Retrieval Test Research Articles

Reinstatement of item-specific contextual details during retrieval supports recombination-related false memories

Flexible retrieval mechanisms that allow us to infer relationships across events may also lead to memory errors or distortion when details of one event are misattributed to the related event. Here, we tested how making successful inferences alters representation of overlapping events, leading to false memories. Participants encoded overlapping associations (‘AB’ and ‘BC’), each of which was superimposed on different indoor and outdoor scenes that were pre-exposed prior to associative learning. Participants were subsequently tested on both the directly learned pairs (‘AB’ and ‘BC’) and inferred relationships across pairs (‘AC’). We predicted that when people make a correct inference, features associated with overlapping events may become integrated in memory. To test this hypothesis, participants completed a final detailed retrieval test, in which they had to recall the scene associated with initially learned ‘AB’ pairs (or ‘BC’ pairs). We found that the outcome of inference decisions impacted the degree to which neural patterns elicited during detailed ‘AB’ retrieval reflected reinstatement of the scene associated with the overlapping ‘BC’ event. After successful inference, neural patterns in the anterior hippocampus, posterior medial prefrontal cortex, and our content-reinstatement region (left inferior temporal gyrus) were more similar to the overlapping, yet incorrect ‘BC’ context relative to after unsuccessful inference. Further, greater hippocampal activity during inference was associated with greater reinstatement of the incorrect, overlapping context in our content-reinstatement region, which in turn tracked contextual misattributions during detailed retrieval. These results suggest recombining memories during successful inference can lead to misattribution of contextual details across related events, resulting in false memories.

Maximizing the catheter-to-vessel size optimizes distal flow control resulting in improved revascularization in vitro for aspiration thrombectomy

BackgroundBalloon guide catheters (BGCs) achieve proximal flow control during thrombectomy but antegrade intracranial flow often persists via the Circle of Willis. Closely sizing an aspiration catheter to the target vessel...

Retrieval Practice Consistently Benefits Student Learning: a Systematic Review of Applied Research in Schools and Classrooms

Given the growing interest in retrieval practice among educators, it is valuable to know when retrieval practice does and does not improve student learning—particularly for educators who have limited classroom time and resources. In this literature review, we developed a narrow operational definition for “classroom research” compared to previous reviews of the literature. We screened nearly 2000 abstracts and systematically coded 50 experiments to establish a clearer picture of benefits from retrieval practice in real world educational settings. Our review yielded 49 effect sizes and a total n = 5374, the majority of which (57%) revealed medium or large benefits from retrieval practice. We found that retrieval practice improved learning for a variety of education levels, content areas, experimental designs, final test delays, retrieval and final test formats, and timing of retrieval practice and feedback; however, only 6% of experiments were conducted in non-WEIRD countries. Based on our review of the literature, we make eight recommendations for future research and provide educators with a better understanding of the robust benefits of retrieval practice across a range of school and classroom settings.

Maternal behavior and the neonatal HPA axis in the Wistar Audiogenic Rat (WAR) strain: Early-life implications for a genetic animal model in epilepsy

Epileptogenesis is a multistage process and seizure susceptibility can be influenced by stress early in life. Wistar Audiogenic Rat (WAR) strain is an interesting model to study the association between stress and epilepsy, since it is naturally susceptible to seizures and present changes in the hypothalamus–pituitary–adrenal (HPA) axis activity. All these features are related to the pathogenic mechanisms usually associated with psychiatric comorbidities present in epilepsy. Therefore, the current study aimed to evaluate the neonate HPA axis function and maternal care under control and stress conditions in the WAR strain. Maternal behavior and neonate HPA axis were evaluated in Wistar and WAR strains under rest and after the presence of stressors. We observed that WAR pups present higher plasmatic corticosterone concentration as compared to Wistar pups. Although WAR dams do not show significant altered maternal behavior at rest, there is a higher latency to recover the litter in the pup retrieval test, while some did not recover all the litter. Wistar Audiogenic Rat dams presented similar behaviors to Wistar dams to a female intruder and maternal care with the pups in the maternal defense test. Taken together, these findings indicate that the WAR strain could show HPA axis disruption early in life and dams present altered maternal behavior under stressful events. Those alterations make the WAR strain an interesting model to evaluate vulnerability to epilepsy and its associated neuropsychiatric comorbidities.

