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Introduction: Repetitive somatosensory stimulation (RSS) is a conventional approach to modulate the neural states of both the primary somatosensory cortex (S1) and the primary motor cortex (M1). However, the impact of RSS on skill acquisition and retention in sensorimotor adaptation remains debated. This study aimed to investigate whether whole-hand water flow (WF), a unique RSS)induced M1 disinhibition, influences sensorimotor adaptation by examining the hypothesis that whole-hand WF leads to M1 disinhibition; thereby, enhancing motor memory retention. Methods: Sixty-eight young healthy participants were randomly allocated to three groups based on the preconditioning received before motor learning: control, whole-hand water immersion (WI), and whole-hand WF. The experimental protocol for all the participants spanned two consecutive days. On the initial day (day 1), baseline transcranial magnetic stimulation (TMS) assessments (T0) were executed before any preconditioning. Subsequently, each group underwent their respective 30  min preconditioning protocol. To ascertain the influence of each preconditioning on the excitability of the M1, subsequent TMS assessments were conducted (T1). Following this, all participants engaged in the motor learning (ML) of a visuomotor tracking task, wherein they were instructed to align a cursor with a target trajectory by modulating the pinch force. Upon completion of the ML session, final TMS assessments (T2) were conducted. All participants were required to perform the same motor learning 24  h later on day 2. Results: The results revealed that whole-hand WF did not significantly influence skill acquisition during sensorimotor adaptation, although it did reduce intracortical inhibition. This phenomenon is consistent with the idea that S1, rather than M1, is involved in skill acquisition during the early stages of sensorimotor adaptation. Moreover, memory retention 24  h after skill acquisition did not differ significantly across the three groups, challenging our initial hypothesis that whole-hand WF enhances memory retention throughout sensorimotor adaptation. This could be due to the inability of whole-hand WF to alter sensorimotor connectivity and integration, as well as the nature of the plastic response elicited by the preconditioning. Discussion: In conclusion, these findings suggest that although whole-hand WF attenuates intracortical inhibition, it does not modulate skill acquisition or motor memory retention during sensorimotor adaptation. [ABSTRACT FROM AUTHOR]

A student's learning system is a system that guides the student's knowledge acquisition process using available learning resources to produce certain learning outcomes that can be evaluated based on the scores of questions in an assessment. Such a learning system is analogous to a control system, which regulates the process of a plant through a controller in order to generate a desired response that can be inferred from sensor measurements. Inspired by this analogy, this study proposes to model the monitoring of students' knowledge acquisition process from a control-theory viewpoint, which is referred to as control knowledge tracing (CtrKT). The proposed CtrKT comprises a dynamic equation that characterizes the temporal variation of students' knowledge states in response to the effects of learning resources and an observation equation that maps their knowledge states to question scores. With this formulation, CtrKT enables tracking students' knowledge states, predicting their assessment performance, and teaching planning. The insights and accuracy of CtrKT in postulating the knowledge acquisition process are analyzed and validated using experimental data from psychology literature and two naturalistic datasets collected from a civil engineering undergraduate course. Results verify the feasibility of using CtrKT to estimate the overall assessment performance of the participants in the psychology experiments and the students in the naturalistic datasets. Lastly, this study explores the use of CtrKT for teaching scheduling and optimization, discusses its modeling issues, and compares it with other knowledge-tracing approaches.

Motor learning is a prominent and extensively studied subject in rehabilitation following various types of neurological disorders. Motor repair and rehabilitation often extend over months and years post-injury with a slow pace of recovery, particularly affecting the fine movements of the distal extremities. This extended period can diminish the motivation and persistence of patients, a facet that has historically been overlooked in motor learning until recent years. Reward, including monetary compensation, social praise, video gaming, music, and virtual reality, is currently garnering heightened attention for its potential to enhance motor motivation and improve function. Numerous studies have examined the effects and attempted to explore potential mechanisms in various motor paradigms, yet they have yielded inconsistent or even contradictory results and conclusions. A comprehensive review is necessary to summarize studies on the effects of rewards on motor learning and to deduce a central pattern from these existing studies. Therefore, in this review, we initially outline a framework of motor learning considering two major types, two major components, and three stages. Subsequently, we summarize the effects of rewards on different stages of motor learning within the mentioned framework and analyze the underlying mechanisms at the level of behavior or neural circuit. Reward accelerates learning speed and enhances the extent of learning during the acquisition and consolidation stages, possibly by regulating the balance between the direct and indirect pathways (activating more D1-MSN than D2-MSN) of the ventral striatum and by increasing motor dynamics and kinematics. However, the effect varies depending on several experimental conditions. During the retention stage, there is a consensus that reward enhances both short-term and long-term memory retention in both types of motor learning, attributed to the LTP learning mechanism mediated by the VTA-M1 dopaminergic projection. Reward is a promising enhancer to bolster waning confidence and motivation, thereby increasing the efficiency of motor learning and rehabilitation. Further exploration of the circuit and functional connections between reward and the motor loop may provide a novel target for neural modulation to promote motor behavior. [ABSTRACT FROM AUTHOR]

Honey bees may experience the adverse effects of environmental contaminants when exposed during foraging trips, or something to that effect. We hypothesized that octopamine (OA), with important functions in reward signaling and learning, can improve the behavior of honey bees under chemical stress. Memory retention and sucrose responsiveness were evaluated using the proboscis extension reflex (PER) assay. The one-day-old bees were exposed separately to diazinon, imidacloprid, paraquat, manganese, and thymol at concentrations of 0.22, 29.04, 55.69, 106.19, and 0.91 ppm, respectively. On the 21st day of exposure, the bees' responses to memory retention and sucrose responsiveness experiments were recorded after the training trial. In addition, PERs were recorded after OA injection. During the intervals, honey bees were exposed to the toxins topically. The expression levels of OA receptor genes, AmoctαR1 and AmoctβR4, were measured. The sucrose responsiveness tests showed no significant differences between the bees stimulated with the control solutions or toxins. Moreover, our results indicated that memory retention significantly declined in honey bees exposed to toxins compared to the controls (P ≤ 0.05). According to the findings, OA improved the memory retention of honey bees exposed to toxins (P ≤ 0.05). The expression levels of AmoctαR1 and AmoctβR4 genes significantly increased in the treated honey bees, especially those exposed to paraquat and manganese, after 30 min post-OA injection. It can be concluded that under chemical stress, OA administration encouraged honey bees to respond to a stimulus. Therefore, it can be added to a nutrient-enriched diet. [ABSTRACT FROM AUTHOR]

The growing usage of digital technologies raised concerns regarding the possible adverse effects of digital amnesia, in which people forget readily available knowledge saved in their gadgets. This study investigated the effects of digital amnesia on memory retention and knowledge construction through experiment studies. The tasks given to the participants required either digital devices or more conventional memory storage and retrieval methods. Memory performance and knowledge construction were assessed through various tests and assessments. The findings indicated that excessive reliance on digital devices for information storage led to digital amnesia. Participants who used digital tools exhibited lower memory retention and shallower information processing compared to those employing traditional memory strategies. The results highlighted the negative implications of digital amnesia for memory retention and knowledge construction. Striking a balance between reliance on digital tools and active engagement in memory processes was crucial. Actively encoding and retrieving information can mitigate risks associated with shallow processing and information overload.

