scholarly journals The intrinsic neonatal hippocampal network: rsfMRI findings

2020 ◽  
Vol 124 (5) ◽  
pp. 1458-1468
Author(s):  
Athena L. Howell ◽  
David E. Osher ◽  
Jin Li ◽  
Zeynep M. Saygin
Keyword(s):  
Functional Connectivity ◽  
Human Memory ◽  
Memory Systems ◽  
Human Data ◽  
Animal Data ◽  
Hippocampal Network ◽  
Insight Into

Although both animal data and human data suggest that the hippocampus is immature at birth, to date, there are no direct assessments of human hippocampal functional connectivity (FC) very early in life. Our study explores the FC of the hippocampus to the cortex at birth, allowing insight into the development of human memory systems. In particular, we find that adults and neonates exhibit vastly different hippocampal connectivity profiles—a finding that likely has large developmental implications.

scholarly journals The intrinsic neonatal hippocampal network: rsfMRI findings

2019 ◽  
Author(s):  
Athena L. Howell ◽  
David E. Osher ◽  
Jin Li ◽  
Zeynep M. Saygin
Keyword(s):  
Human Memory ◽  
Memory Systems ◽  
Cortical Networks ◽  
Animal Data ◽  
Human Connectome Project ◽  
Hippocampal Network ◽  
Hippocampal Networks ◽  
Insight Into ◽  
Differential Connectivity ◽  
Anterior Posterior

AbstractMany adults cannot voluntarily recall memories before the ages of 3-5, a phenomenon referred to as “infantile amnesia” The development of the hippocampal network likely plays a significant part in the emergence of the ability to form long-lasting memories. In adults, the hippocampus has specialized and privileged connections with certain cortical networks, which presumably facilitate its involvement in memory encoding, consolidation, and retrieval. Is the hippocampus already specialized in these cortical connections at birth? And are the topographical principles of connectivity (e.g. long-axis specialization) present at birth? We analyzed resting-state hippocampal connectivity in neonates scanned within one week of birth (Developmental Human Connectome Project) and compared them to adults (Human Connectome Project). We explored the connections of the whole hippocampus and its long-axis specialization to seven canonical cortical networks. We found that the neonatal hippocampal networks show clear immaturity at birth: adults showed hippocampal connectivity that was unique for each cortical network, whereas neonates showed no differentiation in hippocampal connectivity across these networks. Further, neonates lacked long-axis specialization (i.e., along anterior-posterior axis) of the hippocampus in its differential connectivity patterns to the cortical networks. This immaturity in connectivity may contribute to immaturity in memory formation in the first years of life.“New and Noteworthy”While animal data, and anatomical and behavioral human data from young children suggest that the hippocampus is immature at birth, to date, there are no direct assessments of human hippocampal functional connectivity (FC) very early in life. Our study explores the FC of the hippocampus to the cortex at birth, allowing insight into the development of human memory systems.

Human Memory Systems: A Framework for Understanding Dementia

ASHA Leader ◽  
2007 ◽  
Vol 12 (16) ◽  
pp. 8-11 ◽  
Author(s):  
Nidhi Mahendra ◽  
Allegra Apple
Keyword(s):  
Human Memory ◽  
Memory Systems

scholarly journals Occipital Cortex of Blind Individuals Is Functionally Coupled with Executive Control Areas of Frontal Cortex

2015 ◽  
Vol 27 (8) ◽  
pp. 1633-1647 ◽  
Author(s):  
Ben Deen ◽  
Rebecca Saxe ◽  
Marina Bedny
Keyword(s):  
Working Memory ◽  
Functional Connectivity ◽  
Sentence Comprehension ◽  
Memory Load ◽  
Memory Task ◽  
Occipital Cortex ◽  
Memory Systems ◽  
Functional Responses ◽  
Congenitally Blind ◽  
Blind Individuals

In congenital blindness, the occipital cortex responds to a range of nonvisual inputs, including tactile, auditory, and linguistic stimuli. Are these changes in functional responses to stimuli accompanied by altered interactions with nonvisual functional networks? To answer this question, we introduce a data-driven method that searches across cortex for functional connectivity differences across groups. Replicating prior work, we find increased fronto-occipital functional connectivity in congenitally blind relative to blindfolded sighted participants. We demonstrate that this heightened connectivity extends over most of occipital cortex but is specific to a subset of regions in the inferior, dorsal, and medial frontal lobe. To assess the functional profile of these frontal areas, we used an n-back working memory task and a sentence comprehension task. We find that, among prefrontal areas with overconnectivity to occipital cortex, one left inferior frontal region responds to language over music. By contrast, the majority of these regions responded to working memory load but not language. These results suggest that in blindness occipital cortex interacts more with working memory systems and raise new questions about the function and mechanism of occipital plasticity.

