Variance In Cognitive Performance Research Articles

Moderating effect of cognitive reserve on brain integrity and cognitive performance.

Dementia syndrome is one of the most devastating conditions in older adults. As treatments to stop neurodegeneration become available, accurate and timely diagnosis will increase in importance. One issue is that cognitive performance sometimes does not match the corresponding level of neuropathology, affecting diagnostic accuracy. Cognitive reserve (CR), which can preserve cognitive function despite underlying neuropathology, explains at least some variability in cognitive performance. We examined the influence of CR proxies (education and occupational position) on the relationship between hippocampal or total gray matter volume and cognition. We used data from the Czech Brain Aging Study. Participants were clinically confirmed to be without dementia (n = 457, including subjective cognitive decline and amnestic mild cognitive impairment) or with dementia syndrome (n = 113). For participants without dementia, higher education magnified the associations between (a) hippocampal volume and executive control (b = 0.09, p = 0.033), (b) total gray matter volume and language (b = 0.12, p < 0.001), and (c) total gray matter volume and memory (b = 0.08, p = 0.018). Similarly, higher occupational position magnified the association between total gray matter volume and (a) attention/working memory (b = 0.09, p = 0.009), (b) language (b = 0.13, p = 0.002), and (c) memory (b = 0.10, p = 0.013). For participants with dementia, the associations between hippocampal (b = -0.26, p = 0.024) and total gray matter (b = -0.28, p = 0.024) volume and visuospatial skills decreased in magnitude with higher education. We found that the association between brain volume and cognitive performance varies based on CR, with greater CR related to a stronger link between brain volume and cognition before, and a weaker link after, dementia diagnosis.

PMON279 Variability in Cognitive Performance by Sexual Orientation among US Older Adults: Findings from the National Health and Nutrition Examination Survey (NHANES) 2011-2012 and 2013-2014

Abstract Aim Previous evidence suggests that some fields of cognitive function are man dominated while others are woman dominated. Recent research has additionally associated sexual orientation with cognitive function. However, data on the effect of sexual orientation on various cognitive subdomains are limited. We aim to explore the variability in a range of cognitive subdomains (working memory, language, attention, processing speed, and executive functioning) by cis-gender hetero versus homo sexual orientation. Methods We combined NHANES 2011–2012 and NHANES 2013–2014 datasets to study the individuals (60-69 years old) with both sexual health and cognitive assessment data. We analyzed the data to assess the performance of heterosexual and homosexual men and women on various cognitive function assessments. We used 1) word learning and recall modules from the Consortium to Establish a Registry for Alzheimer's disease (CERAD) to examine new verbal learning, immediate and delayed memory; 2) the Animal Fluency test (AFT) to evaluate verbal sematic fluency and 3) the Digital Symbol Substitution test (DSST) to assess attention and processing speed. Mentally impaired individuals or participants who were unable to understand or read English, Spanish, Korean, Vietnamese, traditional or simplified Mandarin, or Cantonese were not asked questions regarding sexual orientation and hence, were excluded from final analysis. Simple Linear regression models were used to quantify the association of sexual orientation and cognitive function. Statistical significant was specified at P &amp;lt; 0.05. Results Our study population consists of 61 homosexual adults (39 men and 22 women) and 3087 heterosexual adults (1486 men and 1601 women). Comparison of heterosexual men and women demonstrated differences typically found between the genders, with heterosexual women performing significantly better on all cognitive function assessments. Homosexual men scored significantly higher than heterosexual men on all cognitive function assessments and performed in the direction of heterosexual women in all cognitive domains. In fact, mean scores for homosexual men were even higher than for heterosexual women in the four of the six cognitive domains tested (CERAD 2 and delayed recall, AFT and DSST). Homosexual women did not differ from heterosexual women and homosexual men on any of the measures of cognitive performance. Therefore, as expected, homosexual women scored higher points than heterosexual men on most cognitive assessments (CERAD 1,3 and delayed recall, and DSST). Conclusion Homosexual men were gender-atypical and performed in the direction of heterosexual women in cognitive domains related to working memory, language, attention, processing speed, and executive functioning. Homosexual women were sex-typical with cognitive skills similar to heterosexual women. These findings underscore the need for further studies to understand the association of sexual orientation with cognitive functioning. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

High Dose of Acute Normobaric Hypoxia Does Not Adversely Affect Sprint Interval Training, Cognitive Performance and Heart Rate Variability in Males and Females.

