Brain Network Dynamics Underlying Visuospatial Judgment: An fMRI Connectivity Study

Previous functional imaging research has consistently indicated involvement of bilateral fronto-parietal networks during the execution of visuospatial tasks. Studies with TMS have suggested that the right hemispheric network, but not the left, is functionally relevant for visuospatial judgments. However, very little is still known about the interactions within these fronto-parietal networks underlying visuospatial processing. In the current study, we investigated task modulation of functional connectivity (instantaneous correlations of regional time courses), and task-specific effective connectivity (direction of influences), within the right fronto-parietal network activated during visuospatial judgments. Ten healthy volunteers performed a behaviorally controlled visuospatial judgment task (ANGLE) or a control task (COLOR) in an fMRI experiment. Visuospatial task-specific activations were found in posterior parietal cortex (PPC) and middle/inferior frontal gyrus (MFG). Functional connectivity within this network was task-modulated, with significantly higher connectivity between PPC and MFG during ANGLE than during COLOR. Effective connectivity analysis for directed influence revealed that visuospatial task-specific projections within this network were predominantly in a frontal-to-parietal direction. Moreover, ANGLE-specific influences from thalamic nuclei to PPC were identified. Exploratory effective connectivity analysis revealed that closely neighboring clusters, within visuospatial regions, were differentially involved in the network. These neighboring clusters had opposite effective connectivity patterns to other nodes of the fronto-parietal network. Our data thus reveal that visuospatial judgments are supported by massive fronto-parietal backprojections, thalamo-parietal influence, and multiple stages, or loops, of information flow within the visuospatial network. We speculate on possible functional contributions of the various network nodes and informational loops in a neurocognitive model.

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The Cortical Organization of Writing Sequence: Evidence From Observing Chinese Characters in Motion

10.21203/rs.3.rs-285417/v1 ◽

2021 ◽

Author(s):

Zhaoqi Zhang ◽

Qiming Yuan ◽

Zeping Liu ◽

Man Zhang ◽

Junjie Wu ◽

...

Keyword(s):

Structural Equation ◽

Chinese Character ◽

Inferior Frontal Gyrus ◽

Hierarchical Control ◽

Brain Regions ◽

Brain Network ◽

Equation Model ◽

Chinese Characters ◽

General Motor ◽

The Right

Abstract Writing sequences play an important role in handwriting of Chinese characters. However, little is known regarding the integral brain patterns and network mechanisms of processing Chinese character writing sequences. The present study decoded brain patterns during observing Chinese characters in motion by using multi-voxel pattern analysis (MVPA), meta-analytic decoding analysis, and extended unified structural equation model (euSEM). We found that perception of Chinese character writing sequence recruited brain regions not only for general motor schema processing, i.e., the right inferior frontal gyrus, shifting and inhibition functions, i.e., the right postcentral gyrus and bilateral pre-SMA/dACC, but also for sensorimotor functions specific for writing sequences. More importantly, these brain regions formed a cooperatively top-down brain network where information was transmitted from brain regions for general motor schema processing to those specific for writing sequences. These findings not only shed light on the neural mechanisms of Chinese character writing sequences, but also extend the hierarchical control model on motor schema processing.

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Disentangling Mathematics from Executive Functions by Investigating Unique Functional Connectivity Patterns Predictive of Mathematics Ability

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_01367 ◽

2019 ◽

Vol 31 (4) ◽

pp. 560-573 ◽

Cited By ~ 1

Author(s):

Kenny Skagerlund ◽

Taylor Bolt ◽

Jason S. Nomi ◽

Mikael Skagenholt ◽

Daniel Västfjäll ◽

...

