scholarly journals The development of spatiotemporal organization of episodic memory in children and its disruption in Williams Syndrome

2019 ◽  
Author(s):  
Marilina Mastrogiuseppe ◽  
Natasha Bertelsen ◽  
Maria Francesca Bedeschi ◽  
Sang Ah Lee
Keyword(s):  
Episodic Memory ◽  
Williams Syndrome ◽  
Developmental Process ◽  
Spatial Location ◽  
Space Time ◽  
Hippocampal Function ◽  
Spatiotemporal Organization ◽  
Location Memory ◽  
Space And Time ◽  
Episodic Memories

AbstractRecent theories of episodic memory propose that the hippocampus provides the spatiotemporal framework for episodic memories. If this is true, does the development of episodic memory depend on the binding of space and time? And does this rely, at least partly, on normal hippocampal function? We investigated the development of episodic memory in children 2–8 years of age (Study 1) and its impairment in Williams Syndrome (Study 2) by implementing a nonverbal object-placement task that dissociates the what, where, and when components of episodic memory. Our results indicate that the binding of space and time in memory emerges first in development around the age of 3 and is impaired in Williams Syndrome. Space-time binding both preceded and predicted success in full episodic memory (what+where+when), and associating objects to spatial location seemed to mediate this developmental process. Importantly, these effects were not explained by improvements in object or location memory.

scholarly journals The spatiotemporal organization of episodic memory and its disruption in a neurodevelopmental disorder

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Marilina Mastrogiuseppe ◽  
Natasha Bertelsen ◽  
Maria Francesca Bedeschi ◽  
Sang Ah Lee
Keyword(s):  
Episodic Memory ◽  
Williams Syndrome ◽  
Developmental Process ◽  
Neurodevelopmental Disorder ◽  
Space Time ◽  
Temporal Information ◽  
Hippocampal Function ◽  
Spatiotemporal Organization ◽  
Visuospatial Deficits ◽  
Spatial Locations

AbstractRecent theories of episodic memory (EM) posit that the hippocampus provides a spatiotemporal framework necessary for representing events. If such theories hold true, then does the development of EM in children depend on the ability to first bind spatial and temporal information? And does this ability rely, at least in part, on normal hippocampal function? We investigated the development of EM in children 2–8 years of age (Study 1) and its impairment in Williams Syndrome, a genetic neurodevelopmental disorder characterized by visuospatial deficits and irregular hippocampal function, (Study 2) by implementing a nonverbal object-placement task that dissociates the what, where, and when components of EM. Consistent with the spatiotemporal-framework view of hippocampal EM, our results indicate that the binding of where and when in memory emerges earliest in development, around the age of 3, and is specifically impaired in WS. Space-time binding both preceded and was critical to full EM (what + where + when), and the successful association of objects to spatial locations seemed to mediate this developmental process.

scholarly journals Space, Time and Episodic Memory: the Hippocampus is all over the Cognitive Map

2017 ◽  
Author(s):  
Arne D. Ekstrom ◽  
Charan Ranganath
Keyword(s):  
Episodic Memory ◽  
Space Time ◽  
Cognitive Map ◽  
Task Demands ◽  
Spatial Processing ◽  
Hippocampal Function ◽  
The Core ◽  
Space And Time ◽  
Core Function ◽  
Break Up

AbstractIn recent years, the field has reached an impasse between models suggesting that the hippocampus is fundamentally involved in spatial processing and models suggesting that the hippocampus automatically encodes all dimensions of experience in the service of memory. Here, we consider key conceptual issues that have impeded progress in our understanding of hippocampal function, and we review findings that establish the scope and limits of hippocampal involvement in navigation and memory. We argue that space and time serve as a primary scaffold to break up experiences into specific contexts, and to organize multimodal input that is to be associated within a context. However, the hippocampus is clearly capable of incorporating additional dimensions into the scaffold if they are determined to be relevant in the event-defined context. Conceiving of the hippocampal representation as constrained by immediate task demands—yet preferring axes that involve space and time—helps to reconcile an otherwise disparate set of findings on the core function of the hippocampus.

scholarly journals Development and decline of the hippocampal long-axis specialization and differentiation during encoding and retrieval of episodic memories

2018 ◽  
Author(s):  
Espen Langnes ◽  
Didac Vidal-Piñeiro ◽  
Markus H. Sneve ◽  
Inge K. Amlien ◽  
Kristine B Walhovd ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Task Engagement ◽  
Childhood And Adolescence ◽  
Associative Memories ◽  
Hippocampal Function ◽  
Successful Completion ◽  
Related Activity ◽  
Younger Adults ◽  
Development And Aging ◽  
Episodic Memories

