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Background It is unknown how much variation in adult mental health problems is associated with differences between societal/cultural groups, over and above differences between individuals. Methods To test these relative contributions, a consortium of indigenous researchers collected Adult Self-Report (ASR) ratings from 16 906 18- to 59-year-olds in 28 societies that represented seven culture clusters identified in the Global Leadership and Organizational Behavioral Effectiveness study (e.g. Confucian, Anglo). The ASR is scored on 17 problem scales, plus a personal strengths scale. Hierarchical linear modeling estimated variance accounted for by individual differences (including measurement error), society, and culture cluster. Multi-level analyses of covariance tested age and gender effects. Results Across the 17 problem scales, the variance accounted for by individual differences ranged from 80.3% for DSM-oriented anxiety problems to 95.2% for DSM-oriented avoidant personality (mean = 90.7%); by society: 3.2% for DSM-oriented somatic problems to 8.0% for DSM-oriented anxiety problems (mean = 6.3%); and by culture cluster: 0.0% for DSM-oriented avoidant personality to 11.6% for DSM-oriented anxiety problems (mean = 3.0%). For strengths, individual differences accounted for 80.8% of variance, societal differences 10.5%, and cultural differences 8.7%. Age and gender had very small effects. Conclusions Overall, adults' self-ratings of mental health problems and strengths were associated much more with individual differences than societal/cultural differences, although this varied across scales. These findings support cross-cultural use of standardized measures to assess mental health problems, but urge caution in assessment of personal strengths.

This review presents a thesis analysis of the monograph «Prevention of aggression and destructive behavior of youth: analysis of international experience». The quality of the content is assessed, the main types of asociality are concluded (bullying, single acts of aggression in educational organizations, etc.). Also, an assessment is made of the compliance of research with advanced branches of science, and the coverage of this work in practice is implemented. The conclusions about the contribution of the authors to the study of the psychology of aggression and destructive behavior, as well as to the definition of practical areas of activity and approaches to the prevention of negative social impacts, are substantiated.

Number line accuracy (NL accuracy) shows improvement over the course of a school education. However, there are practically no cross-country longitudinal studies of NL accuracy over the whole course of elementary school.This study investigated the developmental trajectories of NL accuracy and its types across the elementary school years in two countries-Russia and Kyrgyzstan.The analyses were carried out on the data collected from the sample of 508 schoolchildren at Grades 1, 2, 3 and 4 (aged 6.4-11.9 years) from Russia and Kyrgyzstan, who were surveyed as part of the 'Cross-cultural Longitudinal Analysis of Student Success' project.The participants were administered the 'Number Line' computerized test task and a paper-and-pencil 'Standard Progressive Matrices' test at the end of each academic year.During the course of the elementary school education, NL accuracy increases nonlinearly in both samples from Grade 1 to Grade 4, with a pronounced increase in the rate of improvement from the first to the second year. Cross-country differences in NL accuracy were observed during each year of schooling as well as in the growth of NL accuracy. The development of NL accuracy is described by a model with two developmental types: (1) 'high start and growth' (93% of the pooled sample) and (2) 'low start and no growth' (7%).Both NL accuracy and the rate of its growth during elementary school depend on educational conditions. Cross-country differences in the distribution of schoolchildren by these two developmental types were statistically insignificant.

