Flexible coordinator and switcher hubs for adaptive task control

AbstractFunctional connectivity studies have identified at least two large-scale neural systems that constitute cognitive control networks – the frontoparietal network (FPN) and cingulo-opercular network (CON). Control networks are thought to support goal-directed cognition and behavior. It was previously shown that the FPN flexibly shifts its global connectivity pattern according to task goal, consistent with a “flexible hub” mechanism for cognitive control. Our aim was to build on this finding to develop a functional cartography (a multi-metric profile) of control networks in terms of dynamic network properties. We quantified network properties in (male and female) humans using a high-control-demand cognitive paradigm involving switching among 64 task sets. We hypothesized that cognitive control is enacted by the FPN and CON via distinct but complementary roles reflected in network dynamics. Consistent with a flexible “coordinator” mechanism, FPN connections were varied across tasks, while maintaining within-network connectivity to aid cross-region coordination. Consistent with a flexible “switcher” mechanism, CON regions switched to other networks in a task-dependent manner, driven primarily by reduced within-network connections to other CON regions. This pattern of results suggests FPN acts as a dynamic, global coordinator of goal-relevant information, while CON transiently disbands to lend processing resources to other goal-relevant networks. This cartography of network dynamics reveals a dissociation between two prominent cognitive control networks, suggesting complementary mechanisms underlying goal-directed cognition.Significance StatementCognitive control supports a variety of behaviors requiring flexible cognition, such as rapidly switching between tasks. Furthermore, cognitive control is negatively impacted in a variety of mental illnesses. We used tools from network science to characterize the implementation of cognitive control by large-scale brain systems. This revealed that two systems – the frontoparietal (FPN) and cingulo-opercular (CON) networks – have distinct but complementary roles in controlling global network reconfigurations. The FPN exhibited properties of a flexible coordinator (orchestrating task changes), while CON acted as a flexible switcher (switching specific regions to other systems to lend processing resources). These findings reveal an underlying distinction in cognitive processes that may be applicable to clinical, educational, and machine learning work targeting cognitive flexibility.

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The human brain’s intrinsic network architecture is organized to represent diverse cognitive task information

10.1101/2021.01.25.428141 ◽

2021 ◽

Author(s):

Douglas H. Schultz ◽

Takuya Ito ◽

Michael W. Cole

Keyword(s):

Cognitive Control ◽

Network Architecture ◽

Cognitive Task ◽

Global Network ◽

Connectivity Pattern ◽

Control Networks ◽

Domain Generality ◽

Intrinsic Connectivity ◽

General Capacity ◽

Logic Rule

AbstractA set of distributed cognitive control networks are known to contribute to diverse cognitive demands, yet it is unclear how these networks gain this domain-general capacity. We hypothesized that this capacity is largely due to the particular organization of the human brain’s intrinsic network architecture. Specifically, we tested the possibility that each brain region’s domain generality is reflected in its level of global (hub-like) intrinsic connectivity, as well as its particular global connectivity topography. Consistent with prior work, we found that cognitive control networks exhibited domain generality, as they represented diverse task context information covering sensory, motor response, and logic rule domains. Supporting our hypothesis, we found that the level of global intrinsic connectivity (as estimated with task-free fMRI) was correlated with domain generality during tasks. Further, using a novel information fingerprint mapping approach, we found that each brain region’s unique cognitive rule response profile could be predicted based on its unique intrinsic connectivity pattern. Together these results suggest that the human brain’s intrinsic network architecture supports its ability to represent diverse cognitive task information, largely via the placement of cognitive control networks within the brain’s global network organization.

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Stabilization of Brain Network Dynamics during Childhood and Adolescence is Associated with Gene Expressions

10.1101/2021.03.03.433828 ◽

2021 ◽

Author(s):

Tianyuan Lei ◽

Xuhong Liao ◽

Xiaodan Chen ◽

Tengda Zhao ◽

Yuehua Xu ◽

...

Keyword(s):

Large Scale ◽

Expression Profiles ◽

Brain Networks ◽

Network Dynamics ◽

Brain Network ◽

Global Network ◽

Association Cortex ◽

Childhood And Adolescence ◽

Gene Expressions ◽

Age Related

AbstractFunctional brain networks require dynamic reconfiguration to support flexible cognitive function. However, the developmental principles shaping brain network dynamics remain poorly understood. Here, we report the longitudinal development of large-scale brain network dynamics during childhood and adolescence, and its connection with gene expression profiles. Using a multilayer network model, we show the temporally varying modular architecture of child brain networks, with higher network switching primarily in the association cortex and lower switching in the primary regions. This topographical profile exhibits progressive maturation, which manifests as reduced modular dynamics, particularly in the transmodal (e.g., default-mode and frontoparietal) and sensorimotor regions. These developmental refinements mediate age-related enhancements of global network segregation and are linked with the expression profiles of genes associated with the enrichment of ion transport and nucleobase-containing compound transport. These results highlight a progressive stabilization of brain dynamics, which expand our understanding of the neural mechanisms that underlie cognitive development.

