 dreams was linked to improved task performance, while incorporations at sleep onset were tied to slightly worse performance. No relationship between dream content and procedural task performance was found for meditators.
Elizaveta Solomonova, Simon Dubé, Cloé Blanchette-Carrière et al.
Meditation experience alters how sleep supports memory consolidation. In a study of Vipassana meditation practitioners and meditation-naïve controls who napped in a laboratory, both groups improved similarly on a balance task after sleep, but the brain activity underlying that improvement differed. In meditators, task learning was linked to slow occipital sleep spindles and negatively linked to fast spindles, whereas in controls improvement was associated with increased REM sleep. Meditators also had fewer sleep spindles overall, especially in occipital regions. The findings suggest that long-term meditation practice may reorganize sleep-dependent memory processes and compensate for some memory functions of sleep.