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PURPOSE: Cancer survivors frequently report significant forgetfulness, but standard neuropsychological tests often fail to detect primary memory deficits. Past research has suggested survivors may misattribute forgetfulness to memory decay rather than impairments in initial encoding, but no studies have tested whether this pattern is evident in older survivors, who are more vulnerable to age-related memory difficulties. We examined whether long-term breast cancer survivors treated in older adulthood demonstrate deficits in initial encoding, as opposed to increased rates of memory decay, relative to non-cancer controls. METHODS: Three hundred twenty-eight breast cancer survivors age 60 and above, 5–15 years post-treatment, and 162 age-matched non-cancer controls completed list learning and narrative memory assessments at four time-points over 2 years. Performance on learning trials and delayed recall was analyzed at each time-point to assess group differences in memory encoding, and memory decay was assessed by analyzing changes in performance across delays. RESULTS: Univariate ANCOVAs correcting for age and education showed that survivors had worse initial encoding performance across multiple time-points, which were compensated for with multiple learning trials to produce recall performance comparable to controls. There were no significant group differences in memory decay. CONCLUSIONS: Older long-term breast cancer survivors exhibit a consistent pattern of initial encoding deficits, but memory retention was comparable to controls. Future research should consider the role of encoding deficits and age-related factors when evaluating cognitive function in older survivors. IMPLICATIONS FOR CANCER SURVIVORS: Commonly reported memory problems may stem from encoding deficits in older long-term cancer survivors.

Potamotrygon motoro has been shown to use vision to orient in a laboratory setting and has been successfully trained in cognitive behavioral studies using visual stimuli. This study explores P. motoro’s visual discrimination abilities in the context of two-alternative forced-choice experiments, with a focus on shape and contrast, stimulus orientation, and visual resolution. Results support that stingrays are able to discriminate stimulus-presence and -absence, overall stimulus contrasts, two forms, horizontal from vertical stimulus orientations, and different colors that also vary in brightness. Stingrays tested in visual resolution experiments demonstrated a range of visual acuities from

Background: Maternal sleep deprivation is known to reduce neurogenesis in the hippocampus during pregnancy. Also, it damages and impairs cognitive functions such as learning and memory in the neonates. Objectives: Rosmarinus officinalis (rosemary) extract can play an important role in the treatment of cognitive impairments by inhibiting oxidative stress. This study aimed to investigate the role of hydroalcoholic extract of rosemary in the treatment of cognitive impairment caused by decreased hippocampal neurogenesis in neonates, which was attributed to maternal sleep deprivation during pregnancy. Methods: For this purpose, pregnant rats in the control group underwent sleep deprivation for 72 hours inside a total sleep deprivation machine. The treatment groups comprised pregnant rats, receiving 50, 100, and 200 mg/kg of rosemary extracts per day during pregnancy and underwent sleep deprivation for 72 hours. Next, the avoidance memory of 21-day-old neonatal rats was examined using a shuttle box. These 21-day-old rats were then subjected to evaluate the structure of the hippocampus. Neurogenesis in the neonatal hippocampus was examined under light microscopy by staining of brain slices and counting of neurons and cells shape study. Results: Compared with the control group, the neurogenesis and avoidance memory decreased in neonates affected by maternal sleep deprivation. Conclusion: The results of this study showed that rosemary extract at a dose of 100 mg/kg was able to improve disorders in the infants affected by maternal sleep deprivation.

Acute and chronic ethanol intake, as well as ethanol withdrawal, exert learning disabilities. Of all the neurotransmitters in the brain, endogenous opioid peptides are thought to participate in ethanol effects. Kisspeptins, including kisspeptin-10, are peptides produced in the part of brain involved in the consolidation of memory and orientation. A new derivative of kisspeptin-10 is kissorphin (Tyr-Asn-Trp-Asn-Ser-Phe-NH2), a peptide with anti-opioid-activity. Hence, the aim of our study was to reveal whether kissorphin (1, 3, and 10 nmol, i.v.) was able to prevent or reverse learning deficits such as spatial memory retention and reversal learning induced by acute ethanol administration (1 × 1.75 g/kg., i.p.) and reversal learning induced by ethanol withdrawal (11-13 days from 'binge-like' ethanol input-5.0 g/kg, i.g. for 5 days) in the Barnes maze task in rats. Our study demonstrated that acute kissorphin administration prevented spatial memory (higher doses) impairments and attenuated reversal learning deficits induced by acute ethanol administration, although the reversal learning impairment may have been due to spatial learning impairments rather than cognitive flexibility impairments. Moreover, kissorphin given prior to first reversal learning trial for 3 consecutive days in the Barnes maze task during withdrawal from 'binge-like' ethanol administration, significantly attenuated cognitive flexibility impairment in the ethanol-withdrawal rats. In the acute and chronic ethanol experiments, kissorphin was the most effective at the dose of 10 nmol. In conclusion, the ethanol-induced spatial memory impairment may be reversed by pharmacological manipulation of the endogenous opioid system.

The COVID-19 pandemic has illustrated the need for the development of fast and reliable testing methods for novel, zoonotic, viral diseases in both humans and animals. Pathologies lead to detectable changes in the Volatile Organic Compound (VOC) profile of animals, which can be monitored, thus allowing the development of a rapid VOC-based test. In the current study, we successfully trained honeybees (Apis mellifera) to identify SARS-CoV-2 infected minks (Neovison vison) thanks to Pavlovian conditioning protocols. The bees can be quickly conditioned to respond specifically to infected mink’s odours and could therefore be part of a wider SARS-CoV-2 diagnostic system. We tested two different training protocols to evaluate their performance in terms of learning rate, accuracy and memory retention. We designed a non-invasive rapid test in which multiple bees are tested in parallel on the same samples. This provided reliable results regarding a subject’s health status. Using the data from the training experiments, we simulated a diagnostic evaluation trial to predict the potential efficacy of our diagnostic test, which yielded a diagnostic sensitivity of 92% and specificity of 86%. We suggest that a honeybee-based diagnostics can offer a reliable and rapid test that provides a readily available, low-input addition to the currently available testing methods. A honeybee-based diagnostic test might be particularly relevant for remote and developing communities that lack the resources and infrastructure required for mainstream testing methods.