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How the human brain introspects about one’s own episodes of cognitive control

10.1101/208637 ◽

2017 ◽

Author(s):

David Soto ◽

Mona Theodoraki ◽

Pedro M. Paz-Alonso

Keyword(s):

Cognitive Control ◽

Human Brain ◽

Internal Model ◽

Large Scale ◽

Brain Activity ◽

Temporal Correlation ◽

Control Networks ◽

Control Functions ◽

Cognitive States ◽

Behavioural Performance

AbstractMetacognition refers to our capacity to reflect upon our experiences, thoughts and actions. Metacognition processes are linked to cognitive control functions that allow keeping our actions on-task. But it is unclear how the human brain builds an internal model of one’s cognition and behaviour. We conducted 2 fMRI experiments in which brain activity was recorded ‘online’ as participants engaged in a memory-guided search task and then later ‘offline’ when participants introspected about their prior experience and cognitive states during performance. In Experiment 1 the memory cues were task-relevant while in Experiment 2 they were irrelevant. Across Experiments, the patterns of brain activity, including frontoparietal regions, were similar during on-task and introspection states. However the connectivity profile amongst frontoparietal areas was distint during introspection and modulated by the relevance of the memory cues. Introspection was also characterized by increased temporal correlation between the default-mode network (DMN), frontoparietal and dorsal attention networks and visual cortex. We suggest that memories of one’s own experience during task performance are encoded in large-scale patterns of brain activity and that coupling between DMN and frontoparietal control networks may be crucial to build an internal model of one’s behavioural performance.

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Increased amygdala volume and functional connectivity with cognitive control networks in chronic migraine

10.1101/2020.08.31.20185397 ◽

2020 ◽

Author(s):

Danielle D DeSouza ◽

Samuel R Krimmel ◽

Bharati M Sanjanwala ◽

Addie Peretz ◽

Vinod Menon ◽

...

Keyword(s):

Functional Connectivity ◽

Cognitive Control ◽

Chronic Migraine ◽

Resting State ◽

Large Scale ◽

Pain Catastrophizing ◽

Headache Frequency ◽

Control Networks ◽

Affective Symptoms ◽

Amygdala Volume

Objective: To characterize the role of the amygdala in episodic (EM) and chronic (CM) migraine, we evaluated amygdala volumes, functional connectivity (FC), and associations with clinical and affective measures. Methods: Eighty-eight patients (44 with EM and 44 age- and sex-matched patients with CM) completed anatomical and resting-state functional MRI scans. Amygdala volumes and resting-state FC to three core large-scale cognitive control networks (default mode (DMN), salience (SN), central executive (CEN)) were compared between groups. Associations between amygdala volume and FC, measures of headache severity (frequency and intensity), and cognitive-affective measures (depression, anxiety, pain catastrophizing) were evaluated. Results: Compared to EM, patients with CM had larger amygdala volume bilaterally. Headache frequency and intensity were associated with increased left and right amygdala volume, and depression was associated with increased right amygdala volume. Patients with CM also demonstrated increased left amygdala FC with the DMN, which across patients was related to headache frequency. Left amygdala FC to the SN was correlated with headache intensity while right amygdala FC to the CEN was correlated with pain catastrophizing. Conclusion: Our findings reveal increased amygdala volume and FC with large-scale neurocognitive networks in patients with CM compared to EM. Aberrant amygdala volume and FC measures were associated with increased migraine severity, depression, and pain catastrophizing, pointing to a link between emotion and pain in migraine. Our findings provide novel insights into amygdala involvement in chronic migraine and may inform future interventions aimed at preventing the progression of both headache and its negative cognitive-affective symptoms.

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Metastable neural dynamics underlies cognitive performance across multiple behavioural paradigms

10.1101/657569 ◽

2019 ◽

Author(s):

Thomas H. Alderson ◽

Arun L.W. Bokde ◽

J.A.Scott. Kelso ◽

Liam Maguire ◽

Damien Coyle

Keyword(s):

