Abstract Every day, we encounter far more information than we could possibly remember. Thus, our memory systems must organize and prioritize the details from an experience that can adaptively guide ...the storage and retrieval of specific episodic events. Prior work has shown that shifts in internal goal states can function as event boundaries, chunking experiences into distinct and memorable episodes. In addition, at short delays, memory for contextual information at boundaries has been shown to be enhanced compared with items within each event. However, it remains unclear if these memory enhancements are limited to features that signal a meaningful transition between events. To determine how changes in dynamic goal states influence the organization and content of long-term memory, we designed a 2-day experiment in which participants viewed a series of black-and-white objects surrounded by a color border on a two-by-two grid. The location of the object on the grid determined which of two tasks participants performed on a given trial. To examine if distinct types of goal shifts modulate the effects of event segmentation, we changed the border color, the task, or both after every four items in a sequence. We found that goal shifts influenced the temporal memory in a manner consistent with the formation of distinct events. However, for subjective memory representations in particular, these effects differed by the type of event boundary. Furthermore, to examine if goal shifts lead to the prioritization of goal-relevant features in longer lasting memories, we tested the source memory for each object's color and grid location both immediately and after a 24-hr delay. On the immediate test, boundaries enhanced the memory for all concurrent source features compared with nonboundary items, but only if those boundaries involved a goal shift. In contrast, after a delay, the source memory was selectively enhanced for the feature relevant to the goal shift. These findings suggest that goals can adaptively structure memories by prioritizing contextual features that define a unique episode in memory.
Memory consolidation as an adaptive process Cowan, Emily T.; Schapiro, Anna C.; Dunsmoor, Joseph E. ...
Psychonomic bulletin & review,
12/2021, Volume:
28, Issue:
6
Journal Article
Peer reviewed
Open access
We rely on our long-term memories to guide future behaviors, making it adaptive to prioritize the retention of goal-relevant, salient information in memory. In this review, we discuss findings from ...rodent and human research to demonstrate that active processes during post-encoding consolidation support the selective stabilization of recent experience into adaptive, long-term memories. Building upon literatures focused on dynamics at the cellular level, we highlight that consolidation also transforms memories at the systems level to support future goal-relevant behavior, resulting in more generalized memory traces in the brain and behavior. We synthesize previous literatures spanning animal research, human cognitive neuroscience, and cognitive psychology to propose an integrative framework for adaptive consolidation by which goal-relevant memoranda are “tagged” for subsequent consolidation, resulting in selective transformations to the structure of memories that support flexible, goal-relevant behaviors.
The memory benefit that arises from distributing learning over time rather than in consecutive sessions is one of the most robust effects in cognitive psychology. While prior work has mainly focused ...on repeated exposures to the same information, in the real world, mnemonic content is dynamic, with some pieces of information staying stable while others vary. Thus, open questions remain about the efficacy of the spacing effect in the face of variability in the mnemonic content. Here, in two experiments, we investigated the contributions of mnemonic variability and the timescale of spacing intervals, ranging from seconds to days, to long-term memory. For item memory, both mnemonic variability and spacing intervals were beneficial for memory; however, mnemonic variability was greater at shorter spacing intervals. In contrast, for associative memory, repetition rather than mnemonic variability was beneficial for memory, and spacing benefits only emerged in the absence of mnemonic variability. These results highlight a critical role for mnemonic variability and the timescale of spacing intervals in the spacing effect, bringing this classic memory paradigm into more ecologically valid contexts.
Research has shown that sleep is beneficial for the long-term retention of memories. According to theories of memory consolidation, memories are gradually reorganized, becoming supported by ...widespread, distributed cortical networks, particularly during postencoding periods of sleep. However, the effects of sleep on the organization of memories in the hippocampus itself remains less clear. In a 3-d study, participants encoded separate lists of word-image pairs differing in their opportunity for sleep-dependent consolidation. Pairs were initially studied either before or after an overnight sleep period, and were then restudied in a functional magnetic resonance imaging (fMRI) scan session. We used multivariate pattern similarity analyses to examine fine-grained effects of consolidation on memory representations in the hippocampus. We provide evidence for a dissociation along the long axis of the hippocampus that emerges with consolidation, such that representational patterns for object-word memories initially formed prior to sleep become differentiated in anterior hippocampus and more similar, or overlapping, in posterior hippocampus. Differentiation in anterior hippocampal representations correlated with subsequent behavioral performance. Furthermore, representational overlap in posterior hippocampus correlated with the duration of intervening slow wave sleep. Together, these results demonstrate that sleep-dependent consolidation promotes the reorganization of memory traces along the long axis of the hippocampus.
The detection of novelty indicates changes in the environment and the need to update existing representations. In response to novelty, interactions across the VTA-hippocampal circuit support ...experience-dependent plasticity in the hippocampus. While theories have broadly suggested plasticity-related changes are also instantiated in the cortex, research has also shown evidence for functional heterogeneity in cortical networks. It therefore remains unclear how the hippocampal-VTA circuit engages cortical networks, and whether novelty targets specific cortical regions or diffuse, large-scale cortical networks. To adjudicate the role of the VTA and hippocampus in cortical network plasticity, we used fMRI to compare resting-state functional coupling before and following exposure to novel scene images in human subjects of both sexes. Functional coupling between right anterior hippocampus and VTA was enhanced following novelty exposure. However, we also found evidence for a double dissociation, with anterior hippocampus and VTA showing distinct patterns of post-novelty functional coupling enhancements, targeting task-relevant regions versus large-scale networks, respectively. Further, significant correlations between these networks and the novelty-related plasticity in the anterior hippocampal-VTA functional network suggest that the central hippocampal-VTA network may facilitate the interactions with the cortex. These findings support an extended model of novelty-induced plasticity, in which novelty elicits plasticity-related changes in both local and global cortical networks.
