Towards a conflict account of déjà vu : the role of memory errors and memory expectation conflict in the experience of déjà vu

This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) [grant number BB/M010996/1].Déjà vu can be defined as conflict between a subjective evaluation of familiarity and a concurrent evaluation of novelty. Accounts of the déjà vu experience have not explicitly referred to a “conflict account of déjà vu” despite the acceptance of conflict-based definitions of déjà vu and relatively recent neuroimaging work that has implicated brain areas associated with conflict as underpinning the experience. Conflict monitoring functioning follows a similar age-related trajectory to déjà vu with a peak in young adulthood and a subsequent age-related decline. In this narrative review of the literature to date, we consider how déjà vu is defined and how this has influenced the understanding of déjà vu. We also review how déjà vu can be understood within theories of recognition memory and cognitive control. Finally, we summarise the conflict account of déjà vu and propose that this account of the experience may provide a coherent explanation as to why déjà vu experiences tend to decrease with age in the non-clinical population.Publisher PDFPeer reviewe

Distance- rather than location-based temporal judgements are more accurate during episodic recall in a real-world task

Definitions of episodic memory typically emphasise the importance of spatiotemporal frameworks in the contextual reconstruction of episodic retrieval. However, our ability to retrieve specific temporal contexts of experienced episodes is poor. This has bearing on the prominence of temporal context in the definition and evaluation of episodic memory, particularly among non-human animals. Studies demonstrating that rats rely on elapsed time (distance) rather than specific timestamps (location) to disambiguate events have been used to suggest that human episodic memory is qualitatively different to other species. We examined whether humans were more accurate using a distance- or location-based method for judging when an event happened. Participants (n = 57) were exposed to a series of events and then asked either when (e.g., 1:03 pm) or how long ago (HLA; e.g., 33 min) a specific event took place. HLA judgements were significantly more accurate, particularly for the most recently experienced episode. Additionally, a significantly higher proportion of participants making HLA judgements accurately recalled non-temporal episodic features across all episodes. Finally, for participants given the choice of methods for making temporal judgements, a significantly higher proportion chose to use HLA judgements. These findings suggest that human and non-human temporal judgements are not qualitatively different.PostprintPeer reviewe

Déjà vu experiences in anxiety

Déjà vu occurs when a novel event is experienced with an erroneous sense of familiarity. Memory researchers theorise that this arises due to an error in the processes underlying the recognition memory system. Research has indicated that there may be a link between high levels of anxiety and increased frequency and intensity of déjà vu, however there has been comparatively little characterisation of déjà vu as experienced by individuals with clinical anxiety. We used an online questionnaire to collect data from individuals self-reporting a clinical diagnosis of anxiety, as well as from age-matched controls. The Anxiety Group reported a significantly higher frequency of déjà vu episodes over the previous month than controls. They also reported experiencing déjà vu more frequently and with higher intensity during periods of high anxiety. In addition, the Anxiety Group reported finding déjà vu episodes significantly more distressing than the control group. The findings indicate that there are differences in déjà vu experienced by people reporting high levels of anxiety compared to healthy controls without an anxiety diagnosis. We discuss structural and neural mechanisms thought to underpin déjà vu in relation to these results.PostprintPeer reviewe

How accurate are runners’ prospective predictions of their race times?

Three authors of the study have received financial support during the preparation of this manuscript. Kate McIntosh received summer internship funding from the University of St Andrews (funded internally by the University of St Andrews where Kate was an undergraduate student) to conduct analyses and visualise the data. Konstantinos Liverakos is in receipt of a PhD studentship from the AD Links Trust (funding external to the University of St Andrews where Konstantinos is a PhD student) and has conducted analyses, visualised data, and helped to prepared the manuscript during the period of his PhD. Christopher J.A. Moulin is a senior member of the Institut Universitaire de France.Metacognition is a domain which has illuminated our understanding of the regulation of cognition, but has yet to be applied in detail to more physical activities. We used half marathon finish time predictions from 7211 runners to investigate the factors that influence running performance metacognitive accuracy. In particular, we were concerned with the effects of experience, gender, and age on calibration. We expected more experienced runners to be better calibrated than less experienced ones. Given analogous findings in the domain of metacognition, we expected women to be less overconfident in their predictions, and better calibrated than male runners. Based on the metacognition literature, we expected that if older runners have effectively learned from previous experience, they would be as well-calibrated as younger runners. In contrast, uninformed inferences not based on performance feedback would lead to overestimating performance for older compared to younger runners. As expected, experience in terms of both club membership and previous race completion improved calibration. Unexpectedly though, females were more overconfident than males, overestimating their performance and demonstrating poorer calibration. A positive relationship was observed between age and prediction accuracy, with older runners showing better calibration. The present study demonstrates that data, collected before a test of physical activity, can inform our understanding of how participants anticipate their performance, and how this ability is affected by a number of demographic and situational variables. Athletes and coaches alike should be aware of these variables to better understand, organise, plan, and predict running performance, potentially leading to more appropriate training sessions and faster race finish times.Publisher PDFPeer reviewe

