Recall Experiment Research Articles

How and when whistleblowing influences engagement? The role of emotional ambivalence, congruence between descriptive and injunctive norms

ABSTRACT Integrating ambivalence theory and focus theory of normative conduct, this research has explored after effect mechanism of whistleblowing on whistleblowers’ engagement. A multi-study approach was utilized to test these predictions. Study 1 (a multi-wave field study of working adults) examined the impact of whistleblowing on whistleblowers’ engagement through emotional ambivalence, as well as the moderating effect of congruence between descriptive and injunctive norms. Study 2 (a vignette experiment) further investigate the effects of whistleblowing on whistleblowers’ engagement through emotional ambivalence, aiming to strengthen causal inferences. In Study 3 (a recall experiment), we extended our model to consider a theoretically relevant moderator. Our results showed that the impact of whistleblowing on emotional ambivalence was weakened by whistleblowers’ congruence between descriptive and injunctive norms. Managers ought to give significant consideration to the detrimental impacts of whistleblowing during the post-whistleblowing stage, as well as provide guidance to members of the organization to ensure a proper understanding of social norms. Above conclusions contribute to the general knowledge of after effect mechanism of whistleblowing, providing a deeper insight into whistleblowing’s effects on whistleblowers.

Tackling adversity with open minds: Team personality composition facilitates shared leadership and team resilience

AbstractResilient teams can efficiently resolve disruption and overcome adversity. Despite growing interest in building and maintaining resilient teams, our understanding of the factors that promote team resilience necessitates further theorizing and empirical testing. Based on conservation of resources and shared leadership theories, we propose that team member personality (i.e., mean openness to experience) serves as a resource that facilitates team resilience via shared leadership. Further, we argue that the strength of influence of shared leadership on team resilience is contingent on the variance of openness to experience scores among team members. We draw our conclusions from three studies (i.e., two recall experiments and a multi‐source field study) involving working professionals in virtual teams. Our findings shed light on the interactive role of team member personality in explaining team resilience, thereby extending our knowledge of the personality predictors of shared leadership and team resilience.

Increased metamemory accuracy with practice does not require practice with metamemory.

Given that learners do not always predict their future memory performance accurately, there is a need to better understand how metamemory accuracy can be improved. Prior research suggests that one way to improve is practice-participants tend to become better at predicting their future memory performance over the course of multi-trial learning experiments. However, it is currently unclear whether such improvements result from participants having practised making metamemory judgements or whether comparable improvements occur even in their absence. This issue was investigated in three multi-trial, cued recall experiments wherein participants either did or did not receive practice making judgements of learning. Metamemory accuracy increased across study blocks but did so equally for the two groups. These results indicate that increased metamemory accuracy with practice is not due to participants having practised explicit metamemory monitoring but instead due to other factors associated with multi-trial learning such as retrieval practice and the availability of prior test performance as a metamemory cue.

High-gamma and beta bursts in the Left Supramarginal Gyrus can accurately differentiate verbal memory states and performance.

The left supramarginal gyrus (LSMG) may mediate attention to memory, and gauge memory state and performance. We performed a secondary analysis of 142 verbal delayed free recall experiments, in patients with medically-refractory epilepsy with electrode contacts implanted in the LSMG. In 14 of 142 experiments (in 14 of 113 patients), the cross-validated convolutional neural networks (CNNs) that used 1-dimensional(1-D) pairs of convolved high-gamma and beta tensors, derived from the LSMG recordings, could label recalled words with an area under the receiver operating curve (AUROC) of greater than 60% [range: 60-90%]. These 14 patients were distinguished by: 1) higher amplitudes of high-gamma bursts; 2) distinct electrode placement within the LSMG; and 3) superior performance compared with a CNN that used a 1-D tensor of the broadband recordings in the LSMG. In a pilot study of 7 of these patients, we also cross-validated CNNs using paired 1-D convolved high-gamma and beta tensors, from the LSMG, to: a) distinguish word encoding epochs from free recall epochs [AUC 0.6-1]; and distinguish better performance from poor performance during delayed free recall [AUC 0.5-0.86]. These experiments show that bursts of high-gamma and beta generated in the LSMG are biomarkers of verbal memory state and performance.

