scholarly journals Medial temporal lobe amnesia is associated with a deficit in recovering temporal context

2018 ◽  
Author(s):  
Daniela Palombo ◽  
Joseph M. Di Lascio ◽  
Marc Howard ◽  
Mieke Verfaellie
Keyword(s):  
Episodic Memory ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Response Probability ◽  
Temporal Contiguity ◽  
Temporal Context ◽  
Context Model ◽  
Scale Invariant ◽  
Conditional Response ◽  
Verbal Stimuli

Medial temporal lobe (MTL) lesions are associated with severe impairments in episodic memory. In the framework of the Temporal Context Model (TCM), the hypothesized mechanism for episodic memory is the reinstatement of a prior experienced context (i.e., “jump back in time”), which relies upon the MTL (Howard, Fotedar, Datey, & Hasselmo, 2005). This hypothesis has proven difficult to test in amnesia due to floor-level performance by patients in recall tasks. To circumvent this issue, in the present study we used a “looped-list” format, in which a set of verbal stimuli was presented multiple times in a consistent order. This allowed for comparison of statistical properties such as probability of first recall and lag conditional response probability (lag-CRP) between amnesic patients and healthy controls. Results revealed that the lag-CRP, but not the probability of first recall, is altered in amnesia, suggesting a selective disruption of temporal contiguity. To further characterize the results, we fit a scale-invariant version of TCM (Howard, Shankar, Aue, & Criss, 2015) to the probability of first recall and lag-CRP curves. The modeling results suggested that the deficit in temporal contiguity in amnesia is best described as a failure to recover temporal context. These results provide the first direct evidence for an impairment in a jump-back-in-time mechanism in patients with MTL amnesia.

scholarly journals Medial Temporal Lobe Amnesia Is Associated with a Deficit in Recovering Temporal Context

2019 ◽  
Vol 31 (2) ◽  
pp. 236-248 ◽  
Author(s):  
Daniela J. Palombo ◽  
Joseph M. Di Lascio ◽  
Marc W. Howard ◽  
Mieke Verfaellie
Keyword(s):  
Episodic Memory ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Response Probability ◽  
Temporal Contiguity ◽  
Temporal Context ◽  
Context Model ◽  
Scale Invariant ◽  
Psychological Review ◽  
Conditional Response

Medial-temporal lobe (MTL) lesions are associated with severe impairments in episodic memory. In the framework of the temporal context model, the hypothesized mechanism for episodic memory is the reinstatement of a prior experienced context (i.e., “jump back in time”), which relies upon the MTL [Howard, M. W., Fotedar, M. S., Datey, A. V., & Hasselmo, M. E. The temporal context model in spatial navigation and relational learning: Toward a common explanation of medial temporal lobe function across domains. Psychological Review, 112, 75–116, 2005]. This hypothesis has proven difficult to test in amnesia because of the floor-level performance by patients in recall tasks. To circumvent this issue, in this study, we used a “looped-list” format, in which a set of verbal stimuli was presented multiple times in a consistent order. This allowed for comparison of statistical properties such as probability of first recall and lag-conditional response probability (lag-CRP) between amnesic patients and healthy controls. Results revealed that the lag-CRP, but not the probability of first recall, is altered in amnesia, suggesting a selective disruption of temporal contiguity. To further characterize the results, we fit a scale-invariant version of the temporal context model [Howard, M. W., Shankar, K. H., Aue, W. R., & Criss, A. H. A distributed representation of internal time. Psychological Review, 122, 24–53, 2015] to the probability of first recall and lag-CRP curves. The modeling results suggested that the deficit in temporal contiguity in amnesia is best described as a failure to recover temporal context. These results provide the first direct evidence for an impairment in a jump-back-in-time mechanism in patients with MTL amnesia.

Children show adult-like hippocampal pattern separation for familiar but not novel events

2020 ◽  
Author(s):  
Susan L. Benear ◽  
Elizabeth A. Horwath ◽  
Emily Cowan ◽  
M. Catalina Camacho ◽  
Chi Ngo ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Developmental Change ◽  
Pattern Separation ◽  
Developmental Changes ◽  
Similarity Analysis ◽  
Separation Processes ◽  
Parahippocampal Cortex ◽  
Pattern Similarity

The medial temporal lobe (MTL) undergoes critical developmental change throughout childhood, which aligns with developmental changes in episodic memory. We used representational similarity analysis to compare neural pattern similarity for children and adults in hippocampus and parahippocampal cortex during naturalistic viewing of clips from the same movie or different movies. Some movies were more familiar to participants than others. Neural pattern similarity was generally lower for clips from the same movie, indicating that related content taxes pattern separation-like processes. However, children showed this effect only for movies with which they were familiar, whereas adults showed the effect consistently. These data suggest that children need more exposures to stimuli in order to show mature pattern separation processes.

