scholarly journals Signal propagation via cortical hierarchies

2020 ◽  
Vol 4 (4) ◽  
pp. 1072-1090 ◽  
Author(s):  
Bertha Vézquez-Rodríguez ◽  
Zhen-Qi Liu ◽  
Patric Hagmann ◽  
Bratislav Misic
Keyword(s):  
Shortest Paths ◽  
Signal Propagation ◽  
Brain Regions ◽  
Hierarchical Organization ◽  
Attention Networks ◽  
Diffusion Spectrum Imaging ◽  
Cortical Hierarchy ◽  
Spectrum Imaging ◽  
Structural Networks ◽  
The Brain

The wiring of the brain is organized around a putative unimodal-transmodal hierarchy. Here we investigate how this intrinsic hierarchical organization of the brain shapes the transmission of information among regions. The hierarchical positioning of individual regions was quantified by applying diffusion map embedding to resting-state functional MRI networks. Structural networks were reconstructed from diffusion spectrum imaging and topological shortest paths among all brain regions were computed. Sequences of nodes encountered along a path were then labeled by their hierarchical position, tracing out path motifs. We find that the cortical hierarchy guides communication in the network. Specifically, nodes are more likely to forward signals to nodes closer in the hierarchy and cover a range of unimodal and transmodal regions, potentially enriching or diversifying signals en route. We also find evidence of systematic detours, particularly in attention networks, where communication is rerouted. Altogether, the present work highlights how the cortical hierarchy shapes signal exchange and imparts behaviorally relevant communication patterns in brain networks.

scholarly journals Signal propagation via cortical hierarchies

2020 ◽  
Author(s):  
Bertha Vázquez-Rodríguez ◽  
Zhen-Qi Liu ◽  
Patric Hagmann ◽  
Bratislav Mišić
Keyword(s):  
Shortest Paths ◽  
Signal Propagation ◽  
Brain Regions ◽  
Hierarchical Organization ◽  
Attention Networks ◽  
Diffusion Spectrum Imaging ◽  
Cortical Hierarchy ◽  
Spectrum Imaging ◽  
Structural Networks ◽  
The Brain

The wiring of the brain is organized around a putative unimodal-transmodal hierarchy. Here we investigate how this intrinsic hierarchical organization of the brain shapes the transmission of information among regions. The hierarchical positioning of individual regions was quantified by applying diffusion map embedding to resting state functional MRI networks. Structural networks were reconstructed from diffusion spectrum imaging and topological shortest paths among all brain regions were computed. Sequences of nodes encountered along a path were labelled by their hierarchical position, tracing out path motifs. We find that the cortical hierarchy guides communication in the network. Specifically, nodes are more likely to forward signals to nodes closer in the hierarchy and cover a range of unimodal and transmodal regions, potentially enriching or diversifying signals en route. We also find evidence of systematic detours, particularly in attention networks, where communication is re-routed. Altogether, the present work highlights how the cortical hierarchy shapes signal exchange and imparts behaviourally-relevant communication patterns in brain networks.

scholarly journals Exploring the Relationship between Gray and White Matter in Healthy Adults: A Hybrid Research of Cortical Reconstruction and Tractography

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yongxiang Zhao ◽  
Qianqian Li ◽  
Jiachen Du ◽  
Hongjian He ◽  
Peipeng Liang ◽  
...  
Keyword(s):  
White Matter ◽  
Brain Regions ◽  
Healthy Adults ◽  
Microstructural Properties ◽  
Diffusion Spectrum Imaging ◽  
Diffusion Parameters ◽  
Spectrum Imaging ◽  
Cortical Morphology ◽  
The Relationship ◽  
The Brain

The gray matter (GM) and white matter (WM) are structurally and functionally related in the human brain. Among the numerous neuroimaging studies, yet only a few have investigated these two structures in the same sample. So, there is limited and inconsistent information about how they are correlated in the brain of healthy adults. In this study, we combined cortical reconstruction with diffusion spectrum imaging (DSI) tractography to investigate the relationship between cortical morphology and microstructural properties of major WM tracts in 163 healthy young adults. The results showed that cortical thickness (CTh) was positively correlated with the coherent tract-wise fractional anisotropy (FA) value, and the correlation was stronger in the dorsal areas than in the ventral areas. For other diffusion parameters, CTh was positively correlated with axial diffusivity (AD) of coherent fibers in the frontal areas and negatively correlated with radial diffusivity (RD) of coherent fibers in the dorsal areas. These findings suggest that the correlation between GM and WM is inhomogeneity and could be interpreted with different mechanisms in different brain regions. We hope our research could provide new insights into the studies of diseases in which the GM and WM are both affected.