Simple SummarySprint interval training (SIT) is a feasible and time-efficient alternative to classical endurance training that has gained popularity among athletes because of its ability to elicit physiological and cardiorespiratory adaptations in a shorter amount of time than traditional endurance training. Further, popular altitude/hypoxic training techniques include intermittent hypoxic training, in which athletes exercise at submaximal levels under simulated hypoxia while living at sea level (normoxia). Hypoxic exercise is likely a more potent stimulant to upregulate muscle factors (e.g., mitochondrial biogenesis, oxidative, and glycolytic enzymes) than similar normoxic exercise. However, SIT in hypoxia may disturb acute performance indices during sprint intervals. Hypoxia may also impair cognitive function. Acute hypoxia may decrease cognitive performance in areas such as memory and executive functioning. Moreover, males and females may have distinct athletic performance responses to SIT and hypoxia. However, to date, there is no study that has investigated the effects of different doses of acute normobaric hypoxia on SIT and cognitive performance, nor has there been research investigating potential sex-based differences.Although preliminary studies suggested sex-related differences in physiological responses to hypoxia, the effects of sex on sprint interval training (SIT) performance in different degrees of hypoxia are largely lacking. The aim of this study was to examine the acute effect of different doses of normobaric hypoxia on SIT performance as well as heart rate variability (HRV) and cognitive performance (CP) in amateur-trained team sport players by comparing potential sex differences. In a randomized, double-blind, crossover design, 26 (13 females) amateur team-sport (football, basketball, handball, rugby) players completed acute SIT (6 × 15 s all-out sprints, separated with 2 min active recovery, against a load equivalent to 9% of body weight) on a cycle ergometer, in one of four conditions: (I) normoxia without a mask (FiO2: 20.9%) (CON); (II) normoxia with a mask (FiO2: 20.9%) (NOR); (III) moderate hypoxia (FiO2: 15.4%) with mask (MHYP); and (IV) high hypoxia (FiO2: 13.4%) with mask (HHYP). Peak (PPO) and mean power output (MPO), HRV, heart rate (HR), CP, capillary lactate (BLa), and ratings of perceived exertion (RPE) pre- and post-SIT were compared between CON, NOR, MHYP and HHYP. There were no significant differences found between trials for PPO (p = 0.55), MPO (p = 0.44), RPE (p = 0.39), HR (p = 0.49), HRV (p > 0.05) and CP (response accuracy: p = 0.92; reaction time: p = 0.24). The changes in MP, PP, RPE, HR, CP and HRV were similar between men and women (all p > 0.05). While BLa was similar (p = 0.10) between MHYP and HHYP trials, it was greater compared to CON (p = 0.01) and NOR (p = 0.01), without a sex-effect. In conclusion, compared to normoxia, hypoxia, and wearing a mask, have no effect on SIT acute responses (other than lactate), including PP, MP, RPE, CP, HR, and cardiac autonomic modulation either in men or women.

Functional Outcomes, Injury Variables, and Athlete Characteristics Associated with Post-Concussion Sleep Disturbance.

To examine the relationship between sleep disturbance and functional outcomes following a concussion. Also, to explore athlete and injury-related variables that may be related to risk factors for poor sleep following concussion. 124 collegiate athletes completed a neuropsychological evaluation within 14days of sustaining a sport-related concussion (SRC). Athletes were categorized as sleep disturbed (n= 52) or not sleep disturbed (n= 72). Outcome variables included symptom reports, cognitive performance (mean performance and variability), and mood (depression). Injury characteristics and athlete characteristics explored were loss of consciousness (LOC) associated with the injury, whether the athlete was immediately removed from play, and history of prior concussions. Sleep disturbed athletes reported more symptoms, F(4, 119) = 7.82, p< 0.001, ƞ2= 0.21, were more likely to be symptomatic at the time of testing, χ2(1, N= 124) = 19.79, p< 0.001, φ= 0.40, and were marginally more likely to experience clinically significant depression, χ2(1, N= 120) = 3.03, p= 0.08, φ= 0.16, than not sleep disturbed athletes. There were no cognitive differences between the groups, p> 0.05. A greater proportion of sleep disturbed athletes experienced LOC (30%) compared to not sleep disturbed athletes (13%), χ2(1, N= 118) = 4.99, p= 0.03, φ= -0.21. Sleep disturbances following SRC are associated with a broad range of self-reported symptoms. LOC may be associated with an increased risk of developing sleep disturbances; alternatively, sleep disturbances may increase the risk of LOC following concussion.

