The new science of cognitive sex differences

Exploring Gender Differences in Coding at the Beginning of Primary School

The gender gap in Computer Science (CS) is widely documented worldwide. Only a few studies, however, have investigated whether and how gender differences manifest early in the learning of computing, at the beginning of primary school. Coding, seen as an element of Computational Thinking, has entered the curriculum of primary school education in several countries. As the early years of primary education happen before gender stereotypes in CS are expected to be fully endorsed, the opportunity to learn coding for boys and girls at that age might in principle help reduce the gender gap later observed in CS education. Prior research findings however suggest that an advantage for boys in coding tasks may begin to emerge already since preschool or the early grades of primary education. In the present study we explored whether the coding abilities of 1st graders, at their first experience with coding, are affected by gender differences, and whether their presence associates with gender differences in executive functions (EF), i.e., response inhibition and planning skills. Earlier research has shown strong association between children's coding abilities and their EF, as well as the existence of gender differences in the maturation of response inhibition and planning skills, but with an advantage for girls. In this work we assessed the coding skills and response inhibition and planning skills of 109 Italian first graders, 45 girls and 64 boys, before an introductory coding course (pretest), when the children had no prior experience of coding. We then repeated the assessment after the introductory coding course (posttest). No statistically significant difference between girls and boys emerged at the pretest, whereas an advantage in coding appeared for boys at the posttest. Mediation analyses carried out to test the hypothesis of a mediation role of EF on gender differences in coding show that the gender differences in coding were not mediated by the children's EF (response inhibition or planning). These results suggest that other factors must be accounted for to explain this phenomenon. The different engagement of boys and girls in the coding activities, and/or other motivational and sociocognitive variables, should be explored in future studies.

Spatial anxiety and self-confidence mediate sex/gender differences in mental rotation

A recent meta-synthesis study with a sample of >12 million participants revealed that the male advantage in mental rotation (MR) is the largest cognitive sex/gender difference found in psychological literature. MR requires test takers to mentally rotate three-dimensional cubic figures under time restrictions. Previous studies have investigated how biological and social factors contribute to cognitive sex/gender differences in tasks of this type. Spatial anxiety and self-confidence in MR tasks have received less attention. The present study investigated the contribution of these psychological factors to sex/gender differences in MR performance. Participants (n = 269) completed two MR tasks that differed in task difficulty. Participants also indicated their self-confidence (for each item) and spatial anxiety. The results revealed that pronounced sex/gender differences in spatial anxiety and self-confidence mediate sex/gender in MR performance, especially when task demands are high. The current findings suggest that task-irrelevant factors that are not spatial cognitive in nature contribute largely to the well-known medium to large sex/gender differences in MR. Future studies should further explore mechanisms underlying cognitive sex/gender differences within a biopsychosocial approach.

Divergence in brain size and brain region volumes across wild guppy populations

Complex evolutionary dynamics have produced extensive variation in brain anatomy in the animal world. In guppies, Poecilia reticulata, brain size and anatomy have been extensively studied in the laboratory contributing to our understanding of brain evolution and the cognitive advantages that arise with brain anatomical variation. However, it is unclear whether these laboratory results can be translated to natural populations. Here, we study brain neuroanatomy and its relationship with sexual traits across 18 wild guppy populations in diverse environments. We found extensive variation in female and male relative brain size and brain region volumes across populations in different environment types and with varying degrees of predation risk. In contrast with laboratory studies, we found differences in allometric scaling of brain regions, leading to variation in brain region proportions across populations. Finally, we found an association between sexual traits, mainly the area of black patches and tail length, and brain size. Our results suggest differences in ecological conditions and sexual traits are associated with differences in brain size and brain regions volumes in the wild, as well as sexual dimorphisms in the brain's neuroanatomy.

The dynamic shaping of local cortical circuitry by sex and age, and its relation to Pattern Comparison Processing Speed

Previous resting-state functional magnetic resonance imaging (fMRI) studies have shown that the strength of local neural interactions decreases with distance. Here we extend that line of research to evaluate effects of sex and age on local cortical circuitry in 6 cortical areas (superior frontal, precentral, postcentral, superior parietal, inferior parietal, lateral occipital) using data acquired from 1,054 healthy young adults who participated in the Human Connectome Project. We confirmed previous findings that the strength of zero-lag correlations between prewhitened, resting-state, blood level oxygenation-dependent (BOLD) fMRI time series decreased with distance locally, and documented that the rate of decrease with distance ("spatial steepness") (a) was progressively lower from anterior to posterior areas, (b) was greater in women, especially in anterior areas, (c) increased with age, particularly for women, (d) was significantly correlated with percent inhibition, and (e) was positively and highly significantly correlated with pattern comparison processing speed (PCPS). A hierarchical tree clustering analysis of this dependence of PCPS on spatial steepness revealed a differential organization in processing that information between the two hemispheres, namely a more independent vs. a more integrative processing in the left and right hemispheres, respectively. These findings document sex and age differences in dynamic local cortical interactions, and provide evidence that spatial sharpening of these interactions may underlie cognitive processing speed differently organized in the two hemispheres.

Item analysis of the Child Neuropsychological Assessment Test (TENI): Classical test theory and item response theory

The aim of this study was to analyze the psychometric properties of the Brazilian version of the Test de Evaluación Neuropsicologica Infantil (TENI) using classical test theory (CTT), item response theory (IRT), and differential item functioning (DIF) models. The visuospatial working memory, focused attention, and matrix reasoning subtasks were analyzed. A total of 553 children, aged between 3 and 9 years of age, from eight public and private schools from the urban area of Belo Horizonte were assessed. In general, all subtasks can be treated essentially as unidimensional. Items' discrimination and difficulties increased in the order of presentation, as they were planned, using CTT and IRT. Items with DIF were found in all tasks, with higher probabilities of answering items correctly for boys and for private school children. Our results corroborated the partial use of some TENI subtasks as a promising digital instrument for non-verbal neuropsychological assessment for children.

The contribution of executive functions to sex differences in animal cognition

Cognitive sex differences have been reported in several vertebrate species, mostly in spatial abilities. Here, I review evidence of sex differences in a family of general cognitive functions that control behaviour and cognition, i.e., executive functions such as cognitive flexibility and inhibitory control. Most of this evidence derives from studies in teleost fish. However, analysis of literature from other fields (e.g., biomedicine, genetic, ecology) concerning mammals and birds reveals that more than 40% of species investigated exhibit sex differences in executive functions. Among species, the direction and magnitude of these sex differences vary greatly, even within the same family, suggesting sex-specific selection due to species' reproductive systems and reproductive roles of males and females. Evidence also suggests that sex differences in executive functions might provide males and females highly differentiated cognitive phenotypes. To understand the evolution of cognitive sex differences in vertebrates, future research should consider executive functions.

