Cortex; a journal devoted to the study of the nervous system and behavior
February 1, 2013
Etzel Cardeña, Peter Jönsson, Devin B. Terhune et al.
151 citations
After a hypnotic induction, people who are highly or moderately hypnotizable often report spontaneous changes in consciousness, but few studies have controlled for the demands of specific suggestions or examined the brain activity underlying these experiences. In a neurophenomenological study of 37 individuals with high, medium, and low hypnotizability, participants reported their depth and spontaneous experiences at baseline, after induction, and after rest periods, while EEG measured brain activity. Perceived hypnotic depth increased substantially after induction, especially among highly and moderately hypnotizable individuals, but remained almost unchanged among those low in hypnotizability.
Cortex; a journal devoted to the study of the nervous system and behavior
December 1, 2019
S. Seghezzi, Gianluigi Giannini, L. Zapparoli
95 citations
Self-consciousness includes two distinct experiences: the sense of ownership of one's body and the sense of agency over one's actions. Different neurocognitive models describe their relationship. An additive model proposes that agency requires ownership; an independence hypothesis argues they rely on separate brain systems. An interactive model suggests they are interdependent, with both unique and overlapping neural correlates. A quantitative meta-analysis of neurofunctional studies identified a body-ownership-specific network (left inferior parietal lobule, left extra-striate body area), a sense-of-agency-specific network (left SMA, left posterior insula, right postcentral gyrus, right superior temporal lobe), and a shared network in the...
Cortex; a journal devoted to the study of the nervous system and behavior
April 1, 2014
Quinton Deeley, David A Oakley, Eamonn Walsh et al.
75 citations
Involuntary movements in neuropsychiatric disorders and culturally influenced dissociative states, such as delusions of alien control and spirit possession, involve distinct brain processes. Using fMRI in 15 highly hypnotically susceptible volunteers, suggestions modelled different experiences of loss of self-control: external personal control (like delusions of control), internal personal control (like spirit possession), and impersonal control by a machine (technical delusions). Brain activity and connectivity varied across these conditions.
Cortex; a journal devoted to the study of the nervous system and behavior
September 1, 2022
Clara Alameda, Daniel Sanabria, Luis F. Ciria
69 citations
A systematic review of 25 studies involving 471 participants examined the neural correlates of flow—the subjective experience of automatic, effortless, and intrinsically rewarding task performance. Studies using EEG, fMRI, fNIRS, or tDCS converge on the involvement of anterior brain regions linked to attention, executive function, and reward, such as the dorsolateral prefrontal cortex, medial prefrontal cortex, and inferior frontal gyrus. However, the dynamics of these regions during flow are inconsistent across studies. The evidence is sparse and inconclusive, limiting theoretical debate. Major limitations include a small number of studies, high heterogeneity, and methodological constraints.
Cortex; a journal devoted to the study of the nervous system and behavior
September 1, 2023
Jianghao Liu, Paolo Bartolomeo
68 citations
People with aphantasia, who report absent or nearly absent visual imagery, perform as accurately as typical and unusually vivid imagers on tasks involving object shape, color, written words, faces, and spatial relationships. However, they respond more slowly on both imagery and perceptual tasks, and they report lower confidence in their perceptual judgments. Across all participants, higher vividness of imagery correlates with faster response times. The findings suggest that congenital aphantasia involves slower visual information processing in both imagery and perception, but the precision of that processing is unaffected. This pattern supports the idea that aphantasia may stem from a deficit in phenomenal consciousness or the use of alternative non-visual strategies.
Cortex; a journal devoted to the study of the nervous system and behavior
October 1, 2022
Anna Castelnovo, Julian Amacker, Massimo Maiolo et al.
26 citations
Confusional arousal episodes, a milder form of Disorders of Arousal (DOA), reveal intriguing brain activity patterns. In a study involving a 12-year-old child with sleepwalking, 20 episodes were analyzed using high-density EEG. Findings showed a significant increase in slow wave activity (SWA) across theta, alpha, beta, and gamma frequencies during episodes compared to baseline sleep. Notably, connectivity analysis indicated enhanced communication between brain regions, particularly from the prefrontal cortex and temporal lobe, suggesting a unique brain state associated with night terrors and somnambulism.