Adenosine monophosphate activated protein kinase (AMPK) is essential for the memory improving effect of adiponectin

Adiponectin (APN) plays a major role in the regulation of insulin sensitivity and glucose homeostasis. Insulin and APN have a positive effect on memory. In this study, we examined whether the inhibition of AMPK could block the memory improving effect of APN or affect the IRS1 expression.Animal model of AD was developed by intracerebroventricular (icv) injection of 3 mg/kg streptozotocin (STZ), in 12 weeks old Wistar rats, on days 1 and 3 after cannulation. Dorsomorphin (DM) and APN (600 nM) were injected 30 and 20 min before the acquisition phase, respectively. DM was applied in 3 different doses (0.2, 2 and 20 μM). All behavioral tests were performed on days 15 and 16; the Preference Index (PI) was calculated for novel object recognition (NOR) test, while the step through latency (STL) and total time in dark compartment (TDC) were recorded and analyzed for the passive avoidance task. Relative expression of insulin receptor substrate-1 (IRS-1) protein in the hippocampus was measured by western blotting.In early retrieval test, STZ + APN treatment increased STL (P < 0.0001) and decreased TDC (P < 0.05) in comparison to STZ group, while STZ + APN + DM (2μM) caused a decrease in STL (P < 0.05) and increase in TDC (0.2μM and 2μM DM; P < 0.05). Icv injection of DM (0.2μM and 2μM) before APN decreased the PI significantly (P < 0.05) in comparison to STZ + APN group. APN treatment raised the IRS-1 expression and DM reversed this increment, significantly (P < 0.0001).It is concluded that the memory improving effect of APN is mediated, at least in part, by the AMPK pathway. APN is also able to boost insulin signaling by overexpression of IRS-1 in the hippocampus.

Using a Discourse Task to Explore Semantic Ability in Persons With Cognitive Impairment.

This paper uses a discourse task to explore aspects of semantic production in persons with various degree of cognitive impairment and healthy controls. The purpose of the study was to test if an in-depth semantic analysis of a cognitive-linguistic challenging discourse task could differentiate persons with a cognitive decline from those with a stable cognitive impairment. Both quantitative measures of semantic ability, using tests of oral lexical retrieval, and qualitative analysis of a narrative were used to detect semantic difficulties. Besides group comparisons a classification experiment was performed to investigate if the discourse features could be used to improve classification of the participants who had a stable cognitive impairment from those who had cognitively declined. In sum, both types of assessment methods captured difficulties between the groups, but tests of oral lexical retrieval most successfully differentiated between the cognitively stable and the cognitively declined group. Discourse features improved classification accuracy and the best combination of features discriminated between participants with a stable cognitive impairment and those who had cognitively declined with an area under the curve (AUC) of 0.93.

Content-Based Image Retrieval (CBIR) in Big Histological Image Databases

Background: Automatic analysis of Histopathological Images (HIs) demands image processing and Computational Intelligence (CI) techniques. Both Computer-Aided Diagnosis (CAD) and Content-Based Image-Retrieval (CBIR) systems assist diagnosis, disease discovery, and biological decision-making. Classical tests comprise screening examinations and biopsy. Histopathology slides offer more ample diagnosis data. However, manual examination of microscopic images is labor-intensive and time-consuming and may depend on a subjective assessment by the pathologist, which can be a challenge.&#x0D; Methods: This work discusses a CBIR framework to extract and handle histological data, histological metadata, integrated patient records, specimen metadata, attributes, and similar stored files. This work presents a scalable image-retrieval framework for intelligent HI analysis with real-time retrieval. The potential applications of this framework include image-guided diagnosis, decision support, healthcare education, and efficient biological data management.&#x0D; Results: The considerable amount of biological-related data prompted the development and deployment of large-scale databases and data-driven techniques to bridge the semantic gap between images and diagnostic information. The new cloud computing technologies and the concept of cyber-physical systems have improved the CBIR architectures considerably. The proposed scalable architecture relies on CI and validates performance on several HIs acquired from microscopic tissues. Extensive assessments show improvements in terms of disease classification and retrieval tests.&#x0D; Conclusion: This research effort significant contributions are twofold. 1) Defining a comprehensive and large-scale CBIR framework to analyze HIs with high-dimensional features and CI methods successfully. 2) high-performance updating and optimization strategies improve the querying while better handling new training samples than traditional methods.