Association between Long-Term Air Pollution, Chronic Traffic Noise, and Resting-State Functional Connectivity in the 1000BRAINS Study.

Background:Older adults show a high variability in cognitive performance that cannot be explained by aging alone. Although research has linked air pollution and noise to cognitive impairment and structural brain alterations, the potential impact of air pollution and noise on functional brain organization is unknown.Objective:This study examined the associations between long-term air pollution and traffic noise with measures of functional brain organization in older adults. We hypothesize that exposures to high air pollution and noise levels are associated with age-like changes in functional brain organization, shown by less segregated brain networks.Methods:Data from 574 participants (44.1% female, 56–85 years of age) in the German 1000BRAINS study (2011–2015) were analyzed. Exposure to particulate matter (, , and absorbance), accumulation mode particle number (), and nitrogen dioxide () was estimated applying land-use regression and chemistry transport models. Noise exposures were assessed as weighted 24-h () and nighttime () means. Functional brain organization of seven established brain networks (visual, sensorimotor, dorsal and ventral attention, limbic, frontoparietal and default network) was assessed using resting-state functional brain imaging data. To assess functional brain organization, we determined the degree of segregation between networks by comparing the strength of functional connections within and between networks. We estimated associations between air pollution and noise exposure with network segregation, applying multiple linear regression models adjusted for age, sex, socioeconomic status, and lifestyle variables.Results:Overall, small associations of high exposures with lesser segregated networks were visible. For the sensorimotor networks, we observed small associations between high air pollution and noise and lower network segregation, which had a similar effect size as a 1-y increase in age [e.g., in sensorimotor network, (95% CI: , 0.009) per 0.3 increase in absorbance and (95% CI: , ) per 1-y age increase].Conclusion:High exposure to air pollution and noise was associated with less segregated functional brain networks. https://doi.org/10.1289/EHP9737

Alta capacidad intelectual desde la neuroimagen y la pedagogía diferencial. ¿Hablamos de lo mismo?

Advances in neuroimaging techniques have significantly enhanced our ability to study differences in cognitive efficiency in children and adolescents. However, these studies have traditionally used intelligence quotient (IQ) as the sole measure of cognitive ability. Talent development experts are increasingly drawing attention to the major limitations of exclusively using this measure to identify the variables associated with giftedness, in terms of the validity of the construct they intend to measure and in respect of the measurement’s reliability and stability. The aim of this study is to analyse whether the construct of intelligence on which recent neuroimaging studies are based, the type of instrument used to quantify giftedness and the corresponding neurobiological results are consistent with the advances made by differential pedagogy in respect of the multidimensional construct of intelligence. To this end, a systematic review both of neuroimaging research that seeks to explain the neural correlates of giftedness in children and adolescents, on the one hand, and of research focussing more prominently on the field of giftedness development, on the other, has been carried out. The findings suggest that brain networks and dynamics associated with creativity and motivation may have a bearing on cognitive performance variability. However, as the majority of neuroimaging studies continue to use IQ as the sole measure of intellectual ability, most of the data produced by these studies cannot be generalised for the purpose of determining what differential pedagogy experts refer to as “giftedness”.

