Weak Memory Research Articles

Psychomedicinal plnts of District Udhampur, Jammu and Kashmir, India

People of Udhampur district in Jammu and Kashmir have been traditionally using many medicinal plants for the treatment of different psychological disorders and mental illnesses. These plants are also used in different religious practices like sorcery, rituals and ceremonies since time immemorial. Extensive and intensive field survey carried out during the period of 2017-2021 and found that there are 27 plant species are being used by local inhabitants for the purpose of psycho-medicinal uses. The information gathered from local inhabitants of the study area like old folk, tribal people, shepherds, Vaidyas or medicinal practitioners etc. The collected plant species are properly identified with the help of local floras and authenticated from regional herbaria like Botanical Survey of India, Northern Circle (BSD), Dehradun and Forest Research Institute (DD), Dehradun. The study enlists 27 plant species from 27 different genera belonging to 25 different families. The botanical name alongwith the local name, plant parts used and their uses is included for each plant species. The different psychological disorders or mental illnesses treated through the mentioned psychomedicinal plants are epilepsy, headache and migraine problems, hydrophobia, insomnia, weak memory, sychoneurosis and insanity. Religious ceremonies, rituals and sorcery practices, like exorcism, are performed using these plants to treat insanity, snake bite and to keep away negative energy.

Heterogeneous magnitude of immunological memory to SARS-CoV-2 in recovered individuals.

ObjectiveAlthough the adaptive immune response to SARS‐CoV‐2 has been characterised in the acute and early convalescent phase of the disease, few studies explore whether natural infection elicits long‐lasting immunological memory in recovered individuals. In this work, we aimed to assess the maintenance of immunological memory to SARS‐CoV‐2.MethodsWe evaluated the long‐term virus‐specific cellular and humoral immune response in the members of an Italian Serie A football team, who experienced a cluster of COVID‐19 in March 2020, which was strictly evaluated in the following months.ResultsOur results highlight a heterogeneous magnitude of immunological memory at 5 months after infection. Indeed, 20% of the subjects displayed a weak cellular and humoral memory to SARS‐CoV‐2, suggesting that they may be at higher risk of reinfection. In addition, a history of symptomatic COVID‐19 was associated with higher levels of SARS‐CoV‐2‐reactive CD4+ T cells and specific antibody levels than in asymptomatic individuals.ConclusionCollectively, these data demonstrate that immunity to SARS‐CoV‐2 is maintained five months postinfection even if the magnitude of response is heterogeneous among individuals. This finding suggests that some COVID‐19‐recovered subjects may benefit from vaccination.

Neural correlates of resilience to the effects of hippocampal atrophy on memory

IntroductionCognitive reserve can be defined as a property of the brain that enables an individual to sustain cognitive performance in spite of age-related neural changes. This study uses brain imaging to identify which cognitive reserve mechanisms protect against the detrimental effect of hippocampal atrophy on associative memory. MethodsThe study included 108 older adults from the Quebec Consortium for the early identification of Alzheimer’s disease. They received a magnetic resonance imaging examination to measure memory-related activations and hippocampal volume. Participants also completed a reserve-proxy questionnaire, and received a comprehensive clinical assessment. ResultsHigher scores on the reserve questionnaire were associated with more activation in the right inferior temporal and left occipital fusiform gyri. The activation of the right temporal gyrus moderated the relationship between the volume of the hippocampus and face-name memory. A smaller volume was associated with weaker memory in participants with lower activation, but not in those with greater activation. DiscussionRecruitment of the temporal lobe protects against the detrimental effect of hippocampal atrophy on associative memory and contributes to cognitive reserve.