Effects of note-taking on the accuracy and fluency of consecutive interpreters' immediate free recall of source texts: A three-stage developmental study

Note-taking for consecutive interpreting (CI) is a special type of note-taking in that selective notes are taken in a highly multi-tasking condition under time pressure during a CI speech segment but are used to enable a complete recall of the source speech immediately. Given the specialty of interpreters' note-taking, it is still unclear in what ways note-taking affects interpreters' memory performance. Moreover, the effect of note-taking is theoretically assumed to depend on interpreting expertise, which has not been substantiated by empirical research. This study addresses these questions by investigating the effect of note-taking on the accuracy and fluency of interpreters' memory of the source text at different training stages. An oral recall experiment was administered to student interpreters at three critical note-taking training stages: the initial stage (with one-month training in note-taking), after the critical development stage (with six-month training in note-taking), and the advanced stage (with two-year training in note-taking), with a sample size of 53, 53 and 35 at each stage respectively. Participants listened to and immediately recalled speech segments consecutively in two note-taking conditions: with and without note-taking. Recall accuracy was measured by completeness of information recalled, and recall fluency was measured by oral fluency during recall. Results showed that note-taking significantly enhanced both accuracy and fluency of interpreters' recall of the source text at all the three stages, revealing a facilitative effect of note-taking on source text memory. The size of the note-taking effect increased as interpreting training experience accumulated, indicating that interpreting training enhanced the facilitative role of note-taking. However, the developmental trajectories of the note-taking effect on recall accuracy and fluency differed. As interpreting training proceeded, the note-taking effect on recall fluency was first improved (from Stage 1 to Stage 2), and later was the note-taking effect on recall accuracy (from Stage 1 to Stage 3). The findings shed light on the cognitive mechanisms of how note-taking functions for consecutive interpreters. A potential practical implication for interpreter training is that a step-by-step note-taking training approach may be beneficial.

Shared and unique features of epistemic emotions: Awe, surprise, curiosity, interest, confusion, and boredom.

Epistemic emotions are hardly ever studied together, making it difficult to predict what features are shared versus unique to each emotion. To address this, we conducted two autobiographical recall experiments. We compared awe, surprise, curiosity, interest, confusion, and boredom in terms of elicitors, subjective experience components, and action tendencies. Ratings were analyzed using network analyses, to describe the central features for the whole group of epistemic emotions. In addition, ratings were compared per emotion, to identify key features for each individual emotion. Results showed that valence, arousal, coping potential, and avoidance are central features of all epistemic emotions. Awe, surprise, and interest were relatively positive emotions, which together with curiosity, were associated with arousal, high coping potential, and approach. Confusion and boredom were relatively negative emotions, which were associated with low arousal, low coping potential, and avoidance. Further analyses revealed unique features of (groups of) emotions. For example, awe was associated with exceeded expectancies, while surprise was associated with both exceeded and disconfirmed expectancies. Moreover, curiosity and confusion were associated with having (too) little information, while awe and interest were associated with having sufficient information. All emotions except boredom were associated with exploration, but this was particularly high for curiosity and interest. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A Role for NOD2 in Intestinal Memory T cell Formation and Function

Abstract Aberrant resident memory T cell (TRM) responses have been associated with increased intestinal inflammation and Crohn’s disease (CD) pathology in humans. Genetic mutations in NOD2 are associated with the highest risk of CD development. NOD2 has been shown to be critical for initiating adaptive immune responses at systemic sites. However, the role of NOD2 in establishing memory T cell responses in the intestine remains unclear. Using an acute model of LCMV infection, we interrogated the role of NOD2 in intestinal memory T cell generation and function. Littermate wildtype or NOD2-deficient mice were infected intraperitoneally with LCMV-Armstrong, and the intestinal T cell priming, effector, and memory T cell responses were profiled in the mesenteric lymph nodes (mLN) and small intestinal lamina propria (SILP). Augmented NOD2 signalling at homeostasis and during infection increased endogenous and LCMV-specific CD4+ T cell numbers in the mLN, but not in the spleen. This effect was due to a NOD2-dependent increase in T cell homing to the mLN. Furthermore, NOD2-deficiency resulted in decreased effector and memory T cell numbers in the SILP. This effect was associated with decreased memory T cell functions in NOD2-deficient mice during ex vivo and in vivo recall experiments. Taken together, our experiments suggest a role for NOD2 in mediating optimal T cell priming in the mesenteric lymph nodes, which later affects effector and memory T cell functions in the intestine.