Cognitive Reserve and Cognitive Functioning among Oldest Old Adults: Findings from the Georgia Centenarian Study

ABSTRACT Objectives Living a long life does not guarantee the maintenance of optimal cognitive functioning; however, similar to older adults in general, cognitive reserve may also protect oldest-old adults from cognitive decline. The purpose of this study was to assess cognitive reserve among centenarians and octogenarians and to evaluate a process model of cognitive reserve. Methods A total of 321 centenarians and octogenarians from the Georgia Centenarian Study were included in this study. Cognitive reserve components included level of education, occupational responsibility, current social engagement, past engaged lifestyle, and activity. Cognitive functioning was measured with the Mini-Mental Status Examination. Results Structural equation modeling was computed, and the overall model fit well, χ2 (df = 3) = 5.02, p = .17; CFI = .99, RMSEA = .05. Education is directly and indirectly related to cognitive functioning through occupational responsibility and past engaged lifestyle. Current social engagement is related to cognitive functioning directly and indirectly through current activities. The four direct predictors (i.e., education, current social engagement, current activity, and past engaged lifestyle) explained 35% of the variance in cognitive functioning. Conclusion The results provide important information for cognitive reserve theories with implications for interventions that build cognitive reserve.

A-172 Evaluating Associations Between the Five Negative Symptom Domains and Cognition in Schizophrenia

Abstract Objective: Recently, factor analysis has supported a five-factor model of negative symptoms in schizophrenia (anhedonia, avolition, alogia, asociality, and blunted affect). Associations between these unique negative symptom domains and neurocognition are yet to be examined. The following study investigates relationships between the five distinct negative symptoms and cognitive functioning. Methods: Outpatients diagnosed with schizophrenia (n=245) were assessed during periods of clinical stability for negative symptom severity using the Brief Negative Symptom Scale (BNSS). The MATRICS Consensus Cognitive Battery (MCCB) was used to assess seven domains of neurocognition, including processing speed, working memory, verbal learning, visual learning, reasoning, problem solving, and social cognition. To evaluate external correlates, the five-domain negative symptoms were correlated with measures of neurocognition. Results: Greater negative associations were found between the five negative symptom domains with processing speed, attention, working memory, social cognition, and overall MCCB scores. Correlational analyses demonstrated the strongest negative relationships between the domain of attention with alogia and blunted affect. Conclusions: The present study examined unique associations between cognitive abilities and the five negative symptom domains. Strong negative associations were found between negative symptoms and distinct measures of neurocognition, indicating a unique variance in cognitive performance correlates with severity of negative symptoms. Results suggest greater severity of negative symptoms is associated with greater impairments in select neurocognitive domains. Further research using analytic approaches would offer additional support for this hypothesis. Findings have implications for developing differential treatments targeting the five negative symptom domains separately, as they may have distinct underlying pathophysiological and neurocognitive mechanisms.

Ultrarare Coding Variants and Cognitive Function in Schizophrenia

Impaired cognitive function in schizophrenia is associated with poor functional outcomes, but the role of rare coding variants is unclear. To determine whether ultrarare constrained variants (URCVs) are associated with cognition in patients with schizophrenia. Linear regression was used to perform a within-case genetic association study of URCVs and current cognition and premorbid cognitive ability. A multivariable linear regression analysis of the outcomes associated with URCVs, schizophrenia polygenic risk score, polygenic risk score for intelligence and schizophrenia associated copy number variants on cognitive ability was performed. Exome sequencing data from 802 participants with schizophrenia were assessed for current cognition using the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery and for estimated premorbid IQ using the National Adult Reading Test. Individuals were recruited from clinical and voluntary mental health services in the UK. Those with a diagnosis of intellectual disability or a neurological disorder known to affect cognition were excluded. Data collection occurred between 2007 and 2015. Data were analyzed between April 2020 and March 2022. Association between URCVs, current cognition, and current cognition adjusted for premorbid IQ. Of the 802 participants, 499 (62%) were men and 303 (38%) were women; mean (SD) age at interview was 43.36 (11.87) years. Ultrarare constrained variants (n = 400) were associated with lower current cognition scores (β = -0.18; SE = 0.07; P = .005). In the univariable analysis, premorbid IQ was associated with URCVs (β = -0.12; SE = 0.05; P = .02) and partly attenuated the association with current cognition (β = -0.09; SE = 0.05; P = .08). Multivariable analysis showed that measured genetic factors combined accounted for 6.2% of variance in current cognition, 10.3% of variance in premorbid IQ, and supported outcomes of URCVs associated with current cognition independent of premorbid IQ (β = -0.10; SE = 0.05; P = .03). The findings of this study suggest that URCVs contribute to variance in cognitive function in schizophrenia, with partly independent associations before and after onset of the disorder. Although the estimated effect sizes were small, future studies may show that the effect sizes will be greater with better annotation of pathogenic variants. Genomic data may contribute to identifying those at particularly high risk of cognitive impairment in whom early remedial or preventive measures can be implemented.

