Malleable national collective memories among Black and White Americans.

How do groups remember their shared past? Are there individual differences within a group? How easy is it to change collective memories? The present article addresses these questions by focusing on differences within national subgroups, exploring how national collective memories might differ for Black and White Americans, how individual differences and external influences might moderate or alter any differences, and the temporal extent of any changes that might occur due to external influences. Across four studies, participants were asked to identify the five "most important" events in U.S. history and then asked about their political ideology and racial and national identification, though not in every study. Although individual differences emerged, Black and White participants differed in the types of events they identified as important in U.S. history, with Black participants identifying more race-relevant events than White participants and White participants identifying more traditional founding events than Black participants. As to changes in collective memory, in response to a minimal identity salience manipulation, the murder of George Floyd, and July 4th celebrations, national collective memories evidenced malleability only after the murder of George Floyd. In this instance, the mention of race-relevant events increased, even as the frequency of mention of traditional founding events remained stable. The observed increase in race-relevant events was temporary, however. Findings are discussed in relation to contemporary discussions on collective memory, especially with respect to group differences, individual differences within groups, and mnemonic inertia. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

When the personal and the collective intersects: Memory, future thinking, and perceived agency during the COVID-19 pandemic.

Do collective crises have an impact on the characteristics of mental time travel for individuals and collectives? The COVID-19 pandemic provides a unique context to address this question due to the intersection it created between the personal and the collective domains. In two studies (N = 273), we examined the valence and perceived agency involved in memory and future thinking for personal and collective domains. The second study also included a longitudinal component with 43 participants completing both studies. In research done prior to the pandemic, a valence-based dissociation between personal and collective events was consistently observed in Western samples. We wanted to see if these patterns changed during different stages of the pandemic. In the first study, participants no longer exhibited the usual positivity bias for the personal future, while in the second study, they did not exhibit the usual negativity bias for the collective future. The second aim of the current article was to assess the agency people attribute to themselves and their nation over events and how that relates to valence. People always attributed more agency to themselves over positive events than negative events in both personal and collective domains. Perceived nation agency, however, was associated with positivity in the collective domain but with negativity in the personal domain. Longitudinal analyses confirmed these patterns. Taken together, these results indicate that a collective crisis that has immediate and profound effects on personal lives can alter the patterns observed for mental time travel, especially for the future. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Overestimating the intensity of negative feelings in autobiographical memory: evidence from the 9/11 attack and COVID-19 pandemic.

When recalling autobiographical events, people not only retrieve event details but also the feelings they experienced. The current study examined whether people are able to consistently recall the intensity of past feelings associated with two consequential and negatively valenced events, i.e. the 9/11 attack (N = 769) and the COVID-19 pandemic (N = 726). By comparing experienced and recalled intensities of negative feelings, we discovered that people systematically recall a higher intensity of negative feelings than initially reported - overestimating the intensity of past negative emotional experiences. The COVID-19 dataset also revealed that individuals who experienced greater improvement in emotional well-being displayed smaller biases in recalling their feelings. Across both datasets, the intensity of remembered feelings was correlated with initial feelings and current feelings, but the impact of the current feelings was stronger in the COVID-19 dataset than in the 9/11 dataset. Our results demonstrate that when recalling negative autobiographical events, people tend to overestimate the intensity of prior negative emotional experiences with their degree of bias influenced by current feelings and well-being.

Emotion language use in narratives of the 9/11 attacks predicts long-term memory.

Despite considerable cognitive neuroscience research demonstrating that emotions can influence the encoding and consolidation of memory, research has failed to demonstrate a relationship between self-reported ratings of emotions collected soon after a traumatic event and memory for the event over time. This secondary analysis of data from a multisite longitudinal study of memories of the September 11, 2001 terrorist attacks, asked the question of whether emotional language use could predict memory over time. In the 2 weeks following the 9/11 attacks, participants (N = 691; Mage = 36.8; 72% identifying as male; 76% identifying as white) wrote narratives about how they learned of the attacks and the impact of the attacks on them. Language features of these narratives were extracted using the Linguistic Inquiry Word Count program and used to predict three types of memory: (a) event memory accuracy, (b) flashbulb memory consistency, and (c) emotion memory consistency. These outcomes were assessed at the time of writing, 1, 3, and 10 years after the 9/11 attacks. Results of linear mixed-effects models indicate that greater use of negative emotion words in narratives predicts better event memory accuracy 3 and 10 years after the attacks and worse flashbulb memory consistency 10 years after the attacks. However, emotion word use does not predict emotion memory consistency across time. We also examine whether other exploratory linguistic predictors are associated with memory over time. These findings suggest that written language may serve as a potential early indicator of memory over time. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Simulating conversations: A Markov chain model of a central speaker's mnemonic influence over a group of communicating listeners.

Through their selective rehearsal, Central Speakers can reshape collective memory in a group of listeners, both by increasing accessibility for mentioned items (shared practice effects) and by decreasing relative accessibility for related but unmentioned items (socially shared retrieval induced forgetting, i.e., SSRIF). Subsequent networked communication in the group can further modify these mnemonic influences. Extant empirical work has tended to examine such downstream influences on a Central Speaker's mnemonic influence following a relatively limited number of interactions - often only two or three conversations. We develop a set of Markov chain simulations to model the long-term dynamics of such conversational remembering across a variety of group types, based on reported empirical data. These models indicate that some previously reported effects will stabilize in the long-term collective memory following repeated rounds of conversation. Notably, both shared practice effects and SSRIF persist into future steady states. However, other projected future states differ from those described so far in the empirical literature, specifically: the amplification of shared practice effects in communicational versus solo remembering non-conversational groups, the relatively transient impact of social (dis)identification with a Central Speaker, and the sensitivity of communicating networks to much smaller mnemonic biases introduced by the Central Speaker than groups of individual rememberers. Together, these simulations contribute insights into the long-term temporal dynamics of collective memory by addressing questions difficult to tackle using extant laboratory methods, and provide concrete suggestions for future empirical work.

A day that America will remember: flashbulb memory, collective memory, and future thinking for the capitol riots.

ABSTRACTThis study explores the topics of flashbulb memory, collective identity, future thinking, and shared representations for a public event. We assessed the memories of the Capitol Riots, which happened in Washington DC, on 6 January 2021. Seventy Belgian and seventy-nine American citizens participated in an online study, in which they freely recalled the unfolding of Capitol Riots and answered questions regarding their memory. Inter-subjects similarity of recalled details was analysed using a schematic narrative template (i.e., the event, the causes and the consequences). Results revealed that representations of the event, and its causes were more similar among Belgians compared to Americans, whereas Americans' representations of the consequences showed more similarity than Belgians'. Also, as expected, Americans reported more flashbulb memories (FBMs) than Belgians. The analysis underlined the importance of rehearsal through media and communication in FBM formation. This research revealed a novel relation between FBM and future representations. Regardless of national identity, participants who formed an FBM were more likely to think that the event would be remembered in the future, that the government should memorialise the event, and that a similar attack on the Capitol could happen in the future compared to participants who did not form FBM.

Collective mental time travel: Current research and future directions.

In this chapter, we will provide a review on the emerging psychological literature on collective mental time travel (MTT). Our review will focus on the cognitive aspects of remembering the collective past and imagining the collective future. We will explore factors such as specificity, phenomenal characteristics, content, and valence. We will also include brief overviews of cultural and social psychological research that is relevant to the topic of collective MTT. In these overviews, we will examine the research on narratives, collective continuity, collective angst, and human action. Three main themes will emerge from these discussions: the connection between collective past and future thinking, the differences between collective past and future thinking, and the role of goals, perceived agency, and collective action. We will integrate the findings of cognitive, cultural, and social psychological work through these three themes and offer ways to move collective MTT research forward.

Purification of functional Plasmodium falciparum tubulin allows for the identification of parasite-specific microtubule inhibitors.

Cytoskeletal proteins are essential for parasite proliferation, growth, and transmission, and therefore have the potential to serve as drug targets.1-5 While microtubules and their molecular building block αß-tubulin are established drug targets in a variety of cancers,6,7 we still lack sufficient knowledge of the biochemistry of parasite tubulins to exploit the structural divergence between parasite and human tubulins. For example, it remains to be determined whether compounds of interest can specifically target parasite microtubules without affecting the host cell cytoskeleton. Such mechanistic insights have been limited by the lack of functional parasite tubulin. In this study, we report the purification and characterization of tubulin from Plasmodium falciparum, the causative agent of malaria. We show that the highly purified tubulin is fully functional, as it efficiently assembles into microtubules with specific parameters of dynamic instability. There is a high degree of amino-acid conservation between human and P. falciparum α- and ß-tubulin, sharing approximately 83.7% and 88.5% identity, respectively. However, Plasmodium tubulin is more similar to plant than to mammalian tubulin, raising the possibility of identifying compounds that would selectively disrupt parasite microtubules without affecting the host cell cytoskeleton. As a proof of principle, we describe two compounds that exhibit selective toxicity toward parasite tubulin. Thus, the ability to specifically disrupt protozoan microtubule growth without affecting human microtubules provides an exciting opportunity for the development of novel antimalarials.

A review of treatment methods for insensitive high explosive contaminated wastewater.

Insensitive high explosive materials (IHE) such as 3-nitro-1,2,4-triazol-5-one (NTO) and 2,4-dinitroanisole (DNAN) are increasingly being used in formulations of insensitive munitions alongside 1,3,5-trinitroperhydro-1,3,5-triazine (RDX). Load, assembly and packing (LAP) facilities that process munitions produce wastewater contaminated with IHE which must be treated before discharge. Some facilities can produce as much as 90,000 L of contaminated wastewater per day. In this review, methods of wastewater treatment are assessed in terms of their strengths, weaknesses, opportunities and threats for their use in production of IHE munitions including their limitations and how they could be applied to industrial scale LAP facilities. Adsorption is identified as a suitable treatment method, however the high solubility of NTO, up to 16.6 g.L-1 which is 180 times higher that of TNT, has the potential to exceed the adsorptive capacity of carbon adsorption systems. The key properties of the adsorptive materials along the selection of adsorption models are highlighted and recommendations on how the limitations of carbon adsorption systems for IHE wastewater can be overcome are offered, including the modification of carbons to increase adsorptive capacity or reduce costs.

Changes over 10 years in the retelling of the flashbulb memories of the attack of 11 September 2001.

A flashbulb memory is a highly detailed and vivid autobiographical memory for the circumstances in which one first learned of a surprising, consequential and emotionally arousing event. How retelling of different features of a flashbulb memory changes over time is not totally understood. Moreover, little is known about how the emotional feeling experienced by individuals when they learned about the event modulates these changes. In this study, we explored changes over time in American individuals' retelling of their flashbulb memories of the terrorist attack of 11 September 2001. We conducted textual analysis of 824 testimonies collected from the same 206 individuals 1 week, 11, 25 and again 119 months after the attack. Results showed individuals were more likely to report temporal and emotional details in their retelling early after the event and spatial details in their long-term retelling. In addition, the intensity of emotions felt upon hearing the news about the attack influenced how individuals reported their flashbulb memories over time. Overall, this study provides further support for theories suggesting different rates of forgetting for different canonical features of emotional arousal events.

Knowledge of Chosen Family History and Depressive Symptoms in Sexual Minority Women.

Recent work on intergenerational memory has revealed a positive association between family of origin knowledge and wellbeing in adolescents. However, little is known about the generalizability of these data, as significantly less attention has focused on autobiographical memory sharing and wellbeing in historically marginalized communities. Given the high incidence of familial rejection and abandonment within the LGBTQIA + community, close relationships with individuals outside of one's family of origin, chosen families, often serve as an important source of social support. This study sought to examine the relationship between knowledge of a close non-family member and wellbeing among emerging adult sexual minority women (SMW) according to their gender presentation. A community sample from New York City comprised of heterosexual women (n = 50), masculine-presenting SMW (n = 50), and feminine presenting SMW (n = 50) completed measures associated with their knowledge of their family of origin, knowledge of a close non-family member, as well as self-reported measures of depression, emotion regulation, and socio-demographic questions. Family of origin knowledge was associated with lower levels of depression only among heterosexual women. However, heterosexual and SMW who knew more about their close non-family member reported lower levels of depression. Additionally, emotion regulation (cognitive reappraisals) mediated the relationship between knowing more about one's chosen family and lower depressive symptom severity among heterosexual women, but this relationship was only significant for SMW who were at least moderately open about their sexuality. These findings extend the literature on the benefits of memory sharing to historically marginalized communities by showing that memory sources outside of one's family of origin may be particularly important. Additionally, these data begin to shed light on potential mediating factors, such as emotion regulation and openness about one's sexual identity, that underlie the links between memory sharing and metrics of wellbeing. Taken together, in contexts in which there may not be opportunities to learn about family history from one's family of origin, it appears that access to stories from someone close outside of one's family is also associated with lower levels of depression.

Affinity Purification of Label-free Tubulins from Xenopus Egg Extracts.

Cytoplasmic extracts from unfertilized Xenopus eggs have made important contributions to our understanding of microtubule dynamics, spindle assembly, and scaling. Until recently, these in vitro studies relied on the use of heterologous tubulin. This protocol allows for the purification of physiologically relevant Xenopus tubulins in milligram yield, which are a complex mixture of isoforms with various post-translational modifications. The protocol is applicable to any cell or tissue of interest. For complete details on the use and execution of this protocol, please refer to Hirst et al. (2020).

In Vitro Reconstitution and Imaging of Microtubule Dynamics by Fluorescence and Label-free Microscopy.

Dynamic microtubules are essential for many processes in the lives of eukaryotic cells. To study and understand the mechanisms of microtubule dynamics and regulation, in vitro reconstitution with purified components has proven a vital approach. Imaging microtubule dynamics can be instructive for a given species, isoform composition, or biochemical modification. Here, we describe two methods that visualize microtubule dynamics at high speed and high contrast: (1) total internal reflection fluorescence microscopy and (2) label-free interference reflection microscopy. For complete details on the use and execution of this protocol, please refer to Hirst et al. (2020).

Remembering the big game: social identity and memory for media events.

Two studies examined how memories are formed around championship sporting events, which we classify as media events. The first study employed a test-retest methodology to assess how fans of a sport recall a championship sporting event. The second study examined how fans of specific sports teams recalled two championship sporting events in which their team either won or lost. Of particular interest was the emergence of a collective memory within fan communities. We assessed memory for the event itself (event memory), with an emphasis on the emergence of a collective memory, and memory for the context in which one experienced the event (personal circumstance memory). In contrast to fans of a sport more generally, fans of a particular team recalled events involving their team with detail, converged on collective memories, and provided personal circumstance memories that met the criteria for flashbulb memories. We discuss these results in the context of social identities and the elements involved in narratives of media events. Different types of fandom, our measure of social identity, uniquely influenced the collective memories formed for essential and ancillary elements of narratives surrounding championship sporting events.

Differences in Intrinsic Tubulin Dynamic Properties Contribute to Spindle Length Control in Xenopus Species.

The function of cellular organelles relates not only to their molecular composition but also to their size. However, how the size of dynamic mesoscale structures is established and maintained remains poorly understood [1-3]. Mitotic spindle length, for example, varies several-fold among cell types and among different organisms [4]. Although most studies on spindle size control focus on changes in proteins that regulate microtubule dynamics [5-8], the contribution of the spindle's main building block, the αß-tubulin heterodimer, has yet to be studied. Apart from microtubule-associated proteins and motors, two factors have been shown to contribute to the heterogeneity of microtubule dynamics: tubulin isoform composition [9, 10] and post-translational modifications [11]. In the past, studying the contribution of tubulin and microtubules to spindle assembly has been limited by the fact that physiologically relevant tubulins were not available. Here, we show that tubulins purified from two closely related frogs, Xenopus laevis and Xenopus tropicalis, have surprisingly different microtubule dynamics in vitro. X. laevis microtubules combine very fast growth and infrequent catastrophes. In contrast, X. tropicalis microtubules grow slower and catastrophe more frequently. We show that spindle length and microtubule mass can be controlled by titrating the ratios of the tubulins from the two frog species. Furthermore, we combine our in vitro reconstitution assay and egg extract experiments with computational modeling to show that differences in intrinsic properties of different tubulins contribute to the control of microtubule mass and therefore set steady-state spindle length.

Adsorption behaviour of 1,3,5-trinitroperhydro-1,3,5-triazine, 2,4-dinitroanisole and 3-nitro-1,2,4-triazol-5-one on commercial activated carbons.

Insensitive high explosives are increasingly being used to replace more sensitive formulations, however large quantities of environmentally hazardous wastewater are generated from loading, assembling and packing processes. Currently, there is limited literature regarding the treatment of wastewater contaminated with these hazardous insensitive high explosive materials such as 1,3,5-trinitroperhydro- 1,3,5-triazine (RDX), 2,4-dinitoranisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO). The preferred method of explosive wastewater treatment is adsorption by activated carbon, usually through treatment columns or fluidised beds that are simple to operate and cost effective. The aim of this research was to assess whether commercially available activated carbons would be suitable and economically viable to treat explosive wastewater containing RDX, DNAN and NTO. Bottle point tests were used to determine adsorption capacity and adsorption kinetics for the individual insensitive high explosives with three different activated carbons. Equilibrium data were fitted to the Langmuir, Freundlich and Temkin isotherms to determine the mechanisms of adsorption. Six hour bottle point tests for a mixture of the three insensitive high explosive constituents were used to consider possible preferential adsorption. As expected, RDX and DNAN were adsorbed at concentrations up to 40 mg.L-1 and 150 mg.L-1 respectively by the activated carbons tested, demonstrating the viability of treatment by adsorption. However, at the high concentrations of NTO expected in wastewater (1400 mg.L-1) activated carbons were rapidly saturated, suggesting that treatment of NTO contaminated wastewater would require prohibitively large quantities of activated carbon compared to RDX and DNAN.

Remembering a nation's past to imagine its future: The role of event specificity, phenomenology, valence, and perceived agency.

People are routinely involved in remembering the national past and imagining the national future, especially when making political decisions. These processes, however, have not been explored extensively. The present research aims to address this lacuna. In 2 experiments (N = 203), participants were asked to remember and imagine events that involve the United States. Later, they rated these events in terms of phenomenal characteristics, valence, and perceived agency (circumstance, self, other-people, nation). Their responses were also coded for specificity and content. Past and future responses correlated for specificity, phenomenology, valence, and the four domains of perceived agency. Despite this strong correspondence between past and future thinking, there were also differences. Future responses were less specific and more positive than past responses. Moreover, people thought that they themselves and their nation will have more control over their nation's future compared with the control they attributed to themselves and their nation over its past. The bias to be more optimistic about the nation's future was partly explained by this tendency to see the nation as more agentic in the future. Taken together, these results reveal striking similarities and divergences between autobiographical and collective mental time travel. The present research provides an exploration for the newly emerging field of collective mental time travel. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Convergence on collective memories: Central speakers and distributed remembering.

A primary interest in the psychological study of collective memory concerns the sociocognitive processes by which Central Speakers-politicians, journalists, and other public voices-may reshape the memory of groups of listeners. In 2 experiments, we examine how (a) Central Speakers may induce shared practice effects and socially shared retrieval-induced forgetting (SSRIF) for related but unmentioned items in a group of listeners, (b) how communicational remembering along a serial transmission chain can moderate this initial mnemonic influence, and (c) how listeners' relational motives toward the Central Speaker, operationalized as perceived social group membership, impact both (a) and (b). Experiment 1 shows that a Central Speaker may induce both SSRIF and shared practice effects in a group of listeners, and that, relative to noncommunicating nominal groups, communicational remembering in a looped serial transmission chain amplifies the relative inaccessibility of related but unmentioned items. In Experiment 2, we show that the Central Speaker's perceived group membership moderates the effects of subsequent communicational remembering. When ingroup, communicational remembering amplifies the Central Speaker's SSRIF, when outgroup, subsequent communicational remembering attenuates it. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Reflections on Conversations and Memory.

The study of memory and remembering has traditionally either stripped meaning away from acts of remembering to reveal the "raw material of memory" or explored how meaning guides the reconstruction of the past. In reflecting on the contributions to this topic, there appears to be an emerging "third-way," which holds that there is an inextricable relation between conversations and remembering. The articles in this volume exemplify how conversing is often an act of remembering and represent approaches to memory that might not otherwise be taken if one were to study memory as a within-individual phenomenon. The implications of this approach are far-ranging and present the opportunity to pose new questions about the nature of remembering as it unfolds in conversation. The contributing articles have expanded the scope of what memory researchers can study by adopting a relatively straightforward assumption about the sociality of remembering and the role of the conversation in the social process.

The Mnemonic Consequences of Jurors' Selective Retrieval During Deliberation.

The jury is a defining component of the American criminal justice system, and the courts largely assume that the collaborative nature of jury deliberations will enhance jurors' memory for important trial information. However, research suggests that this kind of collaboration, although sometimes improving memory, can also lead to incomplete and inaccurate "collective" memories. The present research examines whether jury deliberations, where individuals collaboratively recall and discuss trial evidence to render unanimous verdicts, might shape jurors' memories through the robust phenomena of Within-Individual and Socially Shared Retrieval-Induced Forgetting (WI-RIF and SS-RIF, respectively). The results revealed no WI-RIF or SS-RIF. However, we did find evidence in the direction of Within-Individual and Socially-shared Retrieval Induced Facilitation (WI-RIFA and SS-RIFA, respectively) in speakers' and listeners' narrative and open-ended recall of evidentiary details. The present results are discussed in terms of whether jurors' goals during deliberation and the deliberation structure (e.g., six or more discussants) protect against forgetting, or whether possible methodological issues (e.g., the vast amount of information presented) eliminated WI-RIF and SS-RIF and, in turn, make drawing conclusions surrounding the mnemonic impact of jury deliberation difficult. Regardless, the present results suggest jury deliberations are quite limited in terms of how much evidence is actually discussed compared to the total of what could be discussed, and our methodology provides an ecologically valid baseline for future research to better understand the mnemonic consequences associated with jury deliberations and, in turn, jury decision making.