Novelty detection is critical for adaptive behavior, signaling the need to update existing representations. By engaging the bidirectional hippocampal-VTA circuit, novelty has been shown to induce plasticity-related changes in the hippocampus. However, it remains an open question how novelty targets such plasticity-related changes in cortical networks. We show that anterior hippocampus and VTA target cortical networks at different spatial scales, with respective enhancements in post-novelty functional coupling with a task-relevant cortical region and a large-scale memory network. The results presented here support an extended model of novelty-related plasticity, in which engaging the anterior hippocampal-VTA circuit through novelty exposure propagates cortical plasticity through hippocampal and VTA functional pathways at distinct scales, targeting specific or diffuse cortical networks.
Systems consolidation theories posit that consolidation occurs primarily through a coordinated communication between hippocampus and neocortex Moscovitch, M., & Gilboa, A. Systems consolidation, ...transformation and reorganization: Multiple trace theory, trace transformation theory and their competitors.
, 2021; Kumaran, D., Hassabis, D., & McClelland, J. L. What learning systems do intelligent agents need? Complementary learning systems theory updated.
,
, 512–534, 2016; McClelland, J. L., & O'Reilly, R. C. Why there are complementary learning systems in the hippocampus and neocortex: Insights from the successes and failures of connectionist models of learning and memory.
,
, 419–457, 1995. Recent sleep studies in rodents have shown that hippocampus and visual cortex replay the same information at temporal proximity (“co-replay”; Lansink, C. S., Goltstein, P. M., Lankelma, J. V., McNaughton, B. L., & Pennartz, C. M. A. Hippocampus leads ventral striatum in replay of place-reward information.
,
, e1000173, 2009; Peyrache, A., Khamassi, M., Benchenane, K., Wiener, S. I., & Battaglia, F. P. Replay of rule-learning related neural patterns in the prefrontal cortex during sleep.
,
, 919–926, 2009; Wierzynski, C. M., Lubenov, E. V., Gu, M., & Siapas, A. G. State-dependent spike-timing relationships between hippocampal and prefrontal circuits during sleep.
,
, 587–596, 2009; Ji, D., & Wilson, M. A. Coordinated memory replay in the visual cortex and hippocampus during sleep.
,
, 100–107, 2007). We developed a novel repetition time (TR)-based co-reactivation analysis method to study hippocampal–cortical co-replays in humans using fMRI. Thirty-six young adults completed an image (face or scene) and location paired associate encoding task in the scanner, which were preceded and followed by resting state scans. We identified post-encoding rest TRs (± 1) that showed neural reactivation of each image–location trials in both hippocampus (HPC) and category-selective cortex (fusiform face area FFA). This allowed us to characterize temporally proximal coordinated reactivations (“co-reactivations”) between HPC and FFA. Moreover, we found that increased HPC–FFA co-reactivations were associated with incorrectly recognized trials after a 1-week delay (
= .004). Finally, we found that these HPC–FFA co-reactivations were also associated with trials that were initially correctly recognized immediately after encoding but were later forgotten in 1-day (
= .043) and 1-week delay period (
= .031). We discuss these results from a trace transformation perspective Sekeres, M. J., Winocur, G., & Moscovitch, M. The hippocampus and related neocortical structures in memory transformation.
,
, 39–53, 2018; Winocur, G., & Moscovitch, M. Memory transformation and systems consolidation.
,
, 766–780, 2011 and speculate that HPC–FFA co-reactivations may be integrating related events, at the expense of disrupting event-specific details, hence leading to forgetting.
The Origins of Agriculture Cowan, C. Wesley; Minnis, Paul; Pearsall, Deborah M ...
2006, 2006-07-30
eBook
The eight case studies in this book -- each a synthesis of available knowledge about the origins of agriculture in a specific region of the globe -- enable scholars in diverse disciplines to examine ...humanity's transition to agricultural societies. Contributors include: Gary W. Crawford, Robin W. Dennell, and Jack R. Harlan.
Abstract Plastics and their associated chemical pollution have emerged as a global threat. This recognition materialized in March 2022 with the adoption of a groundbreaking mandate among United ...Nations (UN) Member States, signaling the commencement of negotiations for a comprehensive treaty aimed at ending plastic pollution, encompassing the entire lifecycle. The first session of negotiations convened at the International Negotiating Committee (INC-1) in Punta del Este, Uruguay from November 28th–December 2nd, 2022, from there, four other negotiation sessions have either convened or will, with the expected conclusion in December 2024. The current study introduces a methodology for systematically observing and documenting global agreement-making. It utilizes a dataset from the first session of negotiations to explore the event ethnography (EE) methodology for following Multilateral Environmental Agreements (MEA). This paper aims to inspire and guide researchers in employing EE, recognizing its efficacy in navigating the complexities of the extensive Global Plastics Treaty (GPT) negotiations and promoting collaborative efforts for a comprehensive understanding of the process. EE is a method increasingly recognised to study multilateral international negotiations within the science-policy nexus to examine emerging obstacles, trends, power dynamics, and actors (both state and non-state) in action within the negotiations. Finally, a dataset is presented from INC-1 through a practical Excel document; the article then demonstrates one example of how the dataset can be employed to enhance comprehension of the negotiators and observers influencing the GPT negotiations.
The Committee on Relations with Social Workers' Profession of the American Association for Applied Psychology has worked for some years towards the development of a program which would facilitate a ...greater understanding by social workers and professional psychologists of the interrelationships within their fields of work. One important phase of such a program is an interchange of information and point of view through participation in professional meetings and conferences and through articles published in professional journals. The Committee has developed a list of suggestions for all psychologists who are willing to assist in this program especially within their own communities.
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