Cognitive Control ◽

Cognitive Performance ◽

Resting State ◽

Network Architecture ◽

Large Scale ◽

Fluid Intelligence ◽

Coordination Dynamics ◽

Resting State Networks ◽

Control Networks ◽

Local Areas

AbstractDespite resting state networks being associated with a variety of cognitive abilities, it remains unclear how these local areas act in concert to express particular cognitive operations. Theoretical and empirical accounts indicate that large-scale resting state networks reconcile dual tendencies toward integration and segregation by operating in a metastable regime of their coordination dynamics. One proposal is that metastability confers important behavioural qualities by dynamically binding distributed local areas into large-scale neurocognitive entities. We tested this hypothesis by analysing fMRI data in a large cohort of healthy individuals (N=566) and comparing the metastability of the brain’s large-scale resting network architecture at rest and during the performance of several tasks. Task-based reasoning was principally characterised by high metastability in cognitive control networks and low metastability in sensory processing areas. Although metastability between resting state networks increased during task performance, cognitive ability was more closely linked to spontaneous activity. High metastability in the intrinsic connectivity of cognitive control networks was linked to novel problem solving (or fluid intelligence) but was less important in tasks relying on prior experience (or crystallised intelligence). Crucially, subjects with resting architectures similar or ‘pre-configured’ to a task-general arrangement demonstrated superior cognitive performance. Taken together, our findings support a critical linkage between the spontaneous metastability of the large-scale networks of the cerebral cortex and cognition.

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Large-Scale Brain Network Dynamics Supporting Adolescent Cognitive Control

Journal of Neuroscience ◽

10.1523/jneurosci.1634-14.2014 ◽

2014 ◽

Vol 34 (42) ◽

pp. 14096-14107 ◽

Cited By ~ 64

Author(s):

D. B. Dwyer ◽

B. J. Harrison ◽

M. Yucel ◽

S. Whittle ◽

A. Zalesky ◽

...

Keyword(s):

Cognitive Control ◽

Large Scale ◽

Network Dynamics ◽

Brain Network

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Salience network dynamics underlying successful resistance of temptation

10.1101/129676 ◽

2017 ◽

Author(s):

Rosa Steimke ◽

Jason S. Nomi ◽

Vince D Calhoun ◽

Christine Stelzel ◽

Lena M. Paschke ◽

...

Keyword(s):

Individual Differences ◽

Functional Connectivity ◽

Cognitive Control ◽

Target Location ◽

Network Dynamics ◽

Self Control ◽

Salience Network ◽

Primary Role ◽

Dynamic Functional Connectivity ◽

Control Networks

AbstractSelf-control and the ability to resist temptation are critical for successful completion of long-term goals. Contemporary models in cognitive neuroscience emphasize the primary role of prefrontal cognitive control networks in aligning behavior with such goals. Here we use gaze pattern analysis and dynamic functional connectivity fMRI data to explore how individual differences in the ability to resist temptation are related to intrinsic brain dynamics of the cognitive control and salience networks. Behaviorally, individuals exhibit greater gaze distance from target location (e.g. higher distractibility) during presentation of tempting erotic images compared with neutral images. Individuals whose intrinsic dynamic functional connectivity patterns gravitate towards configurations in which salience detection systems are less strongly coupled with visual systems resist tempting distractors more effectively. The ability to resist tempting distractors was not significantly related to intrinsic dynamics of the cognitive control network. These results suggest that susceptibility to temptation is governed in part by individual differences in salience network dynamics, and provide novel evidence for involvement of brain systems outside canonical cognitive control networks in contributing to individual differences in self-control.

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The Effect of Active Site-inhibited Factor VIIa on Tissue Factor-initiated Coagulation Using Platelets before and after Aspirin Administration

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657715 ◽

1997 ◽

Vol 78 (04) ◽

pp. 1202-1208 ◽

Cited By ~ 18

Author(s):

Marianne Kjalke ◽

Julie A Oliver ◽

Dougald M Monroe ◽

Maureane Hoffman ◽

Mirella Ezban ◽

...

Keyword(s):

Tissue Factor ◽

Active Site ◽

Large Scale ◽

Thrombin Generation ◽

Factor Viia ◽

Dependent Manner ◽

Antithrombotic Agent ◽

Before And After ◽

Ic50 Values

SummaryActive site-inactivated factor VIIa has potential as an antithrombotic agent. The effects of D-Phe-L-Phe-L-Arg-chloromethyl ketone-treated factor VIla (FFR-FVIIa) were evaluated in a cell-based system mimicking in vivo initiation of coagulation. FFR-FVIIa inhibited platelet activation (as measured by expression of P-selectin) and subsequent large-scale thrombin generation in a dose-dependent manner with IC50 values of 1.4 ± 0.8 nM (n = 8) and 0.9 ± 0.7 nM (n = 7), respectively. Kd for factor VIIa binding to monocytes ki for FFR-FVIIa competing with factor VIIa were similar (11.4 ± 0.8 pM and 10.6 ± 1.1 pM, respectively), showing that FFR-FVIIa binds to tissue factor in the tenase complex with the same affinity as factor VIIa. Using platelets from volunteers before and after ingestion of aspirin (1.3 g), there were no significant differences in the IC50 values of FFR-FVIIa [after aspirin ingestion, the IC50 values were 1.7 ± 0.9 nM (n = 8) for P-selectin expression, p = 0.37, and 1.4 ± 1.3 nM (n = 7) for thrombin generation, p = 0.38]. This shows that aspirin treatment of platelets does not influence the inhibition of tissue factor-initiated coagulation by FFR-FVIIa, probably because thrombin activation of platelets is not entirely dependent upon expression of thromboxane A2.

