scholarly journals Connectivity between the hippocampus and default mode network during the relief, but not elicitation, of curiosity supports curiosity-enhanced memory enhancements

2021 ◽  
Author(s):  
Charlotte Murphy ◽  
Charan Ranganath ◽  
Matthias J Gruber
Keyword(s):  
Default Mode Network ◽  
Information Seeking ◽  
Short Delay ◽  
Default Mode ◽  
Memory Integration ◽  
Subcortical Regions ◽  
Cortical Regions ◽  
Enhanced Learning ◽  
The Brain

Consistent with the idea that curiosity enhances information seeking, it has been shown that activity within both the dopaminergic circuit and hippocampus supports curiosity-enhanced learning. However, the role of whole-brain mechanisms involved in cognitive control (fronto-parietal network; FPN) and memory integration (default mode network; DMN) that might underpin curiosity states and their effects on memory remain elusive. We hypothesised that the FPN and DMN should distinguish between high- and low-curiosity conditions and be recruited more heavily for later remembered information associated with high-curiosity. Here, we used functional magnetic resonance imaging whilst participants completed a trivia paradigm, in which we presented trivia questions associated with high- and low-curiosity, followed by the associated answer. After a short delay, we tested memory for trivia answers. We adopted a network-based parcellation of the brain into subnetworks of the FPN and DMN to examine how neural activity within, and functional connectivity between, each subnetwork predicts curiosity-enhanced memory. Across elicitation and relief of curiosity, we found focal recruitment of FPNA and widespread recruitment of DMN subnetworks in support of curiosity and curiosity-enhanced memory. Most importantly, during the elicitation of curiosity, functional subcortical connectivity and across cortical networks, but not subcortical-cortical coupling, correlated with curiosity-enhanced memory. However, during the relief of curiosity, coupling between subcortical regions and DMNA emerged in support of curiosity-enhanced memory. Taken together, our results provide the first evidence about how neuromodulatory mechanisms via the hippocampal-dopaminergic circuit trigger states of curiosity and thereby communicate to higher-order cortical regions to facilitate curiosity-enhanced memory.

scholarly journals The Chief Role of Frontal Operational Module of the Brain Default Mode Network in the Potential Recovery of Consciousness from the Vegetative State: A Preliminary Comparison of Three Case Reports

2016 ◽  
Vol 10 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Alexander A. Fingelkurts ◽  
Andrew A. Fingelkurts ◽  
Sergio Bagnato ◽  
Cristina Boccagni ◽  
Giuseppe Galardi
Keyword(s):  
Default Mode Network ◽  
Case Reports ◽  
Sense Of Self ◽  
Vegetative State ◽  
Post Injury ◽  
Course Of Disease ◽  
Default Mode ◽  
Person Perspective ◽  
The Brain

It has been argued that complex subjective sense of self is linked to the brain default-mode network (DMN). Recent discovery of heterogeneity between distinct subnets (or operational modules - OMs) of the DMN leads to a reconceptualization of its role for the experiential sense of self. Considering the recent proposition that the frontal DMN OM is responsible for the first-person perspective and the sense of agency, while the posterior DMN OMs are linked to the continuity of ‘I’ experience (including autobiographical memories) through embodiment and localization within bodily space, we have tested in this study the hypothesis that heterogeneity in the operational synchrony strength within the frontal DMN OM among patients who are in a vegetative state (VS) could inform about a stable self-consciousness recovery later in the course of disease (up to six years post-injury). Using EEG operational synchrony analysis we have demonstrated that among the three OMs of the DMN only the frontal OM showed important heterogeneity in VS patients as a function of later stable clinical outcome. We also found that the frontal DMN OM was characterized by the process of active uncoupling (stronger in persistent VS) of operations performed by the involved neuronal assemblies.

scholarly journals Weak Task Synchronization of Default Mode Network in Task Based Paradigms

2021 ◽  
Author(s):  
Vaibhav Tripathi ◽  
Rahul Garg
Keyword(s):  
Linear Model ◽  
Default Mode Network ◽  
Active Component ◽  
General Linear Model ◽  
General Linear ◽  
Negative Behavior ◽  
Temporal Synchronization ◽  
Default Mode ◽  
The Brain

