Measures Of Spatial Working Memory Research Articles

Aged HIV-1 Tg26 Transgenic Mice display Vascular Dysfunction with No Alterations in Neurocognitive Function or Cerebral Blood Flow

Although combination antiretroviral therapy (cART) has markedly reduced HIV mortality and increased life expectancy, people living with HIV (PLWH) develop premature cognitive and brain aging, classified as HIV-associated neurocognitive disorder (HAND). Vascular dysfunction and expression of HIV-derived proteins have independently been associated with cognitive impairment without causality being established. Thus, we investigated the role of HIV viral proteins in endothelial dysfunction and cognitive impairment in an aged mouse model of HIV. We used 18-month-old Tg26 mice and their wild-type littermate controls. Tg26 mice express 7 out of the 9 HIV viral proteins under the control of the long-term repeat promoter and have previously been shown to exhibit signs of cognitive impairment at eight months of age. Conduction of concentration-response curves to acetylcholine in mesenteric arteries using wire myography revealed impaired endothelium-dependent relaxation in Tg26 mice compared to WT mice. Measurements of brain perfusion with arterial spin labeling magnetic resonance imaging showed no differences in the whole brain and hippocampal cerebral blood flow. In addition, there were no changes in the hippocampus volume, which has been reported to be reduced with cognitive impairments. Two methods were employed to assess the cognitive abilities of the mice: Morris water maze (MWM) and the IntelliCage system. MWM requires human handling while the IntelliCage system is fully automated enabling the testing of mouse cognitive function during their active period and independently of human handling. Tg26 and WT mice underwent ten days of MWM testing and eight days of IntelliCage testing to assess spatial learning and memory. Tg26 mice showed no significant differences in latency to platform, distance swam to platform, or swim velocity when compared to their WT littermates. The IntelliCage results showed no differences in total visits, total visits with nose pokes, or total licks during the reversal learning period. Additionally, there were no significant differences in percent side error or place error indicating that cognitive function is not impaired in Tg26 mice. The Y-maze test further showed no differences in spontaneous alteration, a measure of spatial working memory. Altogether, our data shows that although 18-month-old female Tg26 mice develop endothelial dysfunction, they display no alterations in cerebral blood flow and no cognitive impairment indicating that systemic viral protein expression and vascular dysfunction might minimally contribute to neurocognitive impairment in HIV. R01HL130301 & R01HL155265 (E.J.B). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Sex-specific association between prenatal manganese exposure and working memory in school-aged children in Mexico city: An exploratory multi-media approach

It remains unclear whether manganese (Mn) exposure affects working memory (WM) in a sexually dimorphic manner. Further, no gold standard media exists to measure Mn, suggesting a combined blood and urinary Mn index may better capture the totality of exposure. We investigated the modification effect of child sex on the influence of prenatal Mn exposure on WM in school-age children, exploring two methodological frameworks to integrate exposure estimates across multiple exposure biomarkers. Leveraging the PROGRESS birth cohort in Mexico City, children (N = 559) ages 6–8 completed the between errors and strategy measures of the CANTAB Spatial Working Memory (SWM) task. Mn levels were assayed in blood and urine of mothers during the 2nd and 3rd trimesters and in umbilical cord blood from mothers and children at delivery. Weighted quantile sum regression estimated the association of a multi-media biomarker (MMB) mixture with SWM. We applied a confirmatory factor analysis to similarly quantify a latent blood Mn burden index. We then used an adjusted linear regression to estimate the Mn burden index with SWM measures. Interaction terms were used to estimate the modification effect by child sex for all models. Results showed that the between-errors-specific MMB mixture (i.e., this model demonstrates the impact of the MMB mixture on the between-error scores.) was associated (β = 6.50, 95% CI: 0.91, 12.08) with fewer between errors for boys and more between errors for girls. The strategy-specific MMB mixture (i.e., this model demonstrates the impact of the MMB mixture on the strategy scores) was associated (β = −1.36, 95% CI: 2.55, - 0.18) with less efficient strategy performance for boys and more efficient strategy performance for girls. A higher Mn burden index was associated (β = 0.86, 95% CI: 0.00, 1.72) with more between errors in the overall sample. The vulnerability to prenatal Mn biomarkers on SWM differs in the directionality by child sex. An MMB mixture and composite index of body burden are stronger predictors than a single biomarker for Mn exposure on WM performance.

