Associate Learning Test Research Articles

Memory function in autoimmune encephalitis: a cross-sectional prospective study utilising multiple memory paradigms

Background and objectiveAutoimmune encephalitis (AE) is often associated with clinically significant memory impairment. This study aimed to evaluate memory in a cross-sectional prospective AE cohort using multiple memory paradigms.Methods52 patients (50% seropositive) meeting Graus criteria for possible AE were prospectively recruited between October 2019 and August 202. A comprehensive examination of memory was performed, including tests of supraspan verbal memory (list learning), logicosemantic memory (story learning), figural memory (learning of geometric designs), and verbal associative learning (verbal paired associates). Memory scores were compared to demographically adjusted normative data. Pattern analysis was conducted to assist in the identification of patterns in memory performances.ResultsMean memory scores were not significantly below the normative mean. At an individual patient level, over 20% of the cohort exhibited impaired delayed figural memory, supraspan verbal memory learning and recall. Observed performances were significantly below expected performance for story learning (p = 0.017) and recall (p = 0.003), figural recall (p < 0.0001), initial acquisition (p < 0.001) and final acquisition of a list (p < 0.001) and all delayed recall measures of the list (p < 0.00001). 54.76% of patients exhibited intact psychometrics, and 16 distinct patterns of impairment emerged, indicating variability in memory outcomes.DiscussionWhile statistical evidence for memory impairment did not emerge at an aggregate level, a proportion of patients present with evidence of abnormal memory performance on psychometrics. Variability in impaired memory measures argues for an individualised patient-focused approach to clinical assessment in AE. Future research should validate these findings with a larger sample size and explore the relationships between memory profiles and other cognitive functions.

Association of obesity to reaction time and visual memory in schizophrenia

BackgroundBoth overweight and cognitive deficits are common among people with schizophrenia (SZ) and schizoaffective disorder. The results in earlier studies have been inconsistent on whether overweight is associated with cognitive deficits in psychotic disorders. AimsOur aim in this study was to detect possible associations between obesity and cognitive deficits among study participants with SZ and schizoaffective disorder. MethodsThe study sample included 5382 participants with a clinical diagnosis of SZ or schizoaffective disorder selected from the Finnish SUPER study. Obesity was measured both with body-mass index and waist circumference. The cognitive performance was evaluated with two tests from the Cambridge automated neuropsychological test battery: Reaction time was evaluated with the 5-choice serial reaction time task. Visual memory was evaluated with the paired associative learning test. The final analysis included a total sample of 4498 participants applicable for the analysis of the reaction time and 3967 participants for the analysis of the visual memory. ResultsObesity measured with body-mass index was associated with better performance in reaction time task among both female and male participants. Among male participants, overweight was associated with better performance in the visual memory test. The waist circumference was not associated with cognitive measures. ConclusionsThe results suggest that obesity in people with SZ or schizoaffective disorder might not be associated with cognitive deficits but instead with better cognitive performance. The results were opposite from earlier literature on the general population. More research is required to better understand whether the results might be partly caused by the differences in the etiology of obesity between the general population and people with SZ.

Visual memory and alcohol use in a middle-aged birth cohort

Light and moderate alcohol use has been reported to be associated with both impaired and enhanced cognition. The purpose of this study was to explore whether there was a linear relationship between visual memory and alcohol consumption in males and females in a large middle-aged birth cohort population in cross-sectional and longitudinal settings. Data were collected from 5585 participants completing 31-year (1997–1998) and 46-year (2012–2014) follow-ups including Paired Associate Learning (PAL) test at 46-years follow-up. The participants were originally from 12,231 study population of the Northern Finland Birth Cohort 1966 (NFBC1966). The PAL test was conducted to assess visual memory. Reported alcohol use was measured as total daily use of alcohol, beer, wine, and spirits converted into grams and as frequency and amount of use of beer, wine, and spirits. The total daily alcohol use was not associated with reduced visual memory. The frequency of use of beer and wine in males was associated with better visual memory in cross-sectional and longitudinal settings. Using six or more servings of spirits was associated with worse visual memory in males in cross-sectional and longitudinal settings. The study suggested a lack of a linear association between drinking and visual memory in the middle-aged population.

