A tripartite view of the posterior cingulate cortex

Nature reviews. Neuroscience, Journal Year: 2022, Volume and Issue: 24(3), P. 173 - 189

Published: Dec. 1, 2022

Language: Английский

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Flexible reuse of cortico-hippocampal representations during encoding and recall of naturalistic events

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: March 8, 2023

Abstract Although every life event is unique, there are considerable commonalities across events. However, little known about whether or how the brain flexibly represents information different components at encoding and during remembering. Here, we show that cortico-hippocampal networks systematically represent specific of events depicted in videos, both online experience episodic memory retrieval. Regions an Anterior Temporal Network represented people, generalizing contexts, whereas regions a Posterior Medial context information, people. prefrontal cortex generalized videos depicting same schema, hippocampus maintained event-specific representations. Similar effects were seen real-time recall, suggesting reuse overlapping memories. These representational profiles together provide computationally optimal strategy to scaffold for high-level components, allowing efficient comprehension, recollection, imagination.

Language: Английский

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Specialization of the human hippocampal long axis revisited

Proceedings of the National Academy of Sciences, Journal Year: 2025, Volume and Issue: 122(3)

Published: Jan. 14, 2025

The hippocampus possesses anatomical differences along its long axis. Here, we explored the functional specialization of human hippocampal axis using network-anchored precision MRI in two independent datasets (N = 11 and N 9) paired with behavioral analysis 266 238). Functional connectivity analyses demonstrated that anterior was preferentially correlated a cerebral network associated remembering, while posterior selectively contained region distinct salience. Seed regions placed within recapitulated networks. characterization task data identified replicated double dissociation. sensitive to remembering imagining future, specifically tracking process scene construction, displayed transient responses targets an oddball detection transitions between blocks. These findings suggest unexpected differential reflecting properties partner

Language: Английский

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A Whole-Cortex Probabilistic Diffusion Tractography Connectome

eNeuro, Journal Year: 2021, Volume and Issue: 8(1), P. ENEURO.0416 - 20.2020

Published: Jan. 1, 2021

The WU-Minn Human Connectome Project (HCP) is a publicly-available dataset containing state-of-the-art structural magnetic resonance imaging (MRI), functional MRI (fMRI), and diffusion (dMRI) for over thousand healthy subjects. While the planned scope of HCP included an anatomic connectome, resting-state fMRI (rs-fMRI) forms bulk HCP's current connectomic output. We address this by presenting full-cortex connectome derived from probabilistic tractography organized into HCP-MMP1.0 atlas. Probabilistic methods large sample sizes are preferable whole-connectome mapping as they increase fidelity traced low-probability connections. find that overall, connection strengths lognormally distributed decay exponentially with tract length, connectivity reasonably matches macaque histologic tracing in homologous areas, contralateral homologs left-lateralized language areas hyperconnected, hierarchical similarity influences connectivity. compare dMRI to existing rs-fMRI cortico-cortico-evoked potential matrices it more similar latter. This work helps fulfill promise will make possible comparisons between underlying connectomes various modalities, brain states, clinical conditions.

Language: Английский

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The Ventral and Dorsal Default Mode Networks Are Dissociably Modulated by the Vividness and Valence of Imagined Events

Journal of Neuroscience, Journal Year: 2021, Volume and Issue: 41(24), P. 5243 - 5250

Published: May 17, 2021

Recent work has shown that the brain's default mode network (DMN) is active when people imagine future. Here, we test in human participants (both sexes) whether future imagination can be decomposed into two dissociable psychological processes linked to different subcomponents of DMN. While measuring brain activity with fMRI as subjects events, manipulate vividness these events modulate demands for event construction, and valence evaluation. We found one subcomponent DMN, ventral DMN or medial temporal lobe (MTL) subsystem, responds but not imagined events. In contrast, another subcomponent, dorsal core This separate modifiability by provides strong evidence a neurocognitive dissociation between (1) construction novel, from individual components memory (2) evaluation constructed desirable undesirable.

Language: Английский

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New insights into anatomical connectivity along the anterior–posterior axis of the human hippocampus using in vivo quantitative fibre tracking

eLife, Journal Year: 2022, Volume and Issue: 11

Published: Nov. 8, 2022

The hippocampus supports multiple cognitive functions including episodic memory. Recent work has highlighted functional differences along the anterior–posterior axis of human hippocampus, but neuroanatomical underpinnings these remain unclear. We leveraged track-density imaging to systematically examine anatomical connectivity between cortical mantle and in vivo hippocampus. first identified most highly connected areas detailed degree which they preferentially connect Then, using a tractography pipeline specifically tailored measure location density streamline endpoints within we characterised where Our results provide new insights into how specific regions are associated with different inputs/outputs evidence that both gradients circumscribed dense extrinsic exist These findings inform conceptual debates field emphasise importance considering as heterogeneous structure. Overall, our represent major advance ability map understanding neural architecture hippocampal-dependent memory systems brain.

Language: Английский

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Schemas provide a scaffold for neocortical integration of new memories over time

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Oct. 2, 2022

Memory transformation is increasingly acknowledged in theoretical accounts of systems consolidation, yet how memory quality and neural representation change over time schemas influence this process remains unclear. We examined the behavioral schema-congruent incongruent object-scene pairs retrieved across 10-minutes 72-hours using fMRI. When a congruent schema was available, became coarser time, aided by post-encoding coupling between anterior hippocampus medial prefrontal cortex (mPFC). Only representations were integrated mPFC organized according to schematic context. In hippocampus, pattern similarity changed such that posterior represented specific details general context memories, irrespective congruency. Our findings suggest are used as scaffold facilitate neocortical integration information, illustrate evolution hippocampal organization detailed contextual time.

Language: Английский

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Autobiographical event memory and aging: older adults get the gist

Trends in Cognitive Sciences, Journal Year: 2022, Volume and Issue: 26(12), P. 1079 - 1089

Published: Oct. 1, 2022

Language: Английский

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A neural network model of when to retrieve and encode episodic memories

eLife, Journal Year: 2022, Volume and Issue: 11

Published: Feb. 10, 2022

Recent human behavioral and neuroimaging results suggest that people are selective in when they encode retrieve episodic memories. To explain these findings, we trained a memory-augmented neural network to use its memory support prediction of upcoming states an environment where past situations sometimes reoccur. We found the learned selectively as function several factors, including uncertainty about state. Additionally, encoding memories at end event (but not mid-event) led better subsequent performance. In all cases, benefits retrieval can be explained terms reducing risk retrieving irrelevant Overall, modeling provide resource-rational account why should lead testable predictions.The brain record snapshots details from specific events – such took place this information later. Recalling ‘episodic memories’ help us gain understanding our current surroundings predict what will happen next. Studies have typically involved observing volunteers while perform simple, well-defined tasks, learning recalling lists random pairs words. However, it is less clear how works ‘in wild’ no one quizzing us, going everyday activities. Recently, researchers started study more naturalistic situations, for example, watch movie. Here, Lu et al. built computational model brains store during experiments. The team gave sequence inputs corresponding different stages event, asked was coming Intuitively, might think best would frequently possible. performed is, preferentially storing waiting recover them until there gap model’s situation. This strategy may avoid (in turn) result making incorrect predictions with negative outcomes. makes possible particular experiment. openly shared code so other able their studies understand uses situations.

Language: Английский

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Dissociating distinct cortical networks associated with subregions of the human medial temporal lobe using precision neuroimaging

Neuron, Journal Year: 2023, Volume and Issue: 111(17), P. 2756 - 2772.e7

Published: June 29, 2023

Language: Английский

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