Our empirical research delved into how this interactive digital learning module affected students' learning outcomes and their ability to retain information. We explored three distinct scenarios: an e-learning environment with the interactive digital learning module, an electronic learning module without interactive video, and a traditional classroom environment with a text-based module. This study was conducted with a sample of 180 eleventh-grade students from a senior high school. The results of the experiment revealed that students in the e-learning environment, which incorporated the interactive digital learning module, demonstrated significantly better learning outcomes and retention compared to those in the other settings. Conversely, students who utilized the electronic learning module featuring noninteractive video did not exhibit any notable improvements. These findings suggest that the integration of interactive modular teaching into the learning process enhances student retention, thereby positively influencing their overall learning performance. [ABSTRACT FROM AUTHOR]

Nanoplastics (NPs) exposure to humans can occur through various routes, including the food chain, drinking water, skin contact, and respiration. NPs are plastics with a diameter of less than 100 nm and have the potential to accumulate in tissues, leading to toxic effects. This study aimed to investigate the neurotoxicity of polystyrene NPs on neural progenitor cells (NPCs) and hippocampal neurogenesis in a rodent model. Toxicity screening of polystyrene NPs based on their charge revealed that cationic amine-modified polystyrene (PS–NH 3 +) exhibited cytotoxicity, while anionic carboxylate-modified polystyrene (PS–COO-) and neutral NPs (PS) did not. NPCs treated with PS-NH 3 + showed a significant reduction in growth rate due to G1 cell cycle arrest. PS-NH 3 + increased the expression of cell cycle arrest markers p21 and p27, while decreasing cyclin D expression in NPCs. Interestingly, PS-NH 3 + accumulated in mitochondria, leading to mitochondrial dysfunction and energy depletion, which caused G1 cell cycle arrest. Prolonged exposure to PS-NH 3 + in C17.2 NPCs increased the expression of p16 and senescence-associated secretory phenotype factors, indicating cellular senescence. In vivo studies using C57BL/6 mice demonstrated impaired hippocampal neurogenesis and memory retention after 10 days of PS-NH 3 + administration. This study suggests that NPs could deplete neural stem cell pools in the brain by mitochondrial dysfunction, thereby adversely affecting hippocampal neurogenesis and neurocognitive functions. [Display omitted] • Positively charged polystyrene NP (PS–NH 3 +) is toxic to NPCs. • PS-NH 3 + induces p53-independent cell cycle arrest at the G1 phase in NPCs. • PS-NH 3 + accumulates in mitochondria, causing mitochondrial dysfunction in NPCs. • Long-term exposure to PS-NH 3 + induces senescence in NPCs. • The exposure to PS-NH 3 + impairs hippocampal neurogenesis and mememory retention in young mice. [ABSTRACT FROM AUTHOR]

Recent studies suggest sharks cognitive abilities are comparable to other vertebrates such as mammals and birds, but we still know relatively little about the long-term memory capacity of sharks. We took advantage of the COVID-19 anthropause to determine whether bull sharks conditioned at a provisioning ecotourism site in Fiji would remember the site after an 18-month hiatus in shark feeding activities. We hypothesized that if bull sharks remembered the food rewards associated with divers at the site, they would return to the reactivated site more rapidly than the original recruitment process that occurred when the site was first established in, 2015. We assumed that original recruitment to the newly established site represent a period of learning and conditioning, whereas a significantly faster recolonization of the site would imply memory recall of the original conditioning. We monitored bull shark abundance at the site for three years (1018 dives) from its original establishment in 2015 until all feeding and diving activities were ceased for 18 months in December, 2020. When shark feeding resumed, we documented bull sharks returning to the site over a three-week period (45 dives beginning June 22, 2022) and compared observed abundances with modelled predictions assuming no interruption to provisioning. Results revealed a rapid return to 'business as usual', suggesting that bull sharks still remembered the food reward conditioning despite an 18-month hiatus in provisioning. This supports the existence of long-lasting cognitive capacities in this species and highlights their relevance for managing activities that could disrupt their natural ecology. [ABSTRACT FROM AUTHOR]

IntroductionIdentifying intervention methods that target sleep characteristics involved in memory processing is a priority for the field of cognitive aging. Older adults with greater sleep efficiency and non-rapid eye movement slow-wave activity (SWA) (0.5–4 Hz electroencephalographic activity) tend to exhibit better memory and cognitive abilities. Paradoxically, long total sleep times are consistently associated with poorer cognition in older adults. Thus, maximizing sleep efficiency and SWA may be a priority relative to increasing mere total sleep time. As clinical behavioral sleep treatments do not consistently enhance SWA, and propensity for SWA increases with time spent awake, we examined with a proof-of concept pilot intervention whether a greater dose of time-in-bed (TiB) restriction (75% of habitual TiB) would increase both sleep efficiency and SWA in older adults with difficulties staying asleep without impairing memory performance.MethodsParticipants were adults ages 55–80 with diary-reported sleep efficiency < 90% and wake after sleep onset (WASO) >20 min. Sleep diary, actigraphy, polysomnography (PSG), and paired associate memory acquisition and retention were assessed before and after a week-long TiB restriction intervention (n = 30). TiB was restricted to 75% of diary-reported habitual TiB. A comparison group of n = 5 participants repeated assessments while following their usual sleep schedule to obtain preliminary estimates of effect sizes associated with repeated testing.ResultsSubjective and objective sleep measures robustly improved in the TiB restriction group for sleep quality, sleep depth, sleep efficiency and WASO, at the expense of TiB and time spent in N1 and N2 sleep. As hypothesized, SWA increased robustly with TiB restriction across the 0.5–4 Hz range, as well as subjective sleep depth, subjective and objective WASO. Despite increases in sleepiness ratings, no impairments were found in memory acquisition or retention.ConclusionA TiB restriction dose equivalent to 75% of habitual TiB robustly increased sleep continuity and SWA in older adults with sleep maintenance difficulties, without impairing memory performance. These findings may inform long-term behavioral SWA enhancement interventions aimed at improving memory performance and risk for cognitive impairments.