Muscarinic receptor signaling in the amygdala is required for conditioned taste aversion

The sense of taste provides information regarding the nutrient content, safety or potential toxicity of an edible. This is accomplished via a combination of innate and learned taste preferences. In conditioned taste aversion (CTA), rats learn to avoid ingesting a taste that has previously been paired with gastric malaise. Recent evidence points to a role of cholinergic muscarinic signaling in the amygdala for the learning and storage of emotional memories. The present study tested the participation of muscarinic receptors in the amygdala during the formation of CTA by infusing the non-specific antagonist scopolamine into the basolateral or central subnuclei before or after conditioning, as well as before retrieval. Our data show that regardless of the site of infusion, pre-conditioning administration of scopolamine impaired CTA acquisition whereas post-conditioning infusion did not affect its storage. Also, infusions into the basolateral but not in the central amygdala before retrieval test partially reduced the expression of CTA. Our results indicate that muscarinic receptors activity is required for acquisition but not consolidation of CTA. In addition, our data add to recent evidence pointing to a role of cholinergic signaling in peri-hippocampal structures in the process of memory retrieval.

Could actions improve retrieval performance in 4-to 6-year-old children?

ABSTRACT It has been well documented in adults that compared to verbal learning, learning while the subject performs an action is far more effective. However, the results of previous studies involving children have not reached a consensus. The present study examined the action memory of 4- to 6-year-old children under various encoding conditions (i.e., VTs, EPTs and SPTs) using various retrieval tests (i.e., free recall, cued recall and recognition) to investigate the age-related development and enactment effect in action memory of 4- to 6-year-old children. The results demonstrated that the developmental differences in free recall memory performances under all encoding conditions across children aged 4 to 6 years reached significance. Additionally, cued recall and recognition performances under enacted-encoding conditions (both SPTs and EPTs) were better than those under verbal-encoding condition at all ages. Interestingly, the free recall performance under EPTs was superior to that under SPTs at all ages. Altogether, our findings showed that age-related development and enactment effects of action memory existed in children aged 4 to 6 years, depending on the test modalities, which require different mental resources.

Maternal Motivation: Exploring the Roles of Prolactin and Pup Stimuli

Motherhood entails increased motivation for pups, which become strong reinforcers and guide maternal behaviours. This depends on steroids and lactogens acting on the brain of females during pregnancy and postpartum. Since virgin female mice exposed to pups are nearly spontaneously maternal, the specific roles of endocrine and pup-derived signals in the induction of maternal motivation remain unclear. This work investigates maternal motivation in dams and virgin female mice, using a novel variant of the pup retrieval paradigm, the motivated pup retrieval test. We also analyse the role of prolactin (PRL) and of stimuli derived from a litter of pups and its mother, in the acquisition of maternal motivation. Experimental design included female mice in 3 conditions: lactating dams, comothers (virgins housed and sharing pup care with dams) and pup-naïve virgins. Females underwent 3 motivated-pup-retrieval trials, with pups displaced behind a 10-cm-high wire-mesh barrier. Dams retrieved with significantly lower latencies than comothers or virgins, indicating that full maternal motivation appears only after pregnancy. Although initially comothers and virgins showed no retrieval, comothers significantly improved throughout the experiment, suggesting an induced sensitization process. Lengthening exposure of comothers to the dyad pups-dam (from 2 to 5 days at the beginning of testing) had no strong effects on maternal sensitization. PRL responsiveness was analysed in these animals using immunohistochemical detection of phosphorylated signal transducer and activator of transcription 5 (pSTAT5, PRL-derived signalling marker). As expected, dams showed significantly higher pSTAT5 expression in most of the analysed nuclei. Moreover, comothers displayed significantly higher PRL responsiveness than pup-naïve virgins in the medial preoptic nucleus, even if they display similar circulating PRL levels, which are significantly lower than those of dams. Given the instrumental role of this nucleus in the relay and integration of pup-derived stimuli to facilitate proactive maternal responses, this increase in PRL responsiveness likely reflects the mechanism underlying the maternal sensitization process reported in this work. Since the analyses of maternal motivation and PRL signalling in the brain were performed in the same animals, we were able to explore correlation between both set of data. The results shed light on the neuroendocrine mechanisms underlying maternal motivation and other aspects of maternal behaviour.

