bioRxivOctober 2, 2023Nicholas Souter, Antonia De Freitas, Meichao Zhang et al.
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The default mode network (DMN) lies towards the heteromodal end of the principal gradient of intrinsic connectivity, maximally separated from sensory-motor cortex. It supports memory-based cognition, including the capacity to retrieve conceptual and evaluative information from sensory inputs, and to generate meaningful states internally; however, the functional organisation of DMN that can...
bioRxivSeptember 27, 2023Charles-Francois V Latchoumane, Joon-Hyuk Lee, Seong-Wook Kim et al.
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ABSTRACT: Thalamocortical activity is known to orchestrate sensory gating and consciousness switching. The precise thalamic regions involved, or the firing patterns related to the unconsciousness remain unclear. Interestingly, the highly-expressed thalamic T-type calcium currents have been considered as a candidate for the ionic mechanism for the generation of thalamo-cortically-driven change...
bioRxivSeptember 26, 2023Chloe Dziego, Ina Bornkessel-Schlesewsky, Matthias Schlesewsky et al.
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ABSTRACT: Human performance applications of mindfulness-based training have demonstrated its utility in enhancing cognitive functioning. Previous studies have illustrated how these interventions can improve performance on traditional cognitive tests, however, little investigation has explored the extent to which mindfulness-based training can optimise performance in more dynamic and complex...
bioRxivSeptember 22, 2023Sofia V Salvatore, Peter M Lambert, Ann Benz et al.
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Cortical electroencephalograms (EEG) may help understanding of neuropsychiatric illness and new treatment mechanisms. The aperiodic component (1/ f ) of EEG power spectra is often treated as noise, but recent studies suggest that changes to the aperiodic exponent of power spectra may reflect changes in excitation/inhibition (E/I) balance, a concept linked to antidepressant effects, epilepsy,...
The claustrum is a thin subcortical gray matter structure located between the insula and the putamen. It has numerous bilateral connections with the cortex and is thought to play an important role in higher-level aspects of perception and cognition, with hypotheses including multisensory integration, attention and consciousness. The claustrum’s thin shape makes it difficult to investigate,...
bioRxivSeptember 1, 2023Trang-Anh Estelle Nghiem, Byeongwook Lee, Tzu-Hao Harry Chao et al.
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The default mode network (DMN) is a large-scale brain network known to be suppressed during a wide range of cognitive tasks. However, our comprehension of its role in naturalistic and unconstrained behaviors has remained elusive because most research on the DMN has been conducted within the restrictive confines of MRI scanners. Here we use multisite GCaMP fiber photometry with simultaneous...
Abstract The human brain is a complex system, whose activity exhibits flexible and continuous reorganisation across space and time. The decomposition of whole-brain recordings into harmonic modes has revealed a repertoire of gradient-like activity patterns associated with distinct brain functions. However, the way these activity patterns are expressed over time with their changes in various...
SUMMARY: Substantial changes in behavior, physiology, and brain function occur when alertness decreases 1– 5 . These changes in brain function involve increased synchronization between cortical areas 6,7 as well as alterations in sensory processing pathways and networks connecting the thalamus and cortex 5,8–11 . Cognitive tasks engage overlapping functional networks with sensory pathways...
Perturbational complexity analysis predicts the presence of consciousness in volunteers and patients by stimulating the brain with brief pulses, recording electroencephalographic (EEG) responses, and computing their spatiotemporal complexity. We examined the underlying neural circuits in mice by directly stimulating cortex while recording with EEG and Neuropixels probes during wakefulness and...
bioRxivMarch 10, 2023David Pitcher, Magdalena Sliwinska, Daniel Kaiser
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Recognizing facial expressions is dependent on multiple brain networks specialized for different cognitive functions. In the current study participants ( N =20) were scanned using functional magnetic resonance imaging (fMRI) while they performed a covert facial expression naming task. Immediately prior to scanning thetaburst transcranial magnetic stimulation (TMS) was delivered over the right...
bioRxivJanuary 18, 2023Cristina Delgado-Sallent, Thomas Gener, Pau Nebot et al.
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NMDAR hypofunction is a pathophysiological mechanism relevant for schizophrenia. Acute administration of the NMDAR antagonist phencyclidine (PCP) induces psychosis in patients and animals while subchronic PCP (sPCP) produces cognitive dysfunction for weeks. We investigated the neural correlates of memory and perceptual impairments in mice treated with sPCP and the rescuing abilities of the...
bioRxivJanuary 16, 2023Anastasiya Zaytseva, Evelina Bouckova, McKennon J. Wiles et al.
