Sleep
July 22, 2026
Enyu Lin, Simone Grassini, Henry Railo et al.
Sleep plays an important role in affective processing and affect regulation during wakefulness. Dreaming-the subjective experiences occurring during sleep-has been suggested to reflect, or even contribute to, waking affect regulation. However, the role of dream affect in waking affect regulation has rarely been studied directly. Here, we investigated how dream affect relates to waking affect...
Journal of Sleep Research
April 2, 2026
Ville Loukola, Jarno Tuominen, Eveliina Malinen et al.
Previous studies have examined how the COVID-19 pandemic affected dream recall, dream content, and nightmares. However, relatively little attention has been devoted to the individual and situational factors associated with pandemic-induced changes in dreams. The threat simulation theory of dreaming predicts that threatening situations in our waking life (situational factors) influence...
Neuroimage
January 29, 2026
Dmitri Filimonov, Mika Koivisto, Antti Revonsuo
The past twenty years of research have revealed two event-related potential (ERP) components to be the most reliably occurring neural correlates of consciousness (NCC) in vision: an early visual awareness negativity (VAN) in the N2 and late positivity (LP) in the P3 time window. Three previous extensive reviews concluded that VAN is a proper visual NCC, which is solely modulated by awareness....
September 11, 2025
Ville Loukola, Jarno Tuominen, Eveliina Malinen et al.
preprint
Previous studies have examined how the COVID-19 pandemic affected dream recall, dream content, and nightmares. However, relatively little attention has been devoted to the individual and situational factors associated with pandemic-induced changes in dreams. The threat simulation theory of dreaming predicts that threatening situations in our waking life (situational factors) influence...
Nature Communications
August 13, 2025
William Wong, Rubén Herzog, Kátia Cristine Andrade et al.
10 citations
Magneto/electroencephalography (M/EEG) studies of dreaming are an essential paradigm in the investigation of neurocognitive processes of human consciousness during sleep, but they are limited by the number of observations that can be collected per study. Dream research also involves substantial methodological and conceptual variability, which poses problems for the integration of results. To...
Neuroimage
April 15, 2025
Dmitri Filimonov, Saana Lenkkeri, Mika Koivisto et al.
6 citations
Neural correlates of consciousness (NCC) have been proposed for perceptual awareness in various sensory modalities. To date, perceptual awareness negativity (PAN) and late positivity (LP) are considered the main NCC candidates, and the question remains which one is the NCC proper. Investigating states where the content of consciousness is independent of the physical stimulus, may provide...
Consciousness and Cognition
June 19, 2024
Dmitri Filimonov, Sampo Tanskanen, Antti Revonsuo et al.
The level-of-processing (LoP) hypothesis postulates that transition from unaware to aware visual stimuli is either graded or dichotomous depending on the depth of stimulus processing. Humans can be progressively aware of the low-level features, such as colors or shapes, while the high-level features, such as semantic category, enter consciousness in an all-or none fashion. Unlike in vision,...
Consciousness and Cognition
February 8, 2024
Ville Loukola, Jarno Tuominen, Santeri Kirsilä et al.
4 citations
Previous research indicates that the COVID-19 pandemic has affected dreaming negatively. We compared 1132 dreams collected with prospective two-week dream diary during the pandemic to 166 dreams collected before the pandemic. We hypothesized that the pandemic would increase the number of threatening events, threats related to diseases, and the severity of threats. We also hypothesized that...
Neuroscience of Consciousness
2024
Dmitri Filimonov, Andreas Krabbe, Antti Revonsuo et al.
In search for the neural correlates of consciousness (NCCs), it is important to isolate the true NCCs from their prerequisites, consequences, and co-occurring processes. To date, little is known about how attention affects the event-related potential (ERP) correlates of auditory awareness and there is contradictory evidence on whether one of them, the late positivity (LP), is affected by...
British Journal of Anaesthesia
August 1, 2023
Katja Valli, Linda Radek, Roosa E Kallionpää et al.
Anaesthetic-induced unresponsiveness and non-rapid eye movement (NREM) sleep share common neural pathways and neurophysiological features. We hypothesised that these states bear resemblance also at the experiential level. We compared, in a within-subject design, the prevalence and content of experiences in reports obtained after anaesthetic-induced unresponsiveness and NREM sleep. Healthy males...
The Journal of neuroscience : the official journal of the Society for Neuroscience
June 28, 2023
Oskari Kantonen, Lauri Laaksonen, Michael Alkire et al.
Establishing the neural mechanisms responsible for the altered global states of consciousness during anesthesia and dissociating these from other drug-related effects remains a challenge in consciousness research. We investigated differences in brain activity between connectedness and disconnectedness by administering various anesthetics at concentrations designed to render 50% of the subjects...
May 16, 2023
William Wong, Kátia C. Andrade, Thomas Andrillon et al.
21 citations
preprint
Magneto/electroencephalography (M/EEG) studies of dreaming are an essential paradigm in the investigation of neurocognitive processes of human consciousness during sleep, but they are limited by the number of observations that can be collected per study. Dream research also involves substantial methodological and conceptual variability, which poses problems for the integration of results. To...
Consciousness and Cognition
November 1, 2021
Linda Radek, Lauri Koskinen, Nils Sandman et al.
To understand how anesthetics with different molecular mechanisms affect consciousness, we explored subjective experiences recalled after responsive and unresponsive sedation induced with equisedative doses of dexmedetomidine, propofol, sevoflurane, and S-ketamine in healthy male participants (N = 140). The anesthetics were administered in experimental setting using target-controlled infusion...