Beyond Simple Mean Differences: Analysis of Sex Similarities and Differences in Academic Achievement With the Kaufman Tests of Educational Achievement, Third Edition

Simple mean differences summarized in meta-analyses do not always adequately describe sex similarities and differences. We investigated sex similarities and differences in academic achievement test scores during childhood and adolescence multiple ways based on composite and subtest scores from the Kaufman Test of Educational Achievement (Third edition) norming sample. Sex differences in means were investigated across achievement domains and ability levels. Test score variance and percentages of scores at different parts of score distributions were also compared across sex. The largest and most consistent sex differences were female advantages in writing tests: Larger advantages were found in more complex writing tasks. Females also showed consistent advantages in silent reading fluency. Males demonstrated advantages in math problem solving that emerged at the average ability level. Females were more likely to be high achievers in reading fluency and written expression, whereas males were more likely to be low achievers in reading fluency and aspects of writing, and very low achievers in word recognition, word recognition fluency, and reading vocabulary. Males were more likely to be high achievers in math problem solving. Analysis that goes beyond simple mean differences reveals important sex differences regarding academic achievement, and theories should account for overall patterns of academic achievement similarities and differences.

Brain functional topology differs by sex in cognitively normal older adults

Introduction

Late onset Alzheimer's disease (AD) is the most common form of dementia, in which almost 70% of patients are women.

Hypothesis

We hypothesized that women show worse global FC metrics compared to men, and further hypothesized a sex-specific positive correlation between FC metrics and cognitive scores in women.

Methods

We studied cognitively healthy individuals from the Alzheimer's Disease Neuroimaging Initiative cohort, with resting-state functional Magnetic Resonance Imaging. Metrics derived from graph theoretical analysis and functional connectomics were used to assess the global/regional sex differences in terms of functional integration and segregation, considering the amyloid status and the contributions of APOE E4. Linear mixed effect models with covariates (education, handedness, presence of apolipoprotein [APOE] E4 and intra-subject effect) were utilized to evaluate sex differences. The associations of verbal learning and memory abilities with topological network properties were assessed.

Result

Women had a significantly lower magnitude of the global and regional functional network metrics compared to men. Exploratory association analysis showed that higher global clustering coefficient was associated with lower percent forgetting in women and worse cognitive scores in men.

Conclusion

Women overall show lower magnitude on measures of resting state functional network topology and connectivity. This factor can play a role in their different vulnerability to AD.

Significance statement

Two thirds of AD patients are women but the reasons for these sex difference are not well understood. When this late onset form dementia arises is too late to understand the potential causes of this sex disparities. Studies on cognitively healthy elderly population are a fundamental approach to explore in depth this different vulnerability to the most common form of dementia, currently affecting 6.2 million Americans aged 65 and older are, which means that >1 in 9 people (11.3%) 65 and older are affected by AD. Approaches such as resting-state functional network topology and connectivity may play a key role in understanding and elucidate sex-dependent differences relevant to late-onset dementia syndromes.

Effect of Aging on Educational Differences in the Risk of Cognitive Impairment: A Gender-Specific Analysis Using Korean Longitudinal Study of Aging (2006–2016)

This study examined the effect of aging on gender-specific educational differences in the risk of cognitive impairment using a nationally representative sample of 4278 men and 5495 women aged 45 years and older from the dataset of the Korean Longitudinal Study of Aging. Sociodemographics, lifestyle, and medical conditions were included as covariates in the mixed logistic regression analysis models. The prevalence of cognitive impairment was higher in women than in men at baseline. The risk of cognitive impairment in each age group decreased with education in both men and women. The risk by educational rank was worse at lower levels and increased with age, more so for women than men. Aging appears to widen the impact of educational differences on the risk of cognitive impairment and is more unfavorable for women than for men. Public health policies regarding population aging need to consider this and identify the target population to reduce both the level of and the difference in the risk of cognitive impairment.

Sex Differences of Cerebellum and Cerebrum: Evidence from Graph Convolutional Network

This work aims to exploit a novel graph neural network to predict the sex of the brain topological network, and to find the sex differences in the cerebrum and cerebellum. A two-branch multi-scale graph convolutional network (TMGCN) is designed to analyze the sex differences of the brain. Two complementary templates are used to construct cerebrum and cerebellum networks, respectively, followed by a two-branch sub-network with multi-scale filters and a trainable weighted fusion strategy for the final prediction. Finally, a trainable graph topk-pooling layer is utilized in our model to visualize key brain regions relevant to the prediction. The proposed TMGCN achieves a prediction accuracy of 84.48%. In the cerebellum, the bilateral Crus I-II, lobule VI and VIIb, and the posterior vermis (VI-X) are discriminative for this task. As for the cerebrum, the discriminative brain regions consist of the bilateral inferior temporal gyrus, the bilateral fusiform gyrus, the bilateral parahippocampal gyrus, the bilateral cingulate gyrus, the bilateral medial ventral occipital cortex, the bilateral lateral occipital cortex, the bilateral amygdala, and the bilateral hippocampus. This study tackles the sex prediction problem from a more comprehensive view, and may provide the resting-state fMRI evidence for further study of sex differences in the cerebellum and cerebrum.

Understanding the Magnitude of Psychological Differences Between Women and Men Requires Seeing the Forest and the Trees

Whether women and men are psychologically very similar or quite different is a contentious issue in psychological science. This article clarifies this issue by demonstrating that larger and smaller sex/gender differences can reflect differing ways of organizing the same data. For single psychological constructs, larger differences emerge from averaging multiple indicators that differ by sex/gender to produce scales of a construct’s overall typicality for women versus men. For example, averaging self-ratings on personality traits more typical of women or men yields much larger sex/gender differences on measures of the femininity and masculinity of personality. Sex/gender differences on such broad-gauge, thematic variables are large relative to differences on their component indicators. This increased effect magnitude for aggregated scales reflects gains in both their reliability and validity as indicators of sex/gender. In addition, in psychological domains such as vocational interests that are composed of many variables, at least some of which differ by sex/gender, the multivariate distance between women and men is typically larger than the differences on the component variables. These analyses encourage recognition of the interdependence of sex/gender similarity and difference in psychological data.

