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
Consciousness often persists even when unresponsiveness occurs. In two experiments involving 76 healthy males, brain activity was measured during varying states of consciousness induced by propofol and dexmedetomidine (n = 39) and during sleep-deprived wakefulness and non-REM sleep (n = 37). Most participants reported internally generated experiences while unresponsive. Key brain regions, including the thalamus and cingulate cortices, were found critical for consciousness, showing consistent activity patterns regardless of anesthetic type or sleep state, highlighting a core network essential for conscious awareness.
The Journal of neuroscience : the official journal of the Society for Neuroscience
November 8, 2023
Lindsay P Cameron, Joseph Benetatos, Vern Lewis et al.
88 citations
Serotonergic psychedelics like psilocybin and LSD activate serotonin 5-HT2A receptors in cortical brain regions, altering perception, cognition, and emotions. Their ability to promote neuroplasticity—forming new neural connections and rewiring networks—is thought to underlie therapeutic potential for depression, anxiety, and substance use disorders. These compounds also interact with other serotonin receptor subtypes (5-HT1A, 5-HT2C) and neurotrophin receptors, adding complexity to their effects. Research is exploring nonhallucinogenic derivatives that retain therapeutic benefits without intense psychedelic experiences, potentially reducing adverse reactions. The review also discusses psychedelics as substrates for post-translational protein modification as part of their mechanism.
The Journal of neuroscience : the official journal of the Society for Neuroscience
June 26, 2024
Fynn-Mathis Trautwein, Yoav Schweitzer, Yair Dor-Ziderman et al.
27 citations
Long-term meditators can intentionally reduce the sense of being an embodied self, and this change is linked to decreased high-beta brain activity in the posterior medial cortex. In a study of 46 experienced meditators (19 female, 27 male) who underwent magnetoencephalographic monitoring, those who reported radical disruptions of embodied self-experience—such as loss of agency and a localized first-person perspective—showed the strongest neural reductions. These neural changes correlated with lifetime meditation experience and interview-based reports of experiential shifts, but not with standard self-report questionnaires. The findings suggest that posterior medial cortex oscillations are central to supporting the embodied sense of self.
The Journal of neuroscience : the official journal of the Society for Neuroscience
October 25, 2023
Leila Azizi, Ignacio Polti, Virginie Van Wassenhove
15 citations
The relative duration of alpha brain rhythm bursts (7-14 Hz) during quiet rest predicts how long people retrospectively estimate the rest period lasted, but only when they are not instructed to attend to time. In a magnetoencephalography (MEG) experiment, participants who were unaware they would be asked about time showed that longer alpha burst durations corresponded to longer retrospective time estimates. Alpha burst duration was a better predictor than alpha power or burst amplitude, and no other brain rhythms predicted retrospective duration. When participants timed prospectively, alpha bursts did not predict their estimates. A control experiment showed the relation persists even during a visual counting task. Alpha bursts may embody discrete states of awareness that constitute episodic timing.
The Journal of neuroscience : the official journal of the Society for Neuroscience
May 14, 2025
Çağatay Demirel, Jarrod Gott, Kristoffer Appel et al.
8 citations
Lucid dreaming, where a person becomes aware they are dreaming, is linked to REM sleep. To overcome previous research limitations, a new preprocessing pipeline was applied to pooled EEG data from multiple labs. Sensor-level differences between lucid and nonlucid REM sleep were minimal, but source-level analysis revealed reduced beta power (12-30 Hz) in right central and parietal areas, including the temporoparietal junction, during lucid dreaming. Alpha-band (8-12 Hz) connectivity increased compared to nonlucid REM sleep. During eye signaling of lucidity, gamma1 power (30-36 Hz) increased in right temporo-occipital regions, including the precuneus, and interhemispheric gamma1 connectivity rose. These patterns suggest shifts in network communication underlying changes in perception, self-awareness, and cognitive control.
The Journal of neuroscience : the official journal of the Society for Neuroscience
February 21, 2024
Yunkai Zhu, Charlotte Li, Camille Hendry et al.
8 citations
A left-lateralized, near-vertex negativity in EEG, occurring 200–300 ms after stimulus onset, distinguishes sine-wave speech tokens perceived as speech from those perceived as noise, even when task-irrelevant. This response, interpreted as a phonological perceptual awareness negativity, was absent for frequency-flipped control tokens never perceived as speech. The P3b component was enhanced only for tokens both perceived as speech and task-relevant. The findings suggest that neural correlates of conscious perception, across different types of conscious content, are most likely midlatency negative-going brain responses in content-specific sensory areas.
