Memory reconsolidation is the process in which reactivated long-term memory (LTM) becomes transiently sensitive to amnesic agents that are effective at consolidation. The phenomenon was first ...described more than 50 years ago but did not fit the dominant paradigm that posited that consolidation takes place only once per LTM item. Research on reconsolidation was revitalized only more than a decade ago with the demonstration of reconsolidation in a well-defined behavioral protocol (auditory fear conditioning in the rat) subserved by an identified brain circuit (basolateral amygdala). Since then, reconsolidation has been shown in many studies over a range of species, tasks, and amnesic agents, and cellular and molecular correlates of reconsolidation have also been identified. In this review, I will first define the evidence on which reconsolidation is based, and proceed to discuss some of the conceptual issues facing the field in determining when reconsolidation does and does not occur. Last, I will refer to the potential clinical implications of reconsolidation.
This paper expands Rami Ali’s dissolution of the gamer’s dilemma (Ethics Inf Technol 17:267–274, 2015). Morgan Luck’s gamer’s dilemma (Ethics Inf Technol 11(1):31–36, 2009) rests on our having ...diverging intuition when considering virtual murder and virtual child molestation in video games. Virtual murder is seemingly permissible, when virtual child molestation is not and there is no obvious morally relevant difference between the two. Ali argues that virtual murder and virtual child molestation are equally permissible/impermissible when considered under different modes of engagement. To this end, Ali distinguishes between story-telling gameplay and simulation games, discussing both in depth. I build on the dissolution by looking into competitive gameplay in order to consider what the morally relevant difference between virtual murder and virtual child molestation might be when competing in a video game. I argue that when competitors consent to participate in a competition, the rules of the competition supersede everyday moral intuitions. As such, virtual competitions ought to represent such consent from virtual characters. Virtual children cannot be represented as giving consent to be molested because (1) children cannot be represented as giving sexual consent, and (2) consent to be possibly molested cannot be given. This creates a morally relevant difference between murder and molestation. By fully addressing competitive gameplay, I answer Luck’s worry that Ali’s dissolution is incomplete (Ethics Inf Technol 20:157–162, 2018).
Although the biological bases of forgetting remain obscure, the consensus among cognitive psychologists emphasizes interference processes, rejecting decay in accounting for memory loss. In contrast ...to this view, recent advances in understanding the neurobiology of long-term memory maintenance lead us to propose that a brain-wide well-regulated decay process, occurring mostly during sleep, systematically removes selected memories. Down-regulation of this decay process can increase the life expectancy of a memory and may eventually prevent its loss. Memory interference usually occurs during certain active processing phases, such as encoding and retrieval, and will be stronger in brain areas with minimal sensory integration and less pattern separation. In areas with efficient pattern separation, such as the hippocampus, interference-driven forgetting will be minimal, and, consequently, decay will cause most forgetting.
Consolidated memories can re-enter states of transient instability following reactivation, from which they must again stabilize in order to persist, contradicting the previously dominant view that ...memory and its associated plasticity mechanisms progressively and irreversibly decline with time. We witness exciting times, as neuroscience begins embracing a position, long-held in cognitive psychology, that recognizes memory as a principally dynamic process. In light of remaining controversy, we here establish that the same operational definitions and types of evidence underpin the deduction of both reconsolidation and consolidation, thus validating the extrapolation that post-retrieval memory plasticity reflects processes akin to those that stabilized the memory following acquisition.
The idea that new memories are initially ‘labile’ and sensitive to disruption before becoming permanently stored in the wiring of the brain has been dogma for >100 years. Recently, we have revisited ...the hypothesis that reactivation of a consolidated memory can return it to a labile, sensitive state – in which it can be modified, strengthened, changed or even erased! The data generated from some of the best-described paradigms in memory research, in conjunction with powerful neurobiological technologies, have provided striking support for a very dynamic neurobiological basis of memory, which is beginning to overturn the old dogma.