Selective sub-nucleus effects of intra-amygdala oxytocin on fear extinction

There is growing evidence that the neuropeptide oxytocin (OT) modulates fear and extinction in humans and rodents through actions in corticolimbic circuits including the central amygdala (CeA). Prior studies have, however, been limited to subjects that exhibit intact basal extinction, rather than extinction-impaired populations that could potentially therapeutically benefit from viable OT-targeting treatments. Here, we assessed the effects of pre-extinction training infusion of OT into the CeA, or basolateral amygdala (BLA), on extinction in an inbred mouse strain (S1) model of impaired extinction. We found that intra-CeA OT, at a dose of 0.01 μg, enabled extinction memory formation, as evidenced by lesser freezing as compared to vehicle-infused controls on a drug-free retrieval test. Conversely, infusion of a higher, 1.0 μg OT dose, markedly reduced freezing and increased grooming during extinction training and produced elevated freezing on drug-free retrieval. Infusion of the 0.01 μg dose into the BLA was without behavioral effects. Together, our data show that OT acts in a dose-dependent manner within the CeA to promote extinction in otherwise extinction-deficient mice. These findings provide further support for the potential utility of OT as an adjunctive treatment to extinction-based therapies for trauma and anxiety disorders.

Precise Three-Dimensional Deformation Retrieval in Large and Complex Deformation Areas via Integration of Offset-Based Unwrapping and Improved Multiple-Aperture SAR Interferometry: Application to the 2016 Kumamoto Earthquake

Abstract Conventional synthetic aperture radar (SAR) interferometry (InSAR) has been successfully used to precisely measure surface deformation in the line-of-sight (LOS) direction, while multiple-aperture SAR interferometry (MAI) has provided precise surface deformation in the along-track (AT) direction. Integration of the InSAR and MAI methods enables precise measurement of the two-dimensional (2D) deformation from an interferometric pair; recently, the integration of ascending and descending pairs has allowed the observation of precise three-dimensional (3D) deformation. Precise 3D deformation measurement has been applied to better understand geological events such as earthquakes and volcanic eruptions. The surface deformation related to the 2016 Kumamoto earthquake was large and complex near the fault line; hence, precise 3D deformation retrieval had not yet been attempted. The objectives of this study were to (1) perform a feasibility test of precise 3D deformation retrieval in large and complex deformation areas though the integration of offset-based unwrapped and improved multiple-aperture SAR interferograms and (2) observe the 3D deformation field related to the 2016 Kumamoto earthquake, even near the fault lines. Two ascending pairs and one descending the Advanced Land Observing Satellite-2 (ALOS2) the Phased Array-type L-band Synthetic Aperture Radar-2 (PALSAR2) pair were used for the 3D deformation retrieval. Eleven in situ Global Positioning System (GPS) measurements were used to validate the 3D deformation measurement accuracy. The achieved accuracy was approximately 2.96, 3.75, and 2.86 cm in the east, north, and up directions, respectively. The results show the feasibility of precise 3D deformation measured through the integration of the improved methods, even in a case of large and complex deformation.

0272 Effects of Gestational Sleep Restriction on Maternal Behavior in Rodents: A Systematic Review and Meta-Analysis

Abstract Introduction Sleep restriction during pregnancy is related with postpartum depression in clinical settings. Preclinical studies have been conducted in rodent models of maternal behavior, intending to evaluate the mechanisms behind this relationship, but have raised inconsistent data so far. Our aims were to perform a preclinical meta-analysis, evaluating the actual effects or prenatal sleep restriction on maternal behavior in rodents. Methods A bibliographic search was conducted in Pubmed, Scopus, Web of Science, Psychinfo and Lilacs. Search strategy encompassed three domains: sleep restriction during pregnancy (as intervention), maternal behavior (as outcome) and experimentation animals (as population). Studies were first selected based on titles and abstracts, followed by full text analysis and data extraction. Individual effect size for each articles was calculated using standardized mean difference and meta-analysis was conducted using a DerSimonian and Laird random effects model. Results 144 articles were included in our initial data screening. Sample was reduced to six records after screening. A meta-analysis was performed, including data from two maternal behavior tests (pup retrieval test and ethogram-based analyses). A total of 115 animals were included. Meta-analysis showed that sleep restriction during pregnancy have no significant effects on maternal behavior. Conclusion Clinical studies and meta-analysis have shown that sleep restriction and disorders during pregnancy increase risk for postpartum depression. However, preclinical studies fail to corroborate these results, as sleep restriction during pregnancy does not reduce maternal behavior in rodents. The presence of negative effects in women and the maintenance of normal maternal behavior levels in rodents under comparable intervention demonstrate that other factors might mediate this relationship (among which, sociocultural factors might play a role). The maintenance of maternal behavior seems to be an adaptive behavior, assuring the suitability and survival of the litter, even in face of environmental stresses. Support AFIP, FAVC, CNPq, FAPESP

Bilayer Hydrogel Sheet-Type Intraocular Microrobot for Drug Delivery and Magnetic Nanoparticles Retrieval.