Keyword(s):

Functional Connectivity ◽

Resting State ◽

Inferior Frontal Gyrus ◽

Premotor Cortex ◽

Mathematical Ability ◽

Angular Gyrus ◽

Intraparietal Sulcus ◽

Supramarginal Gyrus ◽

Connectivity Patterns ◽

The Right

What are the underlying neurocognitive mechanisms that give rise to mathematical competence? This study investigated the relationship between tests of mathematical ability completed outside the scanner and resting-state functional connectivity (FC) of cytoarchitectonically defined subdivisions of the parietal cortex in adults. These parietal areas are also involved in executive functions (EFs). Therefore, it remains unclear whether there are unique networks for mathematical processing. We investigate the neural networks for mathematical cognition and three measures of EF using resting-state fMRI data collected from 51 healthy adults. Using 10 ROIs in seed to whole-brain voxel-wise analyses, the results showed that arithmetical ability was correlated with FC between the right anterior intraparietal sulcus (hIP1) and the left supramarginal gyrus and between the right posterior intraparietal sulcus (hIP3) and the left middle frontal gyrus and the right premotor cortex. The connection between the posterior portion of the left angular gyrus and the left inferior frontal gyrus was also correlated with mathematical ability. Covariates of EF eliminated connectivity patterns with nodes in inferior frontal gyrus, angular gyrus, and middle frontal gyrus, suggesting neural overlap. Controlling for EF, we found unique connections correlated with mathematical ability between the right hIP1 and the left supramarginal gyrus and between hIP3 bilaterally to premotor cortex bilaterally. This is partly in line with the “mapping hypothesis” of numerical cognition in which the right intraparietal sulcus subserves nonsymbolic number processing and connects to the left parietal cortex, responsible for calculation procedures. We show that FC within this circuitry is a significant predictor of math ability in adulthood.

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Aberrant Brain Functional Connectivity Strength and Effective Connectivity in Patients with Type 2 Diabetes Mellitus

Journal of Diabetes Research ◽

10.1155/2021/5171618 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Xi Guo ◽

Su Wang ◽

Yu-Chen Chen ◽

Heng-Le Wei ◽

Gang-Ping Zhou ◽

...

Keyword(s):

Functional Connectivity ◽

Disease Duration ◽

Effective Connectivity ◽

Functional Magnetic Resonance ◽

Resonance Imaging ◽

Functional Connectivity Strength ◽

The Right ◽

Brain Functional Connectivity ◽

Connectivity Strength

Alterations of brain functional connectivity in patients with type 2 diabetes mellitus (T2DM) have been reported by resting-state functional magnetic resonance imaging studies, but the underlying precise neuropathological mechanism remains unclear. This study is aimed at investigating the implicit alterations of functional connections in T2DM by integrating functional connectivity strength (FCS) and Granger causality analysis (GCA) and further exploring their associations with clinical characteristics. Sixty T2DM patients and thirty-three sex-, age-, and education-matched healthy controls (HC) were recruited. Global FCS analysis of resting-state functional magnetic resonance imaging was performed to explore seed regions with significant differences between the two groups; then, GCA was applied to detect directional effective connectivity (EC) between the seeds and other brain regions. Correlations of EC with clinical variables were further explored in T2DM patients. Compared with HC, T2DM patients showed lower FCS in the bilateral fusiform gyrus, right superior frontal gyrus (SFG), and right postcentral gyrus, but higher FCS in the right supplementary motor area (SMA). Moreover, altered directional EC was found between the left fusiform gyrus and bilateral lingual gyrus and right medial frontal gyrus (MFG), as well as between the right SFG and bilateral frontal regions. In addition, triglyceride, insulin, and plasma glucose levels were correlated with the abnormal EC of the left fusiform, while disease duration and cognitive function were associated with the abnormal EC of the right SFG in T2DM patients. These results suggest that T2DM patients show aberrant brain function connectivity strength and effective connectivity which is associated with the diabetes-related metabolic characteristics, disease duration, and cognitive function, providing further insights into the complex neural basis of diabetes.

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Dissociative-Traumatic Dimension and Triple Network: An EEG Functional Connectivity Study in a Sample of University Students

Psychopathology ◽

10.1159/000519563 ◽

2021 ◽

pp. 1-9

Author(s):

Giuseppe Alessio Carbone ◽

Claudio Imperatori ◽

Francesco Saverio Bersani ◽

Chiara Massullo ◽

Egle Maria Orlando ◽

...