Optoelectronic devices based on optically responsive materials have gained significant attention due to their low cross talk and reduced power consumption. These devices rely on light‐induced changes in conductance states, which are used to create synaptic weights for image recognition tasks in neural networks. However, a major drawback of such devices is the rapid decay of conductance states after light stimulus removal, which hinders their long‐term memory and performance without a continuous external stimulus in place. To address this issue, a platform neural network scheme is proposed to counter the natural decay of conductance in optoelectronic devices. The approach restores the memory effect of the devices and significantly enhances their performance by several orders of magnitude without using additional energy‐intensive techniques like training pulses or gate fields. Herein, the model is validated experimentally using optoelectronic devices fabricated with two different materials, BP and doped In2O3, and demonstrates the restoration of memory/image retention ability to any material system being studied for optoelectronic synapses and vision. This approach has important implications for the practical application of neuromorphic visual processing technologies, bringing them closer to real‐world applications. [ABSTRACT FROM AUTHOR]

Influential theories and computational models suggest error-based learning plays an important role in language acquisition: Children learn new words by generating predictions about upcoming utterances and revising those predictions when they are erroneous. Critically, revising stronger (rather than weaker) predictions should further enhance learning. Although previously demonstrated in adults, such prediction error boost has not been conclusively shown in children. To close this gap, we tested 107 participants between the ages of 5 and 10. We found little evidence that word learning in this age group benefits from a prediction error boost. Moreover, we also failed to replicate previous evidence for such an effect in adults. Based on a detailed task analysis, we suggest the variation in adult findings may be partly explained by differences in encoding strategies and that, relatedly, the protracted development of the episodic memory system might explain why children do not experience robust benefits from having stronger (rather than weaker) predictions disconfirmed.

Optoelectronic devices based on optically responsive materials have gained significant attention due to their low cross talk and reduced power consumption. These devices rely on light‐induced changes in conductance states, which are used to create synaptic weights for image recognition tasks in neural networks. However, a major drawback of such devices is the rapid decay of conductance states after light stimulus removal, which hinders their long‐term memory and performance without a continuous external stimulus in place. To address this issue, a platform neural network scheme is proposed to counter the natural decay of conductance in optoelectronic devices. The approach restores the memory effect of the devices and significantly enhances their performance by several orders of magnitude without using additional energy‐intensive techniques like training pulses or gate fields. Herein, the model is validated experimentally using optoelectronic devices fabricated with two different materials, BP and doped In2O3, and demonstrates the restoration of memory/image retention ability to any material system being studied for optoelectronic synapses and vision. This approach has important implications for the practical application of neuromorphic visual processing technologies, bringing them closer to real‐world applications.

The study Perceived Impact of Multimedia Tools on Ilesa West Secondary School Students Learning of English Language Concepts. The study is a descriptive study; a total number of 300 respondents were used. The instrument for data collections was inventory and was inventory and was structured by the researcher for data collection and reliability level was 0.75. Data collected were analyzed using descriptive statistics specifically mean, standard deviation, frequency counts and Person Product Moment Correlation (PPCM). The findings of the study revealed that Multimedia tools enable you to gain better understanding of English Language concepts that are unclear to you, Multimedia tools give you rom to receive an answer at the same time, as well as being able to exchange responses to questions with teachers in real time, Multimedia tools encourage you to share our thought and opinion on English Language concepts, Multimedia tools develop your critical thinking skills and enrich your learning experience in learning English Language concepts, Multimedia tools help to develop your language skills chiefly English Language, Multimedia tools assist you in comprehending text by utilizing prior knowledge new terminology, Does the appealing features of the multimedia tools allow you to boost your stimulation to the learning process involved in learning English Language concepts, application of multimedia tools in learning English Language also improve memory retention, learning accomplishment and satisfaction. Also, the study has revealed that there is significant difference in learning effectiveness of student who learned English Language concept with multimedia tools and those who learn without it. It also revealed that there is a significant difference in the attitude of secondary school students to learning English Language concepts when multimedia tools are explored and when not. As a result of the findings in this study, this can strengthen the literatures of Multimedia tools. [ABSTRACT FROM AUTHOR]

Adult neurogenesis generates new functional neurons from adult neural stem cells in various regions, including the subventricular zone (SVZ) of the lateral ventricles and subgranular zone (SGZ) of hippocampal dentate gyrus (DG). Available evidence shows hippocampal neurogenesis can be negatively or positively regulated by dietary components. In a previous study, we reported that curcumin (diferuloylmethane; a polyphenolic found in curry spice) stimulates the proliferation of embryonic neural stem cells (NSCs) by activating adaptive cellular stress responses. Here, we investigated whether subchronic administration of curcumin (once daily at 0.4, 2, or 10 mg/kg for 14 days) promotes hippocampal neurogenesis and neurocognitive function in young (5-week-old) mice. Oral administration of low-dose curcumin (0.4 mg/kg) increased the proliferation and survival of newly generated cells in hippocampus, but surprisingly, high-dose curcumin (10 mg/kg) did not effectively upregulate the proliferation or survival of newborn cells. Furthermore, hippocampal BDNF levels and phosphorylated CREB activity were elevated in only low-dose curcumin-treated mice. Passive avoidance testing revealed that low-dose curcumin increased cross-over latency times, indicating enhanced memory retention, and an in vitro study showed that low-concentration curcumin increased the proliferative activity of neural progenitor cells (NPCs) by upregulating NF1X levels. Collectively, our findings suggest that low-dose curcumin has neurogenic effects and that it may prevent age and neurodegenerative disease-related cognitive deficits. [ABSTRACT FROM AUTHOR]

Distractions and multitasking are generally detrimental to learning and memory.Nevertheless, people often study while listening to music, sitting in noisy coffee shops, orintermittently checking their e-mail. The experiment we replicated examined how distractionsand divided attention influence one’s ability to selectively remember valuable information.Participants studied lists of words that ranged in value from 1 to 10 points while completing adigit-detection task, while listening to music, or without distractions. Most of the figures weresuccessfully replicated using the given dataset and tools like Microsoft Excel and Google Sheets.Since we were able to arrive at the same conclusion as the original author, we believe thisexperiment is valid and reliable for application to further extension studies. Our extension studyexamined correlations between gender and recall ability and between age and recall ability. Weconcluded that there was no significant correlation between these variables, suggesting thesefactors did not affect the outcome. This extension further supports the author’s results, as age andgender were seemingly not confounding variables.