Compressed sensorimotor-to-transmodal hierarchical organization in schizophrenia

2021 ◽  
pp. 1-14
Author(s):  
Debo Dong ◽  
Dezhong Yao ◽  
Yulin Wang ◽  
Seok-Jun Hong ◽  
Sarah Genon ◽  
...  
Keyword(s):  
Sensory Information ◽  
Resting State Fmri ◽  
Brain Regions ◽  
High Order ◽  
Hierarchical Organization ◽  
System Level ◽  
Integrative System ◽  
Sensorimotor Region ◽  
Cortical Hierarchy ◽  
High Level

Abstract Background Schizophrenia has been primarily conceptualized as a disorder of high-order cognitive functions with deficits in executive brain regions. Yet due to the increasing reports of early sensory processing deficit, recent models focus more on the developmental effects of impaired sensory process on high-order functions. The present study examined whether this pathological interaction relates to an overarching system-level imbalance, specifically a disruption in macroscale hierarchy affecting integration and segregation of unimodal and transmodal networks. Methods We applied a novel combination of connectome gradient and stepwise connectivity analysis to resting-state fMRI to characterize the sensorimotor-to-transmodal cortical hierarchy organization (96 patients v. 122 controls). Results We demonstrated compression of the cortical hierarchy organization in schizophrenia, with a prominent compression from the sensorimotor region and a less prominent compression from the frontal−parietal region, resulting in a diminished separation between sensory and fronto-parietal cognitive systems. Further analyses suggested reduced differentiation related to atypical functional connectome transition from unimodal to transmodal brain areas. Specifically, we found hypo-connectivity within unimodal regions and hyper-connectivity between unimodal regions and fronto-parietal and ventral attention regions along the classical sensation-to-cognition continuum (voxel-level corrected, p < 0.05). Conclusions The compression of cortical hierarchy organization represents a novel and integrative system-level substrate underlying the pathological interaction of early sensory and cognitive function in schizophrenia. This abnormal cortical hierarchy organization suggests cascading impairments from the disruption of the somatosensory−motor system and inefficient integration of bottom-up sensory information with attentional demands and executive control processes partially account for high-level cognitive deficits characteristic of schizophrenia.

scholarly journals Association fibre pathways of the brain: parallel observations from diffusion spectrum imaging and autoradiography

Brain ◽  
2007 ◽  
Vol 130 (3) ◽  
pp. 630-653 ◽  
Author(s):  
J. D. Schmahmann ◽  
D. N. Pandya ◽  
R. Wang ◽  
G. Dai ◽  
H. E. D'Arceuil ◽  
...  
Keyword(s):  
Diffusion Spectrum Imaging ◽  
Spectrum Imaging ◽  
The Brain

scholarly journals Attention recruits frontal cortex in human infants

2021 ◽  
Vol 118 (12) ◽  
pp. e2021474118
Author(s):  
Cameron T. Ellis ◽  
Lena J. Skalaban ◽  
Tristan S. Yates ◽  
Nicholas B. Turk-Browne
Keyword(s):  
Brain Regions ◽  
First Year ◽  
Human Infants ◽  
Attention Networks ◽  
Parietal Lobes ◽  
Young Infants ◽  
Child Friendly ◽  
Attentional Cuing ◽  
Infant Attention ◽  
The Brain

