Gradients in brain organization

NeuroImage, Год журнала: 2022, Номер 251, С. 118987 - 118987

Опубликована: Фев. 10, 2022

Язык: Английский

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Functional geometry of the cortex encodes dimensions of consciousness

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Янв. 5, 2023

Abstract Consciousness is a multidimensional phenomenon, but key dimensions such as awareness and wakefulness have been described conceptually rather than neurobiologically. We hypothesize that of consciousness are encoded in multiple neurofunctional the brain. analyze cortical gradients, which continua brain’s overarching functional geometry, to characterize these dimensions. demonstrate disruptions human – due pharmacological, neuropathological, or psychiatric causes associated with degradation one more major gradients depending on state. Network-specific reconfigurations within gradient space behavioral unresponsiveness various etiologies, spatial correlate temporal disruption structured transitions dynamic brain states. In this work, we therefore provide unifying framework for both health disease.

Язык: Английский

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Serotonergic psychedelic drugs LSD and psilocybin reduce the hierarchical differentiation of unimodal and transmodal cortex

NeuroImage, Год журнала: 2022, Номер 256, С. 119220 - 119220

Опубликована: Апрель 26, 2022

Lysergic acid diethylamide (LSD) and psilocybin are serotonergic psychedelic compounds with potential in the treatment of mental health disorders. Past neuroimaging investigations have revealed that both can elicit significant changes to whole-brain functional organization dynamics. A recent proposal linked past findings into a unified model hypothesized reduced hierarchical as key mechanism underlying state, but this has yet be directly tested. We applied non-linear dimensionality reduction technique previously used map connectivity gradients assess cortical LSD state from two published pharmacological resting-state fMRI datasets (N = 15 9, respectively). Results supported our primary hypothesis: The principal gradient connectivity, describing hierarchy unimodal transmodal cortex, was significantly flattened under drugs relative their respective placebo conditions. Between-condition contrasts driven by differentiation at extremes - default frontoparietal networks upper end, somatomotor lower. Gradient-based mapping indicated underpinned disruption modular increased unimodal-transmodal crosstalk. involving second third gradient, which, respectively represent axes sensory executive differentiation, also showed alterations across drugs. These provide support for mechanistic relevant therapeutic applications psychedelics. More fundamentally, we first evidence macroscale sensitive an acute manipulation, supporting role psychedelics scientific tools perturb organization.

Язык: Английский

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The neural correlates of ongoing conscious thought

iScience, Год журнала: 2021, Номер 24(3), С. 102132 - 102132

Опубликована: Фев. 2, 2021

A core goal in cognitive neuroscience is identifying the physical substrates of patterns thought that occupy our daily lives. Contemporary views suggest landscape ongoing experience heterogeneous and can be influenced by features both person context. This perspective piece considers recent work explicitly accounts for heterogeneity context dependence thought. These studies reveal systems linked to attention control are important organizing response changing environmental demands. also establish a role default mode network beyond task-negative or purely episodic content, example, implicating it level vivid detail task contexts spontaneous self-generated experiential states. Together, this demonstrates reflected activity multiple neural systems, distinguish between processes contributing how unfolds from those these experiences regulated.

Язык: Английский

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Anterior insula regulates brain network transitions that gate conscious access

Cell Reports, Год журнала: 2021, Номер 35(5), С. 109081 - 109081

Опубликована: Май 1, 2021

Conscious access to sensory information is likely gated at an intermediate site between primary and transmodal association cortices, but the structure responsible remains unknown. We perform functional neuroimaging determine neural correlates of conscious using a volitional mental imagery task, report paradigm not confounded by motor behavior. Titrating propofol loss behavioral responsiveness in healthy volunteers creates dysfunction anterior insular cortex (AIC) with impairment dynamic transitions default-mode dorsal attention networks. Candidate subcortical regions mediating gating or arousal (thalamus, basal forebrain) fail show this association. The role AIC consistent findings awake participants, whose predicted pre-stimulus activity near perceptual threshold. These data support hypothesis that AIC, situated position cortical hierarchy, regulates brain network gate access.