DATING THROUGH THE FILTERS Nader, Karim
Social philosophy & policy,
01/2020, Letnik:
37, Številka:
2
Journal Article
Recenzirano
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In this essay, I explore ethical considerations that might arise from the use of collaborative filtering algorithms on dating apps. Collaborative filtering algorithms can predict the preferences of a ...target user by looking at the past behavior of similar users. By recommending products through this process, they can influence the news we read, the movies we watch, and more. They are extremely powerful and effective on platforms like Amazon and Google. Recommender systems on dating apps are likely to group people by race, since they exhibit similar patterns of behavior: users on dating platforms seem to segregate themselves based on race, exclude certain races from romantic and sexual consideration (except their own), and generally show a preference for white men and women. As collaborative filtering algorithms learn from these patterns to predict preferences and build recommendations, they can homogenize the behavior of dating app users and exacerbate biased sexual and romantic behavior.
Memory reconsolidation is a fundamental plasticity process in the brain that allows established memories to be changed or erased. However, certain boundary conditions limit the parameters under which ...memories can be made plastic. Strong memories do not destabilize, for instance, although why they are resilient is mostly unknown. Here, we investigated the hypothesis that specific modulatory signals shape memory formation into a state that is reconsolidation-resistant. We find that the activation of the noradrenaline-locus coeruleus system (NOR-LC) during strong fear memory encoding increases molecular mechanisms of stability at the expense of lability in the amygdala of rats. Preventing the NOR-LC from modulating strong fear encoding results in the formation of memories that can undergo reconsolidation within the amygdala and thus are vulnerable to post-reactivation interference. Thus, the memory strength boundary condition on reconsolidation is set at the time of encoding by the action of the NOR-LC.
The strength of a fear memory significantly influences whether it drives adaptive or maladaptive behavior in the future. Yet, how mild and strong fear memories differ in underlying biology is not ...well understood. We hypothesized that this distinction may not be exclusively the result of changes within specific brain regions, but rather the outcome of collective changes in connectivity across multiple regions within the neural network. To test this, rats were fear conditioned in protocols of varying intensities to generate mild or strong memories. Neuronal activation driven by recall was measured using c-fos immunohistochemistry in 12 brain regions implicated in fear learning and memory. The interregional coordinated brain activity was computed and graph-based functional networks were generated to compare how mild and strong fear memories differ at the systems level. Our results show that mild fear recall is supported by a well-connected brain network with small-world properties in which the amygdala is well-positioned to be modulated by other regions. In contrast, this connectivity is disrupted in strong fear memories and the amygdala is isolated from other regions. These findings indicate that the neural systems underlying mild and strong fear memories differ, with implications for understanding and treating disorders of fear dysregulation.
The processes of memory formation and storage are complex and highly dynamic. Once memories are consolidated, they are not necessarily fixed but can be changed long after storage. In particular, ...seemingly stable memories may re-enter an unstable state when they are retrieved, from which they must be re-stabilized during a process known as reconsolidation. During reconsolidation, memories are susceptible to modifications again, thus providing an opportunity to update seemingly stable memories. While initial demonstrations of memory reconsolidation came mainly from animal studies, evidence for reconsolidation in humans is now accumulating as well. Here, we review recent advances in our understanding of human memory reconsolidation. After a summary of findings on the reconsolidation of human fear and episodic memory, we focus particularly on recent neuroimaging data that provide first insights into how reconsolidation processes are implemented in the human brain. Finally, we discuss the implications of memory modifications during reconsolidation for the treatment of mental disorders such as posttraumatic stress disorder and drug addiction.
Memory reconsolidation: an update Nader, Karim; Einarsson, Einar Örn
Annals of the New York Academy of Sciences,
March 2010, Letnik:
1191, Številka:
1
Journal Article
Recenzirano
Memory consolidation refers to the stabilization that a new memory has to undergo in order to persist. Recently, this dominant view of memory has been challenged by renewed interest in ...reconsolidation, where consolidated memories return to a transient unstable state following their retrieval, from which they must again stabilize in order to persist. In this review, we discuss how reconsolidation is supported by the same line of evidence as consolidation and recent findings of boundary conditions of reconsolidation. Furthermore, we discuss how recent controversies on the nature of amnesia following challenges to reconsolidation are using the same paradigm that failed to resolve the nature of amnesia after challenges to consolidation; we also discuss a new paradigm that can lead to more fruitful ways of studying amnesia in general.
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