Evidence of a hierarchical representation in bodily self-consciousness: the neural correlates of embodiment and presence in virtual worlds

Frontiers in Human Neuroscience, Journal Year: 2025, Volume and Issue: 19

Published: April 1, 2025

Bodily Self-Consciousness (BSC) is the perception of bodily awareness that arises from integration neuronal signals in multiple sensory modalities. BSC composed embodiment (the owning a body) and presence being at location). Converging lines evidence suggest are supported by different neural networks. Several models have been proposed to describe how manifests these networks, but networks interact not fully understood. We propose predicated upon embodiment. Specifically, even though for partially overlap, there exists subset brain areas mediate flow information those supporting presence. To test this model, feedback was manipulated virtual environment affect BSC, while measuring behavioral performance physiological responses relevant areas. Correlated versus uncorrelated used manipulate perceptions First- third-person perspective Mean reaction times accuracy were better with correlated first-person perspective. Functional magnetic resonance imaging (fMRI) measurements activity identified frontoparietal temporoparietal appear support presence, respectively. compared effect manipulations on vice versa. The sizes greater than This trend also observed appeared encode both data indicates associated may depend

Language: Английский

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Electrical stimulation of the peripheral and central vestibular system

Current Opinion in Neurology, Journal Year: 2023, Volume and Issue: unknown

Published: Oct. 26, 2023

Purpose of review Electrical stimulation the peripheral and central vestibular system using noninvasive (galvanic stimulation, GVS) or invasive (intracranial electrical brain iEBS) approaches have a long history use in studying self-motion perception balance control. The aim this is to summarize recent electrophysiological studies effects GVS, functional mapping iEBS awake patients. Recent findings GVS has become increasingly common assessment treatment wide range clinical disorders including vestibulopathy Parkinson's disease. results single unit recording provided new insight into neural mechanisms underlying GVS-evoked improvements perceptual motor responses. Furthermore, application patients with epilepsy during surgery causal evidence information processing mostly middle cingulate cortex, posterior insula, inferior parietal lobule, amygdala, precuneus, superior temporal gyrus. Summary established that evokes robust parallel activation both canal otolith afferents significantly different from evoked by natural head motion stimulation. there can induce beneficial plasticity pathways loss. In addition, highlighted an underestimated contribution areas medial part cerebral hemispheres cortical network.

Language: Английский

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Connectivity and functional diversity of different temporo-occipital nodes for action perception

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 15, 2024

The temporo-occipital cortex (TOC) plays a key role in body and action perception, but current understanding of its functions is still limited. TOC regions are heterogeneous their perception poorly understood. This study adopted data-driven approaches to region selectivity investigated the connectivity nodes functional network sensitivity for different whole videos. In two human 7T fMRI experiments using independent component analysis, four adjacent selective were detected within with distinct profiles roles. Action type was observed posterior-ventral node visual cortex, posterior-dorsal precuneus anterior frontal cortex. specific modulations found middle gyrus aggressive condition increased decreased node. But defensive condition, node-nonspecific enhancement TOC-cingulate connectivity. By addressing issue multiple we show dissociation centres related potential hierarchy network.

Language: Английский

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Cortical thickness of the posterior cingulate cortex is associated with the ketamine-induced altered sense of self: An ultra-high field MRI study

Journal of Psychiatric Research, Journal Year: 2024, Volume and Issue: 172, P. 136 - 143

Published: Feb. 8, 2024

Subanesthetic doses of ketamine induce an antidepressant effect within hours in individuals with treatment-resistant depression while it furthermore induces immediate but transient psychotomimetic effects. Among these effects, altered sense self has specifically been associated the response to as well psychedelics. However, there is plenty variation extent drug-induced experience that might be explained by differences basal morphological characteristics, such cortical thickness. Regions have previously a psychedelics-induced and ketamine's mechanism action, are posterior cingulate cortex (PCC) pregenual anterior (pgACC). In this randomized, placebo-controlled, double-blind cross-over magnetic resonance imaging study, thirty-five healthy male participants (mean age±standard deviation (SD) = 25.1 ± 4.2 years) were scanned at 7 T. We investigated whether thickness two DMN regions, PCC pgACC, disembodiment unity scores, which used index ketamine-induced self. observed negative correlation between scores (R −0.54, p < 0.001). contrast, no significant association was found pgACC context existing literature, our findings highlight importance structure involved seems shared different agents effects operating on classes transmitter systems.

Language: Английский

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Fractional amplitude of low-frequency fluctuation and voxel-mirrored homotopic connectivity in patients with persistent postural-perceptual dizziness: resting-state functional magnetic resonance imaging study

Brain Connectivity, Journal Year: 2024, Volume and Issue: 14(5), P. 274 - 283

Published: April 16, 2024

Persistent postural-perception dizziness (PPPD) is a chronic subjective form of characterized by the exacerbation with active or passive movement, complex visual stimuli, and upright posture. Therefore, we aimed to analyze resting-state functional magnetic resonance imaging (fMRI) in patients PPPD using fractional amplitude low-frequency fluctuation (fALFF) voxel-mirrored homotopic connectivity (VMHC) evaluate correlation between abnormal regions brain clinical features investigate pathogenesis PPPD.