By virtue of minimum invasiveness and driving ability using a magnetic field, drug delivery with the aid of a microrobot has an inherent potential for targeted treatment for the eye. The use of microrobots, however, has the limitation of leaving magnetic nanoparticles (MNPs) in the eye that can cause side effects. In this study, a bilayer hydrogel microrobot capable of retrieving MNPs after drug delivery is proposed that overcomes the limitations of existing microrobots. The bilayer hydrogel microrobot is composed of an MNPs layer and a therapeutic layer. Upon applying an alternating magnetic field (AMF) at the target point, the therapeutic layer is dissolved to deliver drug particles, and then the MNPs layer can be retrieved using a magnetic field. The targeting and MNPs retrieval tests validate the drug delivery and MNPs retrieval ability of the microrobot. The ex vivo bovine vitreous and in vitro cell tests demonstrate the potential for the vitreous migration of the microrobot and the therapeutic effect against retinoblastoma Y79 cancer cells. This bilayer hydrogel sheet-type intraocular microrobot provides a new drug delivery paradigm that overcomes the limitations of microrobot by maintaining the advantages of conventional microrobots in delivering drugs to the eye and retrieving MNPs after drug delivery.

MON-019 Maternal Behaviour in Mice Is Modified by a High Fat Diet in Pregnancy

Background: About a third of pregnant women of age 20-39 are obese, which carries significant risks for the mother and fetus, and adversely impacts pregnancy outcome. Specifically, women with obesity are at increased risk for peripartum depression. Maternal behaviour in mice is influenced by changes in hormone signaling in pregnancy, which is associated with effects on adult neurogenesis in the brain. Thus, we used mouse as a model system to gain further insight into the possible relationship between overeating/obesity and brain physiology and maternal behaviour. Objective: To assess the ability of a high-fat diet (HFD) versus a regular chow diet (CD), starting up to 10 weeks pre-pregnancy, to modify glucose clearance before and during pregnancy and affect maternal behaviour in the CD1 mouse. Study Design: Two groups of 3-4 week-old female CD1 mice were fed a HFD (fat=60 kcal%; carbohydrate=20 kcal%; protein=20 kcal%) or CD (fat=14 kcal%; carbohydrate=60 kcal%; protein=26 kcal%) and maintained on their respective diets throughout the study and weighed periodically. After at least 4 weeks of feeding on their diets, mice were allowed to breed. Glucose tolerance was tested using 2 g/kg of i.p. glucose at gestational day (GD) -1) after fasting (16 hours-overnight) as well as during pregnancy at GD16.5. An even number of pregnant and non-pregnant females were selected for each diet for maternal behaviour testing. Tests include an assessment of nest building at GD16.5-17 (use of nesting material and nest quality), and after birth pup retrieval at postpartum day (PD) 3, 4 and 5 (time of retrieval of each of the four pups within six minutes) using video capture. Results: The HFD led to a significant increase in weight relative to mice fed a CD. HFD impaired glucose-load clearances at GD -1 and 16.5 (p<0.05) compared to mice fed a CD. Mice fed on HFD performed poorly in the nest building task (p<0.01) as well as demonstrated a reduced completion rate on the pup retrieval test on PD3 (CD=8/10 vs. HFD 2/9 mice) but their retrieval response latency was improved by PD4 (CD=8/10 vs. HFD 8/9 mice) and PD5 (CD=7/10 vs. HFD 7/9 mice). Conclusions: Initial observations suggest that a HFD for at least 4 weeks before and during pregnancy results in overweight CD1 mice with impaired glucose clearance, and a negative effect on maternal behaviour as assessed by nest-building during pregnancy and pup retrieval postpartum; however, with regard to the latter, mice on the HFD show the ability to learn. Additional behavioural tests for locomotion, anxiety, risk avoidance and object recognition memory during or after pregnancy, as well as associated changes in hormonal signaling and adult neurogenesis are also currently under investigation.