April 9, 2021
Pilleriin Sikka, Katja Valli, Antti Revonsuo et al.
2 citations
preprint
Affective experiences occur across the wake-sleep cycle—from active wakefulness to resting wakefulness (i.e., mind-wandering or daydreaming) to sleep (i.e., dreaming). Yet, we know little about the dynamics of affective experiences across these states. Here, we investigated the within-person fluctuations in the prevalence and valence of affect experienced during mind-wandering and night-time...
The Journal of neuroscience : the official journal of the Society for Neuroscience
February 24, 2021
Annalotta Scheinin, Oskari Kantonen, Michael Alkire et al.
92 citations
What happens in the brain when conscious awareness of the surrounding world fades? We manipulated consciousness in two experiments in a group of healthy males and measured brain activity with positron emission tomography. Measurements were made during wakefulness, escalating and constant levels of two anesthetic agents (experiment 1, n = 39), and during sleep-deprived wakefulness and non-rapid...
Consciousness and Cognition
April 1, 2020
Jona Förster, Mika Koivisto, Antti Revonsuo
176 citations
The first decade of event-related potential (ERP) research had established that the most consistent correlates of the onset of visual consciousness are the early visual awareness negativity (VAN), a posterior negative component in the N2 time range, and the late positivity (LP), an anterior positive component in the P3 time range. Two earlier extensive reviews ten years ago had concluded that...
Neuroscience of Consciousness
2020
William Wong, Valdas Noreika, Levente Móró et al.
35 citations
The Dream Catcher test defines the criteria for a genuine discovery of the neural constituents of phenomenal consciousness. Passing the test implies that some patterns of purely brain-based data directly correspond to the subjective features of phenomenal experience, which would help to bridge the explanatory gap between consciousness and brain. Here, we conducted the Dream Catcher test for the...
The Journal of neuroscience : the official journal of the Society for Neuroscience
June 12, 2019
Pilleriin Sikka, Antti Revonsuo, Valdas Noreika et al.
Affective experiences are central not only to our waking life but also to rapid eye movement (REM) sleep dreams. Despite our increasing understanding of the neural correlates of dreaming, we know little about the neural correlates of dream affect. Frontal alpha asymmetry (FAA) is considered a marker of affective states and traits as well as affect regulation in the waking state. Here, we...
bioRxiv Preprint Server
May 27, 2019
William Wong, Valdas Noreika, Levente Móró et al.
preprint
The Dream Catcher test defines the criteria for a genuine discovery of the neural constituents of phenomenal consciousness. Passing the test implies that some patterns of purely brain-based data directly correspond to the subjective features of phenomenal experience, which would help to bridge the explanatory gap between consciousness and brain. Here, we conducted the Dream Catcher test for the...
bioRxiv Preprint Server
April 12, 2019
Valdas Noreika, Jennifer Windt, Markus Kern et al.
preprint
Recently, cortical correlates of specific dream contents have been reported, such as the activation of the sensorimotor cortex during dreamed hand clenching. Yet, the causal mechanisms underlying specific dream content remain largely elusive. Here, we investigated how alterations in the excitability of sensorimotor areas through transcranial direct current stimulation (tDCS) might alter dream...
British Journal of Anaesthesia
July 1, 2018
Linda Radek, Roosa E Kallionpää, M Karvonen et al.
Experiences during anaesthetic-induced unresponsiveness have previously been investigated by interviews after recovery. To explore whether experiences occur during drug administration, we interviewed participants during target-controlled infusion (TCI) of dexmedetomidine or propofol and after recovery. Healthy participants received dexmedetomidine (n=23) or propofol (n=24) in stepwise...
Journal of Sleep Research
April 1, 2018
Pilleriin Sikka, Antti Revonsuo, Nils Sandman et al.
The aim of this study was to compare the emotional content of dream reports collected at home upon morning awakenings with those collected in the laboratory upon early and late rapid eye movement (REM) sleep awakenings. Eighteen adults (11 women, seven men; mean age = 25.89 ± 4.85) wrote down their home dreams every morning immediately upon awakening during a 7-day period. Participants also...
Journal of Cognitive Neuroscience
September 1, 2017
Mika Koivisto, Simone Grassini, Niina Salminen-Vaparanta et al.
Detecting the presence of an object is a different process than identifying the object as a particular object. This difference has not been taken into account in designing experiments on the neural correlates of consciousness. We compared the electrophysiological correlates of conscious detection and identification directly by measuring ERPs while participants performed either a task only...
The American Journal of Psychology
August 21, 2017
Pilleriin Sikka, Diana Feilhauer, Katja Valli et al.
63 citations
Abstract This study demonstrates that different methods for measuring emotional experiences in dreams—self-ratings of dreams using emotion rating scales versus external ratings in the form of content analysis of narrative dream reports—can lead to strikingly different results and contradicting conclusions about the emotional content of home dreams. During 3 consecutive weeks, every morning upon...
Neuroscience of Consciousness
2015
Henry Railo, Antti Revonsuo, Mika Koivisto
Abstract A fundamental unsettled dispute concerns how fast the brain generates subjective visual experiences. Both early visual cortical activation and later activity in fronto-parietal global neuronal workspace correlate with conscious vision, but resolving which of the correlates causally triggers conscious vision has proved a methodological impasse. We show that participants can report...