Machine Learning Evidence for Sex Differences Consistently Influences Resting-State Functional Magnetic Resonance Imaging Fluctuations Across Multiple Independently Acquired Data Sets

Background/Introduction: Sex classification using functional connectivity from resting-state functional magnetic resonance imaging (rs-fMRI) has shown promising results. This suggested that sex difference might also be embedded in the blood-oxygen-level-dependent properties such as the amplitude of low-frequency fluctuation (ALFF) and the fraction of ALFF (fALFF). This study comprehensively investigates sex differences using a reliable and explainable machine learning (ML) pipeline. Five independent cohorts of rs-fMRI with over than 5500 samples were used to assess sex classification performance and map the spatial distribution of the important brain regions. Methods: Five rs-fMRI samples were used to extract ALFF and fALFF features from predefined brain parcellations and then were fed into an unbiased and explainable ML pipeline with a wide range of methods. The pipeline comprehensively assessed unbiased performance for within-sample and across-sample validation. In addition, the parcellation effect, classifier selection, scanning length, spatial distribution, reproducibility, and feature importance were analyzed and evaluated thoroughly in the study. Results: The results demonstrated high sex classification accuracies from healthy adults (area under the curve >0.89), while degrading for nonhealthy subjects. Sex classification showed moderate to good intraclass correlation coefficient based on parcellation. Linear classifiers outperform nonlinear classifiers. Sex differences could be detected even with a short rs-fMRI scan (e.g., 2 min). The spatial distribution of important features overlaps with previous results from studies. Discussion: Sex differences are consistent in rs-fMRI and should be considered seriously in any study design, analysis, or interpretation. Features that discriminate males and females were found to be distributed across several different brain regions, suggesting a complex mosaic for sex differences in rs-fMRI. Impact statement The presented study unraveled that sex differences are embedded in the blood-oxygen-level dependent (BOLD) and can be predicted using unbiased and explainable machine learning pipeline. The study revealed that psychiatric disorders and demographics might influence the BOLD signal and interact with the classification of sex. The spatial distribution of the important features presented here supports the notion that the brain is a mosaic of male and female features. The findings emphasize the importance of controlling for sex when conducting brain imaging analysis. In addition, the presented framework can be adapted to classify other variables from resting-state BOLD signals.

Is there a g-factor of genderedness? Using a continuous measure of genderedness to assess sex differences in personality, values, cognitive ability, school grades, and educational track

Some of the most persistently recurring research questions concern sex differences. Despite much progress, limited research has thus far been undertaken to investigate whether there is one general construct of genderedness that runs through various domains of human individuality. In order to determine whether being gender typical in one way goes together with being gender typical also in other ways, we investigated whether 16-year-old Finnish girls and boys ( N = 4106) differ in their personality, values, cognitive abilities, academic achievement, and educational track. To do this, we updated the prediction-focused gender diagnosticity approach by methods of cross-validation for more accurate estimation. The preregistered analysis shows that sex differences vary across domains ( Ds = 0.15–1.48), that fine-grained measures, such as grade profiles, can be accurate in predicting sex (77.5%), whereas some summary indices, such as general cognitive ability, do not perform above-chance (52.4%), and that the genderedness correlations, despite all being positive, are too weak (average partial correlation, r´ = .09, range .03–.34) to support a general factor of genderedness. Our more exploratory analyses show that more focus on gender typicality could offer important insights into the role of gender in shaping people’s lives.

The sexual brain, genes, and cognition: A machine-predicted brain sex score explains individual differences in cognitive intelligence and genetic influence in young children

Sex impacts the development of the brain and cognition differently across individuals. However, the literature on brain sex dimorphism in humans is mixed. We aim to investigate the biological underpinnings of the individual variability of sexual dimorphism in the brain and its impact on cognitive performance. To this end, we tested whether the individual difference in brain sex would be linked to that in cognitive performance that is influenced by genetic factors in prepubertal children (N = 9,658, ages 9-10 years old; the Adolescent Brain Cognitive Development study). To capture the interindividual variability of the brain, we estimated the probability of being male or female based on the brain morphometry and connectivity features using machine learning (herein called a brain sex score). The models accurately classified the biological sex with a test ROC-AUC of 93.32%. As a result, a greater brain sex score correlated significantly with greater intelligence (p_fdr  < .001, η p 2 $$ {\eta}_p^2 $$  = .011-.034; adjusted for covariates) and higher cognitive genome-wide polygenic scores (GPSs) (p_fdr  < .001, η p 2 $$ {\eta}_p^2 $$  < .005). Structural equation models revealed that the GPS-intelligence association was significantly modulated by the brain sex score, such that a brain with a higher maleness score (or a lower femaleness score) mediated a positive GPS effect on intelligence (indirect effects = .006-.009; p = .002-.022; sex-stratified analysis). The finding of the sex modulatory effect on the gene-brain-cognition relationship presents a likely biological pathway to the individual and sex differences in the brain and cognitive performance in preadolescence.

What does gender has to do with math? Complex questions require complex answers

Whether mathematics is a gendered domain or not is a long-lasting issue bringing along major social and educational implications. The females' underrepresentation in science, technology, engineering, and mathematics (STEM) has been considered one of the key signs of the math gender gap, although the current view largely attributes the origin of this phenomenon to sociocultural factors. Indeed, recent approaches to math gender differences reached the universal conclusion that nature and nurture exert reciprocal effects on each other, establishing the need for approaching the study of the math gender issue only once its intrinsic complexity has been accepted. Building upon a flourishing literature, this review provides an updated synthesis of the evidence for math gender equality at the start, and for math gender inequality on the go, challenging the role of biological factors. In particular, by combining recent findings from different research areas, the paper discusses the persistence of the "math male myth" and the associated "female are not good at math myth," drawing attention to the complex interplay of social and cultural forces that support such stereotypes. The suggestion is made that longevity of these myths results from the additive effects of two independent cognitive biases associated with gender stereotypes and with math stereotypes, respectively. Scholars' responsibility in amplifying these myths by pursuing some catching lines of research is also discussed.

Sex differences in the association of math achievement with visual-spatial and verbal working memory: Does the type of math test matter?

Previous research on sex differences in mathematical achievement shows mixed findings, which have been argued to depend on types of math tests used and the type of solution strategies (i.e., verbal versus visual‐spatial) these tests evoke. The current study evaluated sex differences in (a) performance (development) on two types of math tests in primary schools and (b) the predictive value of verbal and visual‐spatial working memory on math achievement. Children (N = 3175) from grades 2 through five participated. Visual‐spatial and verbal working memory were assessed using online computerized tasks. Math performance was assessed five times during two school years using a speeded arithmetic test (math fluency) and a word problem test (math problem solving). Results from Multilevel Multigroup Latent Growth Modeling, showed that sex differences in level and growth of math performance were mixed and very small. Sex differences in the predictive value of verbal and visual‐spatial working memory for math performance suggested that boys seemed to rely more on verbal strategies than girls. Explanations focus on cognitive and emotional factors and how these may interact to possibly amplify sex differences as children grow older.

