scholarly journals Relationships between default-mode network connectivity, medial temporal lobe structure, and age-related memory deficits

2015 ◽  
Vol 36 (1) ◽  
pp. 265-272 ◽  
Author(s):  
Andrew M. Ward ◽  
Elizabeth C. Mormino ◽  
Willem Huijbers ◽  
Aaron P. Schultz ◽  
Trey Hedden ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Default Mode Network ◽  
Medial Temporal Lobe ◽  
Network Connectivity ◽  
Memory Deficits ◽  
Default Mode ◽  
Age Related

Default mode network connectivity indicates episodic memory capacity in mesial temporal lobe epilepsy

Epilepsia ◽  
2013 ◽  
Vol 54 (5) ◽  
pp. 809-818 ◽  
Author(s):  
Cornelia McCormick ◽  
Maher Quraan ◽  
Melanie Cohn ◽  
Taufik A. Valiante ◽  
Mary Pat McAndrews
Keyword(s):  
Episodic Memory ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Default Mode Network ◽  
Network Connectivity ◽  
Memory Capacity ◽  
Mesial Temporal Lobe Epilepsy ◽  
Default Mode ◽  
Mesial Temporal Lobe

scholarly journals What can narratives tell us about the neural bases of human memory?

2020 ◽  
Author(s):  
Hongmi Lee ◽  
Buddhika Bellana ◽  
janice chen
Keyword(s):  
Temporal Lobe ◽  
Neural Activity ◽  
Default Mode Network ◽  
Medial Temporal Lobe ◽  
Activity Patterns ◽  
Human Memory ◽  
Memory System ◽  
Situation Models ◽  
Neural Synchrony ◽  
Default Mode

Narratives are increasingly used to study naturalistic human memory and its brain mechanisms. Narratives—audiovisual movies, spoken stories, and written stories—consist of multiple inter-related and temporally unfolding events which are rich in semantic and emotional content. These characteristics drive intersubject neural synchrony in the default mode network, where abstract situation models are represented and reinstated. Medial temporal lobe structures interact with the cortical sub-regions of the default mode network to support the encoding and recall of narrative events. Narrative memories are frequently communicated across individuals, resulting in the transmission of experiences and neural activity patterns between people. Recent advances in neuroimaging and naturalistic stimulus analysis provide valuable insights into narrative memory and the human memory system in general.

scholarly journals Developmental Maturation of the Precuneus as a Functional Core of the Default Mode Network

2019 ◽  
Vol 31 (10) ◽  
pp. 1506-1519 ◽  
Author(s):  
Rosa Li ◽  
Amanda V. Utevsky ◽  
Scott A. Huettel ◽  
Barbara R. Braams ◽  
Sabine Peters ◽  
...  
Keyword(s):  
Default Mode Network ◽  
Network Connectivity ◽  
Developmental Time ◽  
Cross Sectional ◽  
Default Mode ◽  
Time Points ◽  
State Dependent ◽  
Age Related ◽  
Dual Regression

Efforts to map the functional architecture of the developing human brain have shown that connectivity between and within functional neural networks changes from childhood to adulthood. Although prior work has established that the adult precuneus distinctively modifies its connectivity during task versus rest states [Utevsky, A. V., Smith, D. V., & Huettel, S. A. Precuneus is a functional core of the default-mode network. Journal of Neuroscience, 34, 932–940, 2014], it remains unknown how these connectivity patterns emerge over development. Here, we use fMRI data collected at two longitudinal time points from over 250 participants between the ages of 8 and 26 years engaging in two cognitive tasks and a resting-state scan. By applying independent component analysis to both task and rest data, we identified three canonical networks of interest—the rest-based default mode network and the task-based left and right frontoparietal networks (LFPN and RFPN, respectively)—which we explored for developmental changes using dual regression analyses. We found systematic state-dependent functional connectivity in the precuneus, such that engaging in a task (compared with rest) resulted in greater precuneus–LFPN and precuneus–RFPN connectivity, whereas being at rest (compared with task) resulted in greater precuneus–default mode network connectivity. These cross-sectional results replicated across both tasks and at both developmental time points. Finally, we used longitudinal mixed models to show that the degree to which precuneus distinguishes between task and rest states increases with age, due to age-related increasing segregation between precuneus and LFPN at rest. Our results highlight the distinct role of the precuneus in tracking processing state, in a manner that is both present throughout and strengthened across development.

scholarly journals Default Mode Network Ventral Hub Connectivity Associated with Memory Impairment in Temporal Lobe Epilepsy Surgery