Default Mode Network (DMN) has been called a "task-negative" network which deactivates during engaging extrinsic tasks. But the behavior is more nuanced. We analyse the DMN during three different tasks (visual, affect and language; n=54) and find inter trial variability which gets amiss when analysed using General Linear Model (GLM). The region also shows significant across subjects variations which limits the use of Inter Subject Correlation (ISC) method to detect correlated deactivations during the task. We introduce Temporal Synchronization Analysis (TSA), a family of methods that can help detect inter-trial (IT-TSA) and inter-subject (IS-TSA) synchronization across the brain. We find that DMN is weakly synchronized across trials and subjects, challenging the notion of task negative behavior. Our study suggests the role of DMN as an active component associated with self-referential, autobiographical processes which are deactivated differentially and non linearly across trials and subjects in the presence of extrinsic processes.

scholarly journals The role of the default mode network in component processes underlying the wandering mind

2017 ◽  
Vol 12 (7) ◽  
pp. 1047-1062 ◽  
Author(s):  
Giulia L. Poerio ◽  
Mladen Sormaz ◽  
Hao-Ting Wang ◽  
Daniel Margulies ◽  
Elizabeth Jefferies ◽  
...  
Keyword(s):  
Default Mode Network ◽  
Default Mode ◽  
Component Processes

scholarly journals A selective effect of dopamine on information-seeking

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Valentina Vellani ◽  
Lianne P de Vries ◽  
Anne Gaule ◽  
Tali Sharot
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Information Seeking ◽  
Selective Effect ◽  
Reward Seeking ◽  
The Impact ◽  
The Brain ◽  
Insight Into ◽  
Primary Reward

Humans are motivated to seek information from their environment. How the brain motivates this behavior is unknown. One speculation is that the brain employs neuromodulatory systems implicated in primary reward-seeking, in particular dopamine, to instruct information-seeking. However, there has been no causal test for the role of dopamine in information-seeking. Here, we show that administration of a drug that enhances dopamine function (dihydroxy-L-phenylalanine; L-DOPA) reduces the impact of valence on information-seeking. Specifically, while participants under Placebo sought more information about potential gains than losses, under L-DOPA this difference was not observed. The results provide new insight into the neurobiology of information-seeking and generates the prediction that abnormal dopaminergic function (such as in Parkinson’s disease) will result in valence-dependent changes to information-seeking.

scholarly journals I know that I don’t know: Structural and functional connectivity underlying meta-ignorance in pre-schoolers

2018 ◽  
Author(s):  
Elisa Filevich ◽  
Caroline Garcia Forlim ◽  
Carmen Fehrman ◽  
Carina Forster ◽  
Markus Paulus ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Default Mode Network ◽  
Orbitofrontal Cortex ◽  
Cingulate Gyrus ◽  
Partial Knowledge ◽  
Metacognitive Monitoring ◽  
Default Mode ◽  
Posterior Cingulate Gyrus ◽  
Knowledge Condition ◽  
The Brain

Research Highlights[1] Children develop the ability to report that they do not know something at around five years of age.[2] Children who could correctly report their own ignorance in a partial-knowledge task showed thicker cortices within medial orbitofrontal cortex.[3] This region was functionally connected to parts of the default-mode network.[4] The default-mode network might support the development of correct metacognitive monitoring.AbstractMetacognition plays a pivotal role in human development. The ability to realize that we do not know something, or meta-ignorance, emerges after approximately five years of age. We aimed at identifying the brain systems that underlie the developmental emergence of this ability in a preschool sample.Twenty-four children aged between five and six years answered questions under three conditions of a meta-ignorance task twice. In the critical partial knowledge condition, an experimenter first showed two toys to a child, then announced that she would place one of them in a box behind a screen, out of sight from the child. The experimenter then asked the child whether or not she knew which toy was in the box.Children who answered correctly both times to the metacognitive question in the partial knowledge condition (n=9) showed greater cortical thickness in a cluster within left medial orbitofrontal cortex than children who did not (n=15). Further, seed-based functional connectivity analyses of the brain during resting state revealed that this region is functionally connected to the medial orbitofrontal gyrus, posterior cingulate gyrus and precuneus, and mid- and inferior temporal gyri.This finding suggests that the default mode network, critically through its prefrontal regions, supports introspective processing. It leads to the emergence of metacognitive monitoring allowing children to explicitly report their own ignorance.