Integrating Gestures and Words to Communicate in Full-Term and Low-Risk Preterm Late Talkers

Young children use gestures to practice communicative functions that foster their receptive and expressive linguistic skills. Studies investigating the use of gestures by late talkers are limited. This study aimed to investigate the use of gestures and gesture–word combinations and their associations with word comprehension and word and sentence production in late talkers. A further purpose was to examine whether a set of individual and environmental factors accounted for interindividual differences in late talkers’ gesture and gesture–word production. Sixty-one late talkers, including 35 full-term and 26 low-risk preterm children, participated in the study. Parents filled out the Italian short forms of the MacArthur–Bates Communicative Development Inventories (MB–CDI), “Gesture and Words” and “Words and Sentences” when their children were 30-months-old, and they were then invited to participate in a book-sharing session with their child. Children’s gestures and words produced during the book-sharing session were transcribed and coded into CHAT of CHILDES and analyzed with CLAN. Types of spontaneous gestures (pointing and representational gestures) and gesture–word combinations (complementary, equivalent, and supplementary) were coded. Measures of word tokens and MLU were also computed. Correlational analyses documented that children’s use of gesture–word combinations, particularly complementary and supplementary forms, in the book-sharing session was positively associated with linguistic skills both observed during the session (word tokens and MLU) and reported by parents (word comprehension, word production, and sentence production at the MB–CDI). Concerning individual factors, male gender was negatively associated with gesture and gesture–word use, as well as with MB–CDI action/gesture production. In contrast, having a low-risk preterm condition and being later-born were positively associated with the use of gestures and pointing gestures, and having a family history of language and/or learning disorders was positively associated with the use of representational gestures. Furthermore, a low-risk preterm status and a higher cognitive score were positively associated with gesture–word combinations, particularly complementary and supplementary types. With regard to environmental factors, older parental age was negatively associated with late talkers’ use of gestures and pointing gestures. Interindividual differences in late talkers’ gesture and gesture–word production were thus related to several intertwined individual and environmental factors. Among late talkers, use of gestures and gesture–word combinations represents a point of strength promoting receptive and expressive language acquisition.

Sex differences in the intrinsic reading neural networks of Chinese children

Sex differences in reading performance have been considered a relatively stable phenomenon. However, there is no general agreement about their neural basis, which might be due to that sex differences are largely influenced by age. This paper focuses on the sex differences in the reading-related neural network of Chinese children and its interaction with age. We also attempt to predict reading abilities based on neural network. Fifty-three boys and 56 girls (8.2–14.6 years of age) were recruited. We collected their resting-state fMRI and behavioural data. Restricted sex differences were found in the resting-state reading neural network compared to extensive age by sex interaction effect. Specifically, the interactions between sex and age indicated that with increasing age, girls showed greater connectivity strength between visual orthographic areas and other brain areas within the reading network, while boys showed an opposite trend. After controlling age, the prediction models of reading performance for the girls mainly included interhemispheric connections, while the intrahemispheric connections (particularly the phonological route) mainly contributed to predicting the reading ability for boys. Taken together, these findings suggest that sex differences in reading neural networks are modulated by age. Partialling out age, boys and girls also show the stable sex differences in relationship between reading neural circuit and reading behaviour.

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Sex differences in reading neural networks are modulated by age.

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Girls’ RSFCs within reading neural networks increase with age, contrary to boys.

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Intra- and interhemispheric RSFCs predict the reading ability of boys and girls, respectively.

Shared functional connections within and between cortical networks predict cognitive abilities in adult males and females

A thorough understanding of sex-independent and sex-specific neurobiological features that underlie cognitive abilities in healthy individuals is essential for the study of neurological illnesses in which males and females differentially experience and exhibit cognitive impairment. Here, we evaluate sex-independent and sex-specific relationships between functional connectivity and individual cognitive abilities in 392 healthy young adults (196 males) from the Human Connectome Project. First, we establish that sex-independent models comparably predict crystallised abilities in males and females, but only successfully predict fluid abilities in males. Second, we demonstrate sex-specific models comparably predict crystallised abilities within and between sexes, and generally fail to predict fluid abilities in either sex. Third, we reveal that largely overlapping connections between visual, dorsal attention, ventral attention, and temporal parietal networks are associated with better performance on crystallised and fluid cognitive tests in males and females, while connections within visual, somatomotor, and temporal parietal networks are associated with poorer performance. Together, our findings suggest that shared neurobiological features of the functional connectome underlie crystallised and fluid abilities across the sexes.

Sex- and estrous-cycle dependent dorsal hippocampal phosphoproteomic changes induced by low-dose ketamine

Numerous emotional and cognitive processes mediated by the hippocampus present differences between sexes and can be markedly influenced by hormonal status in males and females of several species. In rodents, the dorsal hippocampus (dHPC) is known to contribute to the rapid antidepressant actions of the NMDA receptor antagonist ketamine. We and others have demonstrated a greater sensitivity to the fast-acting antidepressant ketamine in female versus male rats that is estrogen- and progesterone-dependent. However, the underlying mechanisms remain unclear. Using an acute low dose (2.5 mg/kg) of ketamine that is behaviorally effective in female but not male rats, a label-free phosphoproteomics approach was employed to identify ketamine-induced changes in signaling pathway activation and phosphoprotein abundance within the dHPC of intact adult male rats and female rats in either diestrus or proestrus. At baseline, males and females showed striking dissimilarities in the dHPC proteome and phosphoproteome related to synaptic signaling and mitochondrial function-differences also strongly influenced by cycle stage in female rats. Notably, phosphoproteins enriched in PKA signaling emerged as being both significantly sex-dependent at baseline and also the primary target of ketamine-induced protein phosphorylation selectively in female rats, regardless of cycle stage. Reduced phosphoprotein abundance within this pathway was observed in males, suggesting bi-directional effects of low-dose ketamine between sexes. These findings present biological sex and hormonal milieu as critical modulators of ketamine's rapid actions within this brain region and provide greater insight into potential translational and post-translational processes underlying sex- and hormone-dependent modulation of ketamine's therapeutic effects.

Swedish Normative Data for Mindmore: A Comprehensive Cognitive Screening Battery, Both Digital and Self-Administrated

OBJECTIVE

Cognitive impairment is a key element in most mental disorders. Its objective assessment at initial patient contact in primary care can lead to better adjusted and timely care with personalised treatment and recovery. To enable this, we designed the Mindmore self-administrative cognitive screening battery. What is presented here is normative data for the Mindmore battery for the Swedish population.

METHOD

A total of 720 healthy adults (17 to 93 years) completed the Mindmore screening battery, which consists of 14 individual tests across five cognitive domains: attention and processing speed, memory, language, visuospatial functions and executive functions. Regression-based normative data were established for 42 test result measures, investigating linear, non-linear and interaction effects between age, education and sex.