The risk of depression could be evaluated through its multifactorial nature using the polygenic score (PGS) approach. Assuming a “clinical continuum” hypothesis of mental diseases, a preliminary assessment of individuals with elevated risk for developing depression in a non-clinical group is of high relevance. In turn, epidemiological studies suggest including social/lifestyle factors together with PGS to address the “missing heritability” problem. We designed regression models, which included PGS using 27 SNPs and social/lifestyle factors to explain individual differences in depression levels in high-education students from the Volga–Ural region (VUR) of Eurasia. Since issues related to population stratification in PGS scores may lead to imprecise variant effect estimates, we aimed to examine a sensitivity of PGS calculated on summary statistics of depression and neuroticism GWAS from Western Europeans to assess individual proneness to depression levels in the examined sample of Eastern Europeans. A depression score was assessed using the revised version of the Beck Depression Inventory (BDI) in 1065 young adults (age 18–25 years, 79% women, Eastern European ancestry). The models based on weighted PGS demonstrated higher sensitivity to evaluate depression level in the full dataset, explaining up to 2.4% of the variance (p = 3.42 × 10−7); the addition of social parameters enhanced the strength of the model (adjusted r2 = 15%, p < 2.2 × 10−16). A higher effect was observed in models based on weighted PGS in the women group, explaining up to 3.9% (p = 6.03 × 10−9) of variance in depression level assuming a combined SNPs effect and 17% (p < 2.2 × 10−16)—with the addition of social factors in the model. We failed to estimate BDI-measured depression based on summary statistics from Western Europeans GWAS of clinical depression. Although regression models based on PGS from neuroticism (depression-related trait) GWAS in Europeans were associated with a depression level in our sample (adjusted r2 = 0.43%, p = 0.019—for unweighted model), the effect was mainly attributed to the inclusion of social/lifestyle factors as predictors in these models (adjusted r2 = 15%, p < 2.2 × 10−16—for unweighted model). In conclusion, constructed PGS models contribute to a proportion of interindividual variability in BDI-measured depression in high-education students, especially women, from the VUR of Eurasia. External factors, including the specificity of rearing in childhood, used as predictors, improve the predictive ability of these models. Implementation of ethnicity-specific effect estimates in such modeling is important for individual risk assessment.

The results of adaptation of the Russian-language version of the Parental Bonding Instrument (PBI) (Parker, Tupling, Brown, 1979) with "Mother's Attitude" and "Father's Attitude" options are presented in the article. The questionnaire is aimed to assess the perception of parenting attitudes among young people. According to the original (English) version of the questionnaire, aspects of parental attitude perception can be measured as quantitative indicators of the questionnaire scales: 1) "Care" and 2) "Overprotection". The "Care" scale consists of 12 statements such as “Seemed emotionally cold to me”, “Enjoyed talking things over with me”, “Did not talk with me very much”, etc. The "Overprotection" scale includes 13 statements such as "Felt I could not look after myself unless she/he was around", "Let me decide things for myself", "Let me dress in any way I pleased", etc. The study involved 504 high school students enrolled in schools in the Moscow and Leningrad regions, Samara and St. Petersburg, aged from 14.4 to 19.1 years, among them were 174 9th grade students (44.2% male), 169 10th grade students (34.7% male) and 161 11th grade students (51.1% male). The structure of the questionnaire was studied using exploratory factor analysis of the correlation matrix of the responses to 25 items of each version. The method of principal components with Varimax rotation was chosen for the analysis. The confirmatory factor analysis suggested the two-factor structure of the questionnaire was confirmed, with the following scales: “Care” and “Overprotection” for the options "Mother's Attitude" and "Father's Attitude". For reliability assessment, the scales were tested with the Cronbach's alpha coefficient of internal consistency. Satisfactory internal consistency of the scales on both options was revealed. The Cronbach's alphas reach satisfactory values both for Care and Overprotection scales. The effects of gender and age on the questionnaire scores were estimated. According to analysis, there are no sex differences of perception of maternal and paternal attitude in both “Care” and “Overprotection” scales. It was shown that the effect of age was statistically significant for “Overprotection” scale for paternal attitude only, with a small effect size. The effect of interaction of age and sex was statistically significant for “Care” for paternal attitude only, with a small effect size. According to the psychometric indicators presented in this paper, the Russian-language version of PBI can become a reliable tool to measure high school students’ perception of the parental attitude.

The results of large-scale meta-analyses of GWAS and genetic association studies demonstrated the role of allelic variants of a large number of genes in the development of cognitive abilities. Many of the identified genes are expressed in the brain and are involved in the pathogenesis of nervous system diseases. It has been shown that the summarized genetic effect for various cognitive abilities is no more than 50%. For certain genes, such as BDNF, DRD2, FNBP1L, PDE1C, PDE4B, and PDE4D, related to the regulation of neurogenesis and synaptic plasticity, associations with specific cognitive abilities were revealed. We assume the