scholarly journals The brain in motion: How ensemble fluidity drives memory-updating and flexibility

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
William Mau ◽  
Michael E Hasselmo ◽  
Denise J Cai
Keyword(s):  
Neural Firing ◽  
Neuronal Ensembles ◽  
The Past ◽  
Memory Traces ◽  
New Information ◽  
Undesirable Consequence ◽  
Memory Representations ◽  
Network States ◽  
Stable Memory ◽  
The Brain

While memories are often thought of as flashbacks to a previous experience, they do not simply conserve veridical representations of the past but must continually integrate new information to ensure survival in dynamic environments. Therefore, ‘drift’ in neural firing patterns, typically construed as disruptive ‘instability’ or an undesirable consequence of noise, may actually be useful for updating memories. In our view, continual modifications in memory representations reconcile classical theories of stable memory traces with neural drift. Here we review how memory representations are updated through dynamic recruitment of neuronal ensembles on the basis of excitability and functional connectivity at the time of learning. Overall, we emphasize the importance of considering memories not as static entities, but instead as flexible network states that reactivate and evolve across time and experience.

scholarly journals Current and future goals are represented in opposite patterns in object-selective cortex

2018 ◽  
Author(s):  
Anouk M. van Loon ◽  
Katya Olmos Solis ◽  
Johannes J. Fahrenfort ◽  
Christian N. L. Olivers
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Adaptive Behavior ◽  
Target Object ◽  
Neuronal Ensembles ◽  
Search Tasks ◽  
Future Goals ◽  
Memory Representations ◽  
The Brain

AbstractAdaptive behavior requires the separation of current from future goals in working memory. We used fMRI of object-selective cortex to determine the representational (dis)similarities of memory representations serving current and prospective perceptual tasks. Participants remembered an object drawn from three possible categories as the target for one of two consecutive visual search tasks. A cue indicated whether the target object should be looked for first (currently relevant), second (prospectively relevant), or if it could be forgotten (irrelevant). Prior to the first search, representations of current, prospective and irrelevant objects were similar, with strongest decoding for current representations compared to prospective (Experiment 1) and irrelevant (Experiment 2). Remarkably, during the first search, prospective representations could also be decoded, but revealed anti-correlated voxel patterns compared to currently relevant representations of the same category. We propose that the brain separates current from prospective memories within the same neuronal ensembles through opposite representational patterns.

scholarly journals Relating the Past with the Present: Information Integration and Segregation during Ongoing Narrative Processing

2021 ◽  
pp. 1-23
Author(s):  
Claire H. C. Chang ◽  
Christina Lazaridi ◽  
Yaara Yeshurun ◽  
Kenneth A. Norman ◽  
Uri Hasson
Keyword(s):  
Information Integration ◽  
Part C ◽  
The Past ◽  
Narrative Processing ◽  
Shared History ◽  
New Information ◽  
Present Information ◽  
Event Representations ◽  
The Brain

Abstract This study examined how the brain dynamically updates event representations by integrating new information over multiple minutes while segregating irrelevant input. A professional writer custom-designed a narrative with two independent storylines, interleaving across minute-long segments (ABAB). In the last (C) part, characters from the two storylines meet and their shared history is revealed. Part C is designed to induce the spontaneous recall of past events, upon the recurrence of narrative motifs from A/B, and to shed new light on them. Our fMRI results showed storyline-specific neural patterns, which were reinstated (i.e., became more active) during storyline transitions. This effect increased along the processing timescale hierarchy, peaking in the default mode network. Similarly, the neural reinstatement of motifs was found during Part C. Furthermore, participants showing stronger motif reinstatement performed better in integrating A/B and C events, demonstrating the role of memory reactivation in information integration over intervening irrelevant events.

scholarly journals Current and future goals are represented in opposite patterns in object-selective cortex

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Anouk Mariette van Loon ◽  
Katya Olmos-Solis ◽  
Johannes Jacobus Fahrenfort ◽  
Christian NL Olivers
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Adaptive Behavior ◽  
Target Object ◽  
Neuronal Ensembles ◽  
Search Tasks ◽  
Future Goals ◽  
Memory Representations ◽  
The Brain

Adaptive behavior requires the separation of current from future goals in working memory. We used fMRI of object-selective cortex to determine the representational (dis)similarities of memory representations serving current and prospective perceptual tasks. Participants remembered an object drawn from three possible categories as the target for one of two consecutive visual search tasks. A cue indicated whether the target object should be looked for first (currently relevant), second (prospectively relevant), or if it could be forgotten (irrelevant). Prior to the first search, representations of current, prospective and irrelevant objects were similar, with strongest decoding for current representations compared to prospective (Experiment 1) and irrelevant (Experiment 2). Remarkably, during the first search, prospective representations could also be decoded, but revealed anti-correlated voxel patterns compared to currently relevant representations of the same category. We propose that the brain separates current from prospective memories within the same neuronal ensembles through opposite representational patterns.