No position-specific interference from prior lists in cued recognition: A challenge for position coding (and other) theories of serial memory

Position-specific intrusions of items from prior lists are rare but important phenomena that distinguish broad classes of theory in serial memory. They are uniquely predicted by position coding theories, which assume items on all lists are associated with the same set of codes representing their positions. Activating a position code activates items associated with it in current and prior lists in proportion to their distance from the activated position. Thus, prior list intrusions are most likely to come from the coded position. Alternative “item dependent” theories based on associations between items and contexts built from items have difficulty accounting for the position specificity of prior list intrusions. We tested the position coding account with a position-cued recognition task designed to produce prior list interference. Cuing a position should activate a position code, which should activate items in nearby positions in the current and prior lists. We presented lures from the prior list to test for position-specific activation in response time and error rate; lures from nearby positions should interfere more. We found no evidence for such interference in 10 experiments, falsifying the position coding prediction. We ran two serial recall experiments with the same materials and found position-specific prior list intrusions. These results challenge all theories of serial memory: Position coding theories can explain the prior list intrusions in serial recall and but not the absence of prior list interference in cued recognition. Item dependent theories can explain the absence of prior list interference in cued recognition but cannot explain the occurrence of prior list intrusions in serial recall.

A197 A ROLE FOR NOD2 IN INTESTINAL T CELL MEMORY DEVELOPMENT AND FUNCTION

Abstract Background Aberrant resident memory T cell (TRM) responses have been associated with increased intestinal inflammation and Crohn’s disease (CD) pathology in humans. Intestinal TRM cells are not only important for maintaining the integrity of the intestinal epithelial barrier, but also for the rapid clearance of pathogens in the intestine during infection. Understanding the signals received by the intestinal immune system to generate TRM responses is paramount to elucidating treatments for CD. Genetic mutations in NOD2 are associated with the highest risk of CD development. As a host intracellular sensor of bacterial peptidoglycan, NOD2 is critical for initiating both innate and adaptive immune responses. Furthermore, work from our lab as well as those of our collaborators suggest that NOD2 deficiency reduces systemic memory B and T cell responses. However, the role of NOD2 in establishing memory T cell responses in the intestine remains unclear. This work will therefore establish the role of NOD2 signaling in initiating and maintaining optimal TRM responses to achieve intestinal homeostasis and resilience to intestinal inflammation. Aims It is the main objective of this project to determine whether NOD2-mediated signalling affects: 1. Antigen-specific intestinal T cell priming in vivo 2. Bona fide intestinal TRM generation 3. Bona fide intestinal TRM function Methods Intraperitoneal LCMV-Armstrong infection results in long-lived CD4+ and CD8+ resident-memory T cell generation in the intestinal lamina propria of mice. Wildtype and NOD2 deficient littermate mice were infected with LCMV-Armstrong, and the effects on intestinal T cell priming, effector function, and memory T cell function were examined by flow-cytometry, ex vivo and in vivo antigen-recall experiments, qPCR, and viral plaque assays. Results Augmented NOD2 signalling during priming increased LCMV-specific CD4+ T cell numbers in the mesenteric lymph nodes - but not in the spleen, independent of proliferation or cell death. Furthermore, NOD2-deficiency resulted in decreased effector and memory T cell numbers in the small intestinal lamina propria. This effect was associated with decresead memory CD4+ and CD8+ T cell functions in NOD2-deficient mice during ex vivo and in vivo peptide recall experiments. Conclusions NOD2 affects T cell priming in the mesenteric lymph nodes, which later affects effector and memory T cell functions in the intestinal lamina propria. Funding Agencies CAG, CIHREmerging and Pandemic Infections Consortium