No Effect of Calorie Restriction or Dietary Patterns on Spatial Working Memory During a 2-Year Intervention: A Secondary Analysis of the CALERIE Trial

BackgroundThe effect of calorie restriction (CR) on cognitive function is not well understood, and the impact of the dietary patterns consumed during CR has not been investigated. ObjectivesWe analyzed the combined association of CR and dietary quality with spatial working memory (SWM) in healthy adults without obesity. MethodsThe Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) trial was a 2-y, multisite clinical trial. This trial was registered at clinicaltrials.gov as NCT00427193. Participants were randomized to a 25% reduction in EI (n = 143) or an ad libitum Control (n = 76). The Dietary Inflammatory Index (DII) and the Healthy Eating Index (HEI) captured dietary quality, with a lower DII and higher HEI score indicating a healthier diet. The Cambridge Neuropsychological Test Automated Battery battery was used to assess SWM. Longitudinal associations between each dietary pattern index and SWM for CR and Control were assessed by multivariable negative binomial models that included baseline, 12-mo, and 24-mo visits. ResultsParticipants were aged 38.1 ± 7.2 y with a BMI of 25.1 ± 1.7 kg/m2. A total of 70% of the participants were female. Baseline mean DII and HEI scores were −0.15 (range: −3.77, 4.21) and 59.1 (24.1, 91.0) and did not differ between groups. Improvements in DII and HEI were significantly different between CR and Control over 2 y (both P-interaction = 0.001). In longitudinal analyses, there was no association of either index with SWM. Furthermore, though within-group improvements in SWM were observed at 12 mo, there was no statistically significant difference between CR (SWM errors: 9.0; 95% CI: 1.9, 41.6) and Control (11.7; 95% CI: 2.6, 53.5; P > 0.99), holding DII constant. Comparable results were observed at 24 mo and for the HEI. ConclusionsDietary quality during CR was not associated with measures of SWM over 2 y in healthy adults without obesity. These results suggest that, in healthy populations, dietary patterns and CR may have a limited impact on working memory. Further research is required to understand the concurrent effect of these nutritional strategies.

No Effect of Calorie Restriction or Dietary Patterns on Spatial Working Memory During a Two-Year Intervention: A Secondary Analysis of the CALERIE Trial

ObjectivesThe effect of calorie restriction (CR) on cognitive function is controversial, and the effects of consuming a healthy dietary pattern during CR have not been investigated. Furthermore, there is no consensus on what dietary pattern may be the most beneficial for cognition. We analyzed the combined effects of CR and self-selected diet on measures of spatial working memory (SWM) in healthy adults without obesity.MethodsPublicly available data from the CALERIE trial were analyzed. Participants were randomized to a 2-year CR intervention (n = 143) or an ad libitum Control (n = 76). Food records were collected at baseline, 12, and 24 months. The Dietary Inflammatory Index (DII) and the Healthy Eating Index (HEI-2015) were calculated to quantify different measures of dietary healthfulness, where a lower DII and a higher HEI-2015 indicate a healthier score. Cognitive function was assessed by the CANTAB battery, with fewer errors indicating better SWM. Changes in each index during the intervention were assessed by linear mixed models. Longitudinal associations between the indices and SWM were assessed by multivariable negative binomial models.ResultsOn average, participants were 38.1 ± 7.2 years old with a BMI of 25.1 ± 1.7 kg/m2. The average DII and HEI-2015 scores at baseline were −0.47 (range: −4.02, 3.19) and 59.1 (24.1, 91.0) and did not significantly differ between groups. Improvements in DII and HEI-2015 were significantly different between CR and Control over time (P interaction < 0.0001), with greater improvements in CR. In longitudinal analyses, there was no significant effect of improving the healthfulness of the DII or HEI-2015 on SWM. In addition, though there were significant within-group improvements in SWM at 12 months, there was no significant difference between the changes observed in CR (adjusted mean difference: 10.0; 95% CI: 2.2, 45.7) and Control (13.1; 95% CI: 2.9, 59.3; P = 0.93). Comparable results were observed at 24 months.ConclusionsNeither CR nor the healthfulness of the diet were associated with SWM, suggesting that that the potential for CR and dietary patterns to have beneficial effects on working memory may be limited in healthy populations. Further research is required to understand the role of diet in cognitive function in at-risk populations.Funding SourcesJean Mayer USDA HNRCA Doctoral Scholarship; USDA agreement #8050-51,000-105-01S.

