heiDOK (Heidelberg University)
January 1, 2010
Valdas Noreika, Jennifer Windt, Bigna Lenggenhager et al.
54 citations
Brain imaging studies of lucid dreaming have revealed correlations with neural activity, but causal methods are needed to understand the role of the dorsolateral prefrontal cortex in metacognitive insight during dreams. The authors propose using transcranial magnetic stimulation, transcranial direct current stimulation, and galvanic vestibular stimulation to directly interfere with neural functioning during sleep. They argue that aspects of dream lucidity can be investigated in ordinary, nonlucid dreams, enabling more comprehensive and efficient experiments. This approach would deepen understanding of self-consciousness in dreams and integrate dream research into broader neurophilosophical theories of consciousness and the self.
Neuroscience of consciousness
January 1, 2020
William Wong, Valdas Noreika, Levente Móró et al.
35 citations
In a test of whether brain activity alone can reveal when someone is dreaming, researchers used an unsupervised machine learning classifier to distinguish dreamful from dreamless sleep based on EEG spectral power and electrode location. Nine participants contributed 54 one-minute polysomnograms from non-rapid eye movement sleep—27 with dreams and 27 without. A blinded Analysis Team attempted to classify each recording over five iterations with gradually reduced blindness. At no stage did the classifier perform significantly better than chance, indicating that EEG spectral power features could not reliably detect signatures of phenomenal consciousness in this dataset.
Frontiers in Psychology
July 8, 2020
Toby J. Woods, Jennifer Windt, Olivia Carter
25 citations
Expert texts on Shamatha, Transcendental, and Stillness Meditation describe silence/quietness as a key feature of contentless experiences—states where thoughts, perceptions, and mental images are absent. Using evidence synthesis, 135 expert texts were systematically selected and analyzed. Silence/quietness is closely linked to stillness, absence of concepts, mental activity/noise, thoughts, and disturbance. It may also reflect absence of non-auditory perceptions, mental images, and negative feelings, fitting a conception of complete calm. The texts do not clearly distinguish silence/quietness from other features like stillness. Connections between silence/quietness and other features vary in closeness, revealing fine distinctions and ambiguities that raise new research questions.
Phenomenology and the Cognitive Sciences
May 24, 2022
Toby J. Woods, Jennifer Windt, Olivia Carter
17 citations
Meditation experiences often described as contentless—such as those in Shamatha, Transcendental, and Stillness Meditation—are not truly devoid of mental content. A review of 135 expert texts from these three traditions identified 65 features reported or implied across the practices, with most shared among all three. However, Shamatha involves substantially greater attentional stability and vividness. Numerous forms of content, including wakefulness, naturalness, calm, bliss/joy, and freedom, are present in these experiences. The findings challenge the classical view that such states are an identical pure consciousness, leaving it an open question whether they should be classed as such.
Trends in cognitive sciences
March 12, 2025
Thomas Andrillon, Antoine Lutz, Jennifer Windt et al.
14 citations
Moments during wakefulness that seem empty of any reportable thought, called mind blanking (MB), are not simply gaps in experience but distinct mental states with their own characteristics. This review maps MB by examining how people report it, its brain activity, and its links to related phenomena such as meditation and sleep. The authors propose that ongoing experience varies in richness, and contentless events represent a diverse category of mental states. They argue that recognizing MB as a reportable mental category is essential for a full understanding of how the mind works during wakefulness.
Neuroscience and biobehavioral reviews
August 1, 2024
Teresa Campillo-Ferrer, Adriana Alcaraz-Sánchez, Ema Demšar et al.
14 citations
Out-of-body experiences (OBEs), where a person feels located outside their physical body, often occur spontaneously near or during sleep. This review examines sleep-related OBEs and proposes that maintaining consciousness during the transition from wakefulness to REM sleep (sleep-onset REM periods) may enable them. A new conceptual model is introduced to distinguish sleep-related OBEs from similar states like lucid dreaming and sleep paralysis, and to suggest possible brain activity patterns (polysomnographic features) underlying them. The predictive coding framework is applied to connect sleep-related OBEs with those occurring during wakefulness.
Phenomenology and the Cognitive Sciences
June 2, 2022
Toby J. Woods, Jennifer Windt, Olivia Carter
13 citations
Contentless experience, or pure consciousness, is a state free of mental content like thoughts, perceptions, and imagery. Three meditation practices—Shamatha, Transcendental, and Stillness Meditation—are said to access this state, but the paths differ. A review of 135 expert texts reveals that Shamatha and Transcendental Meditation superficially require focusing on an object, while Stillness Meditation does not. However, a detailed analysis shows Shamatha is posturally closer to Stillness Meditation but differs in requiring greater attentional stability, vividness, focusing, less tolerance of mind-wandering, more monitoring, and deliberate control. Achieving contentless experience through Shamatha is slower, more difficult, and less frequent. These findings inform meditation taxonomies, consciousness research, neuroscience, clinical practice, and practitioners.
October 17, 2024
Thomas Andrillon, Antoine Lutz, Jennifer Windt et al.
4 citations
preprint
Mind blanking (MB) refers to moments during wakefulness when people report no specific thoughts. This review maps MB by examining its reportable expressions, brain signatures, and links to meditative practices and sleep (white dreams). The authors propose a mechanistic account linking MB to changes at physiological, neural, and cognitive levels. They argue that ongoing experience varies in richness and that seemingly contentless events are distinct mental states with their own diversity, challenging the view of the mind as primarily content-oriented.
Philosophy and the Mind Sciences
January 5, 2026
Jennifer Windt, Manuela Kirberg, Tomas Andrillon
This special issue brings together theoretical and empirical work on dreaming and waking mind wandering, two areas with growing attention in cognitive neuroscience and psychology but limited philosophical exploration. Despite being studied separately, phenomenological and neurophysiological overlaps between waking mind wandering and sleep-related experiences indicate they are closely linked. These connections prompt questions about the nature and functions of spontaneous mental phenomena, their relationship to wakefulness and sleep, and implications for theories of attention, action, and consciousness.
Consciousness and cognition
January 1, 2026
Manuela Kirberg, Jennifer Windt
Dreaming and mind wandering share features of spontaneous thought, but their precise relationship remains unclear. Bizarreness—unusual features of experience—has traditionally been seen as unique to dreams, though some propose it exists on a continuum where dreaming is an intensified form of mind wandering. Analyzing 379 spontaneous reports from the same participants in a naturalistic setting, the findings show that both dreaming and waking mind wandering have unique bizarreness profiles with similarities and differences. The comparison between the two changes depending on the type, subtype, and content of bizarreness measured. Thus, dreams cannot simply be described as intensified mind wandering; a more nuanced approach with specific measures is needed.
Topoi
December 3, 2025
Gaia Mizzon, Jennifer Windt
The concept of narrative is widely used in philosophical discussions of dreams, but little attention has been paid to how assumptions about the resemblance between fictional narratives and retrospective dream reports have shaped the debate. The authors argue that there is a pervasive tendency to metonymically assimilate fictional narratives first with dream reports and then with dreams themselves, leading to the use of features of literary fiction as an explanatory framework for understanding dreams and their formation. Focusing on the categories of authorship and composition, they show that divergent philosophical accounts share the unacknowledged assumption that dreams have a narrative structure and that dreaming is a process of narrative construction. The paper lays groundwork for exploring narrative thinking in spontaneous thought during both wakefulness and sleep.
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.