Analyzing the effects of memory biases and mood disorders on social performance

Realistic models of decision-making and social interactions, considering the nature of memory and biases, continue to be an area of immense interest. Emotion and mood are a couple of key factors that play a major role in decisions, nature of social interactions, size of the social network, and the level of engagement. Most of the prior work in this direction focused on a single trait, behavior, or bias. However, this work builds an integrated model that considers multiple traits such as loneliness, the drive to interact, the memory, and mood biases in an agent. The agent system comprises of rational, manic, depressed, and bipolar agents. The system is modeled with an interconnected network, and the size of the personal network of each agent is based on its nature. We consider a game of iterated interactions where an agent cooperates based on its past experiences with the other agent. Through simulation, the effects of various biases and comparative performances of agent types is analyzed. Taking the performance of rational agents as the baseline, manic agents do much better, and depressed agents do much worse. The payoffs also exhibit an almost-linear relationship with the extent of mania. It is also observed that agents with stronger memory perform better than those with weaker memory. For rational agents, there is no significant difference between agents with a positive bias and those with a negative bias. Positive bias is linked with higher payoffs in manic and bipolar agents. In depressed agents, negative bias is linked with higher payoffs. In manic agents, an intermediate value of mood dependence offers the highest payoff. But the opposite is seen in depressed agents. In bipolar agents, agents with weak mood dependence perform the best.

Efficient Marginalized Particle Smoother for Indoor CSS–TOF Localization with Non-Gaussian Errors

The time-series state and parameter estimations of indoor localization continue to be a topic of growing importance. To deal with the nonlinear and positive skewed non-Gaussian dynamic of indoor CSS–TOF (Chirp-Spread-Spectrum Time-of-Flight) ranging measurements and position estimations, Monte Carlo Bayesian smoothers are promising as involving the past, present, and future observations. However, the main problems are how to derive trackable smoothing recursions and to avoid the degeneracy of particle-based smoothed distributions. To incorporate the backward smoothing density propagation with the forward probability recursion efficiently, we propose a lightweight Marginalized Particle Smoother (MPS) for nonlinear and non-Gaussian errors mitigation. The performance of the position prediction, filtering, and smoothing are investigated in real-world experiments carried out with vehicle on-board sensors. Results demonstrate the proposed smoother enables a great tool by reducing temporal and spatial errors of mobile trajectories, with the cost of a few sequence delay and a small number of particles. Therefore, MPS outperforms the filtering and smoothing methods under weak assumptions, low computation, and memory requirements. In the view that the sampled trajectories stay numerically stable, the MPS form is validated to be applicable for time-series position tracking.

Effects of developmental language disorder and bilingualism on children’s executive functioning: A longitudinal study

BackgroundChildren’s executive functioning (EF) is often negatively associated with a developmental language disorder (DLD) and positively related to bilingualism. However, both regarding children with DLD and bilingual children, findings are mixed and few studies have investigated the combination of DLD and bilingualism in relation to EF. AimsThis study investigated the effects of DLD and bilingualism on children’s EF development. MethodsMonolingual and bilingual children with DLD and typical development (TD; N = 32 in each group) were tested three times with yearly intervals (MAGE = 71 months at time 1). Verbal and visuospatial working memory, selective attention, and inhibition were assessed. ResultsMonolinguals and bilinguals with DLD had weak working memory and inhibition skills at each time point compared to TD peers, which could partly be explained by verbal short-term memory limitations. Positive effects of bilingualism emerged when controlling for Dutch vocabulary and morphology skills, and were most pronounced at time 1. ConclusionsMonolinguals and bilinguals with DLD have similar and persistent EF deficits, which are partly secondary to verbal short-term memory weaknesses. Bilinguals performed better on EF than monolinguals when Dutch language knowledge was controlled for. This effect was found regardless of DLD and was most prominent at age 5–6 years.

Does sleep-dependent consolidation favour weak memories?

Sleep stabilizes newly acquired memories, a process referred to as memory consolidation. According to recent studies, sleep-dependent consolidation processes might be deployed to different extents for different types of memories. In particular, weaker memories might benefit greater from post-learning sleep than stronger memories. However, under standard testing conditions, sleep-dependent consolidation effects for stronger memories might be obscured by ceiling effects. To test this possibility, we devised a new memory paradigm (Memory Arena) in which participants learned temporospatial arrangements of objects. Prior to a delay period spent either awake or asleep, training thresholds were controlled to yield relatively weak or relatively strong memories. After the delay period, retrieval difficulty was controlled via the presence or absence of a retroactive interference task. Under standard testing conditions (no interference), a sleep-dependent consolidation effect was indeed observed for weaker memories only. Critically though, with increased retrieval demands, sleep-dependent consolidation effects were seen for both weaker and stronger memories. These results suggest that all memories are consolidated during sleep, but that memories of different strengths require different testing conditions to unveil their benefit from post-learning sleep.