Controlling for dogs' (Canis familiaris) use of nonmnemonic strategies in a spatial working memory task.

Short assessments of spatial working memory (SWM) in dogs are becoming popular evaluations of canine aging and individual differences. In a typical SWM task, an experimenter hides a reward inside of a bucket at a specific stimulus position while the dog watches. Then, following a varying delay interval, the dog is released to choose a bucket. The longest delay at which the dog can successfully choose the bucket containing the reward is considered to reflect the dog's SWM duration. Although past studies were informative, the tasks often lacked a valid measure of SWM due to dogs' ability to use nonmnemonic strategies, such as body orientation or sustained attention, to successfully solve these tasks without relying on working memory mechanisms. Therefore, we designed the first study to assess the internal validity of these tasks by directly comparing dogs' performance on two experimental conditions. We found that dogs performed worse in a control condition in which nonmnemonic strategies were eliminated compared with a typical SWM task condition. In addition, our results indicate a strong relationship between the percentage of delay time that a dog spends orienting its head or body to the correct bucket and performance in a typical SWM task. These findings were the first to show a difference in SWM performance when dogs' use of nonmnemonic strategies was controlled and stress the importance of considering the internal validity of these tasks if used to examine SWM in future work. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Brain hemodynamic response in Examiner\u2013Examinee dyads during spatial short-term memory task: an fNIRS study

The Corsi Block-Tapping test (CBT) is a measure of spatial working memory (WM) in clinical practice, requiring an examinee to reproduce sequences of cubes tapped by an examiner. CBT implies complementary behaviors in the examiners and the examinees, as they have to attend a precise turn taking. Previous studies demonstrated that the Prefrontal Cortex (PFC) is activated during CBT, but scarce evidence is available on the neural correlates of CBT in the real setting. We assessed PFC activity in dyads of examiner–examinee participants while completing the real version of CBT, during conditions of increasing and exceeding workload. This procedure allowed to investigate whether brain activity in the dyads is coordinated. Results in the examinees showed that PFC activity was higher when the workload approached or reached participants’ spatial WM span, and lower during workload conditions that were largely below or above their span. Interestingly, findings in the examiners paralleled the ones in the examinees, as examiners’ brain activity increased and decreased in a similar way as the examinees’ one. In the examiners, higher left-hemisphere activity was observed suggesting the likely activation of non-spatial WM processes. Data support a bell-shaped relationship between cognitive load and brain activity, and provide original insights on the cognitive processes activated in the examiner during CBT.

A-108 Differential Change in Eye Movement Performance Among Male Collegiate Athletes With Variable Exposure to Head Impacts

Abstract Objective The primary aim of this study was to evaluate the use of eye movement testing to detect change in cognitive and sensorimotor processing among male club collegiate athletes following a season of participation in collision sports of variable exposure. We predicted that collision sport athletes (COLL) exposed to subconcussive head trauma would demonstrate longer reaction times (latency) on saccadic eye movement tasks with executive demands (antisaccade and memory-guided saccade [MGS] tasks), greater antisaccade inhibitory errors, and poorer MGS accuracy, a measure of spatial working memory, from pre-season to post-season, whereas non-collision sport athletes (NON-COLL) would demonstrate stability overtime. We predicted that longitudinal change in eye movement performance would be greater than change observed on ImPACT (Immediate Post-Concussion Assessment and Cognitive Test). Method Collegiate club athletes with variable exposure to contact sports participation [COLL-High Dose, n = 8; COLL-Low Dose, n = 9; NON-COLL, n = 17] completed eye movement and ImPACT assessments pre-season and post-season. Results NON-COLL demonstrated shorter post-season versus pre-season antisaccade and MGS latencies, whereas COLL groups showed stable, longer, or more attenuated (relative to NON-COLL) shorter latencies (ps ≤ .001). NON-COLL demonstrated improved MGS spatial accuracy over the season, whereas COLL groups showed poorer or stable accuracy (ps &amp;lt; .05). No differential change was observed in pre-season to post-season ImPACT performance among groups. Conclusions This pilot study provides preliminary evidence for the use of eye movement testing as a sensitive marker of subtle changes in attentional control and working memory resulting from participation in collision sports.