Cognitive function and quantitative electroencephalogram analysis in subjects recovered from COVID-19 infection

Background & ObjectivesObjective assessment of post-COVID-19 cognitive dysfunction is highly warranted. This study aimed to evaluate the cognitive dysfunction of COVID-19 survivors with cognitive complaints, both clinically and neurophysiologically, using Quantitative Electroencephalogram (QEEG).MethodsThis case–control study was conducted on 50 recovered subjects from COVID-19 infection with cognitive complaints and 50 age, sex, and educational-matched healthy controls. Both groups were subjected to the following neurocognitive tests: Paired associate learning Test (PALT) and Paced Auditory Serial Addition Test (PASAT). The neurophysiological assessment was also done for both groups using QEEG.ResultsCOVID-19 survivors had significantly lower PALT scores than controls (P < 0.001). QEEG analysis found significantly higher levels of Theta / Beta ratio in both central and parietal areas in patients than in the controls (P < 0.001 for each). The interhemispheric coherence for the frontal, central, and parietal regions was also significantly lower in patients than in the control group regarding alpha and beta bands. There were statistically significant lower scores of PALT and PASAT among cases with severe COVID-19 infection (P = 0.011, 0.005, respectively) and those who needed oxygen support (P = 0.04, 0.01, respectively). On the other hand, a statistically significantly lower mean of frontal alpha inter-hemispheric coherence among patients with severe COVID-19 infection (P = 0.01) and those needing mechanical ventilation support (P = 0.04).ConclusionEpisodic memory deficit is evident in COVID-19 survivors with subjective cognitive complaints accompanied by lower inter-hemispheric coherence in frontal regions. These clinical and neurophysiological changes are associated with hypoxia and COVID-19 severity.

Generating normative data from web-based administration of the Cambridge Neuropsychological Test Automated Battery using a Bayesian framework.

Normative cognitive data can distinguish impairment from healthy cognitive function and pathological decline from normal ageing. Traditional methods for deriving normative data typically require extremely large samples of healthy participants, stratifying test variation by pre-specified age groups and key demographic features (age, sex, education). Linear regression approaches can provide normative data from more sparsely sampled datasets, but non-normal distributions of many cognitive test results may lead to violation of model assumptions, limiting generalisability. The current study proposes a novel Bayesian framework for normative data generation. Participants (n = 728; 368 male and 360 female, age 18-75 years), completed the Cambridge Neuropsychological Test Automated Battery via the research crowdsourcing website Prolific.ac. Participants completed tests of visuospatial recognition memory (Spatial Working Memory test), visual episodic memory (Paired Associate Learning test) and sustained attention (Rapid Visual Information Processing test). Test outcomes were modelled as a function of age using Bayesian Generalised Linear Models, which were able to derive posterior distributions of the authentic data, drawing from a wide family of distributions. Markov Chain Monte Carlo algorithms generated a large synthetic dataset from posterior distributions for each outcome measure, capturing normative distributions of cognition as a function of age, sex and education. Comparison with stratified and linear regression methods showed converging results, with the Bayesian approach producing similar age, sex and education trends in the data, and similar categorisation of individual performance levels. This study documents a novel, reproducible and robust method for describing normative cognitive performance with ageing using a large dataset.

18 Which cognitive complaints among older adults are more concerning than others? Analysis of items in a Subjective Cognitive Decline Questionnaire

Objective:Subjective Cognitive Decline (SCD) is the self-reported experience of one’s own declining cognition prior to objective impairment on clinical neuropsychological testing. While SCD is a promising marker of preclinical Alzheimer’s disease (AD), information is needed to determine which cognitive complaints reflect typical aging versus prodromal degenerative disease. The objective of the current study was to examine the extent to which specific cognitive complaints were associated with two clinical outcomes including: 1) lower performance on cognitive tasks sensitive to preclinical AD; and 2) seeking help (i.e., medical attention) for cognitive difficulties.Participants and Methods:The current sample consisted of 175 healthy older adults (56 Male, 119 Female), aged 51 to 90 (M=72.67, SD=7.12) with a mean education of 16 years (SD=2.3 years) who performed &gt; -1.5 SD on clinical neuropsychological testing. 26.8% of the sample self-reported as race/ethnic minorities (e.g., Hispanic or Non-Hispanic, Black, Asian, Other.) Participants completed a 20-item SCD questionnaire assessing perceived cognitive difficulties in comparison to same aged peers, and tests shown to be sensitive to preclinical AD including the Face Name Associative Learning Test and the Loewenstein-Acevedo Scales for Semantic Interference and Learning. Participants were coded as having sought help for SCD (39%) if they entered the current study from a clinical referral source, OR if they entered through a non-clinical referral stream but indicated that they had previously seen a doctor specifically for memory concerns or spoken to their doctor about memory concerns. Chi square tests were used to examine relationships between SCD item endorsement and help-seeking; ANOVAs were used to the extent to which item endorsement was associated with performance on cognitive tests. Results were considered significant at p &lt; .05.Results:Three SCD items were associated with both lower cognitive test scores and having sought help for SCD (p values ranged from &lt; .001 to .02). Items included difficulty remembering the date or day of the week and remembering a few shopping items without a list. One non-memory item was also associated with both outcomes including difficulty thinking ahead. In contrast, six items were not related to either outcome of interest. Such items included difficulty remembering appointments, remembering where you put things like keys, following a map to a new location, doing two things at once, understanding what you read, or understanding what people say to you. The remaining eleven items explore the extent to which selective associations exist with either help-seeking or cognitive performance.Conclusions:Patients and clinicians alike are often unsure about which cognitive difficulties are typical for aging and which may be the cause for further workup. Current results suggest that certain complaints among cognitively healthy older adults may be cause for more thorough evaluation or monitoring. These complaints include specific memory and nonmemory concerns. Future work is needed to determine if these complaints predict future cognitive decline or conversion to Mild Cognitive Impairment.

The functional connectome of 3,4-methyldioxymethamphetamine-related declarative memory impairments.

The chronic intake of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") bears a strong risk for sustained declarative memory impairments. Although such memory deficits have been repeatedly reported, their neurofunctional origin remains elusive. Therefore, we here investigate the neuronal basis of altered declarative memory in recurrent MDMA users at the level of brain connectivity. We examined a group of 44 chronic MDMA users and 41 demographically matched controls. Declarative memory performance was assessed by the Rey Auditory Verbal Learning Test and a visual associative learning test. To uncover alterations in the whole brain connectome between groups, we employed a data-driven multi-voxel pattern analysis (MVPA) approach on participants' resting-state functional magnetic resonance imaging data. Recent MDMA use was confirmed by hair analyses. MDMA users showed lower performance in delayed recall across tasks compared to well-matched controls with moderate-to-strong effect sizes. MVPA revealed a large cluster located in the left postcentral gyrus of global connectivity differences between groups. Post hoc seed-based connectivity analyses with this cluster unraveled hypoconnectivity to temporal areas belonging to the auditory network and hyperconnectivity to dorsal parietal regions belonging to the dorsal attention network in MDMA users. Seed-based connectivity strength was associated with verbal memory performance in the whole sample as well as with MDMA intake patterns in the user group. Our findings suggest that functional underpinnings of MDMA-related memory impairments encompass altered patterns of multimodal sensory integration within auditory processing regions to a functional heteromodal connector hub, the left postcentral gyrus. In addition, hyperconnectivity in regions of a cognitive control network might indicate compensation for degraded sensory processing.

Psilocybin intoxication did not affect daytime or sleep-related declarative memory consolidation in a small sample exploratory analysis

Psilocybin is investigated as a fast-acting antidepressant used in conjunction with psychotherapy. Intact cognitive functions, including memory, are one of the basic conditions of effective psychedelic-assisted therapy. While cognitive and memory processing is attenuated on various domains during psilocybin intoxication, the effect of psilocybin on the consolidation of memories learned outside of acute intoxication is not known. Thus the main aim of the current study was to test the effects of psilocybin on (A) memory consolidation of previously learned material just after the psilocybin session and (B) on overnight memory consolidation the night just after the psilocybin session. 20 healthy volunteers (10 M/10F) were enrolled in a placebo-controlled, double-blind, cross-over design. Effects on declarative memory consolidation in condition (A) The Groton Maze Learning Task and Rey Auditory Verbal Learning Test were used, and for (B) the Pair Associative Learning Test was used. We did not find psilocybin to improve memory consolidation. At the same time, we did not find psilocybin to negatively affect memory consolidation in any of the tests used. This evidence adds to the safety profile for the use of psilocybin.

Effect of propofol versus sevoflurane on auditory and cognitive functions: a randomized controlled trial

BackgroundHearing loss and cognitive impairment are postoperative complications which need more awareness by anaesthesiologists. We set out to investigate whether sevoflurane or propofol would have a negative impact on auditory function, attention, or auditory memory. This is a prospective randomized controlled study which was conducted on patients who were candidates for elective laparoscopic cholecystectomy under general anesthesia with either the sevoflurane or the propofol. All included participants were subjected to cognitive and auditory evaluation preoperative and 1 week after the operation. Cognitive assessment included: Paired Associate Learning test (PALT) and Paced Auditory Serial Addition Test (PASAT). Audiological assessment was done by measuring the auditory brainstem response (ABR).ResultsThere was no statistically significant difference between both groups in either age (p value = 0.537) or sex (p value = 0.175). In the propofol group, the postoperative values of LT ABR-I and III were significantly higher than the preoperative ones (p value < 0.001, 0.003), all the postoperative RT ABR waves were significantly higher than the preoperative ones (P < 0.05). In the sevoflurane group, the postoperative values for LTABR-I, III, III–V were significantly higher than the preoperative ones with p value (0.012, 0.008 and 0.009) and the postoperative values for RTABR-III, V, I–III, and III–V were significantly higher than preoperative values (P = 0.041, 0.029, 0.005 and < 0.001). There were no statistically significant differences between the propofol and sevoflurane groups in all waves of ABR on both sides (P > 0.05). There was a significant worsening between pre- and postoperative PASAT scores in the propofol and sevoflurane groups, respectively, with p value (< 0.001) with no statistically significant difference between both groups (p value = 0.906). In addition, there was a significant worsening between pre- and postoperative PALT scores in the propofol group only (p value = 0.01) with a statistically significant difference between both groups (p value = 0.038).ConclusionsThere was a statistically significant postoperative impairment in auditory function and attention following both the propofol and sevoflurane anesthesia with no significant difference between the two drugs. Whereas, the auditory memory was significantly impaired following the propofol only.

Classification of temporal lobe epilepsy based on neuropsychological tests and exploration of its underlying neurobiology.

To assist improving long-term postoperative seizure-free rate, we aimed to use machine learning algorithms based on neuropsychological data to differentiate temporal lobe epilepsy (TLE) from extratemporal lobe epilepsy (extraTLE), as well as explore the relationship between magnetic resonance imaging (MRI) and neuropsychological tests. Twenty-three patients with TLE and 23 patients with extraTLE underwent neuropsychological tests and MRI scans before surgery. The least absolute shrinkage and selection operator were firstly employed for feature selection, and a machine learning approach with neuropsychological tests was employed to classify TLE using leave-one-out cross-validation. A generalized linear model was used to analyze the relationship between brain alterations and neuropsychological tests. We found that logistic regression with the selected neuropsychological tests generated classification accuracies of 87.0%, with an area under the receiver operating characteristic curve (AUC) of 0.89. Three neuropsychological tests were acquired as significant neuropsychological signatures for the diagnosis of TLE. We also found that the Right-Left Orientation Test difference was related to the superior temporal and the banks of the superior temporal sulcus (bankssts). The Conditional Association Learning Test (CALT) was associated with the cortical thickness difference in the lateral orbitofrontal area between the two groups, and the Component Verbal Fluency Test was associated with the cortical thickness difference in the lateral occipital cortex between the two groups. These results showed that machine learning-based classification with the selected neuropsychological data can successfully classify TLE with high accuracy compared to previous studies, which could provide kind of warning sign for surgery candidate of TLE patients. In addition, understanding the mechanism of cognitive behavior by neuroimaging information could assist doctors in the presurgical evaluation of TLE.

What do zebra finches learn besides singing? Systematic mapping of the literature and presentation of an efficient associative learning test

The process of learning in birds has been extensively studied, with a focus on species such as pigeons, parrots, chickens, and crows. In recent years, the zebra finch has emerged as a model species in avian cognition, particularly in song learning. However, other cognitive domains such as spatial memory and associative learning could also be critical to fitness and survival, particularly during the intensive juvenile period. In this systematic review, we provide an overview of cognitive studies on zebra finches, with a focus on domains other than song learning. Our findings indicate that spatial, associative, and social learning are the most frequently studied domains, while motoric learning and inhibitory control have been examined less frequently over 30 years of research. All of the 60 studies included in this review were conducted on captive birds, limiting the generalizability of the findings to wild populations. Moreover, only two of the studies were conducted on juveniles, highlighting the need for more research on this critical period of learning. To address this research gap, we propose a high-throughput method for testing associative learning performance in a large number of both juvenile and adult zebra finches. Our results demonstrate that learning can occur in both age groups, thus encouraging researchers to also perform cognitive tests on juveniles. We also note the heterogeneity of methodologies, protocols, and subject exclusion criteria applied by different researchers, which makes it difficult to compare results across studies. Therefore, we call for better communication among researchers to develop standardised methodologies for studying each cognitive domain at different life stages and also in their natural conditions.

The eighteen months’ follow‐up, second version, after the intervention using a rehabilitation program of physical and cognitive rec‐Xercise (REPCREC) for the elderly with mild cognitive impairment (MCI)

AbstractBackgroundTo prevent or slow down the age‐related cognitive decline is an important issue. Therefore we have conducted intervention study with our rehabilitation program of physical and cognitive Rec‐Xercise (REPCREC) for the elderly with MCI.MethodSeventy‐six cases, out of seventy‐nine enrolled individuals, have undergone our evaluation and intervention program (REPCREC). The subjects have been divided into four groups; group A the cognitive REPCREC, group B physical REPCREC, group C both cognitive and physical REPCREC and group D control. The design of this study is a non‐randomized controlled trial. Intervention groups have received the each session once per week up to twelve times. Before and after the intervention, and 3‐, 6‐, 12‐ &amp; 18‐months after the intervention, we have evaluated the following items: physical function, GDS, POMS2, neuropsychological tests [MMSE, RBMT, TMT, Ravenʼs Colored Progressive Matrices(RCPM), Rey‐Osterrieth Complex Figure Test(ROCF), story retention, coding and Miyake’s paired verbal associate learning test(MPVALT)]. A one‐day booster program has been provided at the time of evaluation. For statistical analysis, Fisher’s exact test and Kruscal‐Wallis test for the baseline data, and linear mixed model(LMM) analysis have been performed.ResultThe median age is 79, median MMSE scare is 27.5, and the numbers of each group are A18, B24, C27, and D7 cases. At the baseline, no difference between groups except POMS‐F (p = 0.026). LMM analysis revealed the significant differences: 1) before REPCREC; RCPM of group A (p = 0.013), story retention delayed (p = 0.001) of group A (p = 0.011)▪C (p = 0.037), story retention immediate (p = 0.022), MPVALT (non‐related) (p = 0.048) and ROCF (recall) (p = 0.006), 2) after REPCREC; coding (p = 0.011) of group A (p = 0.049)▪C (p = 0.032) and ROCF(recall) (p = 0.018), 3) 3 months after REPCREC; TMTB (p = 0.031) of group A (p = 0.032) and story retention delayed of group A (p = 0.011).ConclusionThe program REPCREC showed the better effects after REPCREC on non‐verbal intelligence, visuospatial abilities, memory, attention, planning, working memory etc. [RCPM, ROCF (recall), MPVALT] in especially the cognitive REPCREC (group A). And group A showed the significant improvement in TMTB and story retention delayed, even three months after REPCREC. That may indicate the prolonged efficacy of the REPCREP in shift of attention and coherent memory for MCI

ICA69 regulates activity-dependent synaptic strengthening and learning and memory.

Long-term potentiation (LTP) is one of the major cellular mechanisms for learning and memory. Activity-dependent increases in surface AMPA receptors (AMPARs) are important for enhanced synaptic efficacy during LTP. Here, we report a novel function of a secretory trafficking protein, ICA69, in AMPAR trafficking, synaptic plasticity, and animal cognition. ICA69 is first identified as a diabetes-associated protein well characterized for its function in the biogenesis of secretory vesicles and trafficking of insulin from ER, Golgi to post-Golgi in pancreatic beta cells. In the brain, ICA69 is found in the AMPAR protein complex through its interaction with PICK1, which binds directly to GluA2 or GluA3 AMPAR subunits. Here, we showed that ICA69 regulates PICK1's distribution in neurons and stability in the mouse hippocampus, which in turn can impact AMPAR function in the brain. Biochemical analysis of postsynaptic density (PSD) proteins from hippocampi of mice lacking ICA69 (Ica1 knockout) and their wild-type littermates revealed comparable AMPAR protein levels. Electrophysiological recording and morphological analysis of CA1 pyramidal neurons from Ica1 knockout also showed normal AMPAR-mediated currents and dendrite architecture, indicating that ICA69 does not regulate synaptic AMPAR function and neuron morphology at the basal state. However, genetic deletion of ICA69 in mice selectively impairs NMDA receptor (NMDAR)-dependent LTP but not LTD at Schaffer collateral to CA1 synapses, which correlates with behavioral deficits in tests of spatial and associative learning and memory. Together, we identified a critical and selective role of ICA69 in LTP, linking ICA69-mediated synaptic strengthening to hippocampus-dependent learning and memory.