Object Recognition Memory: Distinct Yet Complementary Roles of the Mouse CA1 and Perirhinal Cortex.

While the essential contribution of the hippocampus to spatial memory is well established, object recognition memory has been traditionally attributed to the perirhinal cortex (PRh). However, the results of several studies indicate that under specific procedural conditions, temporary or permanent lesions of the hippocampus affect object memory processes as measured in the Spontaneous Object Recognition (SOR) task. The PRh and hippocampus are considered to contribute distinctly to object recognition memory based on memory strength. Allowing mice more, or less, exploration of novel objects during the encoding phase of the task (i.e., sample session), yields stronger, or weaker, object memory, respectively. The current studies employed temporary local inactivation and immunohistochemistry to determine the differential contributions of neuronal activity in PRh and the CA1 region of the hippocampus to strong and weak object memory. Temporary inactivation of the CA1 immediately after the SOR sample session impaired strong object memory but spared weak object memory; while temporary inactivation of PRh post-sample impaired weak object memory but spared strong object memory. Furthermore, mRNA transcription and de novo protein synthesis are required for the consolidation of episodic memory, and activation patterns of immediate early genes (IEGs), such as c-Fos and Arc, are linked to behaviorally triggered neuronal activation and synaptic plasticity. Analyses of c-Fos and Arc protein expression in PRh and CA1 neurons by immunohistochemistry, and of Arc mRNA by qPCR after distinct stages of SOR, provide additional support that strong object memory is dependent on CA1 neuronal activity, while weak object memory is dependent on PRh neuronal activity. Taken together, the results support the view that both PRh and CA1 are required for object memory under distinct conditions. Specifically, our results are consistent with a model that as the mouse begins to explore a novel object, information about it accumulates within PRh, and a weak memory of the object is encoded. If object exploration continues beyond some threshold, strong memory for the event of object exploration is encoded; the consolidation of which is CA1-dependent. These data serve to reconcile the dissension in the literature by demonstrating functional and complementary roles for CA1 and PRh neurons in rodent object memory.

Different effects of feedback-induced emotion and material-induced emotion on memory

The function of emotion in enhancing memory has been proven by a large number of studies. However, previous studies mainly used emotional materials to induce emotions, and far fewer studies have examined how neutral stimuli and emotional event connections affect memory. In Experiment 1, the feedback from the results was used as an emotional event to explore the impact of connected emotions on memory. In Experiment 2, emotional materials were used to induce emotions, and the effects on memory in the two studies were compared. The emotions induced by the feedback resulted in positive emotions having the strongest effects on memory, while negative emotions had the weakest memory effect. However, when the emotional materials were used, there were different outcomes: negative emotional memories were the best, and neutral memories were the worst. Based on these results, we may conclude that different emotion-inducing methods have different effects on memory and that emotionally enhanced memory is not applicable to all emotion-inducing modes.

Medical Symptom Validity Test (MSVT) profiles in individuals being evaluated for Alzheimer’s disease

Objective:Our purpose was to determine whether Medical Symptom Validity Test (MSVT) profiles could differentiate performance invalidity from true impairment in patients with varying levels of memory impairment and functional ability being evaluated for Alzheimer’s disease (AD). Method: Seventy-three older adults (13 healthy controls, 25 mild cognitive impairment [MCI], 16 mild AD, 19 moderate AD) were evaluated with a neuropsychological battery including the MSVT and activities of daily living (ADL) measures. Using MSVT classification guidelines, examinees’ MSVT profiles were categorized as: 1) valid, 2) invalid, 3) weak memory, or 4) genuine memory impairment (GMIP). Results: Eighty-four percent of moderate AD examinees produced a GMIP. Among MCI and mild AD examinees, who had only modestly affected ADLs, a substantial proportion manifested a GMIP (40% and 62.5%, respectively). An invalid profile was uncommon across patient groups (12.5% in mild AD, 5.3% in moderate AD, and 0% in MCI). Conclusions: The MSVT functions reasonably well in a dementia sample to determine if an examinee has an invalid profile, although for mild AD examinees, the false positive rate is slightly above the recommended 10% cut-off. However, even individuals with MCI, mild AD and relative preservation of ADLs may manifest a GMIP, demonstrating that such profile is found across patients with lower and higher degrees of functional impairment. Given this finding, the usefulness of the GMIP in differentiating performance invalidity from true impairment in patients being evaluated for AD appears limited.