Learning to write in English as a Foreign Language (EFL) has always been an issue for most learners since it requires intensive cognitive activity along with language proficiency. This mixed-methods study aimed to examine if interactive Video Embedded Infographics (VEI) could ease this process in a flipped classroom setting compared to traditional infographics. Twenty-four EFL learners equally divided into two groups as traditional infographics group and the video embedded infographics group participating in a 3-week intensive EFL writing training. Quantitative data was obtained through quizzes, a final exam, and a delayed exam, while semi-structured interviews were implemented to obtain qualitative data. Quantitative results showed no significant difference between groups in terms of test performance, indicating satisfactory scores for both groups. Qualitative findings revealed a positive tendency towards video embedded infographics, most learners found them concise, easy to use, and more compact. Participants also showed positive attitudes towards EFL writing courses in a flipped classroom setting, stating that they found it more practical, stress-free, and efficient compared to traditional EFL writing classrooms. [ABSTRACT FROM AUTHOR]

Program comprehension is a continuously important topic in computer science since the spread of personal computers, and several program comprehension models have been identified as possible directions of active code comprehension. There has been little research on how much programmers remember the code they have once written. We conducted two experiments with a group of Computer Science MSc students. In the first experiment, we examined the code comprehension strategies of the participants. The students were given a task to implement a minor feature in a relatively small C++ project. In the second experiment, we asked the students 2 months later to complete the same task again. Before starting the clock, we asked the students to fill a questionnaire which aimed to measure program code-related memory retention: we inquired about how much the students remembered the code, down to the smallest relevant details, e.g. the name of functions and variables they had to find to complete the task. After the second experiment, we could compare the solution times of those students who participated in both parts. As one result, we could see that these students could solve the task in shorter time than they did in the first experiment. We also looked at the results of the questionnaire: the vast majority of students could not precisely remember more than two or three identifiers from the original code. In this paper, we will show how this result compares to the forgetting curve. [ABSTRACT FROM AUTHOR]

The mechanism of size constancy assures that an object is perceived to be constant in size despite that its retinal size varies with viewing distance. Conversely, an object can be perceived as illusorily larger if the perceived distance becomes greater, due to the size–distance scaling mechanism. The present study aimed at exploring how size–distance scaling is modulated by the encoding duration and how its memory is affected by the retention duration. In Experiment 1, we presented two stimuli simultaneously at two stereoscopic depth planes and manipulated the presentation duration, and found that the magnitude of the size scaling increased with presentation duration. In Experiment 2, we examined the maintenance of size–distance scaling when component stimulus was kept in working memory with variable delays. The results showed that the size scaling was reliably retrieved from working memory if there was no disparity manipulation on the to-be-memorized item, but it decreased with retention if a disparity was applied to the to-be-memorized item. The findings suggest that although the post-scaling size can be stored in working memory, the scaling mechanism may still be in effect when there were conflicts in the oculomotor cues and disparity cues that produces depth perception. [ABSTRACT FROM AUTHOR]

The teaching of Mathematics – in particular, Geometry, through conventional methods has been a challenging task for tutors. Augmented Reality (AR) based applications available in commercial space, have not followed any structured pedagogical approach in the designing process, and also do not ensure that the learning time of students is spent prolifically. In this paper, we explore the use of AR in mathematics for geometry education, to aid visualization of multidimensional objects and long-term retention of concepts by the learners. For designing an appropriate AR application it is necessary to identify some principles which support better memory retention of the students. The application has been specifically designed on the basis of identified principles affecting memory retention. We further explain the development of an AR-based Geometry Learning Assistant (AR-GLA), using a structural approach to pedagogical-design for teaching 3-dimensional geometry to higher school students through improved visualization and enhance their memory retention for related concepts. A sample of 54 K-12 students and 2 teachers with expertise in mathematics were part of the experiment. The students were divided into two different groups; one of the groups was taught with AR-based content whereas the other group was given Interactive Simulation (IS) based learning. The results illustrated that AR-based learning provides better retention of memory as compared to IS-based learning were tested over a period of two months. [ABSTRACT FROM AUTHOR]

Organic artificial synapses are becoming the most desirable format for neuromorphic computing due to their highly tunable resistive states. However, repressively low analog switching range, inferior memory retention, and operational instability greatly hinder the further development of organic synapses. Herein, two donor‐acceptor copolymers consisting of electron‐deficient isoindigo coupled with variable donating moieties for three‐terminal organic synaptic transistors (TOSTs) are reported. It is found that the synaptic function and device stability of TOSTs are significantly improved by enhancing the electron‐donating strength of donor units. Polymer alkylated isoindigo‐bis‐ethylenedioxythiophene exhibits high analog switching range of 170 ×, two orders of magnitude higher than that of normal organic neuromorphic devices. They also demonstrate excellent memory retention of over 5 × 103 s, low switching energy of 13 fJ, and ultrahigh operational stability with 99% of its original current after 100 000 write‐read events in air. Furthermore, the high viability of strong donor strategy is showcased by demonstrating flexible TOSTs with stable synaptic function after repeated mechanical bending as well as organic synapses capable of simulating image information processing. Overall, this work highlights the advantages of the strong donor functionalization strategy to boost the synaptic performance and device stability of TOSTs. [ABSTRACT FROM AUTHOR]

Silk protein products have been used for a wide range of applications. This review focuses on the studies conducted relative to cognitive functions with silk fibroin enzyme hydrolysates (FEH) in humans and animals. All known studies reported in PubMed and Google Scholar have been included. Studies have been conducted on children, high school and college students, adults and seniors, ranging in ages from 7–92 years. Doses of 200–600 mg silk FEH per day for three weeks to 16 weeks have been used. Based on these studies, it can be concluded that silk FEH exhibit beneficial cognitive effects with respect to memory and learning, attention, mental focus, accuracy, memory recall, and overall memory and concentration. These conclusions are supported by studies in rats and mice. Mechanistic studies that have been conducted in animals and cell culture systems are also reviewed. These studies indicate that silk FEH exerts its positive effects on memory and learning by providing neuroprotection via a complex mechanism involving its potent antioxidant and inflammation-inhibiting activities. Acetylcholine (ACh) is secreted by cholinergic neurons, and plays a role in encoding new information. Silk FEH were shown to decrease the levels of the pro-oxidant and pro-inflammatory mediators interlukin-1 (IL-1β), IL-6 and tumor necrosis factor-alpha (TNF-α), protecting the cholinergic system from oxidative stress, thus enhancing ACh levels in the brain, which is known to promote cognitive functions. In addition, the expression of brain-derived neurotrophic factor (BNDF), which is involved in the survival of neurons, is enhanced, and an increase in the expression of the phosphorylated cAMP response element-binding protein (p-CREB) occurs, which is known to play a positive role in cognitive functions. No adverse effects have been reported in association with the use of silk FEH. [ABSTRACT FROM AUTHOR]