Comparative effect of deliberate hypotensive anesthesia using nitroglycerine vs. phentolamine on event related potentials and cognitive functions in patients undergoing septoplasty: a randomized controlled trial

BackgroundPostoperative cognitive dysfunction is a noteworthy complication of deliberate hypotensive anesthesia. The aim of this work was to compare the effect of deliberate hypotensive anesthesia using nitroglycerine versus phentolamine on event-related potentials and cognitive function in patients undergoing septoplasty surgery.MethodsThis prospective randomized controlled trial was conducted on 80 patients indicated for septoplasty under general anesthesia; 40 patients received intra-operative Nitroglycerine and 40 patients received intra-operative Phentolamine. Cognitive assessment (using Paired Associate Learning test (PALT) and Benton Visual Retention test (BVRT)) and P300 recording were done for all included patients pre-operatively and one week postoperatively.ResultsThe scores of PALT and Benton BVRT significantly declined one week following surgery in both Nitroglycerine and Phentolamine groups. There was no statistically significant difference between Nitroglycerine and Phentolamine groups in the postoperative decline in either PALT or BVRT (P-value = 0.342, 0.662 respectively). The values of P300 latency showed a significant delay one week following surgery in both Nitroglycerine and Phentolamine groups (P-value ≤ 0.001, 0.001), but in Nitroglycerine group, the delay is significantly higher than in Phentolamine group (P-value = 0.003). The values of P300 amplitude significantly decreased one week following surgery in both Nitroglycerine and Phentolamine groups (P-value ≤ 0.001, 0.001), but there was no statistically significant difference between Nitroglycerine and Phentolamine groups (P-value = 0.099).ConclusionPhentolamine is preferred over nitroglycerin in deliberate hypotensive anesthesia because it has less harmful effect on cognitive function than nitroglycerin.

Detecting mild cognitive impairment remotely with the modified memory impairment screen by telephone

ABSTRACT The original Memory Impairment Screen by Telephone (MIST) was designed to identify individuals with dementia but was relatively ineffective for identification of less severe impairment observed in mild cognitive impairment (MCI). We expanded the original MIST to create a modified instrument (mMIST) with greater sensitivity to less severe memory impairment. Older men and women with subjective cognitive decline were assessed by phone with the mMIST and subsequently classified independently with MCI or non-pathological cognitive decline. Participants with MCI produced lower scores on the mMIST than did participants without MCI, 10.8 ± 2.7 vs 13.3 ± 1.3, t = 5.68, p < 0.001, and performance on the mMIST predicted performances on the California Verbal Learning Test (CVLT), Verbal Paired Associate Learning Test (VPAL), Montreal Cognitive Assessment (MoCA) total score, and MoCA memory index score, p < 0.001. Receiver operating characteristic (ROC) analyses identified the optimal cut score on the mMIST to distinguish participants with and without MCI with Sensitivity = 73.1%, Specificity = 79.1%, and AUC = 0.79. Predictive values for distinguishing the amnestic form of MCI (aMCI) from non-amnestic MCI were Sensitivity = 81.8%, Specificity = 30%, and AUC = 0.82. These findings indicate that the mMIST is a valid screening instrument for identifying MCI. It can be administered remotely at low cost and low participant burden. Also, the mMIST has potential utility for remote cross-sectional and longitudinal evaluation in research and clinical contexts. Further investigation is indicated to corroborate its utility for assessment of aging patients and research participants.

Association Between Metabolic Syndrome and Decline in Cognitive Function: A Cross-Sectional Study.