Compensatory thalamocortical functional hyperconnectivity in type 2 Diabetes Mellitus.

Type 2 diabetes mellitus (T2DM) is associated with brain damage and cognitive decline. Despite the fact that the thalamus involves aspects of cognition and is typically affected in T2DM, existing knowledge of subregion-level thalamic damage and its associations with cognitive performance in T2DM patients is limited. The thalamus was subdivided into 8 subregions in each hemisphere. Resting-state functional and structural MRI data were collected to calculate resting-state functional connectivity (rsFC) and gray matter volume (GMV) of each thalamic subregion in 62 T2DM patients and 50 healthy controls. Compared with controls, T2DM patients showed increased rsFC of the medial pre-frontal thalamus, posterior parietal thalamus, and occipital thalamus with multiple cortical regions. Moreover, these thalamic functional hyperconnectivity were associated with better cognitive performance and lower glucose variability in T2DM patients. However, there were no group differences in GMV for any thalamic subregions. These findings suggest a possible neural compensation mechanism whereby selective thalamocortical functional hyperconnectivity facilitated by better glycemic control help to preserve cognitive ability in T2DM patients, which may ultimately inform intervention and prevention of T2DM-related cognitive decline in real-world clinical settings.

Linking Brain Age Gap to Mental and Physical Health in the Berlin Aging Study II.

From a biological perspective, humans differ in the speed they age, and this may manifest in both mental and physical health disparities. The discrepancy between an individual’s biological and chronological age of the brain (“brain age gap”) can be assessed by applying machine learning techniques to Magnetic Resonance Imaging (MRI) data. Here, we examined the links between brain age gap and a broad range of cognitive, affective, socioeconomic, lifestyle, and physical health variables in up to 335 adults of the Berlin Aging Study II. Brain age gap was assessed using a validated prediction model that we previously trained on MRI scans of 32,634 UK Biobank individuals. Our statistical analyses revealed overall stronger evidence for a link between higher brain age gap and less favorable health characteristics than expected under the null hypothesis of no effect, with 80% of the tested associations showing hypothesis-consistent effect directions and 23% reaching nominal significance. The most compelling support was observed for a cluster covering both cognitive performance variables (episodic memory, working memory, fluid intelligence, digit symbol substitution test) and socioeconomic variables (years of education and household income). Furthermore, we observed higher brain age gap to be associated with heavy episodic drinking, higher blood pressure, and higher blood glucose. In sum, our results point toward multifaceted links between brain age gap and human health. Understanding differences in biological brain aging may therefore have broad implications for future informed interventions to preserve mental and physical health in old age.

Attention impairment in motor functional neurological disorders: a neuropsychological study

Our objective was to assess cognitive functioning across multiple cognitive domains using a standardised neuropsychological battery in patients with motor functional neurological disorders (mFND). Thirty patients with clinically established mFND and 30 age-, sex- and education-matched control subjects underwent a thorough neuropsychological assessment evaluating (1) attention including processing speed, (2) executive functions including working memory, (3) short-term memory, (4) speech and language and (5) visuospatial functions. Performance validity tests (PVT) and self-report measures of depression, anxiety and cognitive complaints were included in the assessment. Only patients with valid test performance were included in the analysis. Three patients scored below the cut-off scores in PVT. Patients performed significantly worse than controls in the following areas: (1) the attention domain which included a slow processing speed (p = 0.005, Cohen's d = 0.89), (2) executive functions (p = 0.01, Cohen's d = 0.88) and (3) speech and language domains (p = 0.025, Cohen's d = 0.77). Patients with mFND showed greater intra-individual variability in cognitive performance (p = 0.005, Cohen's d = 0.94). Cognitive impairments were independent of depressive symptoms, which were higher in mFND patients. This study revealed both subjective and objective cognitive impairment in patients with mFND. The neuropsychological profile in mFND was characterised primarily by attentional impairment including a slow processing speed and a high intra-individual variability in cognitive performance. Cognitive impairment was associated with a valid test performance, highlighting that the deficits observed were not likely to be explained by a lack of effort in the patient group. Attention is considered to play a key role in mFND pathophysiology, and the results suggest that such impairments are objectively measurable.