Catastrophic forgetting (CF) refers to the sudden and severe loss of prior information in learning systems when acquiring new information. CF has been an Achilles heel of standard artificial neural networks (ANNs) when learning multiple tasks sequentially. The brain, by contrast, has solved this problem during evolution. Modellers now use a variety of strategies to overcome CF, many of which have parallels to cellular and circuit functions in the brain. One common strategy, based on metaplasticity phenomena, controls the future rate of change at key connections to help retain previously learned information. However, the metaplasticity properties so far used are only a subset of those existing in neurobiology. We propose that as models become more sophisticated, there could be value in drawing on a richer set of metaplasticity rules, especially when promoting continual learning in agents moving about the environment. Catastrophic forgetting (CF) is the sudden and severe loss of memory for previously stored information due to the learning of new information. Standard artificial neural networks have traditionally suffered from CF when undertaking sequential learning tasks. A wide variety of strategies have been used to minimise forgetting, such as generative replay, constructive algorithms, complementary systems, sparse storage, and meta-learning. Metaplasticity is the activity-dependent plasticity of future plasticity or learning. Various network models use metaplasticity-type strategies to reduce forgetting during continual learning. Combining metaplasticity-type rules with other strategies often improves network performance even further. Models may benefit even more by drawing on other properties of biological metaplasticity phenomena. [ABSTRACT FROM AUTHOR]

Metalâ€"ferroelectricâ€"insulatorâ€"semiconductor (MFIS) capacitors were characterized to elucidate the optimum design schemes for the ferroelectric field-effect transistor applications. The Hf1âˆ' x Zr x O2 (HZO) thin films (18 nm) were prepared on the SiO2 and ZrO2 insulator layers (ILs) with different film thicknesses. The choice of 10 nm thick ZrO2 IL was found to be an optimum condition to properly balance between the values of electric fields applied to the HZO (E HZO) and ZrO2 (E IL) layers, leading to effective improvement in capacitance coupling ratio and to suppression of charge injection for the MFIS capacitors. Furthermore, the crystalline natures of the crystallized HZO films were also found to be strategically controlled on the ZrO2 ILs, which can additionally enhance the E HZO with reducing the E IL. As consequences, the MFIS capacitors using 10 nm thick ZrO2 IL exhibited the ferroelectric memory window as large as 2.5 V at an application of ±5 V, which corresponds to 2.7 times wider value, compared to that obtained from the device using 2 nm thick SiO2 IL. Long-time memory retention and robust program endurance were also verified for the fabricated MFIS capacitors. [ABSTRACT FROM AUTHOR]

The present work examines the effectiveness and possible limitations of the lexical approach in the process of teaching and learning vocabulary. The authors suggest ways to solve the issues of this approach that arise during its application, while maintaining its main advantages, by using Song-Based Approach in a foreign language classroom. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess whether the degree of learning influences the observation of memory retention and forgetting that follows a linear pattern. According to our retention accuracy from fragmented traces (RAFT) model, one factor that should increase the likelihood of this is when there is greater learning of the material. Higher levels of learning can increase the number of trace components, making it more likely that reconstruction or partial retrieval can lead to an accurate response on a memory test. Here, we report three new experiments, as well as re-analyses of existing data from the literature, to show that increasing the level of learning in some ways can lead to increases in the likelihood of observing linear forgetting. For Experiment 1, people learned materials to different levels. This learning involved cued recall testing during memorisation. Linear forgetting was observed with increased learning. For Experiment 2, learning did not involve cued recall testing. Linear forgetting was not observed. Although our aim was not to test theories of retrieval practice, for Experiment 3, we showed that when people engage in this process, the pattern of retention and forgetting becomes more linear. Overall, these data are consistent with the RAFT theory and support mechanisms that it suggests can lead to the observation of linear forgetting. [ABSTRACT FROM AUTHOR]

The exploration of synaptic plasticity in metal-oxide-based ferroelectric thin-film transistors has been limited. As a perovskite ferroelectric material, LiNbO 3 is widely studied; but its potential use as a neuromorphic device, like synaptic transistors, has not been realized. In this study, a solution-processed ferroelectric thin-film transistor (FeTFT) with an alternating layer of LiNbO 3 and Li 5 AlO 4 as a gate dielectric has been fabricated. This configuration reduces the depolarization field by leveraging the large ionic polarization of Li + ions in the Li 5 AlO 4 layer, while the wide bandgap helps mitigate the leakage current. FeTFT exhibits impressive transistor performance, including a saturation mobility of 0.478 cm 2 V -1 s -1 , an on/off ratio of 3.08 × 10 3 , and a low trap-state density of 1.3 × 10 13 cm -2 . Moreover, the device demonstrates good memory retention, retaining information for nearly 1 day. It successfully emulates synaptic plasticity, specifically short-term plasticity and long-term plasticity. Besides, a 94% training accuracy has been achieved through artificial neural network simulation. Notably, the FeTFT consumes minimal power, with energy consumption of approximately 3.09 nJ per synaptic event, which is remarkably low compared to other reported solution-processed FeTFT devices.

African mesquite AM is widely used as an anti-inflammatory agent in sub-Sahara Africa especially Nigeria. Given its strong anti-inflammatory potency, this study has evaluated the neuroprotective properties of AM in the hippocampus HIP and olfactory bulb OB of rats exposed to Cd, As, Hg, and Pb. Twenty-five albino Sprague Dawley rats were randomly divided into five groups in this experiment. Group 1, the control received only water. Group 2 received heavy metal mixture HMM (PbCl 2 (20 mg/kg), CdCl 2 (1.61 mg/kg), HgCl 2 (0.40 mg/kg), and NaAsO 3 (10 mg/kg), for 60 days. Groups 3, 4, and 5 were treated with HMM along with AM at doses of 500, 1000, and 1500 mg/kg, respectively. AM decreased the Cd, As, Hg, and Pb levels in OB and HIP, restored the activities of antioxidants, Hmox-1, reduced the activities of AChE, NRF2 and NFkB and improved histopathology.