Keyword(s):

Functional Connectivity ◽

University Students ◽

Posterior Parietal Cortex ◽

Self Report ◽

Connectivity Pattern ◽

Eyes Closed ◽

Dissociative Symptoms ◽

Trauma Ct ◽

Eeg Functional Connectivity ◽

The Right

Aims: We investigated the association among triple network electroencephalographic (EEG) functional connectivity, dissociative symptoms, and childhood trauma (CT) in a sample of university students. Sampling and Methods: Seventy-six participants (30 males and 46 females; mean age 22.12 ± 2.35) completed self-report measures investigating dissociative symptoms, CT, and depressive symptoms. Participants also performed an eyes-closed resting-state EEG recording. EEG analyses were conducted through the exact low-resolution electromagnetic tomography (eLORETA) software. Results: A 2-step cluster analysis revealed 2 groups: participants (N = 23) with high dissociative-traumatic dimension symptoms (DTD+) and participants (N = 53) with low DTD symptoms (DTD−). Compared to DTD− subjects, DTD+ participants showed decreased theta connectivity between the salience network (SN) and central executive network (CEN), specifically between the right anterior insula and the left posterior parietal cortex. No significant correlation was detected between EEG data and clinical variables. Conclusion: Our results raise the possibility of a dysfunctional connectivity pattern occurring between the SN and CEN in individuals with high DTD symptoms. Such connectivity pattern might reflect the neuropsychophysiological disintegration related to pathological dissociation.

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Association Between Trait Empathy and Resting Brain Activity in Women With Primary Dysmenorrhea During the Pain and Pain-Free Phases

Frontiers in Psychiatry ◽

10.3389/fpsyt.2020.608928 ◽

2020 ◽

Vol 11 ◽

Author(s):

Wanghuan Dun ◽

Tongtong Fan ◽

Qiming Wang ◽

Ke Wang ◽

Jing Yang ◽

...

Keyword(s):

Brain Activity ◽

Inferior Frontal Gyrus ◽

Brain Network ◽

Primary Dysmenorrhea ◽

Pain Experience ◽

Current State ◽

The Neural Network ◽

The Right ◽

The Brain

Empathy refers to the ability to understand someone else's emotions and fluctuates with the current state in healthy individuals. However, little is known about the neural network of empathy in clinical populations at different pain states. The current study aimed to examine the effects of long-term pain on empathy-related networks and whether empathy varied at different pain states by studying primary dysmenorrhea (PDM) patients. Multivariate partial least squares was employed in 46 PDM women and 46 healthy controls (HC) during periovulatory, luteal, and menstruation phases. We identified neural networks associated with different aspects of empathy in both groups. Part of the obtained empathy-related network in PDM exhibited a similar activity compared with HC, including the right anterior insula and other regions, whereas others have an opposite activity in PDM, including the inferior frontal gyrus and right inferior parietal lobule. These results indicated an abnormal regulation to empathy in PDM. Furthermore, there was no difference in empathy association patterns in PDM between the pain and pain-free states. This study suggested that long-term pain experience may lead to an abnormal function of the brain network for empathy processing that did not vary with the pain or pain-free state across the menstrual cycle.

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Dual n-back training improves functional connectivity of the right inferior frontal gyrus at rest

Scientific Reports ◽

10.1038/s41598-020-77310-9 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Tiina Salminen ◽

Caroline Garcia Forlim ◽

Torsten Schubert ◽

Simone Kühn

Keyword(s):

Functional Connectivity ◽

Inferior Frontal Gyrus ◽

Training Group ◽

Training Intervention ◽

Superior Parietal Cortex ◽

Default State ◽

Improved Performance ◽

The Right ◽

Task Parameters ◽

The Brain

AbstractSeveral studies have shown that the benefits of working memory (WM) training can be attributed to functional and structural neural changes in the underlying neural substrate. In the current study, we investigated whether the functional connectivity of the brain at rest in the default mode network (DMN) changes with WM training. We varied the complexity of the training intervention so, that half of the participants attended dual n-back training whereas the other half attended single n-back training. This way we could assess the effects of different training task parameters on possible connectivity changes. After 16 training sessions, the dual n-back training group showed improved performance accompanied by increased functional connectivity of the ventral DMN in the right inferior frontal gyrus, which correlated with improvements in WM. We also observed decreased functional connectivity in the left superior parietal cortex in this group. The single n-back training group did not show significant training-related changes. These results show that a demanding short-term WM training intervention can alter the default state of the brain.