Modulation of medial temporal lobe activity in epilepsy patients with hippocampal sclerosis during verbal working memory

2009 ◽  
Vol 15 (4) ◽  
pp. 536-546 ◽  
Author(s):  
PABLO CAMPO ◽  
FERNANDO MAESTÚ ◽  
IRENE GARCÍA-MORALES ◽  
ANTONIO GIL-NAGEL ◽  
BRYAN STRANGE ◽  
...  
Keyword(s):  
Working Memory ◽  
Episodic Memory ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Time Course ◽  
Hippocampal Sclerosis ◽  
Stimulus Presentation ◽  
Verbal Working Memory ◽  
Compelling Evidence ◽  
Electrophysiological Studies

AbstractIt has been traditionally assumed that medial temporal lobe (MTL) is not required for working memory (WM). However, animal lesion and electrophysiological studies and human neuropsychological and neuroimaging studies have provided increasing evidences of a critical involvement of MTL in WM. Based on previous findings, the central aim of this study was to investigate the contribution of the MTL to verbal WM encoding. Here, we used magnetoencephalography (MEG) to compare the patterns of MTL activation of 9 epilepsy patients suffering from left hippocampal sclerosis with those of 10 healthy matched controls while they performed a verbal WM task. MEG recordings allow detailed tracking of the time course of MTL activation. We observed impaired WM performance associated with changes in the dynamics of MTL activity in epilepsy patients. Specifically, whereas patients showed decreased activity in damaged MTL, activity in the contralateral MTL was enhanced, an effect that became significant in the 600- to 700-ms interval after stimulus presentation. These findings strongly support the crucial contribution of MTL to verbal WM encoding and provide compelling evidence for the proposal that MTL contributes to both episodic memory and WM. Whether this pattern is signaling reorganization or a normal use of a damaged structure is discussed. (JINS, 2009, 15, 536–546.)

scholarly journals Dynamic Theta Networks in the Human Medial Temporal Lobe Support Episodic Memory

2019 ◽  
Vol 29 (7) ◽  
pp. 1100-1111.e4 ◽  
Author(s):  
Ethan A. Solomon ◽  
Joel M. Stein ◽  
Sandhitsu Das ◽  
Richard Gorniak ◽  
Michael R. Sperling ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Temporal Lobe ◽  
Medial Temporal Lobe

Episodic memory: It's about time (and space)

1999 ◽  
Vol 22 (3) ◽  
pp. 463-464
Author(s):  
Lynn Nadel ◽  
Lee Ryan ◽  
Katrina Keil ◽  
Karen Putnam
Keyword(s):  
Episodic Memory ◽  
Retrograde Amnesia ◽  
Temporal Lobe ◽  
Memory Consolidation ◽  
Medial Temporal Lobe ◽  
Anterograde Amnesia ◽  
Time And Space ◽  
Neuronal Ensembles ◽  
Alternative Approach

Aggleton & Brown rightly point out the shortcomings of the medial temporal lobe hypothesis as an approach to anterograde amnesia. Their broader perspective is a necessary corrective, and one hopes it will be taken very seriously. Although they correctly note the dangers of conflating recognition and recall, they themselves make a similar mistake in discussing familiarity; we suggest an alternative approach. We also discuss implications of their view for an analysis of retrograde amnesia. The notion that there are two routes by which the hippocampus can reactivate neuronal ensembles in the neocortex could help us understand some currently puzzling facts about the dynamics of memory consolidation.

scholarly journals Characterization of brain network supporting episodic memory in the absence of one medial temporal lobe

2019 ◽  
Vol 40 (7) ◽  
pp. 2188-2199 ◽  
Author(s):  
Woorim Jeong ◽  
Hyeongrae Lee ◽  
June Sic Kim ◽  
Chun Kee Chung
Keyword(s):  
Episodic Memory ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Brain Network
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