From early to middle childhood, brain regions that underlie memory consolidation undergo profound maturational changes. However, there is little empirical investigation that directly relates age-related differences in brain structural measures to the memory consolidation processes. The present study examined system-level memory consolidations of intentionally studied object-location associations after one night of sleep (short delay) and after two weeks (long delay) in normally developing 5-to-7-year-old children (n = 50) and young adults (n = 39). Behavioural differences in memory consolidation were related to structural brain measures. Our results showed that children, in comparison to young adults, consolidate correctly learnt object-location associations less robustly over short and long delay. Moreover, using partial least squares correlation method, a unique multivariate profile comprised of specific neocortical (prefrontal, parietal, and occipital), cerebellar, and hippocampal subfield structures was found to be associated with variation in short-delay memory consolidation. A different multivariate profile comprised of a reduced set of brain structures, mainly consisting of neocortical (prefrontal, parietal, and occipital), and selective hippocampal subfield structures (CA1-2 and subiculum) was associated with variation in long-delay memory consolidation. Taken together, the results suggest that multivariate structural pattern of unique sets of brain regions are related to variations in short- and long-delay memory consolidation across children and young adults.RESEARCH HIGHLIGHTSShort- and long-delay memory consolidation is less robust in children than in young adultsShort-delay brain profile comprised of hippocampal, cerebellar, and neocortical brain regionsLong-delay brain profile comprised of neocortical and selected hippocampal brain regions.Brain profiles differ between children and young adults.

In infancy, sleep occurs in multiple nap and overnight bouts that change developmentally in quantity and distribution. Though studies suggest that infant memory benefits from a single nap, no work has assessed the relative benefits of different naps (morning vs. afternoon), nor how multiple naps support memory across the day. We investigated the memory benefit of a morning nap, relative to morning wake, and the effect of these intervals on afternoon nap function in 9-month-olds (n = 15). Infants participated in two within-subjects conditions (separated by 1-2 weeks). In the Nap-Nap condition, infants took their morning and afternoon naps; in the Wake-Nap condition, infants were kept awake during morning naptime, but napped unrestricted in the afternoon. Before each nap/wake interval, infants completed an imitation memory task, with memory assessed again shortly after the nap/wake interval. In the Nap-Nap condition, infants showed memory retention across morning and afternoon naps. In contrast, infants tended to forget items learned across morning wake in the Wake-Nap condition. Moreover, morning wake was associated with a significant decline in post-nap retention of items learned in the afternoon. Furthermore, relations between nap slow-wave activity (SWA) and memory varied across naps, with SWA either not predicting (morning naps) or positively predicting (afternoon naps) memory change in the Nap-Nap condition, but negatively predicting afternoon memory change in the Wake-Nap condition. We conclude that two naps per day (rather than one) aids memory at 9 months, and that skipping the morning nap may moderate relations between afternoon nap physiology and memory.

(1) Background: An age-related cognitive decline is commonly affecting the life of elderly with symptoms involved in progressive impairments to memory and learning. It has been proposed that probiotics could modulate age-related neurological disorders via the gut–brain axis. (2) Methods: To investigate the anti-aging effect of probiotic Lactobacillus plantarum GKM3, both survival tests and cognitive experiments were conducted in the SAMP8 mice model. The six-month-old SAMP8 (n = 20 in each gender) were fed with probiotic GKM3 at a dosage of 5.1 × 109 and 1.0 × 109 cfu/ kg B.W./day until their natural death. Then, the life span was investigated. Three-month-old SAMP8 (n = 10 in each gender) were administered GKM3 for 14 weeks. Then, the behavior tests and oxidation parameters were recorded. (3) Results: GKM3 groups showed significantly increased latency in the passive avoidance test and time of successful avoidance in the active avoidance test. The TBARS and 8-OHdG from mice brains also showed a significant reduction in the groups treated with GKM3. In addition, lower accumulation of the amyloid-β protein was found in SAMP8 mice brains with the supplement of GKM3. (4) Conclusions: These results indicated that L. plantarum GKM3 delayed the process of aging, alleviated age-related cognitive impairment, and reduced oxidative stress.

Purpose Animal experiments have shown that the loss of occlusal support causes impairments in spatial cognition. Many reports have focused on the memory encoding process, and only few studies have investigated the effect on memory retrieval. This study aimed to examine the effects of both the loss and reconstruction of occlusal support on the memory retrieval process and on the number of hippocampal pyramidal cells. Methods The experimental animals were divided into a molarless group, in which molars were extracted, a denture-wearing molarless group with experimental dentures inserted after molar extraction, and a control group. Radial maze trials were performed for 20 consecutive days (acquisition phase). The rats were tested on long-term memory retention following the acquisition phase in eight trials every five days, and in an additional trial 20 days later (probe phase). Results The denture-wearing molarless group showed higher levels of spatial learning and memory than the molarless group. There were no significant differences in memory retrieval during the probe phase between the denture-wearing molarless and the control group. The molarless group showed significantly worse spatial learning and memory and had fewer neurons in the hippocampus than the control group. Conclusions Our results suggest that the loss of occlusal support decreases the number of pyramidal cells in the hippocampus and impairs memory decoding and retrieval. However, this effect is suppressed by the reconstruction of occlusal support.

Background: Vanadium is a potential neurotoxic agent widely distributed in the environment. Understanding the neurotoxic mechanisms of vanadium on learning and memory seems necessary. Methods: We investigated the time-dependent (1-week, 2- week and 4-week) effects of sodium metavanadate (SMV) (25 mg/kg/day; pre-training oral administration) and 4-day intraperitoneal injections of aminoguanidine (AG) as a selective inducible nitric oxide synthase inhibitor (10, 50, and 100 mg/kg) on spatial memory retention in Morris water maze. Animals were trained for 4 days and tested 48 h after the last training trial. Results: The data showed that 4-week oral pre-treatment with SMV (25 mg/kg/day) induced spatial memory retention deficits and decreased the time spent in the target quadrant. We found that 4-day administration of different doses of AG during training trials significantly decreased the time and distance of finding the hidden platforms. Additionally, SMV-induced spatial memory retention impairments were prevented in animals received combined SMV (25 mg/kg/day, 4 weeks) and AG (10 mg/kg/day, 4 days). Conclusion: Our findings showed the protective role of AG on SMV-induced spatial memory retention deficits.