Predictors of mathematics in primary school: Magnitude comparison, verbal and spatial working memory measures

We determined the relative importance of the so-called approximate number system (ANS), symbolic number comparison (SNC) and verbal and spatial short-term and working memory (WM) capacity for mathematics achievement in 1,254 Grade 2, 4 and 6 children. The large sample size assured high power and low false report probability and allowed us to determine effect sizes precisely. We used reading decoding as a control outcome measure to test whether findings were specific to mathematics. Bayesian analysis allowed us to provide support for both null and alternative hypotheses. We found very weak zero-order correlations between ANS measures and math achievement. These correlations were not specific to mathematics, became non-significant once intelligence was considered and ANS measures were not selected as predictors of math by regression models. In contrast, overall SNC accuracy and spatial WM measures were reliable and mostly specific predictors of math achievement. Verbal short-term and WM and SNC reaction time were predictors of both reading and math achievement. We conclude that ANS tasks are not suitable as measures of math development in school-age populations. In contrast, all other cognitive functions we studied are promising markers of mathematics development.

Visual-motor expertise in athletes: Insights from semiparametric modelling of 2317 athletes tested on the Nike SPARQ Sensory Station

ABSTRACTElite athletes not only run faster, hit harder, and jump higher, but also see and react better. However, the specific visual-motor skills that differentiate high-achieving athletes are still not well understood. In this paper we examine 2317 athletes (1871 male) tested on the Nike SPARQ Sensory Station, a digital test battery measuring visual, perceptual and motor skills relevant for sports performance. We develop a multivariate Gaussian transformation model to robustly estimate visual-motor differences by level, gender, and sport type. Results demonstrate that visual-motor performance is superior for athletes at higher levels, with males faster at near-far eye movements and females faster at eye-hand reaction times. Interestingly, athletes who play interceptive sports such as baseball and tennis exhibit better measures of visual clarity, contrast sensitivity and simple reaction time, while athletes from strategic sports like soccer and basketball have higher measures of spatial working memory. These findings provide quantitative evidence of domain-specific visual expertise in athletes.

Long-term Effects of Aripiprazole Treatment during Adolescence on Cognitive Function and Dopamine D2 Receptor Expression in Neurodevelopmentally Normal Rats.

ObjectiveThis study aimed to investigate the long-term effects of aripiprazole treatment during adolescence on behavior, cognitive function, and dopamine D2 receptor (D2R) expression in adult rats.MethodsAdolescent male Sprague-Dawley rats were injected intraperitoneally with aripiprazole, risperidone, or vehicle control for 3 weeks (postnatal day 36–56). After a 2-week washout period, locomotion, anxiety, and spatial working memory were evaluated in adulthood (postnatal day 71–84), using an open field test, elevated plus maze, and Y-maze, respectively. In addition, we assessed D2R levels in the dorsolateral and medial prefrontal cortex (PFC), dorsal and ventral striatum, and hippocampus using western blot analysis.ResultsSpontaneous alternation performance (SAP) in the Y-maze, a measure of spatial working memory, differed significantly among the 3 groups (F = 3.89, p = 0.033). A post-hoc test confirmed that SAP in the aripiprazole group was significantly higher than that in the risperidone group (post-hoc test p = 0.013). D2R levels in the medial PFC (F = 8.72, p = 0.001) and hippocampus (F = 13.54, p < 0.001) were different among the 3 groups. D2R levels in the medial PFC and hippocampus were significantly lower in the aripiprazole-treated rats than that in the risperidone-treated rats (post-hoc test p = 0.025 and p < 0.001, respectively) and controls (post-hoc test p < 0.001, all).ConclusionThis study showed that aripiprazole treatment in adolescence could influence cognitive function and dopaminergic neurotransmission into early adulthood.

