Consciousness and cognition
April 1, 2020
Jona Förster, Mika Koivisto, Antti Revonsuo
176 citations
The earliest and most reliable brain signal linked to visual phenomenal consciousness is the visual awareness negativity (VAN), a negative voltage deflection occurring around 200-300 milliseconds after a stimulus appears over posterior scalp regions. A later positive component, the late positivity (LP), which appears over frontal areas around 300-500 milliseconds, likely reflects later cognitive processes such as reflective or access consciousness rather than phenomenal awareness itself. This conclusion is supported by a review of event-related potential and magnetoencephalography studies published since 2010 that directly compared brain responses to consciously perceived versus unseen stimuli. The evidence strengthens VAN's role as the primary neural correlate of phenomenal consciousness and further undermines LP as a marker of phenomenal awareness.
Neuropsychologia
November 1, 2009
Mika Koivisto, Pasi Kainulainen, Antti Revonsuo
107 citations
Visual attention and awareness are intricately linked, but different types of attention play distinct roles. Experiments tracking brain responses show that spatial attention is necessary for the earliest brain correlate of phenomenal consciousness—the raw experience of seeing. This early marker emerged regardless of whether objects were selected by nonspatial attention, though later parts of it were modified by such selection. In contrast, the brain correlate of reflective consciousness, which allows the contents of phenomenal experience to be used for thought and memory, depended on both spatial attention and nonspatial selection. These findings indicate that the relationship between attention and awareness requires distinguishing between different forms of attention and different levels of consciousness.
Brain and cognition
December 1, 2011
Valdas Noreika, Leila Jylhänkangas, Levente Móró et al.
62 citations
Subjective experiences can occur even when a person appears unresponsive under sedation. In a nonsurgical setting, participants given dexmedetomidine, propofol, sevoflurane, or xenon recalled having subjective experiences in almost 60% of sessions after regaining responsiveness. During dexmedetomidine sessions, such experiences were linked to shallower sedation depth as measured by an EEG-based monitor. The findings indicate that unresponsiveness does not guarantee absence of consciousness, and studies on phenomenal consciousness under anesthetics should assess subjective states through post-recovery interviews.
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.
Epilepsy & behavior : E&B
August 1, 2008
Mirja Johanson, Katja Valli, Antti Revonsuo et al.
19 citations
People with partial epilepsy experience widespread distortions in their subjective experience during seizures, yet the pattern of those distortions remains consistent from one seizure to the next. A standardized questionnaire called the Phenomenology of Consciousness Inventory (PCI) proved suitable for capturing these changes in consciousness. The findings suggest that the PCI could help researchers and clinicians better understand the nature of phenomenal consciousness in epilepsy.
Nature communications
August 13, 2025
William Wong, Rubén Herzog, Kátia Cristine Andrade et al.
10 citations
A new open database, the DREAM database, combines standardized sleep magneto/electroencephalography (M/EEG) recordings with dream reports from 505 participants across 20 datasets, totaling 2,643 awakenings. Each awakening includes at least 20 seconds of high-resolution sleep EEG (≥100 Hz, ≥2 electrodes) and a classification of the sleeper's reported experience. Analyses showed that reports of conscious experiences during sleep can be predicted from objective EEG features in both REM and NREM sleep. The database aims to overcome limitations of small sample sizes and methodological variability in dream research, enabling larger-scale investigations of the neurocognitive basis of dreaming.
NeuroImage
April 15, 2025
Dmitri Filimonov, Saana Lenkkeri, Mika Koivisto et al.
6 citations
The neural correlates of consciousness (NCC) for auditory awareness include auditory awareness negativity (AAN) and late positivity (LP), but it is unclear which is the true NCC. By inducing simple auditory hallucinations through a Pavlovian conditioning paradigm, where participants rated near-threshold tones and stimulus-absent trials, AAN appeared as an early event-related potential difference between aware and unaware stimuli, suggesting it is a genuine NCC for auditory consciousness. Late positivity was absent in these hallucinations, indicating it may not be essential for auditory awareness.
Cognitive neuroscience
September 1, 2010
Antti Revonsuo, Mika Koivisto
3 citations
Event-related brain potential (ERP) evidence supports two key ideas in Lamme's theory of consciousness. The earliest brain signal linked to visual consciousness appears over the back of the head about 100-200 milliseconds after a stimulus is presented, consistent with recurrent processing in visual cortex. This early signal is largely separate from later brain responses that reflect selective attention and working memory. The findings suggest that phenomenal consciousness of a visual stimulus arises before access consciousness, and that attention and awareness rely on different neural processes.
NeuroImage
January 29, 2026
Dmitri Filimonov, Mika Koivisto, Antti Revonsuo
The most reliable brain-activity markers of visual consciousness, measured with EEG, are an early component called visual awareness negativity (VAN) and a later component called late positivity (LP). Three prior reviews concluded that VAN is specifically tied to awareness, while LP also reflects other mental processes. This review of 53 new studies published since 2020 confirms that VAN remains the most robust neural correlate of visual consciousness, whereas LP is not uniquely linked to consciousness. However, questions remain about how VAN relates to attention and other physiological factors.
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 M. 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.