A Scene-Based Episodic Memory System for a Simulated Autonomous Creature

2013 ◽  
Vol 4 (1) ◽  
pp. 32-64 ◽  
Author(s):  
Elisa C. Castro ◽  
Ricardo R. Gudwin
Keyword(s):  
Episodic Memory ◽  
Navigation System ◽  
Cognitive Architecture ◽  
Human Memory ◽  
Memory Systems ◽  
Memory Module ◽  
The Past ◽  
3D Environment ◽  
Main Ideas

In this paper the authors present the development of a scene-based episodic memory module for the cognitive architecture controlling an autonomous virtual creature, in a simulated 3D environment. The scene-based episodic memory has the role of improving the creature’s navigation system, by evoking the objects to be considered in planning, according to episodic remembrance of earlier scenes testified by the creature where these objects were present in the past. They introduce the main background on human memory systems and episodic memory study, and provide the main ideas behind the experiment.

scholarly journals Development of Functional Connectivity during Adolescence: A Longitudinal Study Using an Action–Observation Paradigm

2011 ◽  
Vol 23 (12) ◽  
pp. 3713-3724 ◽  
Author(s):  
Daniel J. Shaw ◽  
Marie-Helene Grosbras ◽  
Gabriel Leonard ◽  
G. Bruce Pike ◽  
Tomáš Paus
Keyword(s):  
Social Cognition ◽  
Functional Connectivity ◽  
Action Observation ◽  
Brain Regions ◽  
Female Adolescents ◽  
Emotional States ◽  
Social Emotional ◽  
Social Stimuli ◽  
The Social ◽  
Insight Into

Successful interpersonal interactions rely on an ability to read the emotional states of others and to modulate one's own behavior in response. The actions of others serve as valuable social stimuli in this respect, offering the observer an insight into the actor's emotional state. Social cognition continues to mature throughout adolescence. Here we assess longitudinally the development of functional connectivity during early adolescence within two neural networks implicated in social cognition: one network of brain regions consistently engaged during action observation and another one associated with mentalizing. Using fMRI, we reveal a greater recruitment of the social–emotional network during the observation of angry hand actions in male relative to female adolescents. These findings are discussed in terms of known sex differences in adolescent social behavior.

Factoren Die Het Onthouden Van Vreemdtalige Woorden Beinvloeden

1981 ◽  
Vol 11 ◽  
pp. 227-245
Author(s):  
Caroline Schouten-Van Parreren
Keyword(s):  
Foreign Language ◽  
Recent Literature ◽  
Memory Systems ◽  
Theoretical Background ◽  
Foreign Languages ◽  
New Words ◽  
Psychological Conditions ◽  
Unknown Words ◽  
Insight Into ◽  
Good Retention

In the recent literature on the methodology of foreign language teaching there is a growing consensus that new words should be presented in texts and not in vocabularies. The theoretical background of this assumption is explained through Van Parreren's theory of trace systems in memory. In particular it is argued that a good retention of new words requires that the traces of meaningfully related words be connected in many diffe-rent ways. Words in texts are already so connected (whereas words in vo-cabularies etc. are not). Moreover it is also possible to treat words in texts in a number of different ways. Although it is thus generally acknowledged that presenting words in texts is preferable, little is known about the nature of the psychological processes of comprehending and retaining new words when presented in texts. In order to gain insight into these processes a qualitative investigation was carried out. Texts in different foreign languages were read by adult subjects. These texts contained several words unknown to them. These words were tested twice: after a short and after a longer interval. While recalling the meaning of the words the subjects had to think aloud. These recall protocols were qualitatively analysed with respect to a number of questions. It was concluded that presenting words in texts offer many possibilities to ''embed" words in meaningful memory systems. However some linguistic and psychological conditions (concerning the text and the treatment of the text by the subjects) have to be taken into ac-count. In particular attention has to be paid only to a part of the unknown words, i.e. to the words in linguistically favourable positions. As a fa-vourable psychological condition for comprehension and retention diversity of treatment of the target words by the subjects seems to be required.

Dysfunction of the human memory systems

2003 ◽  
Vol 16 ◽  
pp. S11-S16 ◽  
Author(s):  
Kathy Dujardin ◽  
Bernard Laurent
Keyword(s):  
Human Memory ◽  
Memory Systems

scholarly journals Increased task-dependent functional connectivity by stimulation of the hippocampal network predicts memory enhancement

2019 ◽  
Author(s):  
Kristen N. Warren ◽  
Molly S. Hermiller ◽  
Aneesha S. Nilakantan ◽  
Joel L. Voss
Keyword(s):  
Functional Connectivity ◽  
Episodic Memory ◽  
Memory Retrieval ◽  
Medial Temporal Lobe ◽  
Network Connectivity ◽  
Network Control ◽  
Retrieval Task ◽  
Memory Processing ◽  
Hippocampal Network ◽  
Hippocampal Networks

AbstractSuccessful episodic memory involves dynamic increases in the coordination of activity across distributed hippocampal networks, including the posterior-medial network (PMN) and the anterior-temporal network (ATN). We tested whether this up-regulation of functional connectivity during memory processing can be enhanced within hippocampal networks by noninvasive stimulation, and whether such task-dependent connectivity enhancement predicts episodic memory improvement. Participants received stimulation targeting either the PMN or an out-of-network control location. We compared the effects of stimulation on fMRI connectivity measured during an autobiographical memory retrieval task versus during rest within the PMN and the ATN. PMN-targeted stimulation significantly increased connectivity during memory retrieval versus rest within the PMN. This effect was not observed in the ATN, or in either network due to control out-of-network stimulation. Task-dependent increases in connectivity due to PMN-targeted stimulation within the medial temporal lobe predicted improved performance of a separate episodic memory test. It is therefore possible to enhance the task-dependent regulation of hippocampal network connectivity that supports memory processing using noninvasive stimulation.

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

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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