The Journal of neuroscience : the official journal of the Society for Neuroscience
May 14, 2025
Diego G Dávila, Andrew McKinstry-Wu, Max B Kelz et al.
5 citations
During wakefulness, people respond to external stimuli, while in dreams or drug-induced dissociated states, vivid internal experiences occur with reduced perception of the outside world. The brain's activity near a critical point between damped and exploding oscillations is linked to conscious experience, and this signature appears in both normal wakefulness and dissociative states but not in dreamless sleep or anesthesia. Using high-density EEG in human male volunteers given escalating ketamine doses, activity became progressively more stable, especially at higher frequencies, as dissociative symptoms increased. This stabilization correlated with reduced ability to perceive external stimuli, not with conscious experience itself. Combining statistical and dynamical measures of criticality may help distinguish wakefulness, dissociation, and unconsciousness.
The Journal of neuroscience : the official journal of the Society for Neuroscience
June 26, 2024
Mahan Hosseini, Alon Zivony, Martin Eimer et al.
5 citations
The N2pc and P3 brain signals, which index selective attention and conscious awareness respectively, are temporally linked. In an experiment with 23 participants monitoring rapid letter and digit streams, dynamic time warping analysis showed that the latencies of these two signals correlated in time, both when participants correctly reported a target digit and when they mistakenly reported a nearby distractor. The link was weaker on distractor intrusion trials. The findings clarify the relationship between attention and access consciousness, and the novel method offers a general approach for assessing temporal links between any two time-series processes.
The Journal of neuroscience : the official journal of the Society for Neuroscience
April 9, 2025
Audrey Dureux, Alessandro Zanini, Azadeh Jafari et al.
3 citations
Ketamine, a drug that blocks NMDA receptors, broadly suppresses brain activity in auditory regions of awake marmoset monkeys, especially when they hear other marmosets' calls. Using ultra-high field fMRI at 9.4 T, the study compared brain responses to vocalizations, scrambled versions, and nonvocal sounds after a subanesthetic dose of ketamine versus saline. Ketamine caused widespread reduction of activations across auditory areas and produced distinct changes in the mediodorsal thalamus and anterior cingulate cortex during vocalization processing. These effects overlap with neural disruptions seen in schizophrenia, suggesting ketamine can model auditory processing deficits in this disorder.
The Journal of neuroscience : the official journal of the Society for Neuroscience
December 11, 2024
Liya Ma, Nupur Katyare, Kevin Johnston et al.
1 citation
Ketamine, an NMDAR antagonist, impairs cognitive control by disrupting frontoparietal dynamics. In macaques performing an antisaccade task, ketamine altered excitation/inhibition balance in the lateral prefrontal and posterior parietal cortices, reduced rule coding in neural oscillations, and lowered frontoparietal coherence in a frequency- and rule-dependent manner. It also decreased bidirectional connectivity between these areas. Greater reductions in connectivity during the delay period of antisaccade trials preceded larger delays in saccade onset under a rule-memorized condition and greater performance deficits under a rule-visible condition. Ketamine also compromised rule coding in prefrontal neurons under both conditions and in parietal neurons only under the rule-visible condition. These results demonstrate how acute NMDAR blockade can reveal mechanisms by which frontoparietal dynamics support cognitive control.
The Journal of neuroscience : the official journal of the Society for Neuroscience
February 3, 2026
Kyle A Brown, Patrick J Morris, Craig J Thomas et al.
The antidepressant effects of ketamine arise from its metabolite (2R,6R)-hydroxynorketamine (2R6R), not from ketamine itself. In mouse hippocampal slices, 2R6R rapidly strengthens synapses and induces long-lasting metaplasticity—a form of plasticity that primes synapses for future change—whereas ketamine alone does not. This rapid and sustained plasticity requires mTOR signaling and can be mimicked by activating mTOR. The sustained phase also depends on IP3 receptors, L-type calcium channels, and delayed BDNF/TrkB signaling, but not on new protein synthesis. The findings outline a sequence of molecular events underlying 2R6R's synaptic actions, with implications for developing rapid-acting antidepressants and understanding activity-dependent plasticity.
The Journal of neuroscience : the official journal of the Society for Neuroscience
November 24, 2025
Mona Irrmischer, Marco Aqil, Lisa Luan et al.