Simple Summary: Learning and memory abilities and their roles in group decision-making have important ecological relevance in routine activities such as foraging and anti-predator behaviors in fish species. The aims of this study were to explore the spatial learning ability of juvenile cichlids (Chindongo demasoni), and the influence of heterogeneity of memory information among group members on group performance in a six-arm radiation maze. The spatial performance of individual fish improved and reached a stable level on the fifth day of training, and the memory of the space task is kept after 11 days of detraining. The spatial performance of heterogeneous groups composed of members with different memory information were found to change linearly with the increase of the proportion of trained members. This indicates that cichlids can obtain associative learning information through training, and it seems unlikely that cichlids' group behavior is determined by minority members in foraging context. Learning and memory abilities and their roles in group decision-making have important ecological relevance in routine activities such as foraging and anti-predator behaviors in fish species. The aims of the present study were to explore individual spatial learning abilities of juvenile cichlids (Chindongo demasoni) in a foraging context, and to explore the influence of heterogeneity of memory information among group members on group performance in a six-arm radiation maze. In the context of an association between landmarks and food, learning ability was evaluated by the speed and accuracy of reaching the arm with food during seven days of reinforcement, and memory retention was tested at intervals of 2, 5, 8 and 11 days of detraining. Then, the speed and accuracy of an eight-member group with different proportions of memory-trained fish were measured. Both speed and accuracy of individual fish improved significantly and linearly in the first five days of training and leveled off between five and seven days, with values 60% shorter (in speed) and 50% higher (in accuracy) compared to those of the first day. Neither speed nor accuracy showed any decrease after 11 days of detraining, suggesting memory retention of the spatial task. When measured in a group, the speed and accuracy of the majority of the group (more than half) in reaching the arm with food changed linearly with an increasing ratio of trained members. This shows that cichlids can acquire associative learning information through a training process, and group behavior of cichlids seems not likely be determined by a minority of group members under a foraging context. [ABSTRACT FROM AUTHOR]

Learning and memory are critical for predator recognition as they allow prey species to develop an adaptive response to a novel situation, thus increasing their chances of survival. In prey species that lack innate predator recognition, alarm cues play a crucial role in learning by their association with novel predator odour. Perception of novel predator odours along with alarm cues allows the prey to learn to detect predatory odours alone in their future encounters. A single event of exposure is considered to be sufficient for the prey to associate predatory cues with alarm cues. However, the minimum time required for learning and memorizing information about predator identity is unknown. Hence we used the tadpoles of Euphlyctis cyanophlyctis to determine the association between the experience window and memory development and its retention. We conditioned tadpoles with a mixture of dragonfly nymph odours and alarm cues for 1, 3, 6, 12 and 24 h, and subsequently assessed their antipredator behaviour at different intervals. Our results show that the minimum duration required for associative learning is ~6 h. Interestingly, the intensity of antipredator response was proportional to the duration of conditioning. Moreover, retention of memory increased with an increase in the duration of conditioning. Hence, we show the significance of conditioning duration in learning. We also show an association between the duration of conditioning and retention of memory. In aquatic ecosystems, where the prey encounters a wide array of predatory cues, our findings open a new avenue for understanding the complexities associated with learning and the development of memory. [ABSTRACT FROM AUTHOR]

Background and Objectives: Learning is essential for understanding mental disorders, normal behavior, and forgetfulness. In this regard, the hippocampus plays an important role in the learning process. It has been reported that gamma-aminobutyric acid (GABA) receptors in the hippocampus are involved in learning and memory mechanisms and some diseases, such as epilepsy and Alzheimerchr('39')s. This study aimed to investigate the effect of coumarin on retention, tissue index, and GABA type A receptor gene expression in the hippocampus of male gonadectomy rats. Methods: The population of this study consisted of 40 Wistar rats, which were randomized into 5 groups (n=8 each). These groups included healthy without treatment, gonadectomized without treatment, gonadectomized receiving solvent or Dimethyl sulfoxide, and gonadectomized receiving coumarin at a dose of 3.5 mg/kg. The treatment was administered intraperitoneally once daily in 2 weeks. A shuttle box was used to test the memory retention of the rats. At the end of the research process, the rats were exterminated in accordance with research ethics. After removing the brains of rats, in each group, in four brains histology test was implemented with Niels staining, and in four other brains, the hippocampus was removed quickly. The hippocampi were placed inside the micro type and frozen with liquid nitrogen. Finally, a gene expression test was taken from the hippocampus using a real-time polymerase chain reaction. Results: Based on the findings, in the memory retention test of initial latency to enter the dark room (step through latency), the gonadectomy group showed a reduction, compared to the healthy group. Moreover, a significant decrease was observed in the number of healthy hippocampal pyramidal neurons; however, GABAA gene expression showed no significant difference. In the gonadectomy groups receiving treatments with different doses of coumarin, the amount of STL (Step Through Latency) and number of healthy pyramidal neurons in the memory retention test showed a significant decrease, compared to the gonadectomy group receiving solvent; nonetheless, a significant increase was revealed in the GABAA-α2 gene expression. Conclusion: It can be concluded that Gonadectomy caused memory impairment and coumarin affects memory impairment by increasing the GABAA-α2 gene expression and decreasing the number of healthy hippocampal neurons.

The tourism activities linked to artificial provisioning of blacktip reef sharks (Carcharhinus melanopterus) and pink whiprays (Pateobatis fai) on a specific site in French Polynesia were suddenly and completely stopped due to a COVID‐19 lockdown that lasted 6 weeks from March 20 until April 30, 2020. Using both drone footage and underwater counting, we were able to track the abundance of those two species before, during, and after reopening and thus investigate the impact of provisioning on wild shark populations. The absence of any stimulus during this long period resulted in almost total desertion of the site by the elasmobranchs. However, 1 day prior to reopening, some individuals of both species positively reacted to the single acoustic stimulus of an engine boat, showing the resilience of conditioning, and some elasmobranchs reacted to acoustic and olfactive stimuli linked to the provisioning practice from the first day after reopening. During the first 2 weeks after reopening, the abundance of both species remained at reduced levels comparable to those observed between 2008 and 2010 for sharks; i.e., around 9 animals in the presence of local tourists. Pre‐lockdown abundance levels, reaching approximatively 15 individuals for sharks and 10 for rays, were considered restored 1 and 2 months after reopening for blacktip reef sharks and pink whiprays, respectively. These findings improve our capacity to better understand the potential effects of artificial provisioning tourism on the abundance of elasmobranchs by showing that conditioning is resilient for several weeks, suggesting that intermittent interruption of elasmobranchs feeding would not really help to decrease its impact on animal welfare. [ABSTRACT FROM AUTHOR]