Multimodal feature binding in object memory retrieval using event-related potentials: Implications for models of semantic memory

To test the hypothesis that semantic processes are represented in multiple subsystems, we recorded electroencephalogram (EEG) as we elicited object memories using the modified Semantic Object Retrieval Test, during which an object feature, presented as a visual word [VW], an auditory word [AW], or a picture [Pic], was followed by a second feature always presented as a visual word. We performed both hypothesis-driven and data-driven analyses using event-related potentials (ERPs) time locked to the second stimulus. We replicated a previously reported left fronto-temporal ERP effect (750–1000 ms post-stimulus) in the VW task, and also found that this ERP component was only present during object memory retrieval in verbal (VW, AW) as opposed to non-verbal (Pic) stimulus types. We also found a right temporal ERP effect (850–1000 ms post-stimulus) that was present in auditory (AW) but not in visual (VW, Pic) stimulus types. In addition, we found an earlier left temporo-parietal ERP effect between 350 and 700 ms post-stimulus and a later midline parietal ERP effect between 700 and 1100 ms post-stimulus, present in all stimulus types, suggesting common neural mechanisms for object retrieval processes and object activation, respectively. These findings support multiple semantic subsystems that respond to varying stimulus modalities, and argue against an ultimate unitary amodal semantic analysis.

A High Fat Diet in Pregnancy Modifies Mouse Maternal Behaviour

BackgroundAbout a third of pregnant women of age 20–39 are obese, which carries significant risks for the mother and fetus, and adversely impacts pregnancy outcome. Specifically, women with obesity are at increased risk for peripartum depression. Maternal behaviour in mice is influenced by changes in hormone signaling in pregnancy, which is associated with effects on adult neurogenesis in the brain. Thus, we used mouse as a model system to gain further insight into the possible relationship between overeating/obesity and brain physiology and maternal behaviour.ObjectiveTo assess the ability of a high‐fat diet (HFD) versus a regular chow diet (CD), starting up to 10 weeks pre‐pregnancy, to modify glucose clearance before and during pregnancy and affect maternal behaviour in the CD1 mouse.ApproachTwo groups of 3–4 week‐old female CD1 mice were fed a HFD (fat=60 kcal%; carbohydrate=20 kcal%; protein=20 kcal%) or CD (fat=14 kcal%; carbohydrate=60 kcal%; protein=26 kcal%) and maintained on their respective diets throughout the study and weighed periodically. After at least 4 weeks of feeding on their diets, mice were allowed to breed. Glucose tolerance was tested using 2 g/kg of i.p. glucose at gestational day (GD) ‐1) after fasting (16 hours‐overnight) as well as during pregnancy at GD16.5. An even number of pregnant and non‐pregnant females were selected for each diet for maternal behaviour testing. Tests include an assessment of nest building at GD16.5–17 (use of nesting material and nest quality), and after birth pup retrieval at postpartum day (PD) 3, 4 and 5 (time of retrieval of each of the four pups within six minutes) using video capture.ResultsThe HFD led to a significant increase in weight relative to mice fed a CD. HFD impaired glucose‐load clearances at GD ‐1 and 16.5 (p&lt;0.05) compared to mice fed a CD. Mice fed on HFD performed poorly in the nest building task (p&lt;0.01) as well as demonstrated a reduced completion rate on the pup retrieval test on PD3 (CD=8/10 vs. HFD 2/9 mice) but their retrieval response latency was improved by PD4 (CD=8/10 vs. HFD 8/9 mice) and PD5 (CD=7/10 vs. HFD 7/9 mice).ConclusionsInitial observations suggest that a HFD for at least 4 weeks before and during pregnancy results in overweight CD1 mice with impaired glucose clearance, and a negative effect on maternal behaviour as assessed by nest‐building during pregnancy and pup retrieval postpartum; however, with regard to the latter, mice on the HFD show the ability to learn. Additional behavioural tests for locomotion, anxiety, risk avoidance and object recognition memory during or after pregnancy, as well as associated changes in hormonal signaling and adult neurogenesis are also currently under investigation.