We investigated whether metabolic syndrome (MetS) is associated with a decline in cognitive function in a cohort of middle-aged and elderly individuals without known cognitive dysfunction diseases in Qatar. We conducted a cross-sectional study on randomly selected participants aged 40-80 years from the Qatar Biobank, with data on cognitive tests and MetS components. Participants with a history of dementia, stroke, or mental disorders were excluded. MetS was diagnosed using the NCEP-ATP III criteria and cognitive performance was assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB). Two cognitive function domains were assessed. These are speed of reaction, measured using the Reaction Time (RT), and short-term visual memory, measured using the Paired Associate Learning (PAL) test. Multivariable logistic regression models were used to determine associations between MetS and poor speed of reaction and poor memory performance. The mean age of the participants included was 49.8 years (SD 6.7). Of these, 51.9% were females and 88.0% were of Qatari nationality. Most of the 1000 participants had MetS (n=302) or 1-2 MetS components (n=523), whereas only 170 had no MetS components. There was a strong association between MetS and poor memory performance (OR 1.76, 95% CI 1.04-2.96, P=0.034), but a weaker association with poor speed of reaction (OR 1.5, 95% CI 0.89-2.50, P=0.125). In middle-aged and elderly individuals, MetS was strongly associated with diminished short-term visual memory, psychomotor coordination and motor speed.

A test of associative olfactory learning in the ant Formica clara (Hymenoptera: Formicidae); the power of a MaLER-based conditioning protocol

Abstract In the present study, we tested associative olfactory learning performance of the ant Formica clara in laboratory conditions based on their MaLER responses. Ants were harnessed with the help of a paper-made holder and conditioned in two groups by forward pairing either limonene or eugenol (conditioned stimuli – CS) with a reward (unconditioned stimulus – US). After conditioning, memory tests were performed for each CS 15, 60 and 90 minutes following the conditioning in the absence of US. A further test was performed for each group with the CS of the other group to see if the ants showed an odor generalization. The frequencies of MaLER-positive responses during tests were used as indication of learning performance. Ants learned the association between the CS and US during conditioning for both odors and showed initially significant and gradually decreasing MaLER-positive responses during tests. The results showed that conditioning to the odors was absolute and no generalization was observed. We conclude that associative learning is a universal strategy for ants to adjust their behaviors to environmental changes around them and the MaLER technique is a powerful and easy to apply technique to test learning and memory capacities in ants.

A Multi‐domain Lifestyle Intervention does not Improve Health and Cognitive Outcomes Among APOE e4 Carriers after 4‐months

AbstractBackgroundAlzheimer’s Disease (AD) currently affects 24 million individuals worldwide, this rate is expected to triple by 2050. The greatest genetic risk for AD is apolipoprotein E (ApoE; e4 allele carriers), e4 carriers typically exhibit abnormal regulation of lipoprotein metabolism. It is important to understand whether multi‐domain lifestyle interventions can mitigate cognitive decline and improve overall health in ApoEe4 carriers. Thus far, the data are mixed due to sample sizes and methodological limitations. Therefore, the purpose of this present investigation is to determine if a digital multi‐domain intervention (MDI) can improve health and cognitive outcomes in cognitively at‐risk e4 carriers over 4 months.MethodAdults 45‐75 years old participated in this present investigation, each participant was randomly assigned to a health coaching intervention group (HC; n=61 non‐carriers; n=24 e4 carriers) or health education control group (HE; n=62 non‐carriers; n=20 e4 carriers). Participants completed weight, height, venous blood draw, a digital memory and associative learning test during baseline and 4‐month follow‐up visits. A 2 (time) x 2 (group) x 2 (APOE) factorial‐ANOVA was utilized to examine differences in the dependent variables (body mass index (BMI), cholesterol, triglycerides, memory, learning). Age, sex, and education were accounted for.ResultTriglycerides significantly increased among HC e4carriers compared to HC non‐carriers (p=.009). BMI significantly increased among carriers regardless of intervention group compared to non‐carriers (p&lt; .001). Cholesterol values showed a decreasing trend among HC non‐carriers, HE carriers, and non‐carriers compared to no change among HC carriers (p=.118). At both time points, e4 carriers in HE and HC exhibited significantly lower scores on memory tasks compared to non‐carriers (p=.020). HC non‐carriers saw a significant increase in associative learning scores, HC e4carriers and HE group (e4 carriers and non‐carriers) showed decreases in an associative learning task (p=.016).ConclusionHC e4 carriers are unresponsive to a MDI lifestyle intervention compared to non‐carriers after 4‐months. These findings could be due to ApoE essential role in circulation lipoprotein metabolism and key role in regulation of cholesterol impacting synaptic function maintenance; e4 allele carriers usually demonstrate higher dysfunction. Follow‐up analyses are required to substantiate current preliminary findings.