Cortex; a journal devoted to the study of the nervous system and behavior
September 1, 2021
Santiago Alcaide, Jacobo Sitt, Tomoyasu Horikawa et al.
13 citations
Waking up from early sleep involves a two-stage brain process. First, subcortical and sensorimotor structures activate before most cortical regions, followed by rapid whole-brain activation, with frontal regions engaging slightly later. A second, slower stage may then occur, where cortical regions activate before subcortical structures and the cerebellum. This pattern suggests subcortical structures play a key role in initiating and maintaining conscious states.
Cortex; a journal devoted to the study of the nervous system and behavior
November 1, 2019
Jean-Paul Noel, Nathan Faivre, Elisa Magosso et al.
6 citations
Artificial neural networks built with feedback connections from multisensory to unisensory cortices, consistent with all-or-none models of conscious access, produced intermediate reaction times when multisensory stimuli were associated with unisensory feedback. In psychophysical testing with 29 subjects completing 10 hours of a multisensory cue-congruency task, reaction times to multisensory cues reported as unisensory fell between those of fully aware and fully unaware cues. These results suggest that graded forms of phenomenal consciousness can arise from neural networks that follow all-or-none principles.
Cortex; a journal devoted to the study of the nervous system and behavior
December 1, 2023
Patrick Mcnamara
5 citations
Grafman and colleagues' research shows that religious beliefs and behaviors are mediated by standard social cognitive networks in the brain, but their work also points beyond treating religious cognition as merely a type of general social cognition. Data from experiments targeting mystical states and reports of encounters with supernatural agents during controlled psychedelic experiments suggest that brain mediation of such experiences involves both disruption or downregulation of social cognitive networks and activation of an additional, partially identified neural process. This indicates that a full neuroscience account of religious beliefs, behaviors, and experiences must extend beyond treating religion as an ordinary social process.
Cortex; a journal devoted to the study of the nervous system and behavior
October 1, 2025
Roger Koenig-Robert, Rebecca Keogh, Joel Pearson
3 citations
As psychedelic therapy becomes more widely legalized, a note of warning is raised about recent reports that people with aphantasia—those lacking a mind's eye—have acquired visual mental imagery after using psychedelics. While gaining or increasing visual imagery may seem appealing, strong mental imagery is linked to several mental health conditions. The potential impact of switching on visual imagery in aphantasics or increasing its strength in neurotypical individuals remains unknown. The authors advocate for greater awareness of these risks and their ethical implications, especially concerning informed consent.
Cortex; a journal devoted to the study of the nervous system and behavior
August 1, 2026
Reina Van der Goot, Amit Regev Krugwasser, Geffen Markusfeld et al.
Visuomotor conflicts that reduce the sense of agency—the feeling of controlling one's actions—are linked to increased alpha- and theta-band brain activity. In an EEG study using virtual reality, participants moved a finger while viewing a virtual hand that either matched their movement, differed anatomically (same movement, different finger), or spatially (same finger, shifted angle). Conflicts robustly decreased self-attribution. Altered trials could be decoded from unaltered ones with up to 68% accuracy starting around 200 milliseconds after movement onset. Cross-decoding revealed shared neural patterns across conflict types emerging around 500 milliseconds, suggesting a temporal progression from early, condition-specific sensorimotor responses to a later domain-general component, consistent with a two-step model of agency.
Cortex; a journal devoted to the study of the nervous system and behavior
June 1, 2026
Audrey Mazancieux, Axel Cleeremans, Adélaïde De Heering
Steady-state visual evoked potentials (SSVEPs) recorded during frequency-tagging can track both objective and subjective conscious perception of faces. In 32 participants viewing image sequences at 6 Hz with faces every fifth image, presented at either 1% or 1.5% contrast, the face-related brain signal at 1.5% contrast was higher during correct gender categorisation than incorrect categorisation and increased linearly with both visibility and confidence ratings. At 1% contrast, no face perception occurred behaviourally, and no brain response to faces was detected. Attention, monitored via a fixation-cross task, related more closely to confidence than visibility. These findings indicate SSVEPs can serve as a marker of conscious perception.