RESULTS

The test results were most affected by age and to a lesser extent by education and sex. All but one test displayed either linear or accelerated age-related decline, or a U-shaped association with age. All but two tests showed beneficial effects of education, either linear or subsiding after 12 years of educational attainment. Sex affected tests in the memory and executive domains. In three tests, an interaction between age and education revealed an increased benefit of education later in life.

CONCLUSION

This study provides normative models for 14 traditional cognitive tests adapted for self-administration through a digital platform. The models will enable more accurate interpretation of test results, hopefully leading to improved clinical decision making and better care for patients with cognitive impairment.

Effect of Phase-Encoding Direction on Gender Differences: A Resting-State Functional Magnetic Resonance Imaging Study

Aim

Neuroimaging studies have highlighted gender differences in brain functions, but conclusions are not well established. Few studies paid attention to the influence of phase-encoding (PE) direction in echo-planar imaging on gender differences, which is a commonly used technique in functional magnetic resonance imaging (fMRI). A disadvantage of echo-planar images is the geometrical distortion and signal loss due to large susceptibility effects along the PE direction. The present research aimed to clarify how PE direction can affect the outcome of a specific research on gender differences.

Methods

We collected resting-state fMRI using anterior to posterior (AP) and posterior to anterior (PA) directions from 113 healthy participants. We calculated several commonly used indices for spontaneous brain activity including amplitude of low frequency fluctuations (ALFF), fractional ALFF (fALFF), regional homogeneity (ReHo), degree centrality (DC), and functional connectivity (FC) of posterior cingulate cortex for each session, and performed three group comparisons: (i) AP versus PA; (ii) male versus female; (iii) interaction between gender and PE direction.

Results

The estimated indices differed substantially between the two PE directions, and the regions that exhibited differences were roughly similar for all the indices. In addition, we found that multiple brain regions showed gender differences in these estimated indices. Further, we observed an interaction effect between gender and PE direction in the bilateral middle frontal gyrus, right precentral gyrus, right postcentral gyrus, right lingual gyrus, and bilateral cerebellum posterior lobe.

Conclusion

These apparent findings revealed that PE direction can partially influence gender differences in spontaneous brain activity of resting-state fMRI. Therefore, future studies should document the adopted PE direction and appropriate selection of PE direction will be important in future resting-state fMRI studies.

Sex Differences in Cognitive Functioning with Aging in the Netherlands

Introduction

Dementia prevalence in older women is higher than that in men. The purpose of the present study was to investigate whether there is a female disadvantage in cognitive functioning at adult age and/or whether a female disadvantage develops with age.

Methods

Data of 5,135 women and 4,756 men from the Longitudinal Aging Study Amsterdam (LASA) and the Doetinchem Cohort Study (DCS) were used. In the LASA, memory, processing speed, fluid intelligence, and global cognitive function were measured every 3–4 years since 1992 in persons aged 55+ years for up to 23 years. In the DCS, memory, processing speed, cognitive flexibility, and global cognitive function were measured every 5 years since 1995 in persons aged 45+ years for up to 20 years. Sex differences in cognitive aging were analyzed using linear mixed models and also examined by the 10-year birth cohort or level of education.

Results

Women had a better memory, processing speed, flexibility, and, in the DCS only, global cognitive function than men (p's < 0.01). However, women showed up to 10% faster decline in these cognitive domains, except for flexibility, where women showed 9% slower decline. In the LASA, women scored poorer on fluid intelligence (p < 0.01), but their decline was 10% slower than that in men. Female advantage was larger in later born cohorts; adjustment for the educational level increased the female advantage.

Conclusion

Women have better memory and processing speed than men at middle age. This female advantage becomes smaller with aging and has increased in more recent birth cohorts.

A meta-analysis of sex differences in animal personality: no evidence for the greater male variability hypothesis

The notion that men are more variable than women has become embedded into scientific thinking. For mental traits like personality, greater male variability has been partly attributed to biology, underpinned by claims that there is generally greater variation among males than females in non-human animals due to stronger sexual selection on males. However, evidence for greater male variability is limited to morphological traits, and there is little information regarding sex differences in personality-like behaviours for non-human animals. Here, we meta-analysed sex differences in means and variances for over 2100 effects (204 studies) from 220 species (covering five broad taxonomic groups) across five personality traits: boldness, aggression, activity, sociality and exploration. We also tested if sexual size dimorphism, a proxy for sex-specific sexual selection, explains variation in the magnitude of sex differences in personality. We found no significant differences in personality between the sexes. In addition, sexual size dimorphism did not explain variation in the magnitude of the observed sex differences in the mean or variance in personality for any taxonomic group. In sum, we find no evidence for widespread sex differences in variability in non-human animal personality.

On Neuroeducation: Why and How to Improve Neuroscientific Literacy in Educational Professionals

New findings from the neurosciences receive much interest for use in the applied field of education. For the past 15 years, neuroeducation and the application of neuroscience knowledge were seen to have promise, but there is presently some lack of progress. The present paper states that this is due to several factors. Neuromyths are still prevalent, and there is a confusion of tongues between the many neurodisciplines and the domains of behavioral and educational sciences. Second, a focus upon cognitive neuroimaging research has yielded findings that are scientifically relevant, but cannot be used for direct application in the classroom. A third factor pertains to the emphasis which has been on didactics and teaching, whereas the promise of neuroeducation for the teacher may lie more on pedagogical inspiration and support. This article states that the most important knowledge and insights have to do with the notion of brain plasticity; the vision that development is driven by an interaction between a person's biology and the social system. This helps individuals to select and process information, and to adapt to the personal environment. The paper describes how brain maturation and neuropsychological development extend through the important period of adolescence and emergent adulthood. Over this long period, there is a major development of the Executive Functions (EFs) that are essential for both cognitive learning, social behavior and emotional processing and, eventually, personal growth. The paper describes the basic neuroscience knowledge and insights - or "neuroscientific literacy" - that the educational professional should have to understand and appreciate the above-described themes. The authors formulate a proposal for four themes of neuroscience content "that every teacher should know." These four themes are based on the Neuroscience Core Concepts formulated by the Society for Neuroscience. The authors emphasize that integrating neuroscientific knowledge and insights in the field of education should not be a one-way street; attempts directed at improving neuroscientific literacy are a transdisciplinary undertaking. Teacher trainers, experts from the neuroscience fields but also behavioral scientists from applied fields (notable applied neuropsychologists) should all contribute to for the educational innovations needed.