Automating the verbal paired associates test to assess memory remotely and at scale

AbstractBackgroundVerbal neuropsychological tests are sensitive to the early signs of neurodegeneration in older adults. However, their dependence on in‐person testing and manual scoring make them unsuitable for large‐scale screening and home‐based monitoring. To address this, we have developed a fully automated verbal paired associate learning (VPA) test. Here we describe the program of work to refine and validate this task, and ensure suitability of the test for remote, repeat administration.MethodsTwo phases of data collection were carried out. In the first, data was collected from 3,264 participants aged 17–86 years (M = 34.5, SD = 12.32) at home and on their own devices. The automated VPA task comprises eight word‐pairs, learned over three attempts. Automatic speech recognition (ASR) scores responses in real‐time, using the Neurovocalix platform. Following this phase, the task was refined to better enable repeat testing. This included producing a large corpus of algorithmically generated pairs, controlling for important linguistic features (e.g. frequency and concreteness), and adding brief familiarisation to the first visit to increase reliability and stability. We assessed: 1) the accuracy of automated scoring 2) the impact of participant characteristics and task design on performance and consistency 3) participant feedback.ResultsData from the first phase showed excellent correspondence between human and automated scoring of VPA, with a correlation .93 (p &lt; 0.001), and the expected sensitivity to ageing number of task performance. Participant demographics and technology choice did not impact correspondence between ASR scoring and manual scoring. In the second phase data collection, we compared VPA performance in participants with (N = 190) and without (N = 186) prior familiarisation. Familiarisation dramatically improved consistency of participant performance, eliminating the significant effect of task order on performance (F &gt; 100, p &lt; 0.001). Participants reported that they found the task engaging and easy to understand, and repeated testing over five sessions in older adults was well tolerated.ConclusionsTogether, these results demonstrate that remote, automated, voice‐based, cognitive assessments are feasible and acceptable. These methods may therefore be useful in the context of home‐based screening or monitoring in remote clinical trials, enabling longitudinal assessment of memory in AD.

Validity of a remote supervised preclinical Alzheimer’s disease cognitive composite (PACC) score in preclinical and prodromal Alzheimer’s disease.

AbstractBackgroundNeuropsychological tests administered to individuals in locations different from the assessor (i.e., remote assessment) can provide substantial reductions in patient burden, study cost and barriers to access. However, such tests must be optimized and validated for use in remote settings. The preclinical cognitive composite score (PACC) is derived from neuropsychological tests of episodic memory, complex attention, and general mental status. This study determined whether a set of neuropsychological tests of these domains, which can provide a PACC score, can be given in a remote supervised setting and remain sensitive to AD related cognitive impairment.MethodOlder adults classified as cognitively unimpaired (CU, n = 30), preclinical AD (n = 30) or prodromal AD (n = 25), with conventional PACC scores known, completed three computerized tests; the International Shopping list Test (ISLT), Continuous Paired Associate Learning Test (CPAL) and the International Digit Symbol Substitution Test, while supervised by a neuropsychologist in in‐clinic and remote settings. All individuals then completed the remote assessments two more times 7days (+/‐4 days) apartResultMain performance measure from each test on each assessment was standardized using the mean and SD of the CU group, assessed under supervision, at baseline. Standardized scores for each assessment were then averaged to yield a PACC score. There was no difference in rates of missing data or group mean score on individual test scores or PACC score, between in‐clinic and remote settings. Compared to the CU group, impairment in performance on the digital PACC in the prodromal AD was substantial (z = ‐1.56) but equivalent between in clinic (9z = 1.57) and remote (z = ‐1.56) settings. Performance on the digital PACC was slightly worse in the preclinical AD group (z = –0.42) but did not differ for settings. The reliability of the digital PACC score was very high (r = 0.87).ConclusionThe digital PACC derived from neuropsychological tests given in remote supervised contexts is acceptable, valid, reliable and sensitive to AD related cognitive impairment when given in‐clinic or remotely.