Exploration and spatial cognition show long-term repeatability but no heritability in the Aegean wall lizard

Recently, biologists have become increasingly interested in cognitive variation among individuals and how it relates to differences in fitness. However, very few studies so far have studied the long-term repeatability and heritability of cognitive performance in wild animals. This is nevertheless crucial information to fully understand the potential ecological and evolutionary impact of individual variation in cognitive performance. In 2019, we assessed exploration, problem solving and spatial and reversal learning in 66 Aegean wall lizards, Podarcis erhardii , then released them in seminatural enclosures consisting of either simple or complex habitat. One year later, we recaptured and retested the surviving lizards and their offspring to estimate the long-term repeatability and heritability of these behavioural and cognitive characteristics. We found that exploration and spatial learning were moderately repeatable, but reversal learning only marginally and learning flexibility and problem solving not at all. Reversal learning ability declined over time in lizards kept in simple habitat, but not in those kept in complex habitats – suggesting habitat-dependent cognitive plasticity. To our knowledge, this is the first study demonstrating (long-term) consistency in cognitive traits within a nonavian reptile. The combination of modest repeatability and low heritability does suggest that, within our study species, personality and cognitive variation among individuals and populations is mostly moulded by environmental effects. • We tested repeatability and heritability of exploration and cognition in lizards. • Only exploration and spatial learning were moderately repeatable between years. • Reversal learning was marginally repeatable. • Lizards showed habitat-dependent changes in their reversal learning abilities. • Heritability estimates were low and nonsignificant.

Unique prediction of developmental psychopathology from genetic and familial risk.

Early detection is critical for easing the rising burden of psychiatric disorders. However, the specificity of psychopathological measurements and genetic predictors is unclear among youth. We measured associations between genetic risk for psychopathology (polygenic risk scores (PRS) and family history (FH) measures) and a wide range of behavioral measures in a large sample (n = 5,204) of early adolescent participants (9-11 years) from the Adolescent Brain and Cognitive Development StudySM . Associations were measured both with and without accounting for shared variance across measures of genetic risk. When controlling for genetic risk for other psychiatric disorders, polygenic risk for problematic opioid use (POU) is uniquely associated with lower behavioral inhibition. Attention deficit hyperactivity disorder (ADHD), depression (DEP), and attempted suicide (SUIC) PRS shared many significant associations with externalizing, internalizing, and psychosis-related behaviors. However, when accounting for all measures of genetic and familial risk, these PRS also showed clear, unique patterns of association. Polygenic risk for ASD, BIP, and SCZ, and attempted suicide uniquely predicted variability in cognitive performance. FH accounted for unique variability in behavior above and beyond PRS and vice versa, with FH measures explaining a greater proportion of unique variability compared to the PRS. Our results indicate that, among youth, many behaviors show shared genetic influences; however, there is also specificity in the profile of emerging psychopathologies for individuals with high genetic risk for particular disorders. This may be useful for quantifying early, differential risk for psychopathology in development.

Rich-Club Analysis of Structural Brain Network Alterations in HIV Positive Patients With Fully Suppressed Plasma Viral Loads