A psychedelic substance (DMT) shifts brain oscillations away from criticality—a state of balanced, complex activity—toward a quieter subcritical regime, particularly in alpha and adjacent frequency bands. This shift increases entropy while reducing complexity. The magnitude of the criticality shift in alpha and theta bands correlates with the intensity of self-dissolution, a core feature of the psychedelic experience. These findings suggest that altered proximity to critical dynamics underlies both the neurological and experiential effects of psychedelics, with implications for understanding altered states of consciousness.
The Journal of neuroscience : the official journal of the Society for Neuroscience
June 3, 2026
Sofia Pantis, Masaya Togo, Dian Lyu et al.
Direct electrical stimulation of the mid-thalamus, near the mediodorsal nucleus, alters conscious experience and reveals asymmetric brain connectivity. In 30 patients with focal epilepsy, 50 Hz stimulation changed conscious experience in 11 of 12 patients, producing visceral, emotional, or somatosensory sensations, often unpleasant. Single-pulse 0.5 Hz stimulation showed strong electrophysiological connectivity between the mid-thalamus and the insula, anterior and midcingulate, prefrontal cortices, and medial temporal lobe. Inflow signals from some cortical sites to the mid-thalamus were significantly stronger than outflow, indicating a clear directional asymmetry in thalamocortical connectivity.
The Journal of neuroscience : the official journal of the Society for Neuroscience
May 27, 2026
Alfredo Spagna, Jianghao Liu, Paolo Bartolomeo
Conscious perception is preceded by distinct patterns of brain activity that depend on whether attention is oriented to the correct location or must be reoriented. Using magnetoencephalography, the study examined neural oscillations before near-threshold visual targets. Validly cued targets (67% of trials) were preceded by early beta-band activity in the right superior parietal lobule about 58 milliseconds after the cue. Invalidly cued targets that were reported were preceded by later beta activity in the right temporo-occipital region, theta-gamma phase-amplitude coupling in the right lateral visual cortex, and low gamma coherence between that region and the left temporoparietal junction.
The Journal of neuroscience : the official journal of the Society for Neuroscience
December 13, 2023
Shaozhi Nie, Sucharit Katyal, Stephen A Engel
During binocular rivalry, when each eye sees a different image, perception alternates unpredictably between them. Models propose that neural signals for each image change gradually until reaching a threshold that triggers a switch, but direct evidence was lacking. Measuring steady-state visual evoked potentials (SSVEPs) via EEG in 84 human participants (62 females, 22 males) viewing orthogonal gratings flickering at different frequencies, the amplitude of the suppressed stimulus's signal increased and the dominant stimulus's signal decreased throughout each percept. Longer percepts corresponded to more gradual changes in these signals. The findings match a model where perceptual transitions arise from accumulating noisy signals, providing the first physiological evidence for such threshold-crossing dynamics in human visual cortex.
The Journal of neuroscience : the official journal of the Society for Neuroscience
September 15, 2021
Torge Dellert, Miriam Müller-Bardorff, Insa Schlossmacher et al.
Conscious visual perception of faces is linked to early processing in sensory brain regions, especially the fusiform gyrus, rather than requiring later widespread frontoparietal network activity. Using simultaneous EEG-fMRI and an inattentional blindness paradigm with three identical phases, participants either spontaneously noticed or remained blind to faces during a distractor task. Bayesian analysis showed conscious face perception most strongly activated the fusiform gyrus (fMRI) and produced the N170 and visual awareness negativity (EEG), with smaller effects in occipital and prefrontal cortex. In contrast, task-relevant face processing activated extensive occipitotemporal, frontoparietal, and attentional networks and elicited a pronounced P3b component, suggesting strong frontoparietal activity and the P3b reflect task-related processes rather than consciousness itself.
The Journal of neuroscience : the official journal of the Society for Neuroscience
December 6, 2017
Hsin-Yi Kao, Dino Dvořák, Eunhye Park et al.
The psychotomimetic drug phencyclidine (PCP) impairs a learned hippocampus-dependent place avoidance behavior in rats, even when injected directly into the dorsal hippocampus. PCP increases 60-100 Hz gamma oscillations in hippocampal CA1, and these increases correlate with cognitive impairment. PCP disrupts the coordination between theta-modulated medium-frequency and slow gamma oscillations, and it disrupts the subsecond temporal organization of discharge among place cells, causing ensemble representations of a familiar space to cease resembling pre-PCP representations despite preserved place fields. These findings indicate that PCP-induced cognitive impairments arise from neural discoordination, specifically excitation-inhibition discoordination, rather than from disruption of place fields themselves.
