scholarly journals Hippocampal-medial prefrontal event segmentation and integration contribute to episodic memory formation

2020 ◽  
Author(s):  
Wei Liu ◽  
Yingjie Shi ◽  
James N Cousins ◽  
Nils Kohn ◽  
Guillen Fernandez
Keyword(s):  
Episodic Memory ◽  
Memory Formation ◽  
Connectivity Pattern ◽  
Activation Pattern ◽  
Sequential Order ◽  
Event Segmentation ◽  
Activation Patterns ◽  
Pattern Similarity ◽  
Connectivity Patterns

How do we encode our continuous life experiences for later retrieval? Theories of event segmentation and integration suggest that the hippocampus binds separately represented events into an ordered narrative. Using an open-access functional Magnetic Resonance Imaging (fMRI) movie watching-recall dataset, we quantified two types of neural similarities (i.e., activation pattern similarity and within-region voxel-based connectivity pattern similarity) between separate events during movie watching and related them to subsequent retrieval of events as well as retrieval of sequential order. We demonstrate that distinct activation patterns of the hippocampus and medial prefrontal cortex form event memories. By contrast, similar within-region connectivity patterns between events facilitate memory formation and are relevant for the retention of events in the correct sequential order. We applied the same approaches to an independent movie watching fMRI dataset and replicational analyses highlighted again the role of hippocampal activation pattern and connectivity pattern in memory formation. We propose that distinct activation patterns represent neural segmentation of events while similar connectivity patterns encode context information, and therefore integrate events into a narrative. Our results provide novel evidence for the role of hippocampal-medial prefrontal event segmentation and integration in episodic memory formation of real-life experience.

scholarly journals Complementary Role of Frontoparietal Activity and Cortical Pattern Similarity in Successful Episodic Memory Encoding

2012 ◽  
Vol 23 (7) ◽  
pp. 1562-1571 ◽  
Author(s):  
Gui Xue ◽  
Qi Dong ◽  
Chuansheng Chen ◽  
Zhong-Lin Lu ◽  
Jeanette A. Mumford ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Memory Encoding ◽  
Complementary Role ◽  
Pattern Similarity

scholarly journals Context and Time Matter: Effects of Emotion and Motivation on Episodic Memory Overtime

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Qing Sun ◽  
Simeng Gu ◽  
Jiongjiong Yang
Keyword(s):  
Word Recognition ◽  
Episodic Memory ◽  
Memory Formation ◽  
Contextual Cues ◽  
Time Intervals ◽  
Matter Effects ◽  
Contextual Features ◽  
Different Dimensions ◽  
Reward And Punishment

Previous studies have shown that compared with neutral cues, stimuli with positive and negative/stressful contexts or reward and punishment cues are remembered better. However, it is unclear whether the enhanced effect differs in emotion or motivation dimensions and the passage of time. We addressed these issues by manipulating different contextual cues for neutral words at different time intervals. In experiment 1, subjects were asked to learn words with picture contexts in positive, negative/stressful, and neutral valences and were tested by old/new word recognition and contextual judgment 10 min, 1 day, and 1 week later. In experiment 2, the reward and punishment motivations were manipulated by monetary cues during learning. Word recognition and contextual judgment were assessed 10 min, 1 day, 1 week, and 1 month after the study. Compared with negative and punishment conditions, the words in positive and reward contexts were recognized better at shorter intervals, which was associated with recollection process. In contrast, the words in negative and punishment contexts were recognized better at longer intervals, which was mainly associated with familiarity process. These results clarified how different dimensions of emotional and motivational contexts influence memory at short and long intervals and highlighted the role of contextual features in memory formation and consolidation.

The Role of Attention in Episodic Memory Impairment During Nicotine Withdrawal

2007 ◽  
Author(s):  
Paul S. Merritt ◽  
Adam Cobb ◽  
Luke Moissinac ◽  
Corpus Christi ◽  
Elliot Hirshman
Keyword(s):  
Episodic Memory ◽  
Memory Impairment ◽  
Nicotine Withdrawal

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.

Knowledge is power: prior knowledge aids memory formation for both congruent and incongruent events, but in different ways.

2017 ◽  
Author(s):  
Andrea Greve ◽  
Elisa Cooper ◽  
Roni Tibon ◽  
Richard Henson
Keyword(s):  
Episodic Memory ◽  
Prior Knowledge ◽  
Memory Performance ◽  
Memory Formation ◽  
Memory Test ◽  
World Knowledge ◽  
Apparent Paradox ◽  
Power Prior

Events that conform to our expectations, i.e, are congruent with our world knowledge or schemas, are better remembered than unrelated events. Yet events that conflict with schemas can also be remembered better. We examined this apparent paradox in four experiments, in which schemas were established by training ordinal relationships between randomly-paired objects, while episodic memory was tested for the number of objects on each trial. Better memory was found for both congruent and incongruent trials, relative to unrelated trials, producing memory performance that was a “U-shaped” function of congruency. Furthermore, the incongruency advantage, but not congruency advantage, emerged even if the information probed by the memory test was irrelevant to the schema, while the congruency advantage, but not incongruency advantage, also emerged after initial encoding. Schemas therefore augment episodic memory in multiple ways, depending on the match between novel and existing information.

Role of MicroRNA Genes miR-1000 and miR-375 in Forming Olfactory Conditional Memory in Drosophila melanogaster

MicroRNA ◽  
2020 ◽  
Vol 09 ◽  
Author(s):  
Sadniman Rahman ◽  
Chaity Modak ◽  
Mousumi Akter ◽  
Mohammad Shamimul Alam
Keyword(s):  
Learning And Memory ◽  
Short Term Memory ◽  
Memory Loss ◽  
Memory Formation ◽  
Neural Integration ◽  
Significant Difference ◽  
Locomotion Speed ◽  
Microrna Genes ◽  
With Memory

Background: Learning and memory is basic aspects in neurogenetics as most of the neurological disorders start with dementia or memory loss. Several genes associated with memory formation have been discovered. MicroRNA genes miR-1000 and miR-375 were reported to be associated with neural integration and glucose homeostasis in some insects and vertebrates. However, neuronal function of these genes is yet to be established in D. melanogaster. Objective: Possible role of miR-1000 and miR-375 in learning and memory formation in this fly has been explored in the present study. Methods: Both appetitive and aversive olfactory conditional learning were tested in the miR-1000 and miR-375 knockout (KO) strains and compared with wild one. Five days old third instar larvae were trained by allowing them to be associated with an odor with reward (fructose) or punishment (salt). Then, the larvae were tested to calculate their preferences to the odor trained with. Learning index (LI) values and larval locomotion speed were calculated for all strains. Results: No significant difference was observed for larval locomotion speed in mutant strains. Knockout strain of miR-1000 showed significant deficiency in both appetitive and aversive memory formation whereas miR-375 KO strain showed a significantly lower response only in appetitive one. Conclusion: The results of the present study indicate important role played by these two genes in forming short-term memory in D. melanogaster.

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