Negative item memory and associative memory: Influences of working memory capacity, anxiety sensitivity, and looming cognition

Background and objectivesTraumatic or negative stimuli facilitate item memory but impair associated context memory. Vulnerability factors related to the maintenance and onset of posttraumatic stress disorder (PTSD), such as anxiety sensitivity, looming cognitive style, dissociation, and low working memory capacity, have been identified. However, little is known about how these factors influence negative item or associative memory. MethodsEighty-five undergraduates completed self-report questionnaires, the operation span with words (OSPAN) task, and an item and associative memory task in which incidental encoding of negative and neutral items and context information (Day 1) was followed by an unexpected retrieval test (Day 2). ResultsThe results showed greater Hit rates and False Alarms on item memory and lower accuracy on context memory with negative stimuli than with neutral stimuli, replicating previous findings. Low working memory capacity and high dissociation were correlated with low negative item memory. Under low working memory capacity, high levels of anxiety sensitivity and looming cognitive style predicted high dissociation levels and low accuracy for negative item memory. There were no individual differences involving associative memory. LimitationsA nonclinical sample was used, which limits the generalizability of our results to clinical samples. ConclusionsDissociation could be a coping strategy for reducing negative item memory. Anxiety sensitivity and looming cognitive style facilitate dissociative coping; however, working memory capacity buffers against these vulnerabilities.

Medical Students Who Prepare for a Lecture Learn More Than Those Who Do Not: An Experimental Study

Purpose: Medical students tend to attend lectures unprepared before studying the literature for an examination. Would students not profit more from lectures if they study the literature first? Method: One hundred and two students from a Saudi-Arabian medical school were included in the study. Half of them received a four-page text to be studied before a 15-minutes lecture; the other half received the lecture first and then the text. Knowledge level was tested using a concept retrieval test at three points in time, before the experiment, after reading the text, and after attending the lecture. This enabled studying the effects of the various treatments separately. Results: The mean student-scores were as follows: After lecture-only: 54.7±23.5, after reading-only: 45.7±11.2, lecture-then-reading: 69.9±15.8 and reading-then-lecture: 78.2±17.4. The combination of lecture and reading in both groups was statistically significantly different from lecture-only. Reading-then-lecture was significantly better than lecture-then-reading. Conclusion: In contrast to existing practices of students in medical education, it is better to study first before attending a lecture. Keywords: Lectures; self-study; concept retrieval test. DOI: 10.7176/JEP/11-8-06 Publication date: March 31 st 2020

Word retrieval across the biomarker-confirmed Alzheimer's disease syndromic spectrum

Alzheimer's disease (AD) is now conceptualized as a biological entity defined by amyloid and tau deposition and neurodegeneration, with heterogeneous clinical presentations. With the aid of in vivo biomarkers, clinicians are better poised to examine clinical syndromic variability arising from a common pathology. Word retrieval deficits, measured using verbal fluency and confrontation naming tests, are hallmark features of the early clinical stages of the amnestic presentations of AD, specifically in category fluency and naming with relatively spared letter fluency. As yet, there is no consensus regarding performance on these tests in atypical clinical phenotypes of AD, including posterior cortical atrophy (PCA) and logopenic primary progressive aphasia (lvPPA), in individuals who are amyloid-positive (Aβ+) but present with different clinical profiles and patterns of neurodegeneration compared to amnestic AD. The goal of the current study is to determine how Aβ+ individuals across the syndromic spectrum of AD perform on three different word retrieval tasks. A secondary goal is to determine the neuroanatomical substrates underlying word retrieval performance in these Aβ+ individuals. Thirty-two Aβ+ participants with the amnestic presentation, 16 with Aβ+ PCA, 22 with Aβ+ lvPPA, and 99 amyloid-negative (Aβ-) control participants were evaluated with verbal fluency and visual confrontation naming tests as well as high-resolution MRI. The Aβ+ patient groups were rated at very mild or mild levels of severity (CDR 0.5 or 1) and had comparable levels of global cognitive impairment (average MMSE = 23.7 ± 3.9). Behaviorally, we found that the word retrieval profile of PCA patients is comparable to that of amnestic patients, characterized by intact letter fluency but impaired category fluency and visual confrontation naming, while lvPPA patients demonstrated impairment across all tests of word retrieval. Across all AD variants, we observed that letter fluency was associated with cortical thickness in prefrontal, central precuneus, lateral parietal and temporal cortex, while category fluency and naming were associated with cortical thickness in left middle frontal gyrus, posterior middle temporal gyrus, and lateral parietal cortex. Visual confrontation naming was uniquely associated with atrophy in inferior temporal and visual association cortex. We conclude that a better understanding of the word retrieval profiles and underlying neurodegeneration across the AD syndromic spectrum will help improve interpretation of neuropsychological profiles with regard to the localization of neurodegeneration, particularly in the atypical AD variants.