Philosophy Compass
April 1, 2020
Jennifer Windt
Conscious experience during sleep is more varied than just dreaming, especially in non-rapid eye movement sleep, where dreamful, dreamless, and unconscious states alternate. The author argues that sleep science and philosophy have focused too narrowly on dreaming, neglecting other sleep-related experiences and the fundamental question of how conscious and unconscious sleep states relate to wakefulness and sleep stages. Surveying recent findings, the author contends that the traditional view of sleep and its connection to consciousness is flawed. A better understanding requires refining frameworks for sleep-related experiences and sleep staging together, integrating phenomenological, neuroscientific, and behavioral evidence to transform our understanding of sleep, wakefulness, and consciousness.
bioRxiv Preprint Server
May 27, 2019
William Wong, Valdas Noreika, Levente Móró et al.
preprint
A test called the Dream Catcher test was conducted for the first time in a simplified form to see if brain activity alone can reveal whether someone is dreaming. Data Team collected brain measurements (polysomnograms) during NREM sleep from 9 participants, producing 54 one-minute recordings—27 from dreamful sleep and 27 from dreamless sleep. A blinded Analysis Team tried to classify each recording as dreamful or dreamless using an unsupervised machine learning classifier based on EEG spectral power and electrode location. Over five iterations with gradually reduced blindness, the team never performed significantly better than chance. The results suggest that EEG spectral power does not carry signatures of phenomenal consciousness, and the study also failed to replicate key findings from earlier reports on dreaming consciousness.
bioRxiv Preprint Server
April 12, 2019
Valdas Noreika, Jennifer Windt, Markus Kern et al.
preprint
Applying transcranial direct current stimulation (tDCS) over the sensorimotor cortex during REM sleep reduces reported dream movement, particularly repetitive actions, without affecting other bodily sensations like touch or balance. This effect coincides with reduced interhemispheric coherence in parietal areas and altered muscle activity correlation between arms. The findings indicate that tDCS causally interferes with the neural mechanisms underlying dream movement, confirming the spatial specificity of the stimulation site and suggesting a reorganization of the motor network during dreaming.
Oxford Handbooks Online
April 5, 2018
Jennifer Windt, Ursula Voss
Lucid dreaming, often seen as a counterexample to the spontaneous nature of dreams because it involves deliberate control, is actually a valuable model for studying spontaneous thought. The chapter argues that lucid insight and control can arise from spontaneous cognitive processes, not just conscious reasoning, and that investigating dream lucidity can clarify how metacognitive awareness interacts with the spontaneous, imagistic thinking that generates dream content. This raises new questions about the relationship between metacognition and spontaneity.
Trends in Cognitive Sciences
December 1, 2016
Jennifer Windt, Tore Nielsen, Evan Thompson
The assumption that consciousness disappears during deep, dreamless sleep is oversimplified. Empirical and theoretical reasons indicate that a range of different types of sleep experience, some distinct from dreaming, can occur in all sleep stages. A novel taxonomy for describing these dreamless sleep experiences is introduced, along with research methods for their investigation. Future studies should focus on memory consolidation, sleep disorders, and sleep state (mis)perception. This proposal suggests new directions for sleep and dream science, the neuroscience of consciousness, and can inform the diagnosis and treatment of sleep disorders.
Frontiers in Human Neuroscience
January 1, 2014
Jennifer Windt, Dominic L Harkness, Bigna Lenggenhager
In ordinary waking life, people cannot tickle themselves because the brain attenuates sensations produced by one's own actions. However, people woken from REM sleep dreams can tickle themselves, and a new web-based study explored whether this also occurs during lucid dreaming. Participants rated sensations during self-tickling and being tickled while awake, imagining, and lucid dreaming. Preliminary results suggest that during lucid control dreams, the usual difference between self-tickling and being tickled by another disappears; both feel similar to self-tickling while awake. The authors speculate that sensory attenuation for self-produced tickles may extend to tickles from dream characters. The study's main contribution is theoretical, using predictive processing to discuss sensory attenuation, self-other distinction, and agency.
Consciousness and Cognition
March 1, 2013
Ursula Voss, Karin Schermelleh-Engel, Jennifer Windt et al.
A new scale, the Lucidity and Consciousness in Dreams scale (LuCiD), distinguishes lucid from non-lucid dreams using eight factors: INSIGHT, CONTROL, THOUGHT, REALISM, MEMORY, DISSOCIATION, NEGATIVE EMOTION, and POSITIVE EMOTION. While all factors relate to dream consciousness, realism and negative emotion do not differ between lucid and non-lucid dreams, indicating that lucid insight is separate from dream bizarreness or changes in subjective realism. The scale was developed through exploratory factor analysis on data from a first survey and validated with confirmatory factor analysis on a second survey.
Ema Demšar, Jennifer Windt
Dream research is complicated by the variability of methods and measures used to collect dream reports. Insights from first-person methods in consciousness research, such as descriptive experience sampling and micro-phenomenology, could improve the study of dreaming's phenomenological features. These interview-based methods, developed for waking experience, are discussed for their applicability to dream research, and promising research directions are outlined.
Chikayo Hemmi, Angus Leung, Jennifer Windt et al.
preprint
The neural correlates of dreaming remain uncertain, especially regarding which brain regions and frequency bands reliably reflect conscious experience during sleep. This registered report describes a study that will use magnetoencephalography (MEG) during evening naps with a targeted serial-awakening paradigm to test whether previously reported EEG-based correlates of dreaming generalize to MEG. Pilot data from one participant supported hypotheses about low-frequency power across frontal and posterior regions but not high-frequency power; another participant provided insufficient evidence. An independent analysis team will test the pre-specified hypotheses on the remaining 10 participants who meet inclusion criteria.