It remains unknown whether transcranial alternating current stimulation (tACS) affects episodic memory and the effect of gamma oscillations delivered to the left prefrontal cortex (PFC) on long-term memory retention has not been fully investigated. We examined whether tACS over the left PFC enhances recognition of episodic memory. The study enrolled 36 healthy young adult volunteers. The participants were randomly assigned to either a tACS group [n = 18; 14 females; mean age ± standard deviation (SD): 21.2 ± 0.4 years] or a sham-control group [n = 18; 14 females; mean age ± SD: 21.2 ± 0.4 years]. Participants received either tACS or sham stimulation both during the learning task that was conducted on day 1 and during a recognition task on day 2. The recognition task was also conducted on days 1 and 7, and response accuracy was measured at all three time points (days 1, 2, and 7). Patients in the tACS group were better able to retain long-term memory than those in the sham-control group. These findings suggest that tACS over the left PFC enhances recognition of episodic memory in healthy young adults.

While language-learning apps have empowered many users to learn languages inexpensively, the underlying technology limits the tasks they can offer to atomic, flashcard-like exercises. In this paper we present an algorithm that can effectively estimate memory traces from user interaction data that is generated in complex language learning tasks such as extensive reading. This technology can be applied to develop complex, intrinsically-motivating, high-value learning tasks based around long texts, television series or podcasts.

Auditory closed-loop stimulation has gained traction in recent years as a means of enhancing slow oscillatory activity and, consequently, sleep-associated memory consolidation. Previous studies on this topic have primarily focused on the consolidation of semantically-congruent associations. In this study, we investigated the effect of auditory closed-loop stimulation on the overnight retention of semantically-incongruent associations. Twelve healthy males (age: M = 20.06, SD = 2.02 years) participated in two experimental conditions (simulation and sham). In the stimulation condition, clicks were delivered in phase with slow oscillation up-states, whereas in the sham condition no auditory stimuli were applied. Corroborating earlier work, stimulation (vs. sham) enhanced the slow oscillation rhythm, phase-coupled spindle activity and slow oscillation power. However, there was no benefit of stimulation on overnight memory retention. These findings suggest that closed-loop stimulation does not benefit semantically-incongruent associations.

Memory complaints are frequently reported by patients with epilepsy and are associated with seizure occurrence. Yet, the direct effects of seizures on memory retention are difficult to assess given their unpredictability. Furthermore, previous investigations have predominantly assessed declarative memory. This study evaluated within-subject effects of seizure occurrence on retention and consolidation of a procedural motor sequence learning task in patients with epilepsy undergoing continuous monitoring for five consecutive days. Of the total sample of patients considered for analyses (N = 53, Mage = 32.92 ± 13.80 y, range = 18–66 y; 43% male), 15 patients experienced seizures and were used for within-patient analyses. Within-patient contrasts showed general improvements over seizure-free (day + night) and seizure-affected retention periods. Yet, exploratory within-subject contrasts for patients diagnosed with temporal lobe epilepsy (n = 10) showed that only seizure-free retention periods resulted in significant improvements, as no performance changes were observed following seizure-affected retention. These results indicate general performance improvements and offline consolidation of procedural memory during the day and night. Furthermore, these results suggest the relevance of healthy temporal lobe functioning for successful consolidation of procedural information, as well as the importance of seizure control for effective retention and consolidation of procedural memory.

The radiation environment astronauts are exposed to in deep space includes galactic cosmic radiation (GCR) with different proportions of all naturally occurring ions. To assist NASA with assessment of risk to the brain following exposure to a mixture of ions broadly representative of the GCR, we assessed the behavioral and cognitive performance of female and male C57BL/6J × DBA2/J F1 (B6D2F1) mice two months following rapidly delivered, sequential 6 beam irradiation with protons (1 GeV, LET = 0.24 keV, 50%), 4He ions (250 MeV/n, LET = 1.6 keV/μm, 20%), 16O ions (250 MeV/n, LET = 25 keV/μm 7.5%), 28Si ions (263 MeV/n, LET = 78 keV/μm, 7.5%), 48Ti ions (1 GeV/n, LET = 107 keV/μm, 7.5%), and 56Fe ions (1 GeV/n, LET = 151 keV/μm, 7.5%) at 0, 25, 50, or 200 cGy) at 4–6 months of age. When the activity over 3 days of open field habituation was analyzed in female mice, those irradiated with 50 cGy moved less and spent less time in the center than sham-irradiated mice. Sham-irradiated female mice and those irradiated with 25 cGy showed object recognition. However, female mice exposed to 50 or 200 cGy did not show object recognition. When fear memory was assessed in passive avoidance tests, sham-irradiated mice and mice irradiated with 25 cGy showed memory retention while mice exposed to 50 or 200 cGy did not. The effects of radiation passive avoidance memory retention were not sex-dependent. There was no effect of radiation on depressive-like behavior in the forced swim test. There was a trend toward an effect of radiation on BDNF levels in the cortex of males, but not for females, with higher levels in male mice irradiated with 50 cGy than sham-irradiated. Finally, sequential 6-ion irradiation impacted the composition of the gut microbiome in a sex-dependent fashion. Taxa were uncovered whose relative abundance in the gut was associated with the radiation dose received. Thus, exposure to sequential six-beam irradiation significantly affects behavioral and cognitive performance and the gut microbiome.

Spaced retrieval practice consists of repetitions of the same retrieval event distributed through time. This learning strategy combines two “desirable difficulties”: retrieval practice and spacing effects. We carried out meta-analyses on 29 studies investigating the benefit of spacing out retrieval practice episodes on final retention. The total dataset was divided into two subsets to investigate two main questions: (1) Does spaced retrieval practice induce better memory retention than massed retrieval practice? (subset 1); (2) Is the expanding spacing schedule superior to the uniform spacing schedule when learning with retrieval practice? (subset 2). Using meta-regression with robust variance estimation, 39 effect sizes were aggregated in subset 1 and 54 in subset 2. Results from subset 1 indicated a strong benefit of spaced retrieval practice in comparison with massed retrieval practice (g = 0.74). Results from subset 2 indicated no significant difference between expanding and uniform spacing schedules of retrieval practice (g = 0.034). Moderator analyses on this subset showed that the number of exposures of an item during retrieval practice explains inconsistencies between studies: the more learners are tested, the more beneficial the expanding schedule is compared with the uniform one. Overall, these results support the advantage of spacing out the retrieval practice episodes on the same content, but do not support the widely held belief that inter-retrieval intervals should be progressively increased until a retention test.