AbstractChange in hippocampal function is a major factor in lifespan development and decline of episodic memory. Evidence indicates a long-axis specialization where anterior hippocampus is more engaged during encoding and posterior during retrieval. We tested the lifespan trajectory of hippocampal long-axis episodic memory-related activity and functional connectivity (FC). 496 participants (6.8-80.8 years) were scanned with functional MRI while encoding and retrieving associative memories. We found clear evidence for a long-axis encoding-retrieval specialization. These long-axis effects declined linearly during development and aging, eventually vanishing in the older adults. This was mainly driven by age effects on retrieval. Retrieval was associated with gradually lower activity from childhood to adulthood, followed by positive age-relationships until 70 years. Interestingly, this pattern characterized task engagement regardless of memory success or failure. Children engaged posterior hippocampus more than anterior, while anterior hippocampus was more activated relative to posterior already in teenagers. Intra-hippocampal connectivity increased during task, and this increase declined with age. In sum, the results suggest that hippocampal long-axis differentiation and communication during episodic memory tasks develop rapidly during childhood and adolescence, are markedly different in older compared to younger adults, and are related to task engagement, not the successful completion of the task.

Examining the effects of two factors on working memory maintenance of bound information in schizophrenia

2009 ◽  
Vol 15 (4) ◽  
pp. 597-605 ◽  
Author(s):  
DAVID LUCK ◽  
LISA BUCHY ◽  
MARTIN LEPAGE ◽  
JEAN-MARIE DANION
Keyword(s):  
Working Memory ◽  
Episodic Memory ◽  
Change Detection ◽  
Spatial Location ◽  
Central Feature ◽  
Lower Performance ◽  
Space And Time ◽  
Two Factors ◽  
Temporal Occurrence ◽  
Feature Information

AbstractIntegrating information in space and time is a central feature of episodic memory. Although disturbance of the binding processes in episodic memory is well established in patients with schizophrenia, data on working memory (WM) remain discrepant. In a change detection procedure, two target displays of pairs of letters located in cells of grid were successively presented. Participants attempted to detect changes in binding information (i.e., recombination of studied features) or feature information (i.e., a novel letter and/or a novel spatial location). Recombinations consisted of features belonging to the same display (intradisplay) or different displays (interdisplays). Results showed that patients demonstrated overall lower performance, with no specific deficit for recognizing bound information or feature information. In addition, patients did not demonstrate deficits for interdisplay recombinations or intradisplay recombinations. Patients’ ability to remember temporal occurrence of stimuli was not affected. Together, these results suggest that in patients with schizophrenia, binding processes in WM are not specifically disturbed. (JINS, 2009, 15, 597–605.)

Espaço, Tempo e Modernidade

GEOgraphia ◽  
2009 ◽  
Vol 2 (3) ◽  
pp. 51
Author(s):  
Gilvan Luiz Hansen
Keyword(s):  
Modern Philosophy ◽  
Space Time ◽  
Space And Time ◽  
Time Concepts

Resumo Este artigo é uma discussão introdutória acerca da importância das concepções de espaço e tempo na modernidade. O objetivo deste texto é enfatizar os aspectos teóricos e práticos dos conceitos de espaço e tempo, mediante a apresentação de três perspectivas de interpretação desta questão na filosofia desenvolvida na modernidade. Palavras-chave: Modernidade, Espaço, Tempo, Filosofia Moderna, J. Habermas.Abstract This article is an introductory debate about the importance of space and time conceptions in modernity. The objective from this text is emphasize the theoretical and practical aspects of space and time concepts, by presentation of three interpretation perspectives of this question in the philosophy developed in modernity. Keywords: Modernity, Space, Time, Modern Philosophy, J. Habermas.

Samuel Beckett's Debt to Aristotle: Cosmology, Syllogism, Space, Time

2010 ◽  
Vol 22 (1) ◽  
pp. 181-195 ◽  
Author(s):  
Anthony Cordingley
Keyword(s):  
Trinity College ◽  
Space Time ◽  
Formal Logic ◽  
Trinity College Dublin ◽  
Space And Time ◽  
Creative Transformation ◽  
Cosmic Order

This essay argues for the presence of Aristotelian ideas of cosmic order, syllogism, space and time in Beckett's . It accounts for how such ideas impact upon the novel's 'I' as he attempts to offer a philosophical 'solution' to his predicament in an underworld divorced from the revolving heavens. Beckett's study of formal logic as a student at Trinity College, Dublin and his private study of philosophy in 1932 is examined in this light; particularly his “Philosophy Notes,” along with some possible further sources for his knowledge. The essay then reveals a creative transformation of Aristotelian ideas in which led to formal innovations, such as the continuous present of its narrative.

scholarly journals Spatial and space-time correlations in systems of subpopulations with genetic drift and migration.