Язык: Английский

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Dynamic expression of brain functional systems disclosed by fine-scale analysis of edge time series

Network Neuroscience, Год журнала: 2021, Номер 5(2), С. 405 - 433

Опубликована: Янв. 1, 2021

Abstract Functional connectivity (FC) describes the statistical dependence between neuronal populations or brain regions in resting-state fMRI studies and is commonly estimated as Pearson correlation of time courses. Clustering community detection reveals densely coupled sets constituting networks functional systems. These systems manifest most clearly when FC sampled over longer epochs but appear to fluctuate on shorter timescales. Here, we propose a new approach reveal temporal fluctuations series. Unwrapping signal correlations yields pairwise co-fluctuation series, one for each node pair edge, allows tracking fine-scale dynamics across network. Co-fluctuations partition network, at step, into exactly two communities. Sampled time, overlay these bipartitions, binary decomposition original very closely approximates connectivity. Bipartitions exhibit characteristic spatiotemporal patterns that are reproducible participants imaging runs, capture individual differences, disclose expression Our findings document transiently intermittently, results from many variable instances system expression. Potential applications this set discussed.

Язык: Английский

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Prediction of stimulus-independent and task-unrelated thought from functional brain networks

Nature Communications, Год журнала: 2021, Номер 12(1)

Опубликована: Март 19, 2021

Abstract Neural substrates of “mind wandering” have been widely reported, yet experiments varied in their contexts and definitions this psychological phenomenon, limiting generalizability. We aimed to develop test the generalizability, specificity, clinical relevance a functional brain network-based marker for well-defined feature mind wandering—stimulus-independent, task-unrelated thought (SITUT). Combining MRI (fMRI) with online experience sampling healthy adults, we defined connectome-wide model inter-regional coupling—dominated by default-frontoparietal control subnetwork interactions—that predicted trial-by-trial SITUT fluctuations within novel individuals. Model predictions generalized an independent sample adults attention-deficit/hyperactivity disorder (ADHD). In three additional resting-state fMRI studies (total n = 1115), including individuals ADHD, demonstrated further prediction (at modest effect sizes) using multiple trait-level in-scanner measures. Our findings suggest that is represented common pattern network interactions across time scales contexts.

Язык: Английский

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The psychological correlates of distinct neural states occurring during wakeful rest

Scientific Reports, Год журнала: 2020, Номер 10(1)

Опубликована: Дек. 3, 2020

Abstract When unoccupied by an explicit external task, humans engage in a wide range of different types self-generated thinking. These are often unrelated to the immediate environment and have unique psychological features. Although contemporary perspectives on ongoing thought recognise heterogeneity these states, we lack both clear understanding how classify specific they can be mapped empirically. In current study, capitalise advances machine learning that allow continuous neural data divided into set distinct temporally re-occurring patterns, or states. We applied this technique large resting state which also acquired retrospective descriptions participants’ experiences during scan. found two identified states were predictive patterns thinking at rest. One highlighted pattern activity commonly seen demanding tasks, time individuals spent was associated with experience focused problem solving future. A second under less conditions, it linked reports intrusive thoughts about past. Finally, tended fall either end hierarchy is reflect brain’s response cognitive demands. Together, results demonstrate approaches take advantage time-varying changes function play important role repertoire Moreover, establish features related variation along similar vein those when brain responds task

Язык: Английский

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Allostasis as a core feature of hierarchical gradients in the human brain

Network Neuroscience, Год журнала: 2022, Номер 6(4), С. 1010 - 1031

Опубликована: Янв. 1, 2022

This paper integrates emerging evidence from two broad streams of scientific literature into one common framework: (a) hierarchical gradients functional connectivity that reflect the brain's large-scale structural architecture (e.g., a lamination gradient in cerebral cortex); and (b) approaches to predictive processing its specific instantiations called

Язык: Английский

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Perceptual coupling and decoupling of the default mode network during mind-wandering and reading

eLife, Год журнала: 2022, Номер 11

Опубликована: Март 21, 2022

While reading, our mind can wander to unrelated autobiographical information, creating a perceptually decoupled state detrimental narrative comprehension. To understand how this mind-wandering emerges, we asked whether retrieving content necessitates functional disengagement from visual input. In Experiment 1, brain activity was recorded using magnetic resonance imaging (fMRI) in an experimental situation mimicking naturally occurring mind-wandering, allowing us precisely delineate neural regions involved memory and reading. Individuals read expository texts ignored personally relevant memories, as well the opposite situation. Medial of default mode network (DMN) were recruited during retrieval. contrast, left temporal lateral prefrontal DMN, ventral cortex, when reading for two used connectivity both at rest tasks establish that (i) DMN linked are more functionally cortex than same engaged reading; (ii) individuals with self-generated mental contents poorer comprehension, while lab, showed decoupling between visually connected sites important primary cortex. A similar pattern found greater coupling site participants reported focus on face conflict cues; moreover, retrieval memories increased these sites. These converging data suggest lose track minds because generating relies cortical within which

Язык: Английский

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