Young infants learn about the world by overtly shifting their attention to perceptually salient events. In adults, attention recruits several brain regions spanning the frontal and parietal lobes. However, it is unclear whether these regions are sufficiently mature in infancy to support attention and, more generally, how infant attention is supported by the brain. We used event-related functional magnetic resonance imaging (fMRI) in 24 sessions from 20 awake behaving infants 3 mo to 12 mo old while they performed a child-friendly attentional cuing task. A target was presented to either the left or right of the infant’s fixation, and offline gaze coding was used to measure the latency with which they saccaded to the target. To manipulate attention, a brief cue was presented before the target in three conditions: on the same side as the upcoming target (valid), on the other side (invalid), or on both sides (neutral). All infants were faster to look at the target on valid versus invalid trials, with valid faster than neutral and invalid slower than neutral, indicating that the cues effectively captured attention. We then compared the fMRI activity evoked by these trial types. Regions of adult attention networks activated more strongly for invalid than valid trials, particularly frontal regions. Neither behavioral nor neural effects varied by infant age within the first year, suggesting that these regions may function early in development to support the orienting of attention. Together, this furthers our mechanistic understanding of how the infant brain controls the allocation of attention.

The Neuroscience of Learning Agility

2021 ◽  
pp. 118-142
Author(s):  
Kim E. Ruyle
Keyword(s):  
Emotional Intelligence ◽  
Prefrontal Cortex ◽  
Executive Function ◽  
Limbic System ◽  
Brain Regions ◽  
Learning Agility ◽  
Attention Networks ◽  
The Relationship ◽  
The Brain

“The Neuroscience of Learning Agility” explores the relationship between neurobiology and learning agility. It provides an overview of the organization of the brain, focusing on the roles of the limbic system and the prefrontal cortex and how these particular brain regions relate to personality, executive function, and the metacompetencies of emotional intelligence and learning agility. The neuroscience of learning is discussed, including the brain’s attention networks, neuroplasticity, and biological underpinnings of memory. An argument is posited that the brain’s perceptions of threats directly impacts one’s personality and, by extension, influences one’s level of learning agility. The chapter concludes by providing neuroscience-based suggestions for developing learning agility.

Novel Cognitive Functions Arise at the Convergence of Macroscale Gradients

2021 ◽  
pp. 1-16
Author(s):  
Heejung Jung ◽  
Tor D. Wager ◽  
R. McKell Carter
Keyword(s):  
Brain Regions ◽  
Higher Order ◽  
Hierarchical Organization ◽  
Functional Modules ◽  
Cortical Areas ◽  
Future Space ◽  
Close Proximity ◽  
Sensory Cortices ◽  
Developmental Characteristics ◽  
The Brain

Abstract Functions in higher-order brain regions are the source of extensive debate. Although past trends have been to describe the brain—especially posterior cortical areas—in terms of a set of functional modules, a new emerging paradigm focuses on the integration of proximal functions. In this review, we synthesize emerging evidence that a variety of novel functions in the higher-order brain regions are due to convergence: convergence of macroscale gradients brings feature-rich representations into close proximity, presenting an opportunity for novel functions to arise. Using the TPJ as an example, we demonstrate that convergence is enabled via three properties of the brain: (1) hierarchical organization, (2) abstraction, and (3) equidistance. As gradients travel from primary sensory cortices to higher-order brain regions, information becomes abstracted and hierarchical, and eventually, gradients meet at a point maximally and equally distant from their sensory origins. This convergence, which produces multifaceted combinations, such as mentalizing another person's thought or projecting into a future space, parallels evolutionary and developmental characteristics in such regions, resulting in new cognitive and affective faculties.

scholarly journals Brain activity fluctuations propagate as waves traversing the cortical hierarchy

2020 ◽  
Author(s):  
Yameng Gu ◽  
Lucas E. Sainburg ◽  
Sizhe Kuang ◽  
Feng Han ◽  
Jack W. Williams ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Spontaneous Activity ◽  
Resting State ◽  
Brain Activity ◽  
Resting State Fmri ◽  
Hierarchical Organization ◽  
Subcortical Structures ◽  
Cortical Hierarchy ◽  
Neural Origin ◽  
The Brain

AbstractThe brain exhibits highly organized patterns of spontaneous activity as measured by resting-state fMRI fluctuations that are being widely used to assess the brain’s functional connectivity. Some evidence suggests that spatiotemporally coherent waves are a core feature of spontaneous activity that shapes functional connectivity, though this has been difficult to establish using fMRI given the temporal constraints of the hemodynamic signal. Here we investigated the structure of spontaneous waves in human fMRI and monkey electrocorticography. In both species, we found clear, repeatable, and directionally constrained activity waves coursed along a spatial axis approximately representing cortical hierarchical organization. These cortical propagations were closely associated with activity changes in distinct subcortical structures, particularly those related to arousal regulation, and modulated across different states of vigilance. The findings demonstrate a neural origin of spatiotemporal fMRI wave propagation at rest and link it to the principal gradient of resting-state fMRI connectivity.