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Altered Intra- and Interregional Synchronization in Resting-State Cerebral Networks Associated with Chronic Tinnitus

Neural Plasticity ◽

10.1155/2015/475382 ◽

2015 ◽

Vol 2015 ◽

pp. 1-11 ◽

Cited By ~ 20

Author(s):

Yu-Chen Chen ◽

Jian Zhang ◽

Xiao-Wei Li ◽

Wenqing Xia ◽

Xu Feng ◽

...

Keyword(s):

Functional Connectivity ◽

Resting State ◽

Brain Activity ◽

Inferior Frontal Gyrus ◽

Resting State Fmri ◽

Brain Regions ◽

Chronic Tinnitus ◽

Healthy Controls ◽

Tinnitus Distress ◽

The Right

Objective. Subjective tinnitus is hypothesized to arise from aberrant neural activity; however, its neural bases are poorly understood. To identify aberrant neural networks involved in chronic tinnitus, we compared the resting-state functional magnetic resonance imaging (fMRI) patterns of tinnitus patients and healthy controls.Materials and Methods. Resting-state fMRI measurements were obtained from a group of chronic tinnitus patients (n=29) with normal hearing and well-matched healthy controls (n=30). Regional homogeneity (ReHo) analysis and functional connectivity analysis were used to identify abnormal brain activity; these abnormalities were compared to tinnitus distress.Results. Relative to healthy controls, tinnitus patients had significant greater ReHo values in several brain regions including the bilateral anterior insula (AI), left inferior frontal gyrus, and right supramarginal gyrus. Furthermore, the left AI showed enhanced functional connectivity with the left middle frontal gyrus (MFG), while the right AI had enhanced functional connectivity with the right MFG; these measures were positively correlated with Tinnitus Handicap Questionnaires (r=0.459,P=0.012andr=0.479,P=0.009, resp.).Conclusions. Chronic tinnitus patients showed abnormal intra- and interregional synchronization in several resting-state cerebral networks; these abnormalities were correlated with clinical tinnitus distress. These results suggest that tinnitus distress is exacerbated by attention networks that focus on internally generated phantom sounds.

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Impact of anaesthesia on static and dynamic functional connectivity in mice

10.1101/2021.03.18.436098 ◽

2021 ◽

Author(s):

Tomokazu Tsurugizawa ◽

Daisuke Yoshimaru

Keyword(s):

Functional Connectivity ◽

Functional Mri ◽

Resting State ◽

Low Frequency ◽

Resting State Fmri ◽

Brain Network ◽

List Type ◽

Thalamic Nuclei ◽

Dynamic Functional Connectivity ◽

Subcortical Regions

AbstractA few studies have compared the static functional connectivity between awake and anaesthetized states in rodents by resting-state fMRI. However, impact of anaesthesia on static and dynamic fluctuations in functional connectivity has not been fully understood. Here, we developed a resting-state fMRI protocol to perform awake and anaesthetized functional MRI in the same mice. Static functional connectivity showed a widespread decrease under anaesthesia, such as when under isoflurane or a mixture of isoflurane and medetomidine. Several interhemispheric connections were key connections for anaesthetized condition from awake. Dynamic functional connectivity demonstrates the shift from frequent broad connections across the cortex, the hypothalamus, and the auditory-visual cortex to frequent local connections within the cortex only. Fractional amplitude of low frequency fluctuation in the thalamic nuclei decreased under both anaesthesia. These results indicate that typical anaesthetics for functional MRI alters the spatiotemporal profile of the dynamic brain network in subcortical regions, including the thalamic nuclei and limbic system.HighlightsResting-state fMRI was compared between awake and anaesthetized in the same mice.Anaesthesia induced a widespread decrease of static functional connectivity.Anaesthesia strengthened local connections within the cortex.fALFF in the thalamus was decreased by anaesthesia.