Thermal investigation for electrified convection flow of Newtonian fluid subjected to damped thermal flux on a permeable medium

The main purpose of this manuscript is to study an unsteady, MHD and free convection flow with the thermal transport for an electrical conducted, incompressible, and linearly viscous fluid flow close to a moving vertical plate in the existence of an exponential heating process. The flow area is considered permeable half-space as well as the utilization of an electromagnetic field perpendicular to fluid motion. The Caputo time-fractional derivative is utilized to present a heat flux constitutive-equation through a weak memory. The Laplace transformation technique is utilized to achieve the exact solutions of the dimensionless governing equations for the temperature field, Nusselt number, fluid velocity, and skin friction coefficient and stated in connection with Wright functions as well as a generalized G-Lorenzo-Hartley function. As a limiting case, a comparison with (Awan et al 2019 Chin. J. Phys. 60 98–106) equation (38) is done to verify the applied technique as well as for validity of our results. The influences of a variety of fractional as well as material factors are pictured with MathCad15. For low estimations of time, Fluid temperature and velocity are increased by decreasing fractional factor γ and both illustrate a contrary behavior for larger estimations of the time The fluid velocity is decreased through the large estimations of the magnetic factor

Memory Impairment in Patients With Schizophrenia and Bipolar Disorder With and Without Psychosis: A Comparative Study

Background: Cognitive impairment is a common symptom in both Schizophrenia (SZ) and Bipolar Disorder (BD), and studies have demonstrated memory impairment in patients with these disorders. Objectives: To compare memory impairment in patients with SZ, BD with psychosis, and BD without psychosis. Materials & Methods: This study was a cross-sectional study conducted on 42 patients referred to Shafa Hospital in Rasht, Iran. Patients were examined in 3 groups of 14 people each (SZ, BD with psychosis, and BD without psychosis). The study tools included a demographic information questionnaire, a Brief Psychiatric Rating Scale (BPRS), and Wechsler’s Memory Scale (WMS) for adults. The obtained data were analyzed by SPSS version 21 using the 1 way analysis of variance (ANOVA). Results: The mean BPRS scores in patients with SZ (47.28) was higher than that in BD with psychosis (43.93) and BD without psychosis (23.14). ANOVA results showed a significant difference between patients with SZ and BD without psychosis (P=0.001), as well as BD with psychosis and BD without psychosis (P=0.001). Also, there was a statistically significant difference in the mean WMS scores between patients with SZ (62.07) and BD with psychosis (76.57) (P=0.009) and between SZ and BD without psychosis (73.5) (P=0.047). BPRS and WMS scores in SZ and BD without psychosis patients had a negative correlation. Conclusion: The results showed that SZ is associated with weaker memory than BD, and a history of psychosis does not have a significant effect on memory function in patients with BD.

Empirical analysis on human dynamics of sharing-bicycles’ user behavior

With the development of mobile communication and global positioning system navigation and positioning technology, analysis of user behavior on mobile Internet has become a hot topic in research area. Sign in sharing-bicycles’ app, find bicycle location, and selected has become a part of mobile Internet user’s daily life. Based on the data analysis of the spatial and temporal characteristics, find out sharing-bicycle’s user behavior obeys power-law distribution. In the time interval, user behavior of sharing-bicycle has strong intermittency and weak memory; the exponent of probability that K edge nodes is three by fitting the distance of sharing-bicycle’s data curve. It is verified that mobile Internet is long to scale-free networks. We conclude seven characteristics of user’s behavior of sharing-bicycle in mobile Internet application from experimental results. The analysis of sharing-bicycle’s behavior has become a complement and extension in human dynamics research field.

Additive manufacturing of the core template for the fabrication of an artificial blood vessel: the relationship between the extruded deposition diameter and the filament/nozzle transition ratio.