Genetics ◽  
1993 ◽  
Vol 133 (3) ◽  
pp. 711-727
Author(s):  
B K Epperson
Keyword(s):  
Population Genetics ◽  
Time Correlation ◽  
Space Time ◽  
Spatial Correlations ◽  
Gene Frequencies ◽  
Migration Patterns ◽  
Migration Rates ◽  
Space And Time ◽  
Time Correlations ◽  
And Migration

Abstract The geographic distribution of genetic variation is an important theoretical and experimental component of population genetics. Previous characterizations of genetic structure of populations have used measures of spatial variance and spatial correlations. Yet a full understanding of the causes and consequences of spatial structure requires complete characterization of the underlying space-time system. This paper examines important interactions between processes and spatial structure in systems of subpopulations with migration and drift, by analyzing correlations of gene frequencies over space and time. We develop methods for studying important features of the complete set of space-time correlations of gene frequencies for the first time in population genetics. These methods also provide a new alternative for studying the purely spatial correlations and the variance, for models with general spatial dimensionalities and migration patterns. These results are obtained by employing theorems, previously unused in population genetics, for space-time autoregressive (STAR) stochastic spatial time series. We include results on systems with subpopulation interactions that have time delay lags (temporal orders) greater than one. We use the space-time correlation structure to develop novel estimators for migration rates that are based on space-time data (samples collected over space and time) rather than on purely spatial data, for real systems. We examine the space-time and spatial correlations for some specific stepping stone migration models. One focus is on the effects of anisotropic migration rates. Partial space-time correlation coefficients can be used for identifying migration patterns. Using STAR models, the spatial, space-time, and partial space-time correlations together provide a framework with an unprecedented level of detail for characterizing, predicting and contrasting space-time theoretical distributions of gene frequencies, and for identifying features such as the pattern of migration and estimating migration rates in experimental studies of genetic variation over space and time.

scholarly journals Bi-Temporal Anodal Transcranial Direct Current Stimulation during Slow-Wave Sleep Boosts Slow-Wave Density but Not Memory Consolidation

2021 ◽  
Vol 11 (4) ◽  
pp. 410
Author(s):  
Simon Ruch ◽  
Kristoffer Fehér ◽  
Stephanie Homan ◽  
Yosuke Morishima ◽  
Sarah Maria Mueller ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Slow Wave ◽  
Direct Current ◽  
Memory Consolidation ◽  
Transcranial Direct Current Stimulation ◽  
Slow Wave Sleep ◽  
Memory Performance ◽  
Direct Current Stimulation ◽  
Sleep Parameters ◽  
Episodic Memories

Slow-wave sleep (SWS) has been shown to promote long-term consolidation of episodic memories in hippocampo–neocortical networks. Previous research has aimed to modulate cortical sleep slow-waves and spindles to facilitate episodic memory consolidation. Here, we instead aimed to modulate hippocampal activity during slow-wave sleep using transcranial direct current stimulation in 18 healthy humans. A pair-associate episodic memory task was used to evaluate sleep-dependent memory consolidation with face–occupation stimuli. Pre- and post-nap retrieval was assessed as a measure of memory performance. Anodal stimulation with 2 mA was applied bilaterally over the lateral temporal cortex, motivated by its particularly extensive connections to the hippocampus. The participants slept in a magnetic resonance (MR)-simulator during the recordings to test the feasibility for a future MR-study. We used a sham-controlled, double-blind, counterbalanced randomized, within-subject crossover design. We show that stimulation vs. sham significantly increased slow-wave density and the temporal coupling of fast spindles and slow-waves. While retention of episodic memories across sleep was not affected across the entire sample of participants, it was impaired in participants with below-average pre-sleep memory performance. Hence, bi-temporal anodal direct current stimulation applied during sleep enhanced sleep parameters that are typically involved in memory consolidation, but it failed to improve memory consolidation and even tended to impair consolidation in poor learners. These findings suggest that artificially enhancing memory-related sleep parameters to improve memory consolidation can actually backfire in those participants who are in most need of memory improvement.

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