ObjectiveEven with successful combination antiretroviral therapy (cART), patients with human immunodeficiency virus positive (HIV+) continue to present structural alterations and neuropsychological impairments. The purpose of this study is to investigate structural brain connectivity alterations and identify the hub regions in HIV+ patients with fully suppressed plasma viral loads.MethodsIn this study, we compared the brain structural connectivity in 48 patients with HIV+ treated with a combination of antiretroviral therapy and 48 healthy controls, using diffusion tensor imaging. Further comparisons were made in 24 patients with asymptomatic neurocognitive impairment (ANI) and 24 individuals with non-HIV-associated neurocognitive disorders forming a subset of HIV+ patients. The graph theory model was used to establish the topological metrics. Rich-club analysis was used to identify hub nodes across groups and abnormal rich-club connections. Correlations of connectivity metrics with cognitive performance and clinical variables were investigated as well.ResultsAt the regional level, HIV+ patients demonstrated lower degree centrality (DC), betweenness centrality (BC), and nodal efficiency (NE) at the occipital lobe and the limbic cortex; and increased BC and nodal cluster coefficient (NCC) in the occipital lobe, the frontal lobe, the insula, and the thalamus. The ANI group demonstrated a significant reduction in the DC, NCC, and NE in widespread brain regions encompassing the occipital lobe, the frontal lobe, the temporal pole, and the limbic system. These results did not survive the Bonferroni correction. HIV+ patients and the ANI group had similar hub nodes that were mainly located in the occipital lobe and subcortical regions. The abnormal connections were mainly located in the occipital lobe in the HIV+ group and in the parietal lobe in the ANI group. The BC in the calcarine fissure was positively correlated with complex motor skills. The disease course was negatively correlated with NE in the middle occipital gyrus.ConclusionThe results suggest that the occipital lobe and the subcortical regions may be important in structural connectivity alterations and cognitive impairment. Rich-club analysis may contribute to our understanding of the neuropathology of HIV-associated neurocognitive disorders.

Cognitive, Sleep, and Autonomic Responses to Induction of a Ketogenic Diet in Military Personnel: A Pilot Study

BACKGROUND: This pilot study examined the effect of a 2-wk ketogenic diet (KD) compared with a carbohydrate (CHO) diet in military personnel on cognitive performance, mood, sleep, and heart rate variability (HRV).METHODS: A randomized-controlled, cross-over trial was conducted with eight male military personnel (age, 36 ± 7 yr; body mass, 83.7 ± 9.2 kg; BMI, 26.0 ± 2.3 kg · m-2). Subjects ingested their habitual diet for 7 d (baseline), then an iso-energetic KD (∼25 g CHO/d) or CHO diet (∼285 g CHO/d) for 14 d (adaptation), separated by a 12-d washout. HRV, fasting capillary blood D-βHB, and glucose concentration, mood, and sleep were measured daily. Cognitive performance was measured on the 7th day of baseline and the 7th and 14th days of adaptation. Data were analyzed using a series of linear mixed models.RESULTS: Mean weekly D-βHB was higher (95% CI, +0.34 to +2.38 mmol · L-1) and glucose was lower (-0.45 to -0.21 mmol · L-1) in the KD compared with the CHO diet. Cognitive performance (Psychomotor Vigilance Task, 2-choice reaction time, and running memory continuous performance test) and mean weekly fatigue, vigor, and sleep (sleep duration, sleep efficiency, and sleep onset latency) were similar between diets. A diet × week interaction for HRV approached significance, with exploratory analyses suggesting HRV was lower compared with baseline during week-2 adapt (-27 to +4 ms) in the KD.DISCUSSION: A 2-wk KD induction in military personnel does not appear to affect cognitive performance, mood, or sleep, but may lower HRV, indicating increased physiological stress.Shaw DM, Henderson L, van den Berg M. Cognitive, sleep, and autonomic responses to induction of a ketogenic diet in military personnel: a pilot study. Aerosp Med Hum Perform. 2022; 93(6):507-516.

The Matrix Matters: Beverage Carbonation Impacts the Timing of Caffeine Effects on Sustained Attention.

Both caffeine and the perception of refreshment delivered by cooling, tingling, and mouth-watering flavors have individually been shown to positively impact cognitive performance and mood, though presently there is limited evidence on their possible combined effects. This study explored the contribution of refreshing compounds in beverages, namely, carbon dioxide and citric acid, on the acute effects of caffeine on sustained attention and self-rated physical and mental energy. A randomized, controlled crossover trial was conducted by testing three products: a carbonated caffeinated beverage; a comparator caffeinated beverage; and a flavor-matched control beverage. Findings from 24 healthy adults revealed product-dependent variations in cognitive performance during a 60-min visual sustained-attention task, suggesting that the carbonated-caffeinated beverage led to faster, greater and more consistent levels of accuracy, compared to the control beverage. Specifically, significant differences were found between: (1) the carbonated-caffeinated beverage and the caffeinated beverage, and (2) between the caffeinated beverage and the control beverage for number of hits, reaction time and false alarm scores. Both caffeinated beverages led to higher physical and mental energy, and lower physical and mental fatigue 60-min post-consumption. These findings suggest beneficial effects on sustained attention through the combination of caffeine with refreshing compounds.