High fat diet alters gut microbiota but not spatial working memory in early middle-aged Sprague Dawley rats.

As the global population ages, and rates of dementia rise, understanding lifestyle factors that play a role in the development and acceleration of cognitive decline is vital to creating therapies and recommendations to improve quality of later life. Obesity has been shown to increase risk for dementia. However, the specific mechanisms for obesity-induced cognitive decline remain unclear. One potential contributor to diet-induced cognitive changes is neuroinflammation. Furthermore, a source of diet-induced inflammation to potentially increase neuroinflammation is via gut dysbiosis. We hypothesized that a high fat diet would cause gut microbe dysbiosis, and subsequently: neuroinflammation and cognitive decline. Using 7-month old male Sprague Dawley rats, this study examined whether 8 weeks on a high fat diet could impact performance on the water radial arm maze, gut microbe diversity and abundance, and microgliosis. We found that a high fat diet altered gut microbe populations compared to a low fat, control diet. However, we did not observe any significant differences between dietary groups on maze performance (a measure of spatial working memory) or microgliosis. Our data reveal a significant change to the gut microbiome without subsequent effects to neuroinflammation (as measured by microglia characterization and counts in the cortex, hippocampus, and hypothalamus) or cognitive performance under the parameters of our study. However, future studies that explore duration of the diet, composition of the diet, age of animal model, and strain of animal model, must be explored.

The Y-Maze for Assessment of Spatial Working and Reference Memory in Mice.

The Y-maze can be used to assess short term memory in mice. Spontaneous alternation, a measure of spatial working memory, can be assessed by allowing mice to explore all three arms of the maze and is driven by an innate curiosity of rodents to explore previously unvisited areas. A mouse with intact working memory, and hence intact prefrontal cortical functions, will remember the arms previously visited and show a tendency to enter a less recently visited arm. Spatial reference memory, which is underlined by the hippocampus, can also be tested by placing the test mice into the Y-maze with one arm closed off during training. After an inter-trial interval of for example 1h, the mouse should remember which arm it has not explored previously and should visit this arm more often. This chapter describes the pre-test conditions, the materials required and the protocol for conducting and interpreting the results of these two related tests.

Spatial working memory is enhanced for movement experts in traditional and embodied tasks

ABSTRACTMovement experts tend to outperform non-experts on some tasks of spatial ability, suggesting that movement experts possess enhanced spatial-cognitive abilities, which may be developed over years of practice. In the current study, movement experts (dancers and athletes) and non-experts completed one verbal working memory task and two spatial working memory tasks—a traditional Corsi block-tapping task and a new full-bodied version of the Corsi task, nicknamed the “Twister Task.” Movement experts outperformed non-experts on both the Corsi and Twister tasks but not on the verbal task, suggesting that movement experience may relate to spatial working memory specifically. Additionally, the Twister task significantly correlated with the traditional Corsi task, providing validation for a new measure of spatial working memory.

Effects of Childhood Gymnastics Program on Spatial Working Memory.

A growing body of evidence has demonstrated the positive effects of physical exercise on cognition in children, and recent studies have specifically investigated the cognitive benefits of exercises involving cognitive-motor interactions, such as gymnastics. This study examined the effect of 8 wk of gymnastics training on behavioral and neurophysiological measures of spatial working memory in children. Forty-four children age 7 to 10 yr were recruited. The experimental group (n = 24; age, 8.7 ± 1.1 yr) was recruited from Yilan County in Taiwan, while the control group (n = 20; age, 8.6 ± 1.1 yr) resided in Taipei City. The experimental group undertook 8 wk of after-school gymnastics training (2 sessions per week, 90 min per session), whereas the control group received no intervention and were instructed to maintain their routine daily activities. Working memory was assessed by performance on a modified delayed match-to-sample test and by event-related potential including the P3 component. Data were collected before and after treatment for the experimental group and at the same time interval for the control group. Response accuracy improved after the experimental intervention regardless of working memory demands. Likewise, the P3 amplitude was larger at the parietal site after gymnastics training regardless of the task difficulty. Our results suggest that a short period of gymnastics training had a general facilitative effect on spatial working memory at both behavioral and neurophysiological levels in children. These finding highlight the potential importance of exercise programs involving cognitive-motor interactions in stimulating development of spatial cognition during childhood.