Perirhinal cortex and the recognition of relative familiarity

Spontaneous object recognition (SOR) is a widely used task of recognition memory in rodents which relies on their propensity to explore novel (or relatively novel) objects. Network models typically define perirhinal cortex as a region required for recognition of previously seen objects largely based on findings that lesions or inactivations of this area produce SOR deficits. However, relatively little is understood about the relationship between the activity of cells in the perirhinal cortex that signal novelty and familiarity and the behavioural responses of animals in the SOR task. Previous studies have used objects that are either highly familiar or absolutely novel, but everyday memory is for objects that sit on a spectrum of familiarity which includes objects that have been seen only a few times, or objects that are similar to objects which have been previously experienced. We present two studies that explore cellular activity (through c-fos imaging) within perirhinal cortex of rats performing SOR where the familiarity of objects has been manipulated. Despite robust recognition memory performance, we show no significant changes in perirhinal activity related to the level of familiarity of the objects. Reasons for this lack of familiarity-related modulation in perirhinal cortex activity are discussed. The current findings support emerging evidence that perirhinal responses to novelty are complex and that task demands are critical to the involvement of perirhinal cortex in the control of object recognition memory

fMRI evidence supporting the role of memory conflict in the déjà vu experience

This research was funded by an anonymous donation to the School of Psychology and Neuroscience at the University of St Andrews.Attempts to generate déjà vu experimentally have largely focused on engineering partial familiarity for stimuli, relying on an ensuing, but unprompted evaluation of conflict to generate the experience. Without verification that experimentally-generated familiarity is accompanied by the awareness of stimulus novelty, these experimental procedures potentially provide an incomplete déjà vu analogue. We used a modified version of the Deese-Roediger-McDermott (DRM) false memory procedure to generate both familiarity and novelty within a déjà vu analogue—we coupled experimentally-generated familiarity with cues indicating that the familiarity was erroneous, using this additional source of mnemonic information to generate cognitive conflict in our participants. We collected fMRI and behavioural data from 21 participants, 16 of whom reported déjà vu. Using univariate contrasts we identified brain regions associated with mnemonic conflict, including the anterior cingulate cortex, medial prefrontal cortex and parietal cortex. This is the first experiment to image an analogue of the déjà vu experience in healthy volunteers. The increased likelihood of déjà vu reports to DRM critical lures correctly identified as “new”, and the activation of neural substrates supporting the experience of cognitive conflict during déjà vu, suggest that the resolution of memory conflict may play an integral role in déjà vu.PostprintPeer reviewe

Bacterial RNA and small antiviral compounds activate caspase-1 through cryopyrin/Nalp3

Missense mutations in the CIAS1 gene cause three autoinflammatory disorders: familial cold autoinflammatory syndrome, Muckle-Wells syndrome and neonatal-onset multiple-system inflammatory disease(1). Cryopyrin (also called Nalp3), the product of CIAS1, is a member of the NOD-LRR protein family that has been linked to the activation of intracellular host defence signalling pathways(2,3). Cryopyrin forms a multi-protein complex termed 'the inflammasome', which contains the apoptosis-associated speck-like protein (ASC) and caspase-1, and promotes caspase-1 activation and processing of pro-interleukin (IL)-1 beta (ref. 4). Here we show the effect of cryopyrin deficiency on inflammasome function and immune responses. Cryopyrin and ASC are essential for caspase-1 activation and IL-1 beta and IL-18 production in response to bacterial RNA and the imidazoquinoline compounds R837 and R848. In contrast, secretion of tumour-necrosis factor-alpha and IL-6, as well as activation of NF-kappa B and mitogen-activated protein kinases (MAPKs) were unaffected by cryopyrin deficiency. Furthermore, we show that Toll-like receptors and cryopyrin control the secretion of IL-1 beta and IL-18 through different intracellular pathways. These results reveal a critical role for cryopyrin in host defence through bacterial RNA-mediated activation of caspase-1, and provide insights regarding the pathogenesis of autoinflammatory syndromes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62569/1/nature04517.pd

Helicobacter pylori CagA Triggers Expression of the Bactericidal Lectin REG3γ via Gastric STAT3 Activation

Background: Most of what is known about the Helicobacter pylori (H. pylori) cytotoxin, CagA, pertains to a much-vaunted role as a determinant of gastric inflammation and cancer. Little attention has been devoted to potential roles of CagA in the majority of H. pylori infected individuals not showing oncogenic progression, particularly in relation to host tolerance. Regenerating islet-derived (REG)3c encodes a secreted C-type lectin that exerts direct bactericidal activity against Grampositive bacteria in the intestine. Here, we extend this paradigm of lectin-mediated innate immunity, showing that REG3c expression is triggered by CagA in the H. pylori-infected stomach. Methodology/Principal Findings: In human gastric mucosal tissues, REG3c expression was significantly increased in CagApositive, compared to CagA-negative H. pylori infected individuals. Using transfected CagA-inducible gastric MKN28 cells, we recapitulated REG3c induction in vitro, also showing that tyrosine phosphorylated, not unphosphorylated CagA triggers REG3c transcription. In concert with induced REG3c, pro-inflammatory signalling downstream of the gp130 cytokine coreceptor via the signal transducer and activator of transcription (STAT)3 and transcription of two cognate ligands, interleukin(IL)-11 and IL-6, were significantly increased. Exogenous IL-11, but not IL-6, directly stimulated STAT3 activation and REG3c transcription. STAT3 siRNA knockdown or IL-11 receptor blockade respectively abrogated or subdued CagAdependent REG3c mRNA induction, thus demonstrating a requirement for uncompromised signalling via the IL-11/STAT

Following the genes: a framework for animal modeling of psychiatric disorders

The number of individual cases of psychiatric disorders that can be ascribed to identified, rare, single mutations is increasing with great rapidity. Such mutations can be recapitulated in mice to generate animal models with direct etiological validity. Defining the underlying pathogenic mechanisms will require an experimental and theoretical framework to make the links from mutation to altered behavior in an animal or psychopathology in a human. Here, we discuss key elements of such a framework, including cell type-based phenotyping, developmental trajectories, linking circuit properties at micro and macro scales and definition of neurobiological phenotypes that are directly translatable to humans

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements