A Review on Emotion-Enhanced Recognition Memory: Response Bias and Context Caused by Emotional Stimuli

The current study aims to present the main lines of the topic by compiling the literature on the effect of emotion on recognition memory and address some considerations for future studies by highlighting the attention-grabbing points related to emotion-memory interaction. A growing body of literature has demonstrated that emotional stimuli are better remembered than their neutral equivalents. Based on these common findings, research in the relevant literature is reviewed in detail regarding various approaches that define and explain emotion; and the effect of emotional dimensions, which are defined within the framework of different approaches, on recognition memory is mentioned. Empirical studies are also reviewed by including the findings on the response biases that emotion might cause. On the other hand, the factor affecting memory performance is not solely due to emotional stimuli' dimensions. Instead, memory performance might be positively affected by the context of emotional stimuli. Additionally, how emotional memory is studied in a controlled laboratory setting is discussed. Within this context, emotional databases developed to investigate emotion-memory interaction and databases designed for research to be carried out in Turkey are discussed. To sum up, within the scope of the current review, it is concluded that future studies on emotion and recognition memory interaction should take response bias caused by emotion, emotional context, and type of emotional stimuli into account to reach more consistent results. Keywords: Emotion, recognition memory, response bias, context, databases

COVID-19 variants, available treatments, and vaccinations: An overview study

SARS-CoV-2 is the recent variation of the corona virus which is infecting people around the world and has affected more than 258 million people worldwide. Upon observation, the virus is similar to the coronavirus which spread from the horseshoe bat or wild animals to human beings. Up to date, there have been three major variants of the coronavirus which have been identified in UK, South Africa, and India which are spreading to other countries. Based on the current data, it is suggested that the incidents of repeated infection with SARS-CoV-2 is related to the level of neutralizing antibodies and the retained memory response which follows infection. Moreover, recently, a critical issue arises in relation to the association of black fungus and COVID-19, and urgent investigation is required. As a treatment method of COVID-19, FDA has recently approved the feasibility of Remdesivir to treat COVID-19 as emergency use authorization (EUA). There are also various possible antivirals which are still undergoing clinical trial. After widespread of the vaccine, the results showed that EUA vaccines have been effective in controlling COVID-19 in patients. However, these licensed vaccines ought to be reviewed to ensure they are also effective in combating the rising variants of SARS-CoV-2.

Innate Memory Reprogramming by Gold Nanoparticles Depends on the Microbial Agents That Induce Memory

Innate immune memory, the ability of innate cells to react in a more protective way to secondary challenges, is induced by exposure to infectious and other exogeous and endogenous agents. Engineered nanoparticles are particulate exogenous agents that, as such, could trigger an inflammatory reaction in monocytes and macrophages and could therefore be also able to induce innate memory. Here, we have evaluated the capacity of engineered gold nanoparticles (AuNPs) to induce a memory response or to modulate the memory responses induced by microbial agents. Microbial agents used were in soluble vs. particulate form (MDP and the gram-positive bacteria Staphylococcus aureus; β-glucan and the β-glucan-producing fungi C. albicans), and as whole microrganisms that were either killed (S. aureus, C. albicans) or viable (the gram-negative bacteria Helicobacter pylori). The memory response was assessed in vitro, by exposing human primary monocytes from 2-7 individual donors to microbial agents with or without AuNPs (primary response), then resting them for 6 days to allow return to baseline, and eventually challenging them with LPS (secondary memory response). Primary and memory responses were tested as production of the innate/inflammatory cytokine TNFα and other inflammatory and anti-inflammatory factors. While inactive on the response induced by soluble microbial stimuli (muramyl dipeptide -MDP-, β-glucan), AuNPs partially reduced the primary response induced by whole microorganisms. AuNPs were also unable to directly induce a memory response but could modulate stimulus-induced memory in a circumscribed fashion, limited to some agents and some cytokines. Thus, the MDP-induced tolerance in terms of TNFα production was further exacerbated by co-priming with AuNPs, resulting in a less inflammatory memory response. Conversely, the H. pylori-induced tolerance was downregulated by AuNPs only relative to the anti-inflammatory cytokine IL-10, which would lead to an overall more inflammatory memory response. These effects of AuNPs may depend on a differential interaction/association between the reactive particle surfaces and the microbial components and agents, which may lead to a change in the exposure profiles. As a general observation, however, the donor-to-donor variability in memory response profiles and reactivity to AuNPs was substantial, suggesting that innate memory depends on the individual history of exposures.

MEMORY RESPONSE OF CAPITAL MARKET PERFORMANCE TO INTEREST RATES ANNOUNCEMENT: ATHEORETICAL EVIDENCE IN NIGERIA

Despite the management of interest rates by the monetary policy authorities over these years, the performance of the capital market has not been impressive in Nigeria. The study analyzed the memory response of the capital market performance to interest rates announcement in Nigeria. The study used monetary policy rate, and deposit market rate as against market capitalization. The study sourced data from the Central Bank of Nigeria Statistical Bulletin between 1985 and 2020. The study adopted the Augmented Dickey-Fuller, and the Autoregressive Distributed Lag for the analysis. The findings showed that, deposit money rate was stationery at levels, while monetary policy rate, and market capitalization were at first differences, and no long run co-integrating equation. The theoretical evidence from the Error correction test findings revealed that, interest rates announcement did not constitute significant variables on the memory of the Nigerian capital market performance. Regular monitory and downward review of interest rates by the Nigerian monetary policy committee were recommended.

DNA Methylation and Immune Memory Response

The generation of memory is a cardinal feature of the adaptive immune response, involving different factors in a complex process of cellular differentiation. This process is essential for protecting the second encounter with pathogens and is the mechanism by which vaccines work. Epigenetic changes play important roles in the regulation of cell differentiation events. There are three types of epigenetic regulation: DNA methylation, histone modification, and microRNA expression. One of these epigenetic changes, DNA methylation, occurs in cytosine residues, mainly in CpG dinucleotides. This brief review aimed to analyse the literature to verify the involvement of DNA methylation during memory T and B cell development. Several studies have highlighted the importance of the DNA methyltransferases, enzymes that catalyse the methylation of DNA, during memory differentiation, maintenance, and function. The methylation profile within different subsets of naïve activated and memory cells could be an interesting tool to help monitor immune memory response.