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Reconfiguration of human evolving large-scale epileptic brain networks prior to seizures: an evaluation with node centralities

Scientific Reports ◽

10.1038/s41598-020-78899-7 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Rieke Fruengel ◽

Timo Bröhl ◽

Thorsten Rings ◽

Klaus Lehnertz

Keyword(s):

Large Scale ◽

Brain Networks ◽

Brain Regions ◽

Brain Network ◽

Theoretical Concept ◽

Global Network ◽

Time Resolved ◽

Functional Connections ◽

Node Centrality ◽

Network Mechanism

AbstractPrevious research has indicated that temporal changes of centrality of specific nodes in human evolving large-scale epileptic brain networks carry information predictive of impending seizures. Centrality is a fundamental network-theoretical concept that allows one to assess the role a node plays in a network. This concept allows for various interpretations, which is reflected in a number of centrality indices. Here we aim to achieve a more general understanding of local and global network reconfigurations during the pre-seizure period as indicated by changes of different node centrality indices. To this end, we investigate—in a time-resolved manner—evolving large-scale epileptic brain networks that we derived from multi-day, multi-electrode intracranial electroencephalograpic recordings from a large but inhomogeneous group of subjects with pharmacoresistant epilepsies with different anatomical origins. We estimate multiple centrality indices to assess the various roles the nodes play while the networks transit from the seizure-free to the pre-seizure period. Our findings allow us to formulate several major scenarios for the reconfiguration of an evolving epileptic brain network prior to seizures, which indicate that there is likely not a single network mechanism underlying seizure generation. Rather, local and global aspects of the pre-seizure network reconfiguration affect virtually all network constituents, from the various brain regions to the functional connections between them.

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Potentiating Effect of Mandelate and Lactate on Chemically Induced Germination in Members of Bacillus cereus Sensu Lato

Applied and Environmental Microbiology ◽

10.1128/aem.01722-17 ◽

2017 ◽

Vol 83 (24) ◽

Author(s):

Alistair H. Bishop

Keyword(s):

Bacillus Cereus ◽

Large Scale ◽

Germination Rate ◽

Dependent Manner ◽

Clostridium Sporogenes ◽

Specific Chemical ◽

Content Type ◽

Ph Range ◽

Significant Discovery ◽

The Impact

ABSTRACT Endospores of the genus Bacillus can be triggered to germinate by a limited number of chemicals. Mandelate had powerful additive effects on the levels and rates of germination produced in non-heat-shocked spores of Bacillus anthracis strain Sterne, Bacillus cereus, and Bacillus thuringiensis when combined with l-alanine and inosine. Mandelate had no germinant effect on its own but was active with these germinants in a dose-dependent manner at concentrations higher than 0.5 mM. The maximum rate and extent of germination were produced in B. anthracis by 100 mM l-alanine with 10 mM inosine; this was equaled by just 25% of these germinants when supplemented with 10 mM mandelate. Half the maximal germination rate was produced by 40% of the optimum germinant concentrations or 15% of them when supplemented with 0.8 mM mandelate. Germination rates in B. thuringiensis were highest around neutrality, but the potentiating effect of mandelate was maintained over a wider pH range than was germination with l-alanine and inosine alone. For all species, lactate also promoted germination in the presence of l-alanine and inosine; this was further increased by mandelate. Ammonium ions also enhanced l-alanine- and inosine-induced germination but only when mandelate was present. In spite of the structural similarities, mandelate did not compete with phenylalanine as a germinant. Mandelate appeared to bind to spores while enhancing germination. There was no effect when mandelate was used in conjunction with nonnutrient germinants. No effect was produced with spores of Bacillus subtilis, Clostridium sporogenes, or C. difficile. IMPORTANCE The number of chemicals that can induce germination in the species related to Bacillus cereus has been defined for many years, and they conform to specific chemical types. Although not a germinant itself, mandelate has a structure that is different from these germination-active compounds, and its addition to this list represents a significant discovery in the fundamental biology of spore germination. This novel activity may also have important applied relevance given the impact of spores of B. cereus in foodborne disease and B. anthracis as a threat agent. The destruction of spores of B. anthracis, for example, particularly over large outdoor areas, poses significant scientific and logistical problems. The addition of mandelate and lactate to the established mixtures of l-alanine and inosine would decrease the amount of the established germinants required and increase the speed and level of germination achieved. The large-scale application of “germinate to decontaminate” strategy may thus become more practicable.

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