scholarly journals Hippocampal signature of associative memory measured by chronic ambulatory intracranial EEG

2018 ◽  
Author(s):  
Simon Henin ◽  
Anita Shankar ◽  
Nicolas Hasulak ◽  
Daniel Friedman ◽  
Patricia Dugan ◽  
...  
Keyword(s):  
Associative Memory ◽  
Focal Epilepsy ◽  
Memory Task ◽  
Surgical Patients ◽  
Cognitive Tasks ◽  
Proof Of Concept ◽  
Intracranial Eeg ◽  
Hippocampal Activity ◽  
Intracranial Electroencephalography

ABSTRACTSome patients with medically refractory focal epilepsy are chronically implanted with a brain-responsive neurostimulation device (the RNS® System), permitting neurophysiological measurements at millisecond resolution. This clinical device can be adapted to measure hippocampal dynamics time-locked to cognitive tasks. We illustrate the technique with a proof of concept in three patients previously implanted with the RNS System as they engage in an associative memory task, measured months apart. Hippocampal activity measured in successful encoding in RNS System patients mirrors that in surgical patients during intracranial electroencephalography (iEEG), suggesting that chronic iEEG allows sensitive measurements of hippocampal physiology over prolonged timescales.

scholarly journals Virtual intracranial electroencephalography for epilepsy surgery using ictal magnetoencephalography

2021 ◽  
Author(s):  
Miao Cao ◽  
Daniel Galvis ◽  
Simon Vogrin ◽  
William Woods ◽  
Sara Vogrin ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Focal Epilepsy ◽  
Network Models ◽  
Brain Regions ◽  
Proof Of Concept ◽  
Brain Areas ◽  
Dynamical Network ◽  
Non Invasive ◽  
Novel Approach ◽  
Intracranial Electroencephalography

Abstract Modelling the interactions that arise from neural dynamics in seizure genesis is challenging but important in the effort to improve the success of epilepsy surgery. Dynamical network models developed from physiological evidence offer insights into rapidly evolving brain networks in the epileptic seizure. A major limitation of previous studies in this field is the dependence on invasive cortical recordings with constrained spatial sampling of brain regions that might be involved in seizure dynamics. Here, we propose a novel approach, virtual intracranial electroencephalography (ViEEG), that combines non-invasive ictal magnetoencephalographic imaging (MEG), dynamical network models and a virtual resection technique. In this proof-of-concept study, we show that ViEEG signals reconstructed from MEG alone preserve critical temporospatial characteristics for dynamical approaches to identify brain areas involved in seizure generation. Our findings demonstrate the advantages of non-invasive ViEEG over the current presurgical ‘gold-standard’ – intracranial electroencephalography (iEEG). Our approach promises to optimise the surgical strategy for patients with complex refractory focal epilepsy.

Effects of frequent cannabis use on hippocampal activity during an associative memory task

2007 ◽  
Vol 17 (4) ◽  
pp. 289-297 ◽  
Author(s):  
Gerry Jager ◽  
Hendrika H. Van Hell ◽  
Maartje M.L. De Win ◽  
Rene S. Kahn ◽  
Wim Van Den Brink ◽  
...  
Keyword(s):  
Associative Memory ◽  
Memory Task ◽  
Cannabis Use ◽  
Hippocampal Activity

scholarly journals Inter-Rater Reliability of Preprocessing EEG Data: Impact of Subjective Artifact Removal on Associative Memory Task ERP Results

2017 ◽  
Vol 11 ◽  
Author(s):  
Steven D. Shirk ◽  
Donald G. McLaren ◽  
Jessica S. Bloomfield ◽  
Alex Powers ◽  
Alec Duffy ◽  
...  
Keyword(s):  
Associative Memory ◽  
Memory Task ◽  
Artifact Removal ◽  
Rater Reliability ◽  
Eeg Data

scholarly journals Theta-gamma coupling binds visual perceptual features in an associative memory task

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Moritz Köster ◽  
Holger Finger ◽  
Sebastian Graetz ◽  
Maren Kater ◽  
Thomas Gruber
Keyword(s):  
Associative Memory ◽  
Memory Task ◽  
Perceptual Features

scholarly journals Conjunctive representation of what and when in monkey hippocampus and lateral prefrontal cortex during an associative memory task

