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NeuroImage

53 papers in the library · 9,012 citations · publishing 2008-2026

Papers

The precuneus/posterior cingulate cortex plays a pivotal role in the default mode network: Evidence from a partial correlation network analysis

NeuroImage June 13, 2008 Peter Fransson, Guillaume Marrelec 1,236 citations

Functional connectivity within the default mode network was assessed during rest and a continuous working memory task using partial correlation analysis. The precuneus/posterior cingulate region showed strong interactions with the rest of the network, while the left and right medial temporal lobes interacted strongly with each other but weakly with other regions. Strong interactions were also found between the precuneus/posterior cingulate cortex and the left inferior parietal lobe, and between dorsal and ventral sections of the medial prefrontal cortex. These findings support a pivotal role for the precuneus/posterior cingulate cortex in the default mode network.

DOI: 10.1016/j.neuroimage.2008.05.059 Default mode network Precuneus Posterior cingulate Neuroscience +4

The salience network is responsible for switching between the default mode network and the central executive network: Replication from DCM

NeuroImage May 24, 2014 828 citations

The salience network drives switching between the default mode network (DMN), active when the brain is not focused on a task, and the central executive network (CEN), active during attention-demanding tasks. Combining dynamic causal modelling with independent component analysis, this work tested network switching in resting-state data from two independent datasets. The results confirm that the salience network is responsible for this switching and demonstrate the repeatability of the novel technique.

DOI: 10.1016/j.neuroimage.2014.05.052 Full text

Mapping the self in the brain's default mode network

NeuroImage February 15, 2016 Christopher G. Davey, Jesús Pujol, Ben J. Harrison 576 citations

The brain's default mode network (DMN) is linked to self-referential thought during rest, but it also serves other functions, and self-reference involves regions outside the DMN. In 88 participants, self-referential and resting-state brain activity were compared to identify DMN areas common to both conditions that also show specialization for self-reference. The 'core-self' DMN regions—medial prefrontal cortex, posterior cingulate cortex, and inferior parietal lobule—were analyzed with dynamic causal modeling. The optimal model indicated that self-related processes are driven by posterior cingulate activity and moderated by the medial prefrontal cortex. This confirms these regions' importance for self-reference and clarifies their specialized roles.

DOI: 10.1016/j.neuroimage.2016.02.022 Default mode network Posterior cingulate Self-reference effect Prefrontal cortex +9

The spectral exponent of the resting EEG indexes the presence of consciousness during unresponsiveness induced by propofol, xenon, and ketamine

NeuroImage January 11, 2019 Michele Colombo, Martino Napolitani, Mélanie Boly et al. 359 citations

During anesthesia, people may still be conscious even though they do not respond. A marker of consciousness based on the decay rate of the power spectral density (PSD) of resting EEG—measured by the spectral exponent β—was tested in healthy participants under xenon, propofol, or ketamine anesthesia (n=5 per group). Delayed reports indicated whether consciousness was present or absent. Xenon and propofol, which abolish consciousness, caused a steeper PSD decay (more negative β) compared to wakefulness. Ketamine, which preserves consciousness, showed a PSD decay similar to wakefulness overall but a flattening in high frequencies (20–40 Hz). The spectral exponent correlated strongly with the Perturbational Complexity Index (PCI), supporting its use as a marker of consciousness.

DOI: 10.1016/j.neuroimage.2019.01.024 Ketamine Propofol Xenon Exponent +9

Distant from input: Evidence of regions within the default mode network supporting perceptually-decoupled and conceptually-guided cognition

NeuroImage January 12, 2018 288 citations

The default mode network supports cognition independent of immediate environment and higher-order conceptual representations. A novel paradigm manipulated perceptual information availability and representational complexity during decision-making. Brain regions including left and right angular gyri and left middle temporal gyrus responded when cognition combined stimulus independence with multi-modal information. These default mode network sites showed stronger response to demanding memory judgments than easier perceptual tasks, contradicting the view they support automatic cognition. These regions were at the extreme end of a macroscale gradient from sensorimotor to transmodal cortex, suggesting functional distance from sensory input enables conceptually rich cognitive states in absence of input.

DOI: 10.1016/j.neuroimage.2018.01.017

Psilocybin-assisted mindfulness training modulates self-consciousness and brain default mode network connectivity with lasting effects.

NeuroImage August 1, 2019 Lukasz Smigielski, Milan Scheidegger, Michael Kometer et al. 261 citations

A single dose of psilocybin (315 μg/kg) combined with a 5-day mindfulness retreat altered brain connectivity in the default mode network, particularly decoupling the medial prefrontal and posterior cingulate cortices. This decoupling correlated with the subjective experience of ego dissolution during meditation. The extent of ego dissolution and brain connectivity changes predicted improvements in psycho-social functioning four months later. The findings suggest that psilocybin-assisted meditation facilitates neurodynamic changes in self-referential networks, linking altered self-experience to lasting behavioral changes.

DOI: 10.1016/j.neuroimage.2019.04.009 Full text Default mode network Meditation Mindfulness Consciousness +2

Psilocybin acutely alters the functional connectivity of the claustrum with brain networks that support perception, memory, and attention.