Exploring the sex and gender correlates of cognitive sex differences

The correlates of cognitive sex differences are yet to be fully understood. Many biological and psychosocial factors modulate these cognitive abilities leading to mixed results in the scientific literature. The current study aims to explore the different parameters potentially influencing cognitive abilities acting in synergy. Sex and gender correlates of cognitive functioning were assessed in a sample of individuals ages 18 to 45 years (N = 87) from diverse sexual orientations. Sex hormones were assessed via saliva samples at four timepoints throughout the testing. Gender roles, sexual orientation and socio-demographics were measured via self-report questionnaires. Participants completed mental rotation and verbal fluency tasks. Men performed better than women at mental rotation, while no significant difference was found for verbal fluency. Significant positive associations were observed between estradiol and word fluency for the naturally cycling women compared to the women using oral contraception. While controlling for sex hormones, a significant interaction effect of sex by gender roles was identified for mental rotation among masculine women. These exploratory results suggest an effect principally driven by sex and sex hormones on cognitive performance that will need to be furthered with larger studies.

Sex and gender difference in cognitive and behavioral studies in developmental age: An introduction

This paper introduces a special issue focused on sex and gender (s/g) cognitive/behavioral differences at developmental ages providing an overview of this multifaceted and debated topic. It will provide a description of the biological systems that are strongly interconnected to generate s/g differences, that is, genetic determinants, sex hormones, differences in brain structure, organization, and/or function, inherited or modifiable under environmental pressures. Developmental studies are rare. Some addressed whether s/g differences in cognitive/behavioral characteristics are evident early in life and are consistent throughout development, entailing that s/g differences can follow the evolving steps in girls and boys in different domains. The data are far from being homogeneous and consistent about s/g difference in language, social skills, and visuo/spatial abilities. The differences are small, often with overlapping performances, similar to what is seen in adulthood. Given that several variables and the interactions between them are implicated, further longitudinal studies adopting adequate assessment tools, very large size multicultural samples stratified in different, well-sized and precise age groups, considering biological and sociocultural variables, are needed. Due to the complexity of the issue, there is still the need to support and adopt an s/g difference approach also in cognitive and behavioral studies at developmental ages. Finally, these studies have not only scientific importance and relevant cultural, anthropological, and social implications, but are also useful for pedagogical programming as well as for the study of the different susceptibility to develop CNS diseases and consequently to promote different therapies and treatments.

Spatial and mathematics skills: Similarities and differences related to age, SES, and gender

Performance on a range of spatial and mathematics tasks was measured in a sample of 1592 students in kindergarten, third grade, and sixth grade. In a previously published analysis of these data, performance was analyzed by grade only. In the present analyses, we examined whether the relations between spatial skill and mathematics skill differed across socio-economic levels, for boys versus girls, or both. Our first aim was to test for group differences in spatial skill and mathematics skill. We found that children from higher income families showed significantly better performance on both spatial and mathematics measures, and boys outperformed girls on spatial measures in all three grades, but only outperformed girls on mathematics measures in kindergarten. Further, comparisons using factor analysis indicated that the income-related gap in mathematics performance increased across the grade levels, while the income-related gap in spatial performance remained constant. Our second aim was to test whether spatial skill mediated any of these effects, and we found that it did, either partially or fully, in all four cases. Our third aim was to test whether the "separate but correlated" two-factor latent structure previously reported for spatial skill and mathematics skill was (Mix et al., 2016; Mix et al., 2017) replicated across grade, SES, and sex. Multi-group confirmatory factor analyses conducted for each of these subgroups indicated that the same latent structure was present, despite differences in overall performance. These findings replicate and extend prior work on SES and sex differences related to spatial and mathematics skill, but provide evidence that the relations between the domains are stable and consistent across subgroups.

Associations between Sleep and Work-Related Cognitive and Emotional Functioning in Police Employees

AIM

We aimed to examine the cross-sectional and longitudinal associations between sleep and work-related impaired cognitive and emotional functioning in police employees.

METHODS

This study included 410 participants (52% men) employed in a police district in Norway at baseline, of which 50% also participated in the study at 6 months later follow-up. The questionnaires included items measuring work schedule, sleep length, insomnia, as well as impaired cognitive and emotional functioning at work.

RESULTS

The results showed that insomnia was related to impaired work-related emotional functioning measured at baseline, and to impaired cognitive functioning measured at both baseline and follow-up. Sleep length and rotating shift work were not associated with future decline in cognitive or emotional functioning.

CONCLUSION

Our study indicates that the relationship between insomnia and emotional functioning at work may be transient, whereas insomnia can be related to both immediate and future impaired cognitive functioning. Replication of the findings in larger samples is advised. The findings call for an emphasis on the prevention and treatment of sleep problems among police employees as a mean of maintaining and improving cognitive and emotional functioning at work, and thereby reducing the risk for impaired performance and negative health and safety outcomes.

Exposure to ambient air pollution and socio-economic status on intelligence quotient among schoolchildren in a developing country

Evidence suggests the association between ambient airborne particulate matters and children's IQ and psychological development in the early stages of life. However, data on the relationship between ambient air particulate matters and children's IQ are rare in developing countries and less privileged areas. In this study, the association between PM₁₀ and PM_2.5 and the IQ of children in different areas were investigated in terms of pollution levels. In 2019, 369 children between the ages of 6 and 8 years old were randomly selected in three regions of southern Iran after screening through a questionnaire. In this study, PM₁₀ and PM_2.5 were determined using a direct reading device. IQ was surveyed according to Raymond B. Cattell scale I-A. The confounder factors including age, gender, economic conditions, maternal education, and type of delivery were adjusted. The average PM₁₀ in areas with low, medium, and high pollution levels were measured to be 59.14±25.24 μg/m³, 89.7±37.34 μg/m³, and 121.44±43.49 μg/m³, respectively, while PM_2.5 were found to be 38.97±16.87 μg/m³, 58±23.94 μg/m³, and 84.18±31.32 μg/m³, respectively. The IQ of children in the area with a high pollution was 16.628 lower than that in the area with low pollution (β= 16.628; [95% CI: 13.295 to 19.96]; P ≤ 0.0001). In addition, IQ in the area with high pollution level was found to be 7.48 lower than that in moderate pollution. ( β= 7.489; [95% CI: 4.109 to 10.870]; P ≤ 0.0001). Exposure to increased PM₁₀ and PM_2.5 is associated with decreased IQ in children.