Language: Английский

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Is self-disturbance in schizophrenia due to inter- and intra-hemispheric white matter dysconnectivity?

Schizophrenia Research, Journal Year: 2024, Volume and Issue: 270, P. 129 - 131

Published: June 19, 2024

Language: Английский

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Enhancing interoceptive sensibility through exteroceptive–interoceptive sensory substitution

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: June 27, 2024

Exploring a novel approach to mental health technology, this study illuminates the intricate interplay between exteroception (the perception of external world), and interoception internal world). Drawing on principles sensory substitution, we investigated how interoceptive signals, particularly respiration, could be conveyed through exteroceptive modalities, namely vision hearing. To end, developed unique, immersive multisensory environment that translates respiratory signals in real-time into dynamic visual auditory stimuli. The system was evaluated by employing battery various psychological assessments, with findings indicating significant increase participants' sensibility an enhancement state flow, signifying positive engagement experience. Furthermore, correlation these two variables emerged, revealing bidirectional flow sensibility. Our research is first present substitution for substituting senses, specifically as transformative method interventions, paving way future research.

Language: Английский

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Neuroimaging of autobiographical memory in dementia with Lewy bodies: a story of insula

Brain Communications, Journal Year: 2024, Volume and Issue: 6(4)

Published: Jan. 1, 2024

Although deficits in learning and retrieving new information are well characterized dementia with Lewy bodies, autobiographical memory has never been explored this disease. Yet, impairments a pervasive feature of dementia, other neurodegenerative diseases. Moreover, corresponds to an extension over time the self, which we hypothesize is altered bodies impairment could be linked insular atrophy occurring from early stage In study, sought characterize explore their neural correlates on assumption that damage impact including its most elaborate components, such as memory. Twenty patients prodromal mild were selected participate exploratory study along 20 healthy control subjects. The Autobiographical Interview was used assess Performances compared between subjects, analysis across life periods recall conditions performed. 3D magnetic resonance images acquired for all participants, correlational analyses performed patient group using voxel-based morphometry. behavioural results showed performances significantly impaired body subjects temporally ungraded manner, both free specific probe (

Language: Английский

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I feel your pain: higher empathy is associated with higher posterior default mode network activity

Pain, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 1, 2024

Empathy is characterized as the ability to share one's experience and associated with altruism. Previous work using blood oxygen level-dependent (BOLD) functional MRI (fMRI) has found that empathy greater activation in brain mechanisms supporting mentalizing (temporoparietal junction), salience (anterior cingulate cortex; insula), self-reference (medial prefrontal precuneus). However, BOLD fMRI some limitations may not reliably capture tonic of empathy. To address this, present study used a perfusion-based arterial spin labeling approach provides direct quantifiable measurement cerebral flow (1 mL/100 g tissue/min) less susceptible low-frequency fluctuations empathy-based "carry-over" effects be introduced by fMRI-based block designs. Twenty-nine healthy females (mean age = 29 years) were administered noxious heat (48°C; left forearm) during fMRI. In next 2 scans, female volunteers viewed stranger (laboratory technician) their romantic partner, respectively, receive pain-evoking real-time positioned proximal scanner acquisition. Visual analog scale (0 "not unpleasant"; 10 "most unpleasant sensation imaginable") ratings collected after each condition. There was significantly (P 0.01) higher while viewing partner pain right temporoparietal junction, amygdala, anterior insula, orbitofrontal cortex, precuneus when compared stranger. Higher primary visual cortical activation. The findings indicate embodiment another's

Language: Английский

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Brain substates induced by DMT relate to sympathetic output and meaningfulness of the experience

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Feb. 19, 2024

Abstract N,N-Dimethyltryptamine (DMT) is a serotonergic psychedelic, known to rapidly induce short-lasting alterations in conscious experience, characterized by profound and immersive sense of physical transcendence alongside rich vivid auditory distortions visual imagery. Multimodal neuroimaging data paired with dynamic analysis techniques offer valuable approach for identifying unique signatures brain activity – linked autonomic physiology naturally unfolding during the altered state consciousness induced DMT. We leveraged simultaneous fMRI EKG acquired 14 healthy volunteers prior to, during, after intravenous administration DMT, and, separately, placebo. was preprocessed derive individual matrices, reflecting similarity time, community detection algorithms were applied on these matrices identify substates; used continuous heart rate. identified substate occurring immediately DMT injection, hippocampal medial parietal deactivations increased superior temporal lobe under Deactivations hippocampus cortex correlated usual space self-referential processes, deconstruction essential features ordinary consciousness. Superior activations instead audio/visual hallucinations experience “ entities ”, emergence sensory experiences Finally, rate positively hippocampus/medial deactivation negatively processes. These results suggest chain influence linking sympathetic regulation which combined, may contribute positive mental health outcomes related processing following psychedelic administration.

Language: Английский

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