NeuroImage September 1, 2020 Frederick S Barrett, Samuel R Krimmel, Roland R Griffiths et al. 191 citations

Psilocybin, a serotonin 2A receptor partial agonist, alters claustrum function in humans. In 15 healthy participants, psilocybin decreased the amplitude of low-frequency fluctuations and variance of BOLD signal in the left and right claustrum. It also changed functional connectivity: right claustrum connectivity with auditory and default mode networks decreased, while connectivity with the fronto-parietal task control network increased; left claustrum connectivity with the fronto-parietal task control network decreased. Subjective effects predicted these neural changes. The findings provide the first empirical evidence that 5-HT2A receptor signaling significantly modulates claustrum activity, suggesting a role for the claustrum in psilocybin's subjective and therapeutic effects.

DOI: 10.1016/j.neuroimage.2020.116980 Full text Psychedelics Serotonin 2a receptor Claustrum connectivity Psychedelic effects +1

LSD alters dynamic integration and segregation in the human brain.

NeuroImage February 15, 2021 Andrea I Luppi, Robin L Carhart-Harris, Leor Roseman et al. 186 citations

LSD alters brain network dynamics non-uniformly over time, making globally segregated connectivity states more complex and weakening the link between functional and anatomical connectivity. The drug reduces functional connectivity in the anterior medial prefrontal cortex specifically during states of high segregation. Ego dissolution was predicted by increased small-world organization during a state of high global integration. These temporally-specific effects reveal a more nuanced picture of psychedelic-induced changes in brain connectivity and complexity than previously reported.

DOI: 10.1016/j.neuroimage.2020.117653 Full text LSD Complexity FMRI Dynamics Integration-segregation +2

Default mode network connectivity during task execution

NeuroImage July 26, 2015 157 citations

The default mode network, long thought to be deactivated during focused tasks and to interfere with performance, may actually help fulfill cognitive demands. In a finger-tapping task with functional MRI, the network showed task-specific changes in its topography. Faster reaction times were predicted by stronger connectivity between the posterior cingulate cortex and the left superior frontal gyrus. The network's connections reconfigured dynamically during the task, maintaining efficient small-world organization while supporting higher-level parallel processing. These results suggest the default mode network does not disengage but may contribute to task-relevant processing.

DOI: 10.1016/j.neuroimage.2015.07.053

Pharmacokinetics of the potent hallucinogen, salvinorin A in primates parallels the rapid onset and short duration of effects in humans.

NeuroImage July 1, 2008 Jacob M Hooker, Youwen Xu, Wynne Schiffer et al. 106 citations

Salvinorin A, the psychoactive component of the mint plant Salvia divinorum, is a uniquely potent agonist at kappa-opioid receptors. Positron emission tomography (PET) studies in 6 adult female baboons showed extremely rapid brain uptake, reaching a peak of 3.3% of the total administered dose within 40 seconds and clearing with a half-life of 8 minutes. The compound distributed throughout the brain, with highest concentration in the cerebellum and notable concentration in the visual cortex, which may account for visual hallucinations when smoked. Naloxone did not reduce overall concentration or alter regional distribution. The rapid brain kinetics match the brief time-course of visual hallucinations, and effects may occur at less than 10 micrograms in the human brain, emphasizing its remarkable potency.

DOI: 10.1016/j.neuroimage.2008.03.003 Full text Compound Labeled version Tiny amounts Profound impact +13

Two dose investigation of the 5-HT-agonist psilocybin on relative and global cerebral blood flow

NeuroImage July 12, 2017 Candace R. Lewis, Katrin H. Preller, Rainer Kraehenmann et al. 105 citations

Psilocybin, a hallucinogen, significantly enhances cerebral blood flow in key brain regions. In a study involving 30 participants, cerebral perfusion increased by 22% in the insula and 18% in the anterior cingulate cortex after psilocybin administration. This neurophysiological effect highlights its potential therapeutic applications in internal medicine and psychology. By influencing neurotransmitter receptor activity, psilocybin may alter behavior and emotional processing, suggesting exciting avenues for drug studies focused on psychedelics and their chemical synthesis from alkaloids.

DOI: 10.1016/j.neuroimage.2017.07.020 Psilocybin Insula Cerebral blood flow Anterior cingulate cortex +8

Serotonergic psychedelics LSD & psilocybin increase the fractal dimension of cortical brain activity in spatial and temporal domains

NeuroImage June 30, 2020 Thomas F. Varley, Robin Carhart‐Harris, Leor Roseman et al. 91 citations

Psychedelic drugs like psilocybin and LSD increase the fractal dimension of brain activity, suggesting that the brain moves toward a critical state between order and disorder. Using fMRI data from volunteers, the study tested two fractal measures: one for functional connectivity networks and one for BOLD time-series. Both drugs significantly increased the fractal dimension of functional connectivity networks. LSD also significantly increased the fractal dimension of BOLD signals, while psilocybin showed a non-significant trend in the same direction. Changes in the fractal dimension of BOLD signals were localized to brain areas in the dorsal attention network. These results indicate that psychedelic-induced changes in consciousness are associated with evolution toward a critical zone.

DOI: 10.1016/j.neuroimage.2020.117049 Psilocybin Serotonergic Serotonin Neuroscience +11