2020 ◽  
Author(s):  
Elliot G. Neal ◽  
Long Di ◽  
You Jeong Park ◽  
Austin Finch ◽  
Ferdinand Korneli ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Epilepsy Surgery ◽  
Default Mode Network ◽  
Memory Task ◽  
Network Connectivity ◽  
Default Mode ◽  
Non Invasive ◽  
Before And After ◽  
The Relationship

AbstractIn patients undergoing surgery for intractable temporal lobe epilepsy, the relationship between the default mode network and patients’ neurocognitive outcome remains unclear. The objective of this study is to employ non-invasive network mapping to identify the relationship between subdivisions of the default mode network and neurocognitive function before and after epilepsy surgery in patients with temporal lobe epilepsy.Twenty-seven medically patients with medically refractory temporal lobe epilepsy were prospectively enrolled and received resting state functional MRI and neuropsychological testing both pre- and post-operatively. Connectivity within the default mode network was modeled and average connectivity within the networks was calculated.Higher pre-operative connectivity in the ventral default mode network hub correlated with impaired baseline performance in a visual memory task. Post-operatively, a decrease in ventral but not dorsal default mode network connectivity was correlated with a deterioration of verbal and logical memory after surgery.Overall, higher connectivity in the ventral default mode network hub was associated with poor memory function in patients with temporal lobe epilepsy both before and after temporal lobe surgery. Pre-operatively, higher ventral connectivity was associated with worse visual function. Post-operatively, decreased connectivity of the ventral and dorsal default mode network was correlated with a greater decrease in logical and verbal memory when compared with the pre-operation baseline. An imbalance in default mode network connectivity towards the ventral stream and more widespread epilepsy networks may be used to predict memory impairments following surgical intervention and may lead to more tailored surgical decision making based on this non-invasive network modeling.

scholarly journals The retrosplenial cortex: A memory gateway between the cortical default mode network and the medial temporal lobe

2018 ◽  
Vol 39 (5) ◽  
pp. 2020-2034 ◽  
Author(s):  
Neda Kaboodvand ◽  
Lars Bäckman ◽  
Lars Nyberg ◽  
Alireza Salami
Keyword(s):  
Temporal Lobe ◽  
Default Mode Network ◽  
Medial Temporal Lobe ◽  
Retrosplenial Cortex ◽  
Default Mode

scholarly journals Dissecting the default mode network: direct structural evidence on the morphology and axonal connectivity of the fifth component of the cingulum bundle

2020 ◽  
pp. 1-12
Author(s):  
Georgios P. Skandalakis ◽  
Spyridon Komaitis ◽  
Aristotelis Kalyvas ◽  
Evgenia Lani ◽  
Chrysoula Kontrafouri ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Default Mode Network ◽  
Medial Temporal Lobe ◽  
Spatial Relationship ◽  
Distinct Group ◽  
Lateral Direction ◽  
Default Mode ◽  
Cingulum Bundle ◽  
Face Area ◽  
Close Spatial Relationship

OBJECTIVEAlthough a growing body of data support the functional connectivity between the precuneus and the medial temporal lobe during states of resting consciousness as well as during a diverse array of higher-order functions, direct structural evidence on this subcortical circuitry is scarce. Here, the authors investigate the very existence, anatomical consistency, morphology, and spatial relationships of the cingulum bundle V (CB-V), a fiber tract that has been reported to reside close to the inferior arm of the cingulum (CingI).METHODSFifteen normal, formalin-fixed cerebral hemispheres from adults were treated with Klingler’s method and subsequently investigated through the fiber microdissection technique in a medial to lateral direction.RESULTSA distinct group of fibers is invariably identified in the subcortical territory of the posteromedial cortex, connecting the precuneus and the medial temporal lobe. This tract follows the trajectory of the parietooccipital sulcus in a close spatial relationship with the CingI and the sledge runner fasciculus. It extends inferiorly to the parahippocampal place area and retrosplenial complex area, followed by a lateral curve to terminate toward the fusiform face area (Brodmann area [BA] 37) and lateral piriform area (BA35). Taking into account the aforementioned subcortical architecture, the CB-V allegedly participates as a major subcortical stream within the default mode network, possibly subserving the transfer of multimodal cues relevant to visuospatial, facial, and mnemonic information to the precuneal hub. Although robust clinical evidence on the functional role of this stream is lacking, the modern neurosurgeon should be aware of this tract when manipulating cerebral areas en route to lesions residing in or around the ventricular trigone.CONCLUSIONSThrough the fiber microdissection technique, the authors were able to provide original, direct structural evidence on the existence, morphology, axonal connectivity, and correlative anatomy of what proved to be a discrete white matter pathway, previously described as the CB-V, connecting the precuneus and medial temporal lobe.

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