2019 ◽  
Author(s):  
Nathanael A. Cruzado ◽  
Zoran Tiganj ◽  
Scott L. Brincat ◽  
Earl K. Miller ◽  
Marc W. Howard
Keyword(s):  
Prefrontal Cortex ◽  
Associative Memory ◽  
Memory Task ◽  
Neural Recording ◽  
Temporal Coding ◽  
Adaptive Memory ◽  
Lateral Prefrontal Cortex ◽  
The Past ◽  
Large Numbers

AbstractAdaptive memory requires the organism to form associations that bridge between events separated in time. Many studies show interactions between hippocampus (HPC) and prefrontal cortex (PFC) during formation of such associations. We analyze neural recording from monkey HPC and PFC during a memory task that requires the monkey to associate stimuli separated by about a second in time. After the first stimulus was presented, large numbers of units in both HPC and PFC fired in sequence. Many units fired only when a particular stimulus was presented at a particular time in the past. These results indicate that both HPC and PFC maintain a temporal record of events that could be used to form associations across time. This temporal record of the past is a key component of the temporal coding hypothesis, a hypothesis in psychology that memory not only encodes what happened, but when it happened.

scholarly journals Postural responses to specific types of long-term memory during visually induced roll self-motion

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261266
Author(s):  
Maëlle Tixier ◽  
Stéphane Rousset ◽  
Pierre-Alain Barraud ◽  
Corinne Cian
Keyword(s):  
Visual Motion ◽  
Memory Task ◽  
Cognitive Tasks ◽  
Long Term Memory ◽  
Uniform Motion ◽  
Term Memory ◽  
Postural Responses ◽  
Background Motion ◽  
Self Motion

A large body of research has shown that visually induced self-motion (vection) and cognitive processing may interfere with each other. The aim of this study was to assess the interactive effects of a visual motion inducing vection (uniform motion in roll) versus a visual motion without vection (non-uniform motion) and long-term memory processing using the characteristics of standing posture (quiet stance). As the level of interference may be related to the nature of the cognitive tasks used, we examined the effect of visual motion on a memory task which requires a spatial process (episodic recollection) versus a memory task which does not require this process (semantic comparisons). Results confirm data of the literature showing that compensatory postural response in the same direction as background motion. Repeatedly watching visual uniform motion or increasing the cognitive load with a memory task did not decrease postural deviations. Finally, participants were differentially controlling their balance according to the memory task but this difference was significant only in the vection condition and in the plane of background motion. Increased sway regularity (decreased entropy) combined with decreased postural stability (increase variance) during vection for the episodic task would indicate an ineffective postural control. The different interference of episodic and semantic memory on posture during visual motion is consistent with the involvement of spatial processes during episodic memory recollection. It can be suggested that spatial disorientation due to visual roll motion preferentially interferes with spatial cognitive tasks, as spatial tasks can draw on resources expended to control posture.

Functional Connectivity Relationships Predict Similarities in Task Activation and Pattern Information during Associative Memory Encoding

2014 ◽  
Vol 26 (5) ◽  
pp. 1085-1099 ◽  
Author(s):  
Maureen Ritchey ◽  
Andrew P. Yonelinas ◽  
Charan Ranganath
Keyword(s):  
Functional Connectivity ◽  
Functional Properties ◽  
Associative Memory ◽  
Large Scale ◽  
Memory Task ◽  
Neural Systems ◽  
General Level ◽  
Specific Information ◽  
Memory Encoding ◽  
Cortical Regions

Neural systems may be characterized by measuring functional interactions in the healthy brain, but it is unclear whether components of systems defined in this way share functional properties. For instance, within the medial temporal lobes (MTL), different subregions show different patterns of cortical connectivity. It is unknown, however, whether these intrinsic connections predict similarities in how these regions respond during memory encoding. Here, we defined brain networks using resting state functional connectivity (RSFC) then quantified the functional similarity of regions within each network during an associative memory encoding task. Results showed that anterior MTL regions affiliated with a network of anterior temporal cortical regions, whereas posterior MTL regions affiliated with a network of posterior medial cortical regions. Importantly, these connectivity relationships also predicted similarities among regions during the associative memory task. Both in terms of task-evoked activation and trial-specific information carried in multivoxel patterns, regions within each network were more similar to one another than were regions in different networks. These findings suggest that functional heterogeneity among MTL subregions may be related to their participation in distinct large-scale cortical systems involved in memory. At a more general level, the results suggest that components of neural systems defined on the basis of RSFC share similar functional properties in terms of recruitment during cognitive tasks and information carried in voxel patterns.

Sign in / Sign up

Export Citation Format

Share Document