The Journal of neuroscience : the official journal of the Society for Neuroscience
November 8, 2017
Johan F Storm, Melanie Boly, Adenauer G Casali et al.
The mind-body problem—how consciousness arises from brain processes—has long been considered a philosophical puzzle but is now being tackled empirically. This review describes progress since Crick and Koch (1998) proposed searching for the neural correlates of consciousness (NCC). It covers content-specific NCCs, which link particular brain activity to specific experiences, and the full NCC, which supports entire conscious states. The authors discuss methodological advances for isolating conscious experience from enabling functions, suggest that reconsidering the frontal cortex's role may refine NCCs, advocate for objective brain-based measures of consciousness independent of sensory or executive processes, and show how animal studies reveal network phenomena relevant to consciousness mechanisms.
The Journal of neuroscience : the official journal of the Society for Neuroscience
October 4, 2017
Brian Odegaard, Robert T Knight, Hakwan Lau
Activity in the prefrontal cortex (PFC) is critical for conscious perception, contradicting claims that PFC lesions do not affect subjective experience, that PFC activity does not reflect perceptual content, or that its role is solely due to task-related reporting. Empirical evidence shows PFC is essential for subjective experience in perception, not just for performing visual tasks. Confusing these two aspects can lead to misunderstandings.
The Journal of neuroscience : the official journal of the Society for Neuroscience
May 14, 2008
Wulf Hevers, Stephen H Hadley, Hartmut Lüddens et al.
Ketamine, but not the related drug phencyclidine (PCP), enhances the activity of specific GABA(A) receptor subtypes (alpha6beta2delta and alpha6beta3delta) at anesthetic concentrations, directly activating them at higher concentrations. This effect was observed in oocyte expression systems and in cerebellar granule neurons from mice, and was absent in neurons from mice lacking the alpha6 or delta subunits. The findings suggest that ketamine's greater central nervous system depressant effects, compared to PCP, may arise from its selective modulation of these GABA(A) receptors, which are abundant in the cerebellum.
The Journal of neuroscience : the official journal of the Society for Neuroscience
July 1, 1999
G G Kinney, L O Wilkinson, K L Saywell et al.
Certain drugs, such as phencyclidine (PCP) and 8-OH-DPAT, disrupt prepulse inhibition (PPI) of the startle response in both Sprague Dawley and Wistar rats. However, apomorphine and amphetamine only disrupt PPI in Wistar rats, not in Sprague Dawley rats. This strain difference is specific to PPI, as apomorphine-induced hyperlocomotion, another measure of dopamine receptor activation, was similar in both strains. The findings suggest that the effects of dopamine receptor agonists on PPI can be dissociated from their effects on other behavioral models of dopamine activation.
The Journal of neuroscience : the official journal of the Society for Neuroscience
July 15, 1998
B Adams, B Moghaddam
PCP and its analog ketamine produce a behavioral syndrome that models some aspects of schizophrenia. Previously, the psychotomimetic and cognitive-impairing effects were attributed mainly to the corticolimbic dopamine system. This study measured dopamine and glutamate efflux in the prefrontal cortex and nucleus accumbens of rodents after PCP injection, using microdialysis. PCP increased both dopamine and glutamate levels. Dopamine remained elevated above baseline 2.5 hours after injection, yet locomotor activity returned to baseline in less than 2 hours, and working memory impairment (measured by a delayed alternation task) was only evident up to 60 minutes after injection.
The Journal of neuroscience : the official journal of the Society for Neuroscience
December 1, 1986
R G Sorensen, M P Blaustein
Phencyclidine (PCP) binds with high affinity to a specific receptor in rat brain membranes, which is likely a voltage-gated, noninactivating potassium channel. Several potassium channel blockers, including aminopyridines and tetraalkylamines, displace PCP from this binding site, supporting the hypothesis. A photolabile PCP analog, m-azido-PCP, binds reversibly to two classes of sites on rat brain synaptic membranes: a high-affinity site (dissociation constant 0.14 ± 0.01 µM) and a low-affinity site (255 ± 55 µM). The high-affinity site corresponds to the PCP receptor. The rank order of potency for displacing PCP from this site among aminopyridines is 4-AP ≈ 3,4-diAP > 2-AP ≫ 3-AP; among tetraalkylamines it is TBA > TEA ≫ TMA.