A lack of retrieval practice effects in children's recognition and recall memory of novel words during storybook reading

IntroductionRetrieval practice enhances adults' long-term memory over restudying. However, it is less clear whether young children also benefit from retrieval practice. This study assessed whether retrieval practice could support children's novel word learning in the context of storybook reading.MethodIn Experiments 1–3, preschoolers (N = 167, RangeAge = 26–68 months) were presented with 10 novel word-object pairs across four consecutive storybook readings. Half of the children were read the storybook four times (i.e., SSSS), whereas the other half of the children were read the storybook once and were then asked to retrieve the novel words during the subsequent three readings (i.e., STTT). Children's recall and recognition memory for the novel words was tested after a 5-min delay.Results and discussionResults revealed that although children had high retrieval success during learning, retrieval practice did not provide an advantage over re-reading for children's recall (Experiment 1), even when additional mapping and retrieval opportunities were provided (Experiment 2); that is, children who engaged in retrieval practice did not outperform children who re-read the storybooks. A retrieval practice effect also did not emerge in children's recognition memory of novel words (Experiment 3). Taken together, this study suggests that retrieval practice may only benefit young children under specific learning conditions. Future research should therefore consider characteristics of the learner and broader learning context to explain developmental differences in retrieval practice effects.

The attentional boost effect in free recall dynamics.

With the attentional boost effect (ABE), responding to a briefly presented target in a detection task enhances the encoding of other items presented at the same time. However, the effects of target detection on context memory for the event in which the stimulus appeared remain unclear. Here, we present findings from verbal free recall and recognition experiments that test the effects of target detection during encoding on temporal and relational aspects of context memory. Consistent with prior demonstrations of limited effects of target detection on context memory, in Experiment 1 there was no evidence that target detection influenced the likelihood of transitioning to items that were presented at similar times during encoding, or that were in the same encoding condition. These null effects were replicated in a second experiment, which added an old/new recognition and relational memory test. These results indicate that target detection during encoding has minimal effects on the formation of temporal associations between words in memory.

False memories for ending of events.

Memories are not perfect recordings of the past and can be subject to systematic biases. Memory distortions are often caused by our experience of what typically happens in a given situation. However, it is unclear whether memory for events is biased by the knowledge that events usually have a predictable structure (a beginning, middle, and an end). Using video clips of everyday situations, we tested how interrupting events at unexpected time points affects memory of how those events ended. In four free recall experiments (1, 2, 4, and 5), we found that interrupting clips just before a salient piece of action was completed, resulted in the false recall of details about how the clip might have ended. We refer to this as "event extension." On the other hand, interrupting clips just after one scene had ended and a new scene started, resulted in omissions of details about the true ending of the clip (Experiments 4 and 5). We found that these effects were present, albeit attenuated, when testing memory shortly after watching the video clips compared to a week later (Experiments 5a and 5b). The event extension effect was not present when memory was tested with a recognition paradigm (Experiment 3). Overall, we conclude that when people watch videos that violate their expectations of typical event structure, they show a bias to later recall the videos as if they had ended at a predictable event boundary, exhibiting event extension or the omission of details depending on where the original video was interrupted. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The Role of Dorsal Raphe Nucleus Serotonergic Systems in Emotional Learning and Memory in Male BALB/c Mice