Predictors of cognitive, behavioural and academic difficulties in NF1

The impact of the Neurofibromatosis type 1 (NF1) on cognition have been subject to much clinical investigation, but environmental modifiers of disease expression have not yet been systematically investigated. The aim of this paper is to determine the role of demographic and environmental factors such as age, sex, socioeconomic status, parental NF1 status and neurological complications on the cognitive, behavioural and academic outcomes in NF1. Participants included 206 children aged 4-18 years seen within the Manchester clinical research NF1 service. Multiple linear regression models were used to study the effect of the hypothesized predictor variables on cognitive, behavioural and academic outcomes. Relative to population norms, 80% of the NF1 sample demonstrated significantly lower scores in at least one cognitive, behavioural or academic domains. Family history of NF1 and lower SES were independently associated with poorer cognitive, behavioural and academic outcomes. Neurological problems such as epilepsy and hydrocephalus were associated with lower IQ and academic skills. Cognitive and behavioural phenotypes emerge commonly via a complex interplay between genes and environmental factors, and this is true also of a monogenic condition such as NF1. Early interventions and remedial education may be targeted to risk groups such those with familial NF1, families with lower SES and those with associated neurological comorbidities.

The accumulation of subconcussive impacts on cognitive, imaging, and biomarker outcomes in child and college-aged athletes: a systematic review

Examine the effect of subconcussive impact accumulation on cognitive/functional, imaging, and biomarker outcomes over the course of a single season, specifically in contact sport athletes at collegiate level or younger. Systematic review following PRISMA guidelines and using Oxford Center for Evidence-Based Medicine 2011 Levels of Evidence and Newcastle Ottawa Assessment Scale. PubMed MEDLINE, PsycInfo, SPORT-Discus, Web of Science. Original research in English that addressed the influence of subconcussive impacts on outcomes of interest with minimum preseason and postseason measurement in current youth, high school, or college-aged contact sport athletes. 796 articles were initially identified, and 48 articles were included in this review. The studies mostly involved male football athletes in high school or college and demonstrated an underrepresentation of female and youth studies. Additionally, operationalization of previous concussion history and concussion among studies was very inconsistent. Major methodological differences existed across studies, with ImPACT and diffusion tensor imaging being the most commonly used modalities. Biomarker studies generally showed negative effects, cognitive/functional studies mostly revealed no effects, and advanced imaging studies showed generally negative findings over the season; however, there was variability in the findings across all types of studies. This systematic review revealed growing literature on this topic, but inconsistent methodology and operationalization across studies makes it challenging to draw concrete conclusions. Overall, cognitive measures alone do not seem to detect changes across this timeframe while imaging and biomarker measures may be more sensitive to changes following subconcussive impacts.

Gender differences in early stages of language development. Some evidence and possible explanations

It is a common feeling that girls speak earlier than boys; however, whether or not there are gender differences in early language acquisition remains controversial. The present paper aims to review the research on gender effects in early language acquisition and development, to determine whether, and from which age, an advantage for girls does eventually emerge. The focus is on the production of actions and communicative gestures, and early lexical comprehension and production, by girls and boys. The data from various studies that were conducted with direct and indirect tools suggest that some gender differences in actions, gesture, and lexical development depend on the interactions of different factors. Studies differ in terms of age ranges, sample sizes, and tools used, and the girl advantage is often slight and/or not evident at all ages considered. Statistical significance for gender differences appears to depend on the greater individual variability among boys, with respect to girls, which results in a greater number of boys classified as children with poor verbal ability. Biological (e.g., different maturational rates), neuropsychological (e.g., different cognitive strategies in solving tasks), and cultural (e.g., differences in the way parents relate socially to boys and girls) factors appear to interact, to create feedback loops of mutual reinforcement.

Age, Sex, and Inhibitory Control: Identifying A Specific Impairment in Memorial, But Not Perceptual Inhibition in Older Women

Objectives

Declines in the ability to inhibit information, and the consequences to memory of unsuccessful inhibition, have been frequently reported to increase with age. However, few studies have investigated whether sex moderates such effects. Here, we examined whether inhibitory ability may vary as a function of age and sex, and the interaction between these two factors.

Method

202 older (mean age = 69.40 years) and younger (mean age =30.59 years) participants who had equivalent educational attainment and self-reported health completed 2 tasks that varied only in the time point at which inhibition should occur: either prior to, or after, encoding.

Results

While we did not find evidence for age or sex differences in inhibitory processes when information needed to be inhibited prior to encoding, when encoded information being actively held in working memory needed to be suppressed, we found that older women were particularly impaired relative to both younger women and men of either age group.

Discussion

These results provide further support for the presence of memorial inhibitory deficits in older age, but add nuance by implicating biological sex as an important mediator in this relationship, with it more difficult for older women to inhibit what was once relevant in memory.

Autism spectrum disorder: An examination of sex differences in neuropsychological and self-report measures of executive and non-executive cognitive function

LAY ABSTRACT

Research comparing females and males with a diagnosis of autism suggests that there are sex differences in some characteristics such as behaviour regulation. One area not studied in detail is whether females and males with autism perform differently in tests of cognitive ability. The results of previous research are quite mixed. One explanation may be that some research comparing females and males with autism did not include a neurotypical control group for comparison. As a result, it is not clear whether the sex differences in cognitive ability observed in people with autism are similar to differences between neurotypical males and females. To better understand whether there are unique differences between males and females with autism, it is important to also compare them with neurotypical males and females. In our research, we included a neurotypical group and compared males and females with and without a diagnosis of autism. We found that the sex differences in autism are similar to what we observe in males and females without autism. Our study showed that compared with males, females (with and without autism) do better in assessments of processing speed, cognitive flexibility, verbal learning and memory and semantic fluency. Our results suggest that although females show different cognitive performance to males, these sex differences were not specific to the group with a diagnosis of autism.

The effect of colour on reading performance in children, measured by a sensor hub: From the perspective of gender

In recent decades reported findings regarding gender differences in reading achievement, cognitive abilities and maturation process in boys and girls are conflicting. As reading is one of the most important processes in the maturation of an individual, the aim of the study was to better understand gender differences between primary school students. The study evaluates differences in Heart Rate Variability (HRV), Electroencephalography (EEG), Electrodermal Activities (EDA) and eye movement of participants during the reading task. Taking into account that colour may affect reading skills, in that it affects the emotional and physiological state of the body, the research attempts to provide a better understanding of gender differences in reading through examining the effect of colour, as applied to reading content. The physiological responses of 50 children (25 boys and 25 girls) to 12 different background and overlay colours of reading content were measured and summarised during the reading process. Our findings show that boys have shorter reading duration scores and a longer Saccade Count, Saccade Duration Total, and Saccade Duration Average when reading on a coloured background, especially purple, which could be caused by their motivation and by the type of reading task. Also, the boys had higher values for the Delta band and the Whole Range of EEG measurements in comparison to the girls when reading on coloured backgrounds, which could reflect the faster maturation of the girls. Regarding EDA measurements we did not find systematic differences between groups either on white or on coloured/overlay background. We found the most significant differences arose in the HRV parameters, namely (SDNN (ms), STD HR (beats/min), RMSSD (ms), NN50 (beats), pNN50 (%), CVRR) when children read the text on coloured/overlay backgrounds, where the girls showed systematically higher values on HRV measurements in comparison to the boys, mostly with yellow, red, and orange overlay colours.