We recently reported that constitutive ablation of cyclophilin-D (Cyp-D) in mice reduces oxygen consumption (VO2) while paradoxically increasing exercise endurance, thereby demonstrating increased O2 utilization efficiency. This response was associated with augmented glucose uptake and glucose utilization, in part mediated through adenosine monophosphate-activated kinase signaling. We now hypothesized that Cyp-D knock-out (KO) mice might also exhibit improved cognitive-behavioral performance and that these favorable adaptive responses may persist under hypoxic conditions. We therefore assessed under normoxic (20.9% O2, simulating ground O2 levels) and hypoxic (8% O2, simulating 7600 m altitude O2 levels) conditions exercise capacity and cognitive-behavioral performance. We used a treadmill test to assess exercise capacity, a pole-test to assess agility, an elevated-plus-maze test to assess anti-anxiety, and a passive avoidance test to assess learning and memory retention. Compared to wild type, Cyp-D KO mice showed comparable treadmill work under normoxia (48 ± 12 vs 47 ± 9 Joules) but increased treadmill work (12 ± 1 vs 8 ± 1 Joules; p = 0.02) under hypoxia. Cyp-D KO mice displayed increased pole-descending time (17 ± 3 vs 8 ± 2 s; p ≤ 0.05) under normoxia but shorter pole-descending time (21 ± 3 vs 37 ± 4 s; p ≤ 0.01) under hypoxia. In addition, the Cyp-D KO mice demonstrated increased elevated plus-maze open arm time (91 ± 31 vs 23 ± 12 s; p ≤ 0.05) under hypoxia and increased latency to enter dark chamber (261 ± 23 vs 185 ± 42 s; p ≤ 0.05) under normoxia. Thus, our experiments showed that under normoxia Cyp-D KO mice displayed anti-anxiety behavior and improved learning and memory retention. Under hypoxia, Cyp-D KO mice displayed increased exercise capacity, increased agility, and increased anti-anxiety consistent with our previously reported findings of increased O2 utilization efficiency. Identifying interventions to elicit these effects could be beneficial in a myriad of physiological and clinical conditions in which increasing O2 utilization efficiency would be advantageous.

Sleep is recognized as a physiological state associated with learning, with studies showing that knowledge acquisition improves with naps. Little work has examined sleep-dependent learning in people with developmental disorders, for whom sleep quality is often impaired. We examined the effect of natural, in-home naps on word learning in typical young children and children with Down syndrome (DS). Despite similar immediate memory retention, naps benefitted memory performance in typical children but hindered performance in children with DS, who retained less when tested after a nap, but were more accurate after a wake interval. These effects of napping persisted 24 h later in both groups, even after an intervening overnight period of sleep. During naps in typical children, memory retention for object-label associations correlated positively with percent of time in rapid eye movement (REM) sleep. However, in children with DS, a population with reduced REM, learning was impaired, but only after the nap. This finding shows that a nap can increase memory loss in a subpopulation, highlighting that naps are not universally beneficial. Further, in healthy preschooler’s naps, processes in REM sleep may benefit learning.

Background High-fidelity simulation is known to improve participant learning and behavioral performance. Simulation scenarios generate stress that affects memory retention and may impact future performance. The authors hypothesized that more participants would recall three or more critical key messages at three months when a relaxation break was performed before debriefing of critical event scenarios. Methods Each resident actively participated in one scenario and observed another. Residents were randomized in two parallel-arms. The intervention was a 5-min standardized relaxation break immediately before debriefing; controls had no break before debriefing. Five scenario-specific messages were read aloud by instructors during debriefings. Residents were asked by telephone three months later to recall the five messages from their two scenarios, and were scored for each scenario by blinded investigators. The primary endpoint was the number of residents participating actively who recalled three or more messages. Secondary endpoints included: number of residents observing who recalled three or more messages, anxiety level, and debriefing quality. Results In total, 149 residents were randomized and included. There were 52 of 73 (71%) residents participating actively who recalled three or more messages at three months in the intervention group versus 35 of 76 (46%) among controls (difference: 25% [95% CI, 10 to 40%], P = 0.004). No significant difference was found between groups for observers, anxiety or debriefing quality. Conclusions There was an additional 25% of active participants who recalled the critical messages at three months when a relaxation break was performed before debriefing of scenarios. Benefits of relaxation to enhance learning should be considered for medical education.

Background: Since 2004, zebrafish have become the state-of-the-art, in vivo model for biomedical research due to their genetic and physiological homology with humans, inexpensive high-quantity breeding, and quick development in a highly-controlled environment suitable for longitudinal studies. New Method: To fully utilize the zebrafish model, a novel, automated, high-throughput system was designed. Shoals of five zebrafish were placed in 16 tanks and automatically fed over two days for a total of 16 training sessions. Color LED lights were used as the stimulus for each shoal coinciding with the release of food for a duration of 20 seconds. This system was tested on two age groups: 6- and 11-month-old. Results: After three training sessions, the median height of the school in the tank during stimulus was significantly higher than that of the naive fish during the first training session. All subsequent training sessions demonstrated similar behaviour. A decline in memory retention, as defined by a reduction in the median height during light stimulus (i.e. no simultaneous food delivery), was observed 8 days post training. Comparison with existing methods: The high-throughput nature of this system allows for simultaneous training of 16 tanks of fish under identical conditions without human interaction and provides a means to rapidly assess their learning and memory behaviours. Conclusion: Results provide a baseline for understanding the normal cognitive processes of learning and memory retention in zebrafish. This work paves the way for future studies on the impacts of therapeutic agents on these cognitive processes.