Assessment of Graph Metrics and Lateralization of Brain Connectivity in Progression of Alzheimer's Disease Using fMRI

2017 ◽  
Vol 9 (4) ◽  
pp. 46-66 ◽  
Author(s):  
Bhuvaneshwari Bhaskaran ◽  
Kavitha Anandan
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Default Mode Network ◽  
Brain Connectivity ◽  
Brain Network ◽  
Brain Disorder ◽  
Default Mode ◽  
Graph Metrics ◽  
Functional Topology ◽  
The Brain

Alzheimer's disease (AD) is a progressive brain disorder which has a long preclinical phase. The beta-amyloid plaques and tangles in the brain are considered as the main pathological causes. Functional connectivity is typically examined in capturing brain network dynamics in AD. A definitive underconnectivity is observed in patients through the progressive stages of AD. Graph theoretic modeling approaches have been effective in understanding the brain dynamics. In this article, the brain connectivity patterns and the functional topology through the progression of Alzheimer's disease are analysed using resting state fMRI. The altered network topology is analysed by graphed theoretical measures and explains cognitive deficits caused by the progression of this disease. Results show that the functional topology is disrupted in the default mode network regions as the disease progresses in patients. Further, it is observed that there is a lack of left lateralization involving default mode network regions as the severity in AD increases.

scholarly journals Temporal circuit of macroscale dynamic brain activity supports human consciousness

2020 ◽  
Vol 6 (11) ◽  
pp. eaaz0087 ◽  
Author(s):  
Zirui Huang ◽  
Jun Zhang ◽  
Jinsong Wu ◽  
George A. Mashour ◽  
Anthony G. Hudetz
Keyword(s):  
Default Mode Network ◽  
Functional Role ◽  
Brain Activity ◽  
Human Consciousness ◽  
Attention Network ◽  
Attention Networks ◽  
Default Mode ◽  
Dorsal Attention Network ◽  
Brain States

The ongoing stream of human consciousness relies on two distinct cortical systems, the default mode network and the dorsal attention network, which alternate their activity in an anticorrelated manner. We examined how the two systems are regulated in the conscious brain and how they are disrupted when consciousness is diminished. We provide evidence for a “temporal circuit” characterized by a set of trajectories along which dynamic brain activity occurs. We demonstrate that the transitions between default mode and dorsal attention networks are embedded in this temporal circuit, in which a balanced reciprocal accessibility of brain states is characteristic of consciousness. Conversely, isolation of the default mode and dorsal attention networks from the temporal circuit is associated with unresponsiveness of diverse etiologies. These findings advance the foundational understanding of the functional role of anticorrelated systems in consciousness.

scholarly journals Multimodal Imaging of Alzheimer Pathophysiology in the Brain's Default Mode Network

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Jonghan Shin ◽  
Vladimir Kepe ◽  
Gary W. Small ◽  
Michael E. Phelps ◽  
Jorge R. Barrio
Keyword(s):  
Default Mode Network ◽  
Multimodal Imaging ◽  
Temporal Cortex ◽  
Brain Regions ◽  
Default Network ◽  
Spatial Correlations ◽  
Tau Pathology ◽  
Significant Discrepancy ◽  
Default Mode ◽  
The Brain

The spatial correlations between the brain's default mode network (DMN) and the brain regions known to develop pathophysiology in Alzheimer's disease (AD) have recently attracted much attention. In this paper, we compare results of different functional and structural imaging modalities, including MRI and PET, and highlight different patterns of anomalies observed within the DMN. Multitracer PET imaging in subjects with and without dementia has demonstrated that [C-11]PIB- and [F-18]FDDNP-binding patterns in patients with AD overlap within nodes of the brain's default network including the prefrontal, lateral parietal, lateral temporal, and posterior cingulate cortices, with the exception of the medial temporal cortex (especially, the hippocampus) where significant discrepancy between increased [F-18]FDDNP binding and negligible [C-11]PIB-binding was observed. [F-18]FDDNP binding in the medial temporal cortex—a key constituent of the DMN—coincides with both the presence of amyloid and tau pathology, and also with cortical areas with maximal atrophy as demonstrated by T1-weighted MR imaging of AD patients.

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