Selective serotonin reuptake inhibitors (SSRIs) are the first-line pharmacological treatment for a variety of anxiety-, trauma- and stressor-related disorders. Although they are efficacious, therapeutic improvements require several weeks of treatment and are often associated with an initial exacerbation of symptoms. The dorsal raphe nucleus (DR) has been proposed as an important target for the modulation of emotional responses and the therapeutic effects of SSRIs. Using a fear-conditioning paradigm we aimed to understand how SSRIs affect emotional learning and memory, and their effects on serotonergic circuitry. Adult male BALB/c mice were treated with vehicle (n = 16) or the SSRI fluoxetine (18 mg/kg/d) acutely (n = 16), or chronically (21d, n = 16), prior to fear conditioning. Treatment was stopped, and half of the mice (n = 8/treatment group) were exposed to cued fear memory recall 72 h later. Activation of DR serotonergic neurons during fear conditioning (Experiment 1) or fear memory recall (Experiment 2), was measured using dual-label immunohistochemistry for Tph2 and c-Fos. Acute and chronic fluoxetine treatment reduced associative fear learning without affecting memory recall and had opposite effects on anxiety-like behaviour. Acute fluoxetine decreased serotonergic activity in the DR, while chronic treatment led to serotonergic activity that was indistinguishable from that of control levels in DRD and DRV subpopulations. Chronic fluoxetine facilitated fear extinction, which was associated with rostral DRD inhibition. These findings provide further evidence that SSRIs can alter aspects of learning and memory processes and are consistent with a role for discrete populations of DR serotonergic neurons in regulating fear- and anxiety-related behaviours.

Scene Perception and Visuospatial Memory Converge at the Anterior Edge of Visually Responsive Cortex.

To fluidly engage with the world, our brains must simultaneously represent both the scene in front of us and our memory of the immediate surrounding environment (i.e., local visuospatial context). How does the brain's functional architecture enable sensory and mnemonic representations to closely interface while also avoiding sensory-mnemonic interference? Here, we asked this question using first-person, head-mounted virtual reality and fMRI. Using virtual reality, human participants of both sexes learned a set of immersive, real-world visuospatial environments in which we systematically manipulated the extent of visuospatial context associated with a scene image in memory across three learning conditions, spanning from a single FOV to a city street. We used individualized, within-subject fMRI to determine which brain areas support memory of the visuospatial context associated with a scene during recall (Experiment 1) and recognition (Experiment 2). Across the whole brain, activity in three patches of cortex was modulated by the amount of known visuospatial context, each located immediately anterior to one of the three scene perception areas of high-level visual cortex. Individual subject analyses revealed that these anterior patches corresponded to three functionally defined place memory areas, which selectively respond when visually recalling personally familiar places. In addition to showing activity levels that were modulated by the amount of visuospatial context, multivariate analyses showed that these anterior areas represented the identity of the specific environment being recalled. Together, these results suggest a convergence zone for scene perception and memory of the local visuospatial context at the anterior edge of high-level visual cortex.SIGNIFICANCE STATEMENT As we move through the world, the visual scene around us is integrated with our memory of the wider visuospatial context. Here, we sought to understand how the functional architecture of the brain enables coexisting representations of the current visual scene and memory of the surrounding environment. Using a combination of immersive virtual reality and fMRI, we show that memory of visuospatial context outside the current FOV is represented in a distinct set of brain areas immediately anterior and adjacent to the perceptually oriented scene-selective areas of high-level visual cortex. This functional architecture would allow efficient interaction between immediately adjacent mnemonic and perceptual areas while also minimizing interference between mnemonic and perceptual representations.

To-be-forgotten information shows more relative forgetting over time than to-be-remembered information

People can intentionally forget studied material when cued to do so. Corresponding evidence has arisen from studies on item-method directed forgetting, in which participants are asked to forget single items directly upon presentation. We measured memory performance of to-be-remembered (TBR) and to-be-forgotten (TBF) items across retention intervals of up to 1 week and fitted power functions of time to the observed recall (Experiment 1) and recognition (Experiment 2) rates. In both experiments and each retention interval condition, memory performance for the TBR items was higher than for the TBF items, supporting the view that directed forgetting effects are lasting. Recall and recognition rates of both TBR and TBF items were well fit by the power function. However, the relative forgetting rates of the two item types differed, with a higher forgetting rate for the TBF than the TBR items. The findings are consistent with the view that TBR and TBF items differ (mainly) in recruitment of rehearsal processes and resulting memory strength.