scholarly journals Altered Sensorimotor-to-Transmodal Hierarchical Organization in Schizophrenia

2020 ◽  
Author(s):  
Debo Dong ◽  
Dezhong Yao ◽  
Yulin Wang ◽  
Seok-Jun Hong ◽  
Sarah Genon ◽  
...  
Keyword(s):  
Sensory Information ◽  
Brain Regions ◽  
High Order ◽  
Hierarchical Organization ◽  
System Level ◽  
Integrative System ◽  
Developmental Effects ◽  
Sensorimotor Region ◽  
Cortical Hierarchy ◽  
High Level

AbstractFor decades, schizophrenia has been primarily conceptualized as a disorder of high-order cognitive functions with deficits in executive brain regions. Yet due to the increasing reports of early sensory processing deficit, recent models focus more on the developmental effects of impaired sensory process on high-order functions. The present study examined whether this pathological interaction relates to an overarching system-level imbalance, specifically a disruption in macroscale hierarchy affecting integration and segregation of unimodal and transmodal networks. We applied a novel combination of connectome gradient and stepwise connectivity analysis to resting-state functional magnetic resonance imaging (rsfMRI) to characterize the sensorimotor-to-transmodal cortical hierarchy organization (96 patients vs. 122 controls). Using these techniques, we demonstrated compression of the cortical hierarchy organization in schizophrenia, with a prominent compression from the sensorimotor region and a less prominent compression from the frontal-parietal region, resulting in a diminished separation between sensory and fronto-parietal cognitive systems. Further analyses suggested reduced differentiation related to atypical functional connectome transition from unimodal to transmodal brain areas. Specifically, we found hypo-connectivity within unimodal regions and hyper-connectivity between unimodal regions and frontoparietal and ventral attention regions along the classical sensation-to-cognition continuum established in prior neuroanatomical work. The compression of cortical hierarchy organization represents a novel and integrative system-level substrate underlying the pathological interaction of early sensory and cognitive function in schizophrenia. This abnormal cortical hierarchy organization suggests cascaded impairments stemming from the disrupted somatosensory-motor system and inefficient integration of bottom-up sensory information with attentional demands and executive control processes partially account for high-level cognitive deficits characteristic of schizophrenia.

scholarly journals Adolescent tuning of association cortex in human structural brain networks

2017 ◽  
Author(s):  
František Váša ◽  
Jakob Seidlitz ◽  
Rafael Romero-Garcia ◽  
Kirstie J. Whitaker ◽  
Gideon Rosenthal ◽  
...  
Keyword(s):  
Sharp Decrease ◽  
Brain Regions ◽  
Brain Network ◽  
Association Cortex ◽  
Structural Correlation ◽  
Age Related ◽  
Cortical Regions ◽  
Structural Networks ◽  
The Brain ◽  
Age Related Changes

AbstractMotivated by prior data on local cortical shrinkage and intracortical myelination, we predicted age-related changes in topological organisation of cortical structural networks during adolescence. We estimated structural correlation from magnetic resonance imaging measures of cortical thickness at 308 regions in a sample of N=297 healthy participants, aged 14-24 years. We used a novel sliding-window analysis to measure age-related changes in network attributes globally, locally and in the context of several community partitions of the network. We found that the strength of structural correlation generally decreased as a function of age. Association cortical regions demonstrated a sharp decrease in nodal degree (hubness) from 14 years, reaching a minimum at approximately 19 years, and then levelling off or even slightly increasing until 24 years. Greater and more prolonged age-related changes in degree of cortical regions within the brain network were associated with faster rates of adolescent cortical myelination and shrinkage. The brain regions that demonstrated the greatest age-related changes were concentrated within prefrontal modules. We conclude that human adolescence is associated with biologically plausible changes in structural imaging markers of brain network organization, consistent with the concept of tuning or consolidating anatomical connectivity between frontal cortex and the rest of the connectome.

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