[Purpose] The purpose is to verify the effectiveness of the 2-step test in predicting cognitive decline in elderly individuals. [Subjects and Methods] One hundred eighty-two participants aged over 65 years underwent the 2-step test, cognitive function tests and higher level competence testing. Participants were classified as Robust

Ants are a well-characterized insect model for the study of visual learning and orientation, but the extent to which colour vision is involved in these tasks remains unknown. We investigated the colour preference, learning and memory retention of Camponotus blandus foragers under controlled laboratory conditions. Our results show that C. blandus foragers exhibit a strong innate preference for ultraviolet (UV, 365 nm) over blue (450 nm) and green (528 nm) wavelengths. The ants can learn to discriminate 365 nm from either 528 nm or 450 nm, independent of intensity changes. However, they fail to discriminate between 450 nm and 528 nm. Modelling of putative colour spaces involving different numbers of photoreceptor types revealed that colour discrimination performance of individual ants is best explained by dichromacy, comprising a short-wavelength (UV) receptor with peak sensitivity at about 360 nm, and a long-wavelength receptor with peak sensitivity between 470 nm and 560 nm. Foragers trained to discriminate blue or green from UV light are able to retain the learned colour information in an early mid-term (e-MTM), late mid-term (l-MTM), early long-term (e-LTM) and late long-term (l-LTM) memory from where it can be retrieved after 1 h, 12 h, 24 h, 3 days and 7 days after training, indicating that colour learning may induce different memory phases in ants. Overall, our results show that ants can use chromatic information in a way that should promote efficient foraging in complex natural environments.

Coriander is cultivated throughout the world for its nutritional value. The present study was undertaken with an objective to study the effects of oral administration of coriander on memory boosting and regaining. Here we investigated the influence of oral intake of coriander on behavioural task performance by using T-maze and radial arm maze and physiological measures relative to a milk control group. We have observed significant memory boosting and memory regaining effects of coriander when administered orally. This effect may be due to memory-improving property and anticholinesterase activity of coriander. Hence we recommend that coriander can be used as a remedy in the management of Alzheimer's disease.KYAMC Journal Vol. 4, No.-2, Jan 2014, Page 398-401

Purpose: The purpose of this study was to investigate the education retention effect of endotracheal and laryngeal tube intubation using a manikin study. Methods: The study consisted of measuring intubation time, intubation success rate, and confidence of intubation after education. The evaluation o...

Lectures, a form of passive learning, are a modality of teaching used in medical education. Active learning strategies allow learners and teachers to interact and be more engaged with the subject matter in a manner that encourages discussion, critical thinking, and advanced clinical reasoning skills. Learning to be effective requires vigilance, which promotes memory retention and should afford a way for learners to build on preexisting knowledge via scaffolding and concept mapping that uses critical thinking. Educators should also to use evaluation models that seek to improve patient care, health care systems, and community health.

Decreased spatial memory is common in aging populations and reduces their quality of life. Although its role is still controversial, low testosterone (T) may contribute to impaired cognition in aged men. This study aimed to identify the role of T in age-related deficiencies in spatial memory among male rats. Young adult (3 months old) and aged (21 months old) Wistar rats were assigned to independent groups: intact, orchidectomized, or orchidectomized + subcutaneous pellets of T propionate. The phases of spatial memory acquisition (4 daily trials/4 days) and spatial memory retention (1 trial/day, 3 and 12 days after acquisition) were evaluated using the Barnes maze. Compared with young adults, aged intact rats took longer to find the goal, made more mistakes, and showed only slight improvements in goal sector exploration across the acquisition period. The young orchidectomized rats showed no improvement in performance over the days during the acquisition phase. T treatment in hormonally deprived old rats produced a small improvement in goal sector exploration and number of errors during the acquisition phase. Meanwhile, in young adults, this treatment improved the goal sector searching in the retention phase (12 days after acquisition training). Our results suggested that age-related spatial memory deficits cannot be entirely explained by the decline in T levels; however, this androgen produced subtle and mild beneficial effects on spatial memory in young and old males. Taken together, our findings suggest age differences in the role of T on spatial memory in males.

Alzheimer's disease is defined by abnormal levels of amyloid and tau biomarkers. Even cognitively normal older adults with clinically relevant amyloid and tau levels perform worse on memory tests. However, it is unclear if the relationship between biomarker level and memory extends below clinical thresholds. We hypothesized that even subclinical biomarker levels are associated with memory when measured with neuropsychological tests designed to detect dysfunction in preclinical disease states. In a group of cognitively normal, “biomarker-negative” older men and women, we investigated the relationship between cerebrospinal fluid biomarker levels and memory measured with the ModRey, a list-learning task designed to assess memory in preclinical and cognitively normal adults. Cerebrospinal amyloid levels were associated with ModRey memory retention, the proportion of information retained after a delay period. When older adults with mild impairment were included, cerebrospinal fluid tau levels were also associated with ModRey retention. The association of amyloid and tau levels with memory was independent of each other. These results suggest cognitive changes associated with Alzheimer's disease pathology might occur earlier than currently thought.

Introduction Academic pressure and its associated stress are responsible for disturbances in the circadian cycle of the students. Adequate sleep has crucial role in enhancing cognitive skills especially memory retention. Poor night time sleep quality and consequent daytime sleepiness affects physical and cognitive health of the students. In this study, sleep quality among medical students is evaluated. Methods It was an observational, cross-sectional study conducted with undergraduate medical students. Pittsburgh Sleep Quality Index (PSQI) was used to assess the sleep quality. The data was analyzed using Statistical Package for the Social Sciences (SPSS) 22.0 (IBM Corp., Armonk, NY, USA). Results Of 281 students, 155 (55.16%) were pre-clinical students and 126 (44.83%) were clinical students; 207 (73.66%) were female students and 74 (26.33%) were male. The overall frequency of poor sleepers was 172 (61.2%); 95 (55.2%) of these were clinical sciences and 77 (44.8%) were basic sciences students. Sleep latency, duration, and efficiency were more impaired in clinical students (p-value ≤ 0.05). Use of sleep medications and daytime dysfunction was more common in clinical students (p-value ≤ 0.05). Conclusion Medical students are continuously under high academic stress and pressure. Adequate sleep is essential for them to refresh them every day and help in learning and memory processing. Medical students in advance years of education have worse sleep quality than those in early years. Efforts should be taken to improve their sleep quality in order to protect the psychological and emotional health of future doctors.