Di-n-butyl phthalate (DBP) is commonly used as a plasticizer and its usage continues to increase in conjunction with plastic consumption. DBP is readily released into air, drinking water, and soil, and unfortunately, is a potent endocrine disrupter that impairs central nervous system functions. Previously DBP was found to (1) arrest the cell cycle of C17.2 neural progenitor cells (NPCs) at the G1 phase, (2) reduce numbers of newly generated neural stem cells in the mouse hippocampus, and (3) adversely affect learning and memory. Other investigators also noted DBP-mediated neurotoxic effects, but as yet, no study has addressed the adverse effects of DBP on neuronal differentiation. Data demonstrated that at 200 μM DBP induced apoptosis in rat embryo primary neurons by increasing reactive oxygen species levels and inducing mitochondrial dysfunction. However, no significant effect was detected on neurons at concentrations of ≤100 μM. In contrast, doublecortin/microtubule associated protein-2 (DCX/MAP2) immunocytochemistry showed that DBP at 100 μM delayed neuronal maturation by increasing protein levels of DCX (an immature neuronal marker), without markedly affecting cell viability. Further in vivo studies confirmed that DCX+ cell numbers were significantly elevated in the hippocampus of DBP-treated mice, indicating that DBP delayed neuronal maturation, which is known to be associated with impaired memory retention. Data demonstrated that DBP might disrupt neuronal maturation, which is correlated with reduced neurocognitive functions. [ABSTRACT FROM AUTHOR]

We propose a novel active learning framework for activity recognition using wearable sensors. Our work is unique in that it takes limitations of the oracle into account when selecting sensor data for annotation by the oracle. Our approach is inspired by human-beings’ limited capacity to respond to prompts on their mobile device. This capacity constraint is manifested not only in the number of queries that a person can respond to in a given time-frame but also in the time lag between the query issuance and the oracle response. We introduce the notion of mindful active learning and propose a computational framework, called EMMA, to maximize the active learning performance taking informativeness of sensor data, query budget, and human memory into account. We formulate this optimization problem, propose an approach to model memory retention, discuss the complexity of the problem, and propose a greedy heuristic to solve the optimization problem. Additionally, we design an approach to perform mindful active learning in batch where multiple sensor observations are selected simultaneously for querying the oracle. We demonstrate the effectiveness of our approach using three publicly available activity datasets and by simulating oracles with various memory strengths. We show that the activity recognition accuracy ranges from 21 to 97 percent depending on memory strength, query budget, and difficulty of the machine learning task. Our results also indicate that EMMA achieves an accuracy level that is, on average, 13.5 percent higher than the case when only informativeness of the sensor data is considered for active learning. Moreover, we show that the performance of our approach is at most 20 percent less than the experimental upper-bound and up to 80 percent higher than the experimental lower-bound. To evaluate the performance of EMMA for batch active learning, we design two instantiations of EMMA to perform active learning in batch mode. We show that these algorithms improve the algorithm training time at the cost of a reduced accuracy in performance. Another finding in our work is that integrating clustering into the process of selecting sensor observations for batch active learning improves the activity learning performance by 11.1 percent on average, mainly due to reducing the redundancy among the selected sensor observations. We observe that mindful active learning is most beneficial when the query budget is small and/or the oracle’s memory is weak. This observation emphasizes advantages of utilizing mindful active learning strategies in mobile health settings that involve interaction with older adults and other populations with cognitive impairments. [ABSTRACT FROM AUTHOR]

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Mathematics is one of the fundamental subjects for engineering students. While learning mathematics, students often find it difficult or lose interest due to the complexity of the subject. Augmented reality (AR) could aid students to learn certain concepts or theories that were difficult to understand in the classroom and also has the capability to enhance the instructional/learning material. In this study, an AR‐based learning setting named geometry learning assistant (GLA) was developed to teach geometry to students in a mathematics course. GLA provides an interactive and immersive experience to the students that helped them to learn about 3D vectors and direction ratios. The application includes vector addition, cross product, position vector, direction ratios, and dot product with real‐time examples for better learning. Experimental research was organized to investigate the impact of AR intervention on learner's memory retention abilities and learning. Eighty 1st‐year polytechnic students participated in the study and they were divided randomly into two groups: experimental group (N = 40) and control group (N = 40). Students of the experimental group were made to learn using AR‐based GLA, whereas the students from the control group were treated using interactive simulation (IS). The experimental results showed that the learners from the experimental group have better memory retention abilities after 2 and 4 weeks of the learning activity. AR‐based GLA provided a 3D immersive learning experience to the students that enhanced their visualization of the core concepts, which additionally improved their memory retention abilities. [ABSTRACT FROM AUTHOR]

User behavior modeling and interest prediction are always the key elements in preference analysis, product recommendation and personalized service. The psychological memory theory has been proved capable of reflecting changes in user interest. However, merely focusing on the memory forgetting mechanism (the retention-only model) or considering the superimposition of interest retention in short term (the gradual-retention model), existing methods have a poor prediction capability because of ignoring the long-term impact of repeated behaviors. In this paper, we propose a step-enhancement of memory retention (SEMR) model which integrates the cross-enhancement-effects of multiple historical behaviors under different time windows to characterize user interest. In addition, we use some extended correction methods to eliminate the effect of discontinuous records. Numerical experiments using real TV viewing data validate the efficiency of our proposed model and methods, which reduce the average prediction error to 0.3, outperforming the traditional models by around 50%.

Introduction: Repetitive somatosensory stimulation (RSS) is a conventional approach to modulate the neural states of both the primary somatosensory cortex (S1) and the primary motor cortex (M1). However, the impact of RSS on skill acquisition and retention in sensorimotor adaptation remains debated. This study aimed to investigate whether whole-hand water flow (WF), a unique RSS-induced M1 disinhibition, influences sensorimotor adaptation by examining the hypothesis that whole-hand WF leads to M1 disinhibition; thereby, enhancing motor memory retention., Methods: Sixty-eight young healthy participants were randomly allocated to three groups based on the preconditioning received before motor learning: control, whole-hand water immersion (WI), and whole-hand WF. The experimental protocol for all the participants spanned two consecutive days. On the initial day (day 1), baseline transcranial magnetic stimulation (TMS) assessments (T0) were executed before any preconditioning. Subsequently, each group underwent their respective 30 min preconditioning protocol. To ascertain the influence of each preconditioning on the excitability of the M1, subsequent TMS assessments were conducted (T1). Following this, all participants engaged in the motor learning (ML) of a visuomotor tracking task, wherein they were instructed to align a cursor with a target trajectory by modulating the pinch force. Upon completion of the ML session, final TMS assessments (T2) were conducted. All participants were required to perform the same motor learning 24 h later on day 2., Results: The results revealed that whole-hand WF did not significantly influence skill acquisition during sensorimotor adaptation, although it did reduce intracortical inhibition. This phenomenon is consistent with the idea that S1, rather than M1, is involved in skill acquisition during the early stages of sensorimotor adaptation. Moreover, memory retention 24 h after skill acquisition did not differ significantly across the three groups, challenging our initial hypothesis that whole-hand WF enhances memory retention throughout sensorimotor adaptation. This could be due to the inability of whole-hand WF to alter sensorimotor connectivity and integration, as well as the nature of the plastic response elicited by the preconditioning., Discussion: In conclusion, these findings suggest that although whole-hand WF attenuates intracortical inhibition, it does not modulate skill acquisition or motor memory retention during sensorimotor adaptation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Le Cong, Sato, Ikarashi, Ochi, Fujimoto and Yamashiro.)