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Causally informed activity flow models provide mechanistic insight into the emergence of cognitive processes from brain network interactions

10.1101/2021.04.16.440226 ◽

2021 ◽

Author(s):

Ruben Sanchez-Romero ◽

Takuya Ito ◽

Ravi D. Mill ◽

Stephen José Hanson ◽

Michael W. Cole

Keyword(s):

Functional Connectivity ◽

Effective Connectivity ◽

Pearson Correlation ◽

Explanatory Power ◽

Memory Task ◽

Brain Regions ◽

Brain Network ◽

List Type ◽

Flow Models ◽

Insight Into

AbstractBrain activity flow models estimate the movement of task-evoked activity over brain connections to help explain the emergence of task-related functionality. Activity flow estimates have been shown to accurately predict task-evoked brain activations across a wide variety of brain regions and task conditions. However, these predictions have had limited explanatory power, given known issues with causal interpretations of the standard functional connectivity measures used to parameterize activity flow models. We show here that functional/effective connectivity (FC) measures grounded in causal principles facilitate mechanistic interpretation of activity flow models. Starting from Pearson correlation (the current field standard), we progress from FC measures with poor to excellent causal grounding, demonstrating a continuum of causal validity using simulations and empirical fMRI data. Finally, we apply a causal FC method to a dorsolateral prefrontal cortex region, demonstrating causal network mechanisms contributing to its strong activation during a 2-back (relative to a 0-back) working memory task. Together, these results reveal the promise of parameterizing activity flow models using causal FC methods to identify network mechanisms underlying cognitive computations in the human brain.Highlights-Activity flow models provide insight into how cognitive neural effects emerge from brain network interactions.-Functional connectivity methods grounded in causal principles facilitate mechanistic interpretations of task activity flow models.-Mechanistic activity flow models accurately predict task-evoked neural effects across a wide variety of brain regions and cognitive tasks.

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Structural and effective brain connectivity underlying biological motion detection

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1812859115 ◽

2018 ◽

Vol 115 (51) ◽

pp. E12034-E12042 ◽

Cited By ~ 18

Author(s):

Arseny A. Sokolov ◽

Peter Zeidman ◽

Michael Erb ◽

Philippe Ryvlin ◽

Karl J. Friston ◽

...

Keyword(s):

Biological Motion ◽

Effective Connectivity ◽

Inferior Frontal Gyrus ◽

Functional Integration ◽

Temporal Cortex ◽

Causal Modeling ◽

High Angular Resolution ◽

Wide Range ◽

Crus I ◽

The Right

The perception of actions underwrites a wide range of socio-cognitive functions. Previous neuroimaging and lesion studies identified several components of the brain network for visual biological motion (BM) processing, but interactions among these components and their relationship to behavior remain little understood. Here, using a recently developed integrative analysis of structural and effective connectivity derived from high angular resolution diffusion imaging (HARDI) and functional magnetic resonance imaging (fMRI), we assess the cerebro-cerebellar network for processing of camouflaged point-light BM. Dynamic causal modeling (DCM) informed by probabilistic tractography indicates that the right superior temporal sulcus (STS) serves as an integrator within the temporal module. However, the STS does not appear to be a “gatekeeper” in the functional integration of the occipito-temporal and frontal regions: The fusiform gyrus (FFG) and middle temporal cortex (MTC) are also connected to the right inferior frontal gyrus (IFG) and insula, indicating multiple parallel pathways. BM-specific loops of effective connectivity are seen between the left lateral cerebellar lobule Crus I and right STS, as well as between the left Crus I and right insula. The prevalence of a structural pathway between the FFG and STS is associated with better BM detection. Moreover, a canonical variate analysis shows that the visual sensitivity to BM is best predicted by BM-specific effective connectivity from the FFG to STS and from the IFG, insula, and STS to the early visual cortex. Overall, the study characterizes the architecture of the cerebro-cerebellar network for BM processing and offers prospects for assessing the social brain.

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