Modality effects in free recall: A retrieved-context account.

The modality effect refers to the robust finding that memory performance differs for items presented aurally, as compared with visually. Whereas auditory presentation leads to stronger recency performance in immediate recall, visual presentation often produces better primacy performance (the inverse modality effect). To investigate and model these differences, we conducted two large-scale web-based immediate free recall experiments. In both experiments, participants studied visual and auditory word lists of varying lengths and rates of presentation. We observed typical modality and inverse modality effects, while also discovering that participants were more likely to initiate recall from recent items on auditory trials than on visual trials. However, modality effects persisted regardless of the first item recalled. Meanwhile, an analysis of intrusion errors revealed that participants were more likely on visual trials than on auditory trials to erroneously recall words from one list prior. Furthermore, words presented in the same modality as the present list intruded more often than those presented in a different modality. We next developed a retrieved-context account of the modality effect by fitting the Context Maintenance and Retrieval model to data across multiple list lengths. Through our simulations, we demonstrate that the modality effect can be explained by faster contextual drift and stronger context-to-item association formation during auditory presentation, relative to visual. Our modeling shows that modality effects can arise without hypothesizing distinct memory stores for recent and remote information. Finally, we propose that modality effects may derive primarily from the temporal dynamics of stimuli, rather than their modality. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The effect of cognitive load on code-switching

Aims and objectives: This study explores the effect of cognitive load on code-switching (CS), by examining whether an increase in cognitive load can lead to a different amount and/or pattern of CS use, and whether there is an interplay between the effect of cognitive load and the effect of social factors (i.e., language and use, and attitudes towards CS). Methodology: Thirty-one Chinese-English bilinguals participated in a picture recall experiment consisting of three sessions, with an incremental increase in cognitive load which was achieved by manipulating the number of attentional targets that should be attended to. The increase in cognitive load was validated by a self-report survey adapted from Paas. Information on social variables was collected by a language use questionnaire. Data and analysis: The amount and pattern (intraclausal vs interclausal) of CS were coded and quantified. One-way analysis of variance (ANOVA) was performed to compare the within-participant use of CS across the sessions. Hierarchal regression analyses were also conducted to examine how cognitive load and the social variables of interest predicted the between-participant variation of CS in each session. Findings/conclusions: The results showed that the participants used significantly less intraclausal CS in Session 3, in which they reported the highest degree of cognitive load. In addition, the results of hierarchical regression analyses for overall CS use in Session 2 confirmed the significant effect of cognitive load. The influence of attitudes towards CS was also shown to be another significant predictor with large effect size. However, in the more demanding Session 3, none of the factors of interest could predict between-participant variation in CS use. Originality: This study is among the first to examine how cognitive load affects nonlaboratory CS. Significance/implications: This study argues for a recognition of the cognitive processing basis of socially driven language use, linking sociolinguistic and psycholinguistic perspectives on the use of CS.

Retrieval dynamics in resolving relational inconsistency during verbal analogical reasoning.

Reasoning about verbal analogies requires selective retrieval of relevant relational information. A consequence of this may be that inhibitory processes in memory cause reduced recall of information associated with analogy-irrelevant relations. The current experiments apply the retrieval-induced forgetting framework to investigate the potential role of such inhibitory processes in analogical reasoning. Participants studied verbal analogies in A-B :: C-D form. Then, half of the A-B pairs from the study phase appeared in verbal analogy problems but with a new C term (A-B :: C-?), and half the items did not appear in verbal analogy problems. A final recall test was then administered for all the original analogies. When the new C term in the analogical reasoning phase conveyed a new relation that was inconsistent with the original relation, reduced recall for items appearing in analogies was observed (Experiment 1). However, when the new C term conveyed a relation that was consistent with the original relation, no forgetting effect was observed (Experiment 1). This forgetting effect occurred even when a hint of the original relation was provided at final recall (Experiment 2). These results indicate that reasoning about analogies may involve inhibitory processes that help reduce competition among competing relations. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