An artificial blood vessel with a tubular structure was additively manufactured via fused deposition modeling (FDM) starting from a single strand of polyvinyl alcohol (PVA) filament coated with a specific thickness of biocompatible polydimethylsiloxane (PDMS), followed by removal of the inner core via hydrogen peroxide leaching under sonication. In particular, we examined the relationship between the extruded deposition diameter and the filament migration speed/nozzle control speed (referred to as the filament/nozzle transition ratio), which is almost independent of the extruded deposition flow rate due to the weak die-swelling and memory effects of the extruded PVA arising from its intrinsically low viscoelasticity. The chemical stability of the PDMS during sonication in the hydrogen peroxide solution was then determined by spectroscopic techniques. The PDMS displayed no mechanical degradation in the hydrogen peroxide solution, resulting in similar fracture elongation and yield strength to those of the pristine specimen without the leaching treatment. As a further advantage, the inside surface of the PDMS was smooth regardless of the hydrogen peroxide leaching under sonication. The potential application of the as-developed scaffold in soft tissue engineering (particularly that involving vascular tissue regeneration) was demonstrated by the successful transplantation of the artificial blood vessel in a right-hand surgical replica used in a clinical simulation.

Cosmo: a concurrent separation logic for multicore OCaml

Multicore OCaml extends OCaml with support for shared-memory concurrency. It is equipped with a weak memory model, for which an operational semantics has been published. This begs the question: what reasoning rules can one rely upon while writing or verifying Multicore OCaml code? To answer it, we instantiate Iris, a modern descendant of Concurrent Separation Logic, for Multicore OCaml. This yields a low-level program logic whose reasoning rules expose the details of the memory model. On top of it, we build a higher-level logic, Cosmo, which trades off some expressive power in return for a simple set of reasoning rules that allow accessing nonatomic locations in a data-race-free manner, exploiting the sequentially-consistent behavior of atomic locations, and exploiting the release/acquire behavior of atomic locations. Cosmo allows both low-level reasoning, where the details of the Multicore OCaml memory model are apparent, and high-level reasoning, which is independent of this memory model. We illustrate this claim via a number of case studies: we verify several implementations of locks with respect to a classic, memory-model-independent specification. Thus, a coarse-grained application that uses locks as the sole means of synchronization can be verified in the Concurrent-Separation-Logic fragment of Cosmo, without any knowledge of the weak memory model.

Is working memory inherently more "precise" than long-term memory? Extremely high fidelity visual long-term memories for frequently encountered objects.

Long-term memory is often considered easily corruptible, imprecise, and inaccurate, especially in comparison to working memory. However, most research used to support these findings relies on weak long-term memories: those where people have had only one brief exposure to an item. Here we investigated the fidelity of visual long-term memory in more naturalistic setting, with repeated exposures, and ask how it compares to visual working memory fidelity. Using psychophysical methods designed to precisely measure the fidelity of visual memory, we demonstrate that long-term memory for the color of frequently seen objects is as accurate as working memory for the color of a single item seen 1 s ago. In particular, we show that repetition greatly improves long-term memory, including the ability to discriminate an item from a very similar item (fidelity), in both a lab setting (Experiments 1-3) and a naturalistic setting (brand logos, Experiment 4). Overall, our results demonstrate the impressive nature of visual long-term memory fidelity, which we find is even higher fidelity than previously indicated in situations involving repetitions. Furthermore, our results suggest that there is no distinction between the fidelity of visual working memory and visual long-term memory, but instead both memory systems are capable of storing similar incredibly high-fidelity memories under the right circumstances. Our results also provide further evidence that there is no fundamental distinction between the "precision" of memory and the "likelihood of retrieving a memory," instead suggesting a single continuous measure of memory strength best accounts for working and long-term memory. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Left-handers, retrained left-handers and right-handers: A comparative study