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Ketamine is shown to enhance excitatory synaptic drive in the hippocampus, which is presumed to underlie its rapid antidepressant effects. Moreover, ketamine’s therapeutic actions are likely mediated by enhancing neuronal Ca2+ signaling. However, ketamine is a noncompetitive NMDA receptor (NMDAR) antagonist that inhibits excitatory synaptic transmission and postsynaptic Ca2+ signaling. Thus, it...
Abstract Psychoactive mushrooms in the genus Psilocybe have immense cultural value and have been used for centuries in Mesoamerica. Despite a recent surge in interest in these mushrooms due to emerging evidence that psilocybin, the main psychoactive compound, is a promising therapeutic for a variety of mental illnesses, their phylogeny and taxonomy remain substantially incomplete. Moreover, the...
bioRxivJuly 27, 2022Salma Salhi, Youssef Kora, Gisu Ham et al.
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The underlying anatomical structure is fundamental to the study of brain networks and is likely to play a key role in the generation of conscious experience. We conduct a computational and graph-theoretical study of the human structural connectome incorporating a variety of subcortical structures including the brainstem, which is typically not considered in similar studies. Our computational...
bioRxivJuly 22, 2022Salma Salhi, Youssef Kora, Gisu Ham et al.
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The underlying anatomical structure is fundamental to the study of brain networks and is likely to play a key role in the generation of conscious experience. We conduct a computational and graph-theoretical study of the human structural connectome incorporating a variety of subcortical structures including the brainstem, which is typically not considered in similar studies. Our computational...
A bstract : Human body awareness is malleable and adaptive to changing contexts. The illusory sense of body-ownership has been studied since the publication of the rubber hand illusion, where ambiguous body ownership feeling, expressed as “the dummy hand is my hand even though that is not true”, was first defined. Phenomenologically, the ambiguous body ownership is attributed to a conflict...
bioRxivOctober 12, 2021Sophie Waldron, Rachel Pass, Simonas Griesius et al.
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Genetic studies implicate disruption to the DLG2 gene in copy number variants as increasing risk for schizophrenia, autism spectrum disorders and intellectual disability. To investigate psychiatric endophenotypes associated with DLG2 haploinsufficiency (and concomitant PSD-93 protein reduction) a novel clinically relevant Dlg2+/- rat was assessed for abnormalities in anxiety, sensorimotor...
We show that both pharmacological and non-pharmacological treatments of depression activate TrkB receptors—a well-established target of antidepressants—by inducing a physiological response coupled to sedation. Several rapid-acting antidepressants trigger TrkB signaling by evoking a state associated with electroencephalographic slow-wave activity, behavioral immobility, reduced cerebral glucose...
bioRxivJuly 14, 2021Jian Li, W. Curley, B. Guérin et al.
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The default mode network (DMN) mediates self-awareness and introspection, core components of human consciousness. Therapies to restore consciousness in patients with severe brain injuries have historically targeted subcortical sites in the brainstem, thalamus, hypothalamus, basal forebrain, and basal ganglia, with the goal of reactivating cortical DMN nodes. However, the subcortical...
Stroboscopic stimulation has been previously shown to induce visual hallucinations and altered states of consciousness, state by entraining the brain to the driving frequency, similar to those reported during the psychedelics although little systematic research exists on the effect of specific stimulation frequency on experience. The present study investigated the effects of different...
Event-related potentials (ERPs) associated with the involuntary orientation of (bottom-up) attention towards an unexpected sound are of larger amplitude in high dream recallers (HR) than in low dream recallers (LR) during passive listening, suggesting different attentional functioning. We measured bottom-up and top-down attentional performance and their cerebral correlates in 18 HR (11 women,...
Mounting evidence suggests that during conscious states, the electrodynamics of the cortex are poised near a critical point or phase transition, and that this near-critical behavior supports the vast flow of information through cortical networks during conscious states. Here, for the first time, we empirically identify the specific critical point near which conscious cortical dynamics operate...
bioRxivMay 21, 2021K. Kishida, L. P. Sands
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The private and dynamic nature of conscious subjective experience poses an empirical challenge that has led neuroscience-based theories about consciousness to note the importance of ‘the hard problem’ of explaining how subjective phenomenal experience can arise from neural activity but set it aside and focus on the ‘easier’ problems associated with information representation and behavior. This...
Experienced meditators reduce the activity of the default mode network (DMN), a brain system preferentially active when people are not engaged in specific tasks. However, the neural modulation of the DMN in novices remain largely unexplored. By using electroencephalography, we investigated the DMN functional connectivity in two groups of novices: the meditation group practiced six consecutive...