A173 ELUCIDATING THE EFFECTS OF NOD2-MEDIATED SIGNALLING ON INTESTINAL RESIDENT-MEMORY T-CELL FORMATION AND FUNCTION

Abstract Background Aberrant resident memory T-cell (TRM) responses have been associated with increased intestinal inflammation and Crohn’s disease (CD) pathology in humans. Intestinal TRM cells are not only important for maintaining the integrity of the intestinal epithelial barrier, but also for the rapid clearance of pathogens in the intestine during infection. Understanding the signals received by the intestinal immune system to generate TRM responses is paramount to elucidating treatments for CD. Genetic mutations in NOD2 are associated with the highest risk of CD development. As a host intracellular sensor of bacterial peptidoglycan, NOD2 is critical for initiating both innate and adaptive immune responses. Furthermore, work from our lab as well as those of our collaborators suggest that NOD2 deficiency reduces systemic memory B and T-cell responses. However, the role of NOD2 in establishing memory T-cell responses in the intestine remains unclear. This work will therefore establish the role of NOD2 signaling in initiating and maintaining optimal TRM responses to achieve intestinal homeostasis and resilience to intestinal inflammation. Purpose It is the main objective of this project to determine whether NOD2-mediated signalling affects: 1. Antigen-specific T-cell priming in vivo 2. Bona fide intestinal TRM generation 3. Bona fide intestinal TRM function Method To address the effects of NOD2-signalling on intestinal T-cell priming in vivo, wildtype (WT) mice were adoptively transferred 50,000 naïve LCMV-specific (SMARTA) CD4+ T-cells. Mice were subsequently infected with LCMV-Armstrong in the presence or absence of the NOD2 agonist; MDP. 5-days following infection, the numbers and percentage of LCMV-specific T-cells in the mesenteric lymph nodes and spleen were examined. To examine the effects of NOD2 on intestinal TRM generation, littermate WT and NOD2 KO mice were infected with LCMV-Armstrong. Thirty-six-days following infection, the percentage and number of LCMV-specific CD4+ T-cells were profiled in the small and large intestinal lamina-propria by means of gp66-77 class-II MHC-tetramer staining. In another set of experiments, littermate WT and NOD2 KO mice were re-infected with LCMV-C13 30-days following LCMV-Armstrong immunization, and the interferon-response in the small intestine was profiled by quantitative PCR to assess the effect of NOD2-deficiency on antigen recall responses. Result(s) NOD2-stimulation by means of MDP injection increased the percentage and number of adoptively transferred SMARTA CD4+ T-cells in the mesenteric lymph nodes upon LCMV infection. Furthermore, NOD2-deficiency did not alter intestinal LCMV-specific CD4+ TRM seeding in the small and large intestinal lamina propria 36 days after infection. However, in vivo antigen recall experiments showed a decreased intestinal IFN response in NOD2 KO mice. Conclusion(s) Our findings reveal a potential role of NOD2 in the intestinal CD4+ T-cell priming and subsequent Ag-specific memory response. Disclosure of Interest None Declared

No differences in memory performance for instances of historical victimization and historical perpetration: Evidence from five large-scale experiments

In their pursuit of a moral ingroup identity, groups tend to flatter and deceive themselves, leading to predictable biases in their collective memory. Specifically, such memory biases are expected in the form of worse memory for morally problematic acts of historical perpetration. In five high-powered recall and recognition experiments (N = 3,424) using between- (Studies 1–4) and within-subjects designs (Study 5) as well as historically accurate (all studies), randomly sampled (Studies 3–4) stimulus material in three contexts (Germany, the UK, the U.S.), we tested whether individual memories of collective events can be distorted not only in a way that attenuates ingroup-threatening perpetration information but also in a way that highlights morally affirming victimhood information. Deviating from expectations, none of our studies revealed significant differences in memory performance depending on the ingroup's role as victim or perpetrator. Instead, equivalence testing (Studies 4–5) even rejected the presence of the minimal effect size we defined to support the proposed memory bias. We discuss the implications of this absence of individual memory distortions for the formation of social representations of history.