Cortex; a journal devoted to the study of the nervous system and behavior
May 1, 2024
Antonio Maffei, Filippo Gambarota, Mario Liotti et al.
Visual awareness of fear expressed on a face is associated with a frontal brain response occurring 150–300 milliseconds after seeing the face, beyond the earlier face-sensitive N170 component. Using high-density EEG and a staircase procedure to individually calibrate perceptual thresholds, the study compared brain activity when participants were aware versus unaware of the emotion on otherwise identical faces. A data-driven cluster analysis showed that awareness of fear specifically modulated a frontal event-related potential in that time window. The findings are discussed in relation to current theories of visual consciousness and proposed neural correlates of consciousness.
Cortex; a journal devoted to the study of the nervous system and behavior
March 1, 2024
Elise G Rowe, Marta I. Garrido, Naotsugu Tsuchiya
Current theories of consciousness disagree on whether the prefrontal cortex (PFC) is necessary for conscious perception. No-report paradigms, which separate task reporting from conscious experience, have shown reduced PFC activity but have not tested the PFC's role in monitoring sensory cortex patterns. Reanalyzing EEG data from a no-report inattentional blindness paradigm, researchers used Granger causality and multivariate classifiers to examine feedforward input from visual areas to the PFC. Unexpectedly, information about the sensory stimulus was present in these input patterns regardless of whether the stimulus was consciously seen. This suggests that theories of consciousness must be revised, as the contents of consciousness are decodable from posterior-to-PFC inputs even without awareness or report.
Cortex; a journal devoted to the study of the nervous system and behavior
January 1, 2020
Surya Gayet, Iris Douw, V. V. D. Burg et al.
Directing top-down attention to a specific location or a narrowly defined feature (color) does not accelerate the conscious detection of suppressed visual stimuli at that location or of that feature, even when attention is successfully manipulated. However, when attention is directed to a color using a broader attentional template (ill-defined shape), conscious access is faster for probes in the attended color. These findings suggest that the specificity of attentional templates imposes limitations on the ability of top-down attention to bias which visual information reaches consciousness.
Cortex; a journal devoted to the study of the nervous system and behavior
November 1, 2019
María Hernández-Lorca, Kristian Sandberg, Dominique Kessel et al.
Conscious perception of emotional images is linked to brain activity in the visual awareness negativity (VAN) time range (130–320 ms after stimulus onset), which is the earliest neural correlate of consciousness and extends beyond simple visual features. An emotional modulation of event-related potentials—termed emotional content awareness modulation (ECAM)—appears at this VAN latency. In binocular rivalry, where neutral and emotional images compete for conscious perception, positive valence is more likely to dominate as the first percept, indicating an emotional bias toward positive content. Negative and positive emotional content modulate conscious perception differently. These findings connect early perceptual brain activity with emotional influences on what we consciously see.
Cortex; a journal devoted to the study of the nervous system and behavior
July 1, 2018
Christophe Lopez, Maya Elzière
Out-of-body experiences (OBEs), where awareness feels located outside the physical body, occur in epilepsy, migraine, and depersonalization, and are not uncommon in the general population. Current models link OBEs to a failure to integrate visual, somatosensory, and vestibular signals, particularly visual-vestibular mismatch. This prospective observational study of 210 patients with dizziness and 210 matched healthy controls found significantly higher OBE occurrence in dizzy patients (14%) than controls (5%). Most patients first experienced OBEs after dizziness onset, primarily linked to peripheral vestibular disorders. Depersonalization-derealization, depression, anxiety, and migraine predicted OBEs in patients; depersonalization-derealization alone predicted OBEs in controls. OBEs in dizziness likely arise from perceptual incoherence from vestibular dysfunction combined with psychological and neurological factors.
Cortex; a journal devoted to the study of the nervous system and behavior
November 1, 2017
Maor Zeev-Wolf, Yair Dor-Ziderman, Abraham Goldstein et al.