Summary: The self‐administered interview (SAI©) is a booklet in which eyewitnesses write down their memories of an incident without assistance. The SAI can gather a significant amount of eyewitness information, and completing the SAI soon after witnessing an event can improve later recall. This study aimed to reveal the factor of effectiveness of the SAI and specifically focused on the method of handwriting. Participants watched a video and immediately recalled the event in the three conditions: SAI‐writing, SAI‐speaking, and free recall (speaking). One week later, participants again recalled the event via free recall. The results showed that participants in the SAI‐writing condition reported more correct information than those in the other conditions at both time points. This suggests that a factor of effectiveness of the SAI is the method of writing. Thus, initial written recall using the SAI could facilitate later recall in police investigative interviews. [ABSTRACT FROM AUTHOR]

The brain can learn new tasks without forgetting old ones. This memory retention is closely associated with the long-term stability of synaptic strength. To understand the capacity of pyramidal neurons to preserve memory under different tasks, we established a plasticity model based on the postsynaptic membrane energy state, in which the change in synaptic strength depends on the difference between the energy state after stimulation and the resting energy state. If the post-stimulation energy state is higher than the resting energy state, then synaptic depression occurs. On the contrary, the synapse is strengthened. Our model unifies homo- and heterosynaptic plasticity and can reproduce synaptic plasticity observed in multiple experiments, such as spike-timing-dependent plasticity, and cooperative plasticity with few and common parameters. Based on the proposed plasticity model, we conducted a simulation study on how the activation patterns of dendritic branches by different tasks affect the synaptic connection strength of pyramidal neurons. We further investigate the formation mechanism by which different tasks activate different dendritic branches. Simulation results show that compare to the classic plasticity model, the plasticity model we proposed can achieve a better spatial separation of different branches activated by different tasks in pyramidal neurons, which deepens our insight into the memory retention mechanism of brains. [ABSTRACT FROM AUTHOR]

We investigated how the semantic properties of verbsinfluence the way in which language users process sentencesand how well they remember the verb. In particular, our studyfocused on the frequency of motion repetition, that is, howmany times actions generally repeat in a row. Theexperimental sentences contained action verbs, such assneezing, knocking on a door, clapping, and bouncing a ball.Half of the target sentences contained verbs that refer toactions that generally repeat once or twice in a row in the realworld (determined by norming), such as sneezing, coughing,and knocking on a door. The other half contained verbsreferring to actions that typically repeat many times in row,such as hiccupping, clapping, and bouncing a ball. NativeKorean speakers performed a sensicality judgment task wherethey decided whether given Korean sentences were sensicalor not. We also tested how well participants remember theverbs in target sentences. The results show an effect of actionrepetition frequency: Participants judged sentences with lowrepetition frequency verbs more accurately than sentencescontaining high repetition frequency verbs. We propose thatverbs describing multiple repetitions may place a greaterprocessing load than verbs involving fewer repetitions

Silk protein products have been used for a wide range of applications. This review focuses on the studies conducted relative to cognitive functions with silk fibroin enzyme hydrolysates (FEH) in humans and animals. All known studies reported in PubMed and Google Scholar have been included. Studies have been conducted on children, high school and college students, adults and seniors, ranging in ages from 7–92 years. Doses of 200–600 mg silk FEH per day for three weeks to 16 weeks have been used. Based on these studies, it can be concluded that silk FEH exhibit beneficial cognitive effects with respect to memory and learning, attention, mental focus, accuracy, memory recall, and overall memory and concentration. These conclusions are supported by studies in rats and mice. Mechanistic studies that have been conducted in animals and cell culture systems are also reviewed. These studies indicate that silk FEH exerts its positive effects on memory and learning by providing neuroprotection via a complex mechanism involving its potent antioxidant and inflammation-inhibiting activities. Acetylcholine (ACh) is secreted by cholinergic neurons, and plays a role in encoding new information. Silk FEH were shown to decrease the levels of the pro-oxidant and pro-inflammatory mediators interlukin-1 (IL-1β), IL-6 and tumor necrosis factor-alpha (TNF-α), protecting the cholinergic system from oxidative stress, thus enhancing ACh levels in the brain, which is known to promote cognitive functions. In addition, the expression of brain-derived neurotrophic factor (BNDF), which is involved in the survival of neurons, is enhanced, and an increase in the expression of the phosphorylated cAMP response element-binding protein (p-CREB) occurs, which is known to play a positive role in cognitive functions. No adverse effects have been reported in association with the use of silk FEH.

[Display omitted] • Amitraz is a common acaricide used inside honeybee hive. • Thiacloprid is known low toxic to honey bee. • Sub-lethal doses of amitraz and thiacloprid did not affect bees' motivation. • Single pesticide treatment did not affect the learning and memory of honey bees. • Combined exposure of amitraz and thiacloprid reduced learning, memory and sugar responsiveness of honey bees. Pollinators, honey bees in particular, are continuously exposed to various mixtures of pesticides, which contribute to their population decline. Both amitraz and thiacloprid have been proven less toxic to honey bees and are frequently applied in- and out-hive, respectively. We examined the sub-lethal effects of amitraz, thiacloprid and their sequential exposure on learning, memory and sugar responsiveness in Apis mellifera using the Proboscis extension response (PER). Sub-lethal doses of amitraz (0.1, 0.2 and 0.4 µg/bee) and thiacloprid (0.05, 0.1 and 0.2 µg/bee) were tested. Sub-lethal effects were observed only at the highest doses of each pesticide treatment; amitraz (0.4 µg/bee) and thiacloprid (0.2 µg/bee) but not in lower doses. In sequential treatment of amitraz and thiacloprid, reduced acquisition and memory retention were significant across all tested doses. The same profile was also obtained on sugar responsiveness of foragers. Our results suggest that the sequential exposure would pose higher risk to honey bee compared to single pesticide exposure by reducing the bees' appetitive olfactory learning, memory and sugar acuity more than individual pesticide exposures. [ABSTRACT FROM AUTHOR]