Cognitive abilities in first-degree relatives of individuals with bipolar disorder

BackgroundAlthough the study of cognition in first degree relatives (FDRs) is not new, findings in this group are still somewhat inconsistent and much of the research examining FDR populations include individuals under the age of 25, who are arguably still at significant risk to go on to develop BD. The present study aimed to establish the value of cognitive performance as a genuine endophenotypic marker of familial risk for bipolar disorder (BD), by examining cognition in FDRs aged 25 years or older. MethodsThe current study compared the cognitive performance of 27 unaffected FDRs to 47 healthy controls (HCs) and 28 BD patients using the MATRICS Consensus Cognitive Battery (MCCB). ResultsResults indicated that FDRs had impaired verbal learning performance, as well as selective impairments on a measure of speed of processing; and a measure of spatial working memory compared to HC. LimitationsLimitations relate to the potential insensitivity of some of the tests in the MCCB for detecting cognitive deficits that have been previously noted in BD and FDR samples using other batteries. ConclusionsFindings from this study implicate verbal learning, processing speed and working memory performance as promising candidate endophenotypes of familial risk for BD.

Neuron and neuroblast numbers and cytogenesis in the dentate gyrus of aged APPswe/PS1dE9 transgenic mice: Effect of long-term treatment with paroxetine

Altered neurogenesis may influence hippocampal functions such as learning and memory in Alzheimer's disease. Selective serotonin reuptake inhibitors enhance neurogenesis and have been reported to reduce cerebral amyloidosis in both humans and transgenic mice. We have used stereology to assess the longitudinal changes in the number of doublecortin-expressing neuroblasts and number of granular neurons in the dentate gyrus of APPswe/PS1dE9 transgenic mice. Furthermore, we investigated the effect of long-term paroxetine treatment on the number of neuroblasts and granular neurons, hippocampal amyloidosis, and spontaneous alternation behaviour, a measure of spatial working memory, in transgenic mice. We observed no difference in granular neurons between transgenic and wild type mice up till 18months of age, and no differences with age in wild type mice. The number of neuroblasts and the performance in the spontaneous alternation task was reduced in aged transgenic mice. Paroxetine treatment from 9 to 18months of age reduced hippocampal amyloidosis without affecting the number of neuroblasts or granular neurons. These findings suggest that the amyloidosis affects the differentiation of neuroblasts and spatial working memory, independent of changes in total granular neurons. Furthermore, while long-term paroxetine treatment may be able to reduce hippocampal amyloidosis, it appears to have no effect on total number of granular neurons or spatial working memory.

Age-dependent effects on social interaction of NMDA GluN2A receptor subtype-selective antagonism.

NMDA receptor-mediated neurotransmission is implicated in the regulation of normal sociability in mice. The heterotetrameric NMDA receptor is composed of two obligatory GluN1 and either two "modulatory" GluN2A or GluN2B receptor subunits. GluN2A and GluN2B-containing receptors differ in terms of their developmental expression, distribution between synaptic and extrasynaptic locations, and channel kinetic properties, among other differences. Because age-dependent differences in disruptive effects of GluN2A and GluN2B subtype-selective antagonists on sociability and locomotor activity have been reported in rats, the current investigation explored age-dependent effects of PEAQX, a GluN2A subtype-selective antagonist, on sociability, stereotypic behaviors emerging during social interaction, and spatial working memory in 4- and 8-week old male Swiss Webster mice. The data implicate an age-dependent contribution of GluN2A-containing NMDA receptors to the regulation of normal social interaction in mice. Specifically, at a dose of PEAQX devoid of any effect on locomotor activity and mouse rotarod performance, the social interaction of 8-week old mice was disrupted without any effect on the social salience of a stimulus mouse. Moreover, PEAQX attenuated stereotypic behavior emerging during social interaction in 4- and 8-week old mice. However, PEAQX had no effect on spontaneous alternations, a measure of spatial working memory, suggesting that neural circuits mediating sociability and spatial working memory may be discrete and dissociable from each other. Also, the data suggest that the regulation of stereotypic behaviors and sociability may occur independently of each other. Because expression of GluN2A-containing NMDA receptors occurs at a later developmental stage, they may be more involved in mediating the pathogenesis of ASDs in patients with histories of "regression" after a period of normal development than GluN2B receptors.