scholarly journals Relating the past with the present: Information integration and segregation during ongoing narrative processing

2020 ◽  
Author(s):  
Claire H. C. Chang ◽  
Christina Lazaridi ◽  
Yaara Yeshurun ◽  
Kenneth A. Norman ◽  
Uri Hasson
Keyword(s):  
Information Integration ◽  
Part C ◽  
The Past ◽  
Narrative Processing ◽  
Shared History ◽  
New Information ◽  
Present Information ◽  
Event Representations ◽  
The Brain

This study examined how the brain dynamically updates event representations by integrating new information over multiple minutes while segregating irrelevant input. A professional writer custom-designed a narrative with two independent storylines, interleaving across minute-long segments (ABAB). In the last (C) part, characters from the two storylines meet and their shared history is revealed. Part C is designed to induce the spontaneous recall of past events, upon the recurrence of narrative motifs from A/B, and to shed new light on them. Our fMRI results showed storyline-specific neural patterns, which were reinstated (i.e. became more active) during storyline transitions. This effect increased along the processing timescale hierarchy, peaking in the default mode network. Similarly, the neural reinstatement of motifs was found during part C. Furthermore, participants showing stronger motif reinstatement performed better in integrating A/B and C events, demonstrating the role of memory reactivation in information integration over intervening irrelevant events.

scholarly journals Relating the past with the present: Information integration and segregation during ongoing narrative processing

2020 ◽  
Author(s):  
Claire Chang ◽  
Christina Lazaridi ◽  
Yaara Yeshurun ◽  
Kenneth Norman ◽  
Uri Hasson
Keyword(s):  
Information Integration ◽  
Part C ◽  
The Past ◽  
Narrative Processing ◽  
Shared History ◽  
New Information ◽  
Present Information ◽  
Event Representations ◽  
The Brain

Abstract This study examined how the brain dynamically updates event representations by integrating new information over multiple minutes while segregating irrelevant input. A professional writer custom-designed a narrative with two independent storylines, interleaving across minute-long segments (ABAB). In the last (C) part, characters from the two storylines meet and their shared history is revealed. Part C is designed to induce the spontaneous recall of past events, upon the recurrence of narrative motifs from A/B, and to shed new light on them. Our fMRI results showed storyline-specific neural patterns, which were reinstated (i.e. became more active) during storyline transition. This effect increased along the processing timescale hierarchy, peaking in the default mode network. Similarly, the neural reinstatement of motifs was found during part C. Furthermore, participants showing stronger motif reinstatement performed better in integrating A/B and C events, demonstrating the role of memory reactivation in information integration over intervening irrelevant events.

scholarly journals Using big data to map the network organization of the brain

2014 ◽  
Vol 37 (1) ◽  
pp. 101-102 ◽  
Author(s):  
James E. Swain ◽  
Chandra Sripada ◽  
John D. Swain
Keyword(s):  
Social Sciences ◽  
Big Data ◽  
Network Theory ◽  
Social Network Theory ◽  
Data Sets ◽  
Brain Organization ◽  
Neuronal Ensembles ◽  
The Past ◽  
The Social ◽  
The Brain

AbstractThe past few years have shown a major rise in network analysis of “big data” sets in the social sciences, revealing non-obvious patterns of organization and dynamic principles. We speculate that the dependency dimension – individuality versus sociality – might offer important insights into the dynamics of neurons and neuronal ensembles. Connectomic neural analyses, informed by social network theory, may be helpful in understanding underlying fundamental principles of brain organization.

scholarly journals Here's the twist: How the brain updates naturalistic event memories as our understanding of the past changes

2021 ◽  
Author(s):  
Asieh Zadbood ◽  
Samuel A. Nastase ◽  
Janice Chen ◽  
Kenneth A. Norman ◽  
Uri Hasson
Keyword(s):  
Neural Representation ◽  
Neural Activation ◽  
Response Patterns ◽  
Activation Patterns ◽  
The Past ◽  
Neural Representations ◽  
New Information ◽  
Behavioral Signatures ◽  
Incoming Information ◽  
The Brain

The brain actively reshapes past memories in light of new incoming information. In the current study, we ask how the brain supports this updatinge process during the encoding and recall of naturalistic stimuli. One group of participants watched a movie ("The Sixth Sense") with a cinematic "twist" at the end that dramatically changed the interpretation of previous events. Next, participants were asked to verbally recall the movie events, taking into account the new "twist" information. Most participants updated their recall to incorporate the twist. Two additional groups recalled the movie without having to update their memories during recall: one group never saw the twist; another group was exposed to the twist prior to the beginning of the movie, and thus the twist information was incorporated both during encoding and recall. We found that providing participants with information about the twist beforehand altered neural response patterns during movie-viewing in the default mode network (DMN). Moreover, presenting participants with the twist at the end of the movie changed the neural representation of the previously-encoded information during recall in a subset of DMN regions. Further evidence for this transformation was obtained by comparing the neural activation patterns during encoding and recall and correlating them with behavioral signatures of memory updating. Our results demonstrate that neural representations of past events encoded in the DMN are dynamically integrated with new information that reshapes our memory in natural contexts.