Single prolonged stress (SPS) is an experimental model that recapitulates in rodents some of the core symptoms of post-traumatic stress disorder (PTSD). Although women have a two-fold greater risk to develop PTSD, most preclinical studies have been carried out in males. Furthermore, the long-term effects of behavioral alterations induced by SPS have been rarely investigated. Here, we evaluated the long-term effects of SPS on PTSD-relevant behavioral domains in rats and whether these effects were sex-dependent. To this aim, separate cohorts of male and female adult rats were subjected to SPS and, 30 days later, long-term effects were assessed. We found that SPS exposure reduced locomotor activity in both sexes in an open field task. Males only showed increased anxiety-like behavior in the elevated plus maze and marble burying tests, enhanced acoustic startle response and impaired spatial memory retention while females were unaffected. SPS exposure did not alter auditory fear memory dynamics in males, but it did alter extinction retrieval in females. We provide the first evidence that SPS reproduces long-term emotional alterations in male, but not in female, rats which were observed 30 days following trauma exposure, thus resembling some of the hallmark symptoms of PTSD. Furthermore, our results show for the first time a long-term SPS-induced alteration of cued fear extinction in females. Our findings are relevant to future research on trauma-related disorders and may help develop sex-specific interventions to treat PTSD.

Introduction: Inhaler drugs are the basis of the treatment in asthma due to their local effects. Errors in inhaler techniques in asthma increase health care costs, hospitalization, and result in a lack of disease control. A brochure and a puzzle material were prepared as alternatives to face-to-face training in this study. It is aimed to evaluate the adequacy of these training materials in the diagnosis and the first month of treatment. Materials and Methods: Patients aged between 4-12 years diagnosed with asthma and their family members aged between 20-49 years who had not received inhaler drug training before were included in the study. A prospective, cross-sectional, quasi-experimental study was planned. Results: A total of 109 family members and patients were included. There was no difference between the groups in inhaler technique total scores in diagnosis. There was no difference in inhaler technique full score rates between the groups in the diagnosis and the first month. Conclusion: It was determined that puzzle games and brochures can be used as an alternative for treatment applications such as inhaler drugs with spacers. Further studies are needed to evaluate the effect of puzzle games and brochures with face-to-face training on long-term memory retention.

The effectiveness of retrieval practice for aiding long-term memory, referred to as the testing effect, has been widely demonstrated. However, the specific neurocognitive mechanisms underlying this phenomenon remain unclear. In the present study, we sought to explore the role of pre-retrieval processes at initial testing on later recognition performance by using event-related potentials (ERPs). Subjects studied two lists of words (Chinese characters) and then performed a recognition task or a source memory task, or restudied the word lists. At the end of the experiment, subjects received a final recognition test based on the remember-know paradigm. Behaviorally, initial testing (active retrieval) enhanced memory retention relative to restudying (passive retrieval). The retrieval mode at initial testing was indexed by more positive-going ERPs for unstudied items in the active-retrieval tasks than in passive retrieval from 300 to 900 ms. Follow-up analyses showed that the magnitude of the early ERP retrieval mode effect (300-500 ms) was predictive of the behavioral testing effect later on. In addition, the ERPs for correctly rejected new items during initial testing differed between the two active-retrieval tasks from 500 to 900 ms, and this ERP retrieval orientation effect predicted differential behavioral testing gains between the two active-retrieval conditions. Our findings confirm that initial testing promotes later retrieval relative to restudying, and they further suggest that adopting pre-retrieval processing in the forms of retrieval mode and retrieval orientation might contribute to these memory enhancements.

Objective To identify the effects of the consumption of non-nutritive sweeteners on memory retention and on the histology of the hippocampus. Methods In this study, 20 mice were used to determine if there is an effect of consuming the maximum allowable dose of the non-nutritive sweeteners on the memory retention and on the histology of the hippocampus. The mice were distributed into four groups and the treatments were given via oral gavage: Group 1 (water), Group 2 (aspartame: 1 000 mg/kg), Group 3 (stevia: 1 000 mg/kg) and Group 4 (sucralose: 16 000 mg/kg). Treatments were administered to the different experimental groups for 32 days, after which memory retention was tested using the two-day water maze protocol. After the tests, the mice were sacrificed and the brain was analyzed histologically for neurotrophic effects. Results Based on the results of the two-day water maze protocol, there were no differences between the non-nutritive sweeteners and the control group. However, stevia showed high cellular apoptosis followed by aspartame, sucralose and control group. Conclusions There was no significant effect on the memory of the mice. It showed histologically however, that stevia had a significant neurotropic effect compared to the other sweeteners.

The novel object recognition, or novel-object preference (NOP) test is employed to assess recognition memory in a variety of organisms. The subject is exposed to two identical objects, then after a delay, it is placed back in the original environment containing one of the original objects and a novel object. If the subject spends more time exploring one object, this can be interpreted as memory retention. To date, this test has not been fully explored in zebrafish (Danio rerio). Zebrafish possess recognition memory for simple 2- and 3-dimensional geometrical shapes, yet it is unknown if this translates to complex 3-dimensional objects. In this study we evaluated recognition memory in zebrafish using complex objects of different sizes. Contrary to rodents, zebrafish preferentially explored familiar over novel objects. Familiarity preference disappeared after delays of 5 mins. Leopard danios, another strain of D. rerio, also preferred the familiar object after a 1 min delay. Object preference could be re-established in zebra danios by administration of nicotine tartrate salt (50mg/L) prior to stimuli presentation, suggesting a memory-enhancing effect of nicotine. Additionally, exploration biases were present only when the objects were of intermediate size (2 × 5 cm). Our results demonstrate zebra and leopard danios have recognition memory, and that low nicotine doses can improve this memory type in zebra danios. However, exploration biases, from which memory is inferred, depend on object size. These findings suggest zebrafish ecology might influence object preference, as zebrafish neophobia could reflect natural anti-predatory behaviour.