Combining MRI and cognitive evaluation to classify concussion in university athletes.

Current methods of concussion assessment lack the objectivity and reliability to detect neurological injury. This multi-site study uses combinations of neuroimaging (diffusion tensor imaging and resting state functional MRI) and cognitive measures to train algorithms to detect the presence of concussion in university athletes. Athletes (29 concussed, 48 controls) completed symptom reports, brief cognitive evaluation, and MRI within 72h of injury. Hierarchical linear regression compared groups on cognitive and neuroimaging measures while controlling for sex and data collection site. Logistic regression and support vector machine models were trained using cognitive and neuroimaging measures and evaluated for overall accuracy, sensitivity, and specificity. Concussed athletes reported greater symptoms than controls (∆R2 = 0.32, p < .001), and performed worse on tests of concentration (∆R2 = 0.07, p < .05) and delayed memory (∆R2 = 0.17, p < .001). Concussed athletes showed lower functional connectivity within the frontoparietal and primary visual networks (p < .05), but did not differ on mean diffusivity and fractional anisotropy. Of the cognitive measures, classifiers trained using delayed memory yielded the best performance with overall accuracy of 71%, though sensitivity was poor at 46%. Of the neuroimaging measures, classifiers trained using mean diffusivity yielded similar accuracy. Combining cognitive measures with mean diffusivity increased overall accuracy to 74% and sensitivity to 64%, comparable to the sensitivity of symptom report. Trained algorithms incorporating both MRI and cognitive performance variables can reliably detect common neurobiological sequelae of acute concussion. The integration of multi-modal data can serve as an objective, reliable tool in the assessment and diagnosis of concussion.

The prevalence and characteristics of MCCB cognitive impairment in unmedicated patients with bipolar II depression and major depressive disorder

BackgroundCognitive impairment has been acknowledged as a core clinical manifestation of bipolar disorder (BD) as well as major depressive disorder (MDD). Determining the prevalence and characteristics of cognitive impairment is important for clinical interventions. This study investigated the prevalence and characteristics of cognitive impairment based on the Measurement and Treatment Research to Improve Cognition Schizophrenia Consensus Cognitive Battery (MCCB) in both BD and MDD. MethodOne hundred and forty-nine BD II depression, 147 MDD, and 124 demographically matched healthy controls (HC) underwent MCCB cognitive assessment. The prevalence of MCCB cognitive impairment and group difference comparisons were performed. Additionally, association analysis was performed to investigate the relationship between cognitive performance and clinical variables. ResultsCompared to the HC group, both BD II depression and MDD groups had a significantly reduced performance for all MCCB cognitive domains (all p < 0.05). The numerical scores for visual learning were lower in the BD II depression group compared to the MDD group. 32.89% of the BD II depression patients had clinically significant impairment (>1.5 SD below the normal mean) in two or more MCCB domains compared to 23.13% for MDD patients. ConclusionsA high percent of patients in the BD II depression and MDD group exhibited MCCB cognitive impairments with clinical significance. Cognitive impairments were more common in BD II depression patients compared to MDD patients, particularly for visual learning. These findings suggest that clinicians should be aware of the severe cognitive impairment in mood disorders and establish effective cognitive screening and intervention strategies.

Variability in Cognitive Task Performance is Associated With Future Symptoms of Externalizing Psychopathology and Lower Functional Network Segregation

Intra-individual variability (IIV) during cognitive task performance is a key behavioral assay of attention. Across the lifespan, lower IIV is associated with higher anticorrelation between the dorsal attention network (DAN) and default mode network (DMN), which is thought to represent effective allocation of attention through functional network segregation. However, whether these behavioral and neural markers of sustained attention are (i) related to each other and (ii) can predict future attention-related deficits has not yet been investigated in a developmental, population-based cohort.