Neuro-Clinical Signatures of Language Impairments: A Theoretical Framework for Function-to-structure Mapping in Clinics

2020 ◽  
Vol 20 (9) ◽  
pp. 800-811 ◽  
Author(s):  
Ferath Kherif ◽  
Sandrine Muller
Keyword(s):  
Brain Mapping ◽  
Theoretical Framework ◽  
Brain Regions ◽  
Language Impairments ◽  
Structure Mapping ◽  
Language Functions ◽  
The Past ◽  
Language Recovery ◽  
The Brain ◽  
Bow Tie

In the past decades, neuroscientists and clinicians have collected a considerable amount of data and drastically increased our knowledge about the mapping of language in the brain. The emerging picture from the accumulated knowledge is that there are complex and combinatorial relationships between language functions and anatomical brain regions. Understanding the underlying principles of this complex mapping is of paramount importance for the identification of the brain signature of language and Neuro-Clinical signatures that explain language impairments and predict language recovery after stroke. We review recent attempts to addresses this question of language-brain mapping. We introduce the different concepts of mapping (from diffeomorphic one-to-one mapping to many-to-many mapping). We build those different forms of mapping to derive a theoretical framework where the current principles of brain architectures including redundancy, degeneracy, pluri-potentiality and bow-tie network are described.

Chemo- and Optogenetic Strategies for the Elucidation of Pain Pathways

2019 ◽  
pp. 816-832 ◽  
Author(s):  
Sascha R. A. Alles ◽  
Anne-Marie Malfait ◽  
Richard J. Miller
Keyword(s):  
Chronic Pain ◽  
Pain Response ◽  
Conscious Perception ◽  
Novel Therapies ◽  
The Past ◽  
Nociceptive Pathways ◽  
Pain Pathways ◽  
Technical Advances ◽  
The Brain

Pain is not a simple phenomenon and, beyond its conscious perception, involves circuitry that allows the brain to provide an affective context for nociception, which can influence mood and memory. In the past decade, neurobiological techniques have been developed that allow investigators to elucidate the importance of particular groups of neurons in different aspects of the pain response, something that may have important translational implications for the development of novel therapies. Chemo- and optogenetics represent two of the most important technical advances of recent times for gaining understanding of physiological circuitry underlying complex behaviors. The use of these techniques for teasing out the role of neurons and glia in nociceptive pathways is a rapidly growing area of research. The major findings of studies focused on understanding circuitry involved in different aspects of nociception and pain are highlighted in this article. In addition, attention is drawn to the possibility of modification of chemo- and optogenetic techniques for use as potential therapies for treatment of chronic pain disorders in human patients.

scholarly journals DNA Methylation Profiles of Tph1A and BDNF in Gut and Brain of L. Rhamnosus-Treated Zebrafish

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 142
Author(s):  
Mariella Cuomo ◽  
Luca Borrelli ◽  
Rosa Della Monica ◽  
Lorena Coretti ◽  
Giulia De Riso ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Molecular Mechanisms ◽  
The Past ◽  
Targeted Analysis ◽  
Lack Of Information ◽  
High Resolution Power ◽  
Resolution Level ◽  
Health And Disease ◽  
High Doses ◽  
The Brain

The bidirectional microbiota–gut–brain axis has raised increasing interest over the past years in the context of health and disease, but there is a lack of information on molecular mechanisms underlying this connection. We hypothesized that change in microbiota composition may affect brain epigenetics leading to long-lasting effects on specific brain gene regulation. To test this hypothesis, we used Zebrafish (Danio Rerio) as a model system. As previously shown, treatment with high doses of probiotics can modulate behavior in Zebrafish, causing significant changes in the expression of some brain-relevant genes, such as BDNF and Tph1A. Using an ultra-deep targeted analysis, we investigated the methylation state of the BDNF and Tph1A promoter region in the brain and gut of probiotic-treated and untreated Zebrafishes. Thanks to the high resolution power of our analysis, we evaluated cell-to-cell methylation differences. At this resolution level, we found slight DNA methylation changes in probiotic-treated samples, likely related to a subgroup of brain and gut cells, and that specific DNA methylation signatures significantly correlated with specific behavioral scores.

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