Poor nutrition, poor mobility, obesity and ageing increase the possibility of neuronal disorder and Alzheimer’s disease. This study examined effect of Cornus mas flavonoids on memory retention and the level of plasma glucose and lipids in an intra-cerebroventricular streptozotocin-induced experimental Alzheimer’s disease model in Wistar rats. Intracerebroventricular administration of streptozotocine (3 mg kg–1) was performed and the animals memory were evaluated through passive avoidance tasks. Five groups (saline-saline control, streptozotocine-saline, and streptozotocine with different flavonoid doses [5, 10, 20 mg kg –1 ]) were examined. Animals received different doses of C. mas flavonoids or saline for three weeks starting one day before surgery. Rat weight was measured at the beginning of each week. Injection of streptozotocine significantly reduced memory retention, compared to the control group. Flavonoid treatment increased memory retention in a dose-dependent manner, and triglyceride and glucose concentration decreased memory retention. At the same time, high-density lipoprotein concentration increased without any effect on low-density lipoprotein concentration. The dose of 10 mg kg –1 decreased rat weight significantly. Our findings show that C. mas flavonoids can optimize cognitive deficits caused by injections of streptozotocine and also have a few positive effects on reducing the risk factors in the serum.

Abstrac t-Enginee ring smart-material s with emerge nt properti es requires designi ng and characte rizing systems with desirabl e behavio urs. Neurom orphic (brain-like) architectures require plasticity, where the strength of the connections and the time with which they decay can be modulated based on the magnitude and the repetition of the applied stimuli. This functionality is emulated in our complex nanowire network material through electrical resistive switching. The formation of nano-sized filamentary connections between overlapping wires across the network facilitates a controllable transition from a high resistance state to one (or more) lower resistance states with corresponding memory retention times. We report on the neuromorphic inspired behaviors that emerge from networks of metal nanowires coated with TiO 2 shells.

International audience; Memorability can be regarded as a useful metric of video importance to help make a choice between competing videos. Research on computational understanding of video memorability is however in its early stages. There is no available dataset for modelling purposes, and the few previous attempts provided protocols to collect video memorability data that would be difficult to generalize. Furthermore, the computational features needed to build a robust memorability predictor remain largely undiscovered. In this article, we propose a new protocol to collect long-term video memorability annotations. We measure the memory performances of 104 participants from weeks to years after memorization to build a dataset of 660 videos for video memorability prediction. This dataset is made available for the research community. We then analyze the collected data in order to better understand video memorability, in particular the effects of response time, duration of memory retention and repetition of visualization on video memorability. We finally investigate the use of various types of audio and visual features and build a computational model for video memorability prediction. We conclude that high level visual semantics help better predict the memorability of videos.

Honey bees transfer different informational components of the discovered feeding source to their nestmates during the waggle dance. To decode the multicomponent information of this complex behavior, dance followers have to attend to the most relevant signal elements while filtering out less relevant ones. To achieve that, dance followers should present improved abilities to acquire information compared with those bees not engaged in this behavior. Through proboscis extension response assays, sensory and cognitive abilities were tested in follower and non-follower bees. Individuals were captured within the hive, immediately after following waggle runs or a bit further from the dancer. Both behavioral categories present low and similar spontaneous odor responses (SORs). However, followers exhibit differences in responsiveness to sucrose and odor discrimination: followers showed increased gustatory responsiveness and, after olfactory differential conditioning, better memory retention than non-followers. Thus, the abilities of the dance followers related to appetitive behavior would allow them to improve the acquisition of the dance surrounding information. Fil: Moauro, Mariel Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina Fil: Balbuena, María Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina Fil: Farina, Walter Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina

Background and Objectives:: Spexin is a neuropeptide involved in learning and memory. The aim of the present study was to investigate the effect of intrahippocampal CA3 injection of spexin on passive avoidance learning and memory in normal and castrated rats. Methods: A total of 42 adult male rats were divided into 6 groups. Sham 1 (received 0.5 µL ACSF); sham 2 (sham castrated rats that received 0.5 µL ACSF); experimental 1 and 2 (healthy rats that received 0.5 µL spexin 10 or 30 nmol/rat); experimental 3 and 4 (castrated rats that received 0.5 µL spexin 10 or 30 nmol/rat). In all groups, injection was done in the CA3 region of hippocampus. CA3 region of hippocampus was cannulated unilaterally by the stereotaxic procedure. Results: Present data showed that castrated significantly (P < 0.05) increased lighting time in comparison to sham 2 group in memory sessions. In normal rats intrahippocampal CA3 injection of spexin in 2 doses significantly (P < 0.05) increased lighting time in comparison to the sham group in learning and memory sessions. In castrated rats, intrahippocampal CA3 injection of spexin 30 nmole/rat significantly (P < 0.05) induced even further increase in lighting time as compared to the sham group in memory sessions. In memory consolidation and memory retention sessions lighting time was significantly (P < 0.05) higher in castrated rats than normal animals. Conclusions: According to the present results, castration and spexin at 2 doses in normal rats improve learning and memory; while in castrated rats spexin, in 30 nM/rat, produced more improvement in memory. Memory improvement in castrated rats was higher than that in normal rats.

The consumption of a specifically prepared silk fibroin protein enzymatic hydrolysate (FPEH) has been reported to improve cognitive function in healthy humans. The objective of the current study is to evaluate the dose-dependent effects of the FPEH on memory. Healthy adults with an average age of approximately 55 years were administered doses of 0, 280, 400 and 600 mg of FPEH per day in two divided doses for 3 weeks. The Rey–Kim Auditory Verbal Learning Test and the Rey–Kim Complex Figure Test of the Rey–Kim Memory Test were used to evaluate memory at baseline and after 3 weeks. The scores for each test were combined into the memory quotient score (MQ). Learning gradient, memory maintenance, retrieval efficacy, and drawing/recall scores were also compared. After 3 weeks of FPEH, dose-dependent increases were observed for the MQ, the learning gradient, the numbers of words remembered, the retrieval efficiency, and drawing/recall. The optimal dose for FPEH was 400 or 600 mg, depending on the end point measured. No adverse effects were reported. FPEH significantly improved measurements of memory in healthy adults by 3 weeks at doses over 280 mg daily, with an apparent plateau effect at 400–600 mg daily.

This study provides further evidence for improvement of memory by oral consumption of cardamom. The present study was undertaken with an objective to study the effects of oral administration of cardamom on memory boosting and regaining. Here we investigate the influence of oral intake of cardamom on behavioral task performance by using T-maze and radial arm maze and physiological measures relative to a milk control group. We have observed significant memory boosting and memory regaining effects of cardamom when administered orally. This effect may be due to facilitation of acetylcholine activity by decreasing acetyl cholinesterase activity of cardamom. Hence we recommend further research in this area by investigating compound metabolism to optimize quantification of memory performance following cardamom consumption

This paper is concerned with the training of recurrent neural networks as goal-oriented dialog agents using reinforcement learning. Training such agents with policy gradients typically requires a large amount of samples. However, the collection of the required data in form of conversations between chat-bots and human agents is time-consuming and expensive. To mitigate this problem, we describe an efficient policy gradient method using positive memory retention, which significantly increases the sample-efficiency. We show that our method is 10 times more sample-efficient than policy gradients in extensive experiments on a new synthetic number guessing game. Moreover, in a real-word visual object discovery game, the proposed method is twice as sample-efficient as policy gradients and shows state-of-the-art performance., Comment: Published in IEEE Spoken Language Technology (SLT 2018), Athens, Greece

Using rat model of experimental anxiety-depressive disorder caused by postnatal administration of methionyl-2(S)-cyanopyrrolidine, an inhibitor of dipeptidyl peptidase IV, we compared conditioned active avoidance response and memory retention in males and females. In experimental males and females, conditioning was impaired in comparison with the control. In experimental groups, females were worse learners than males, while in control groups, females were better learners than males. Memory retention in experimental animals did not differ from that in controls 24 h after learning. Two months after learning, control females demonstrated better retention than control males.

Humans and rats poisoned with sarin develop chronic neurological disabilities that are not prevented with standardized antidotal therapy. We hypothesized that rats poisoned with the sarin analogue diisopropylfluorophosphate (DFP) and resuscitated with atropine and pralidoxime would have long-term memory deficits that were preventable with naltrexone treatment. Long Evans rats (250–275 g) were randomized to: DFP (N = 8): single subcutaneous (SC) injection of DFP (5 mg/kg). Treatment (N = 9): DFP (5 mg/kg) followed by chronic naltrexone (5 mg/kg/day × 12 weeks). Control (N = 12): single SC injection of isopropyl alcohol, (DFP vehicle) followed by chronic naltrexone (5 mg/kg/day). If toxicity developed after injection, antidotal therapy was initiated with atropine (2 mg/kg) and pralidoxime (25 mg/kg) and repeated as needed. After 12 weeks, rats underwent testing for place learning (acquisition) across 5 days of training using the Morris Water Maze. On day 6 a memory retention test was performed. Statistical analysis was performed using IBM SPSS Statistics. Rats receiving DFP rapidly developed toxicity requiring antidotal rescue. No differences in acquisition were seen between the DFP vs. DFP + naltrexone rats. During memory testing, DFP-poisoned rats spent significantly less time (29.4 ± 2.11 versus 38.5 ± 2.5 s, p 0.05) on the test for memory retention. Poisoning with DFP induced impaired memory retention. Deficits were not prevented by acute rescue with atropine and pralidoxime. Chronic naltrexone treatment led to preserved memory after DFP poisoning.

Surpassing the initial ‘wow’ effect of a complex juggling trick and producing long-lasting engaging performances are the main goals of any juggling act. Conveying to the audience the skill and the effort required for a performance is often difficult. In this paper, we use a wearable EEG headset to investigate how juggling skills can be inferred from a juggler’s brain. We observed characteristic brain activity and synchronization while juggling in both an expert and an intermediate juggler. We also found that processing of visuomotor skills and memory retention can be distinguished during motor imagery and simulated juggling conditions. For the first time, we were able to monitor a juggler’s brain in action. We have shown that using EEG while juggling could both improve our understanding of neuronal mechanisms governing visuomotor control and, importantly, represent a potential to enrich artistic performance and increase audience engagement.

As m-learning (mobile-learning) applications are rapidly growing, it is important to incorporate principles of human cognition in those applications. In the present study, a foreign language learning application environment was developed using various learning methods in order to identify optimal m-learning applications. Using computer-based learning experiments that assimilate an m-learning environment, participants were tested over their long-term memory retention of newly learned German vocabulary words. Specifically, we compared the effectiveness of rote learning, retrieval practice, repeated retrieval practice, and the keyword method. Experiment 1 showed that repeated retrieval practice was more beneficial for memory especially for longer retention intervals. Experiment 2 yielded that repeated retrieval practice was more effective for learning German vocabulary words than the keyword and rote learning methods. No statistical differences were found between the keyword and rote learning conditions. The present research suggests that retrieval practice can be effectively incorporated in m-learning applications. Implications and future directions are discussed.

The active examination of a specific subject is essential for an effective learning experience and memory retention. Mobile, technology-driven exploration settings particularly suggest themselves for tapping into the potential of visual reinforcement and the generation effect in order to help establish relevant knowledge. In this paper, we introduce such an approach based on the in-situ contour drawing of items of interest. Developed both for single-user and collaborative scenarios, it enables users to receive immediate feedback on their input which can be evaluated locally and independent of connectivity status. The contour drawing activity constitutes a novel element of the CollaTrEx framework for collaborative context-aware mobile training and exploration. Its design and performance are discussed based on a prototypical implementation for tablet devices and an exemplary application.

Major Depression is a prevalent mental disorder that is characterized by negative mood and reduced motivation, and frequently results in social withdrawal and memory-related deficits. Repeated stressors, such as adverse life events, increase the risk for development of the disorder. Consequently, individual variability in stress response greatly weighs on depression-vulnerability and -resilience. Here, we employed the social defeat-induced persistent stress (SDPS) paradigm to identify depression-prone individuals and to examine the temporal development of depression in the months following exposure to brief defeat stress. Male Wistar rats were socially defeated (5 defeat episodes) and single-housed for a prolonged period of time (~24 weeks). We assessed the emergence of a sustained depressive-like state by repeatedly evaluating social motivation (social approach avoidance) and spatial memory (object place recognition) in SDPS rats during the isolation period. Individual variability in the effects of SDPS yielded two extreme subpopulations: an SDPS-prone group that showed gradual affective and cognitive deterioration in terms of social approach and memory retention, and a SDPS-resilient group that did not develop this phenotype. Notably, in SDPS-prone individuals, the affective deficits preceded later cognitive impairments, providing a novel temporal profile of the development of pathology in this preclinical model of sustained depression.