Altered white matter integrity in whole brain and segments of corpus callosum, in young social drinkers with binge drinking pattern.

Binge drinking is associated with impaired cognitive functioning, but the relationship of cognitive impairments and white matter integrity is less known. We used diffusion tensor imaging (DTI) to investigate the relationships of binge drinking, whole brain white matter integrity and cognitive performance during young adulthood (18 to 25 years), a period of continued brain development in two sessions 1 year apart. Binge drinkers (n = 20) and non-binge drinkers (n = 20) underwent DTI and completed measures of spatial working memory and motor impulsivity. Fractional anisotropy (FA), a measure derived from DTI, was estimated from whole brain and from five segments of the corpus callosum (CC): prefrontal, premotor/supplementary motor, motor, (SMA) sensory and parietal/temporal/occipital (PTO). FA was lower for binge than for non-binge men but not women at Session 1 and 2 for all measurements except for FA in the motor segment, which was significantly increased from Session 1 to Session 2. Lower FA in the prefrontal and PTO CC segments was associated with higher binge score, whereas lower FA in all five segments was associated with greater drug use in men and worse spatial working memory both in men and women. These findings extend the literature by showing that in early adulthood, binge drinking and drug use are linked with degradations in neural white matter and that compromised white matter at this period of brain development is linked with impaired cognitive functioning.

Test–retest reliability analysis of the Cambridge Neuropsychological Automated Tests for the assessment of dementia in older people living in retirement homes

ABSTRACTThe validity of the Cambridge Neuropsychological Automated Tests has been widely studied, but their reliability has not. This study aimed to estimate the test–retest reliability of these tests in a sample of 34 older adults, aged 69 to 90 years old, without neuropsychiatric diagnoses and living in retirement homes in the district of Lisbon, Portugal. The battery was administered twice, with a 4-week interval between sessions. The Paired Associates Learning (PAL), Spatial Working Memory (SWM), Rapid Visual Information Processing, and Reaction Time tests revealed measures with high-to-adequate test–retest correlations (.71–.89), although several PAL and SWM measures showed susceptibility to practice effects. Two estimated standardized regression-based methods were found to be more efficient at correcting for practice effects than a method of fixed correction. We also found weak test–retest correlations (.56–.68) for several measures. These results suggest that some, but not all, measures are suitable for cognitive assessment and monitoring in this population.

Evidence of A Pharmacological Dissociation Between The Robust Effects of Methylphenidate on Adhd Symptoms and Weaker Effects on Working Memory

Working memory (WM) deficits often co-occur with, but do not define, attention deficit hyperactivity disorder (ADHD). Preclinical and neuroimaging studies show that ADHD and WM deficits are dissociated at the level of individual dopamine receptor function. We hypothesized that there would also be a pharmacological dissociation of the effects of stimulants on ADHD and WM. ADHD subjects were derived from three prospective clinical trials involving treatment with OROS methylphenidate for at least 6 weeks. Subjects were adolescents and adults with DSM-IV ADHD with systematic assessments of WM and ADHD symptoms. Cohen’s d was used to evaluate effect size between baseline and week 6 for all assessments, and Pearson correlations were used to evaluate the relationship between assessments at baseline and between change scores for assessments from baseline to week 6. Cohen's d estimates for the Cambridge Neuropsychological Test Automated Battery spatial working memory measures differed significantly by 1.8 standard deviations (t= -10.8, df= 70, p < 0.001) and 1.9 standard deviations (t= -11.1, df= 70, p < 0.001) for the strategy and total between errors subcategories respectively. Confidence intervals did not overlap with those of the Adult ADHD Investigator Symptom Rating Scale (AISRS). A similar effect was observed for changes in AISRS and the Behavior Rating Inventory of Executive Function working memory scale where the Cohen's d estimates differed significantly by 1.1 standard