Present study was aimed at further extension of the scientific data concerning the influence of retraining in left-handers as well as concerning some disabilities ascribed to the left-handedness. Study participants filled in the questionnaire about the incidence of fears and depression, bedwetting and stuttering, spatial confusion, complaints on weak memory and attention. Responses were analyzed regarding the handedness of the respondents, qualified as left-hander, right-hander and retrained left-hander. The number of reports on bedwetting and slowness in writing, as well as on spatial left/right confusion was found higher in left-handers as compared to right-handers. The number of reports on fears was found higher in retrained left-handers. Left-handers, retrained left-handers and right-handers did not differ in the number of reports on stuttering, depression, week memory and not sustained attention. Mental rotation task performance was studied in another group of left-handed and right-handed participants. Handedness was determined by the test on hand performance. Left-handers were found to make more mistakes in mental rotation task performance as compared to right-handers. We conclude that expectancy of bedwetting, slowness in writing and mental spatial left/right confusion is higher in left-handers as compared to right-handers. Retraining of left-handers is suggested to cause fears, however it is not related to stuttering, depression, slowness in reading and writing, worsening of memory and attention. Stuttering is equally expectable among left-handers, retrained left-handers and right-handers.

Eye movement analyses of strong and weak memories and goal-driven forgetting

Research indicates that eye movements can reveal expressions of memory for previously studied relationships. Specifically, eye movements are disproportionately drawn to test items that were originally studied with the test scene, compared to other equally familiar items in the test display – an effect known as preferential viewing (e.g., Hannula, Ryan, Tranel, & Cohen, 2007). Across four studies we assessed how strength-based differences in memory are reflected in preferential viewing. Participants studied objects superimposed on background scenes and were tested with three-object displays superimposed on the scenes viewed previously. Eye movements were monitored at test. In Experiment 1 we employed an item-method directed forgetting (DF) procedure to manipulate memory strength. In Experiment 2, viewing patterns were examined across differences in memory strength assessed through subjective confidence ratings. In Experiment 3, we used spaced repetitions to objectively strengthen items, and Experiment 4 involved a list-method DF manipulation. Across all experiments, eye movements consistently differentiated the effect of DF from other strength-based differences in memory, producing different viewing patterns. They also differentiated between incidental and successful intentional forgetting. Finally, despite a null effect in recognition accuracy in list-method DF, viewing patterns revealed both common as well as critical differences between list-method DF and item-method DF. We discuss the eye movement findings from the perspective of theoretical accounts of DF and other strength-based differences in memory.

Exposure to Novelty Promotes Long-Term Contextual Fear Memory Formation in Juvenile Mice: Evidence for a Behavioral Tagging.

Episodic memories acquired early in life are fragile and rapidly forgotten in both humans and nonhuman animals. However, early life experiences have been documented to profoundly affect brain function and physiology throughout life, suggesting that in certain circumstances, the developing brain is capable of producing long-term memory (LTM). In this study, we asked whether exposure to a novel environment, a process named "behavioral tagging," may promote the persistence of weak memories in male juvenile mice. Using a contextual fear conditioning (CFC) paradigm, we found that a weak training protocol, which typically induces a transient form of memory, results in LTM when paired with an exploration to a novel but not a familiar environment that occurs close in time to the training session. The promoting effect of the novel context exploration (NCE) on CFC-LTM formation is dependent on the activation of dopamine D1/D5 receptors and requires novel protein synthesis in the dorsal hippocampus. Moreover, NCE increases the size of overlapping CA1 neuronal ensembles engaged by CFC and NCE. These results provide direct support for the existence of a behavioral tagging process, in which exposure to novelty provides newly synthesized proteins to stabilize the contextual fear memory trace in juvenile mice.

The neural correlates of context retrieval in false recognition.

Previous research has demonstrated that some false recognitions are accompanied by retrieval of contexts in which the corresponding semantic associates were presented during the study phase. What kind of neural processes support context retrieval in false recognition? Using functional MRI (fMRI), we tested the hypothesis that context retrieval in false recognition might be supported by brain areas in the core recollection network which also support context retrieval in true recognition. During the study, lists of semantically associated words were presented together with scene pictures that served as contexts. During test, participants judged whether the presented word was old or new. If old, they judged which scene picture was its context and rated memory strength for the context. The results revealed that several regions in the core recollection network, including the bilateral hippocampus, left angular gyrus, and left anterior cingulate cortex, showed greater activations for true recognitions with strong context memory than those with weak context memory. More importantly, these same regions also showed greater activations for false recognitions with strong context memory than those with weak context memory. These findings helped account for why some false recognitions are vivid and accompanied by retrieval of context.