Structural connectivity differs between males and females in the brain object manipulation network

Object control skills are one of the most important abilities in daily life. Knowledge of object manipulation is an essential factor in improving object control skills. Although males and females equally try to use object manipulation knowledge, their object control abilities often differ. To explain this difference, we investigated how structural brain networks in males and females are differentially organized in the tool-preferring areas of the object manipulation network. The structural connectivity between the primary motor and premotor regions and between the inferior parietal regions in males was significantly higher than that in females. However, females showed greater structural connectivity in various regions of the object manipulation network, including the paracentral lobule, inferior parietal regions, superior parietal cortices, MT+ complex and neighboring visual areas, and dorsal stream visual cortex. The global node strength found in the female parietal network was significantly higher than that in males but not for the entire object manipulation, ventral temporal, and motor networks. These findings indicated that the parietal network in females has greater inter-regional structural connectivity to retrieve manipulation knowledge than that in males. This study suggests that differential structural networks in males and females might influence object manipulation knowledge retrieval.

Females' negative affective valence to math-related words

Emotional perceptions of math-related information can have profound effects on attitudes about math, which, in turn, may lead to decreased math achievements. A large body of research has documented that females have less positive attitudes and more negative affectivity to math than males. This study examined emotional valence ratings of math-related verbal stimuli among adults and performed a pioneering investigation of gender differences in emotional perceptions. A random sample of 290 adults completed a battery of online affect questionnaires designated to measure the relations of various math-related words to the field of mathematics (i.e., math loading) and compared the emotional valence of these words to words known to have negative and neutral valence. Results revealed that: (1) math-related words were rated as less threatening than words with negative valence, but more threatening than neutral words; (2) math loading ratings were the strongest and most significant predictor of the emotional valence ratings of math-related words; and (3) females rated math-related words and words with negative, but not neutral, valence as more threatening than males. The study concludes that negative affective valence is linked with math-related information, especially among females, and this finding has implications for researchers, parents, and educators.

Cognition across the Lifespan: Investigating Age, Sex, and Other Sociodemographic Influences

Maintaining cognitive health across the lifespan has been the focus of a multi-billion-dollar industry. In order to guide treatment and interventions, a clear understanding of the way that proficiency in different cognitive domains develops and declines in both sexes across the lifespan is necessary. Additionally, there are sex differences in a range of other factors, including psychiatric illnesses such as anxiety, depression, and substance use, that are also known to affect cognition, although the scale of this interaction is unknown. Our objective was to assess differences in cognitive function across the lifespan in men and women in a large, representative sample. Leveraging online cognitive testing, a sample of 9451 men and 9451 women ranging in age from 12 to 69 (M = 28.21) matched on socio-demographic factors were studied. Segmented regression was used to model three cognitive domains—working memory, verbal abilities, and reasoning. Sex differences in all three domains were minimal; however, after broadening the sample in terms of socio-demographic factors, sex differences appeared. These results suggest that cognition across the lifespan differs for men and women, but is greatly influenced by environmental factors. We discuss these findings within a framework that describes sex differences in cognition as likely guided by a complex interplay between biology and environment.

An Adaptable, Open-Access Test Battery to Study the Fractionation of Executive-Functions in Diverse Populations

The umbrella-term 'executive functions' (EF) includes various domain-general, goal-directed cognitive abilities responsible for behavioral self-regulation. The influential unity and diversity model of EF posits the existence of three correlated yet separable executive domains: inhibition, shifting and updating. These domains may be influenced by factors such as socioeconomic status (SES) and culture, possibly due to the way EF tasks are devised and to biased choice of stimuli, focusing on first-world testees. Here, we propose a FREE (Free Research Executive Function Evaluation) test battery that includes two open-access tasks for each of the three abovementioned executive domains to allow latent variables to be obtained. The tasks were selected from those that have been shown to be representative of each domain, that are not copyrighted and do not require special hardware/software to be administered. These tasks were adapted for use in populations with varying SES/schooling levels by simplifying tasks/instructions and using easily recognized stimuli such as pictures. Items are answered verbally and tasks are self-paced to minimize interference from individual differences in psychomotor and perceptual speed, to better isolate executive from other cognitive abilities. We tested these tasks on 146 early adolescents (aged 9-15 years) of both sexes and varying SES, because this is the age group in which the executive domains of interest become distinguishable and in order to confirm that SES effects were minimized. Performance was determined by Rate Correct Scores (correct answers divided by total time taken to complete blocks/trial), which consider speed-accuracy trade-offs. Scores were sensitive to the expected improvement in performance with age and rarely/inconsistently affected by sex and SES, as expected, with no floor or ceiling effects, or skewed distribution, thus suggesting their adequacy for diverse populations in these respects. Using structural equation modeling, evidence based on internal structure was obtained by replicating the three correlated-factor solution proposed by the authors of the model. We conclude that the FREE test battery, which is open access and described in detail, holds promise as a tool for research that can be adapted for a wide range of populations, as well as altered and/or complemented in coming studies.

Disparity in Educational Attainment Partially Explains Cognitive Gender Differences in Older Rural South Africans

OBJECTIVES

Direction and magnitude of gender differences in late-life cognitive function are inextricably tied to sociocultural context. Our study evaluates education and literacy as primary drivers of gender equality in cognitive performance among middle-aged and older adults in rural South Africa.

METHOD

Data were collected on 1,938 participants aged 40-79 from Agincourt, South Africa. Cognitive function was measured via the Oxford Cognitive Screen-Plus, a tablet-based assessment with low literacy demands. Four cognitive domains were derived through confirmatory factor analysis: episodic memory, executive function, visual spatial, and language. Structural equation models tested domain-specific gender effects, incrementally controlling for demographic, education, health, and socioeconomic variables.

RESULTS

In the model adjusting only for demographic factors, men outperformed women on executive function and visual-spatial domains. Adding education and literacy to the model revealed a robust female advantage in episodic memory, and reduced the magnitude of male advantage in executive function and visual and spatial by 47% and 42%, respectively. Health and socioeconomic factors did not alter patterns of gender associations in subsequent models.

DISCUSSION

In this older South African cohort, gender inequality in cognitive performance was partially attributable to educational differences. Understanding biopsychosocial mechanisms that promote cognitive resilience in older women is critically important given the predominantly female composition of aging populations worldwide.