Feeling located within one's body and viewing the world from that perspective is a key aspect of consciousness. Current theories emphasize multisensory integration and the right temporal-parietal junction (rTPJ) in supporting self-location, based on bottom-up sensory manipulations or direct brain disruption. This study used hypnotic suggestion, a non-invasive top-down technique, to manipulate self-location in 18 participants while recording brain activity with MEG. Spectral analyses of spontaneous data before and during an induced out-of-body experience revealed high correlations between alpha and high-gamma power and the degree of perceived change in self-location. Correlated regions included temporal-occipital areas, rTPJ, and frontal and midline regions, supporting an oscillatory-based predictive coding framework.
Cortex; a journal devoted to the study of the nervous system and behavior
January 1, 2011
Jason J Braithwaite, Dana Samson, Ian Apperly et al.
People who report out-of-body experiences (OBEs) show more perceptual anomalies, particularly related to temporal-lobe instability and body-distortion processing, and are impaired at mentally transforming their own body. Two studies with university students found that 26% reported at least one OBE. OBEers scored higher on the Cardiff anomalous perception scale, and those with elevated temporal-lobe or body-distortion measures performed worse on a mental own-body transformation task. These results extend findings from epileptic patients to the general population, suggesting disrupted temporal-lobe and body-based processing underlies OBE-type experiences.
Cortex; a journal devoted to the study of the nervous system and behavior
January 1, 2008
Jessica I Fleck, Deborah L Green, Jennifer L Stevenson et al.
People high in transliminality—a trait linked to magical thinking, paranormal belief, and creativity—show distinct patterns of resting brain activity compared to those low in transliminality. High-transliminality individuals had lower alpha, beta, and gamma power over the left posterior association cortex and lower high alpha, low beta, and gamma power over the right superior temporal region, but greater gamma power over the frontal-midline region. These differences align with patterns seen in schizotypy and schizophrenia spectrum disorders, supporting theories that altered brain asymmetries may predispose people to unusual experiences and beliefs.
Cortex; a journal devoted to the study of the nervous system and behavior
February 1, 2006
Jeffrey A Gray, David M Parslow, Michael J Brammer et al.
Coloured hearing synaesthetes experience colors when hearing words, and some also experience the 'alien colour effect' (ACE), where color names trigger a different color than the one named. The ACE slows color naming in a Stroop task, reflecting cognitive interference from consciously experienced synaesthetic colors. Functional magnetic resonance imaging shows that hippocampal activation distinguishes synaesthetes with the ACE from those without it and from non-synaesthetes. These findings challenge reductive functionalism, which identifies mental states with causal roles. In synaesthesia, color qualia arise from both hearing words and seeing surfaces, and in the ACE these functions oppose each other, providing empirical grounds to argue that reductive functionalism cannot account for conscious experiences.
Cortex; a journal devoted to the study of the nervous system and behavior
October 1, 2005
Alexei V Samsonovich, Giorgio A Ascoli
The self as the subject of experience is distinct from self-awareness, body image, or narrative identity. The authors argue that the self as the immediate subject cannot be dismissed as an illusion. They adapt Chalmers' framework for consciousness to formulate axioms for the self-concept and use a thought experiment called the "mirror quest" to show that the framework may need revision to account for the subject. This analysis leads to a novel position called "subjective nonreductive functionalism," which has implications for brain sciences as an epistemological model.
Cortex; a journal devoted to the study of the nervous system and behavior
December 1, 1981
N H Kerr, D Foulkes
A male patient with extensive damage to the right hemisphere, causing blindness in the left half of his visual field, was studied over two nights in a sleep lab. Dream reports were collected after six awakenings from REM sleep. His dreams were typically sequential and narrative but lacked continuous visual imagery; any visual images were fragmentary and static. He also could not perform waking tasks requiring mental representation of space. These observations suggest that dream narratives may arise from different brain sources than the visual content of dreams, and that visual dream experiences may depend on right-hemisphere processing. Differences from a prior study may be due to different interview techniques.
Cortex; a journal devoted to the study of the nervous system and behavior
September 1, 1977
P Greenwood, D H Wilson, M S Gazzaniga
People with split-brain surgery (severed corpus callosum and anterior commissure) were able to recall visual dream content when awakened from REM sleep. This finding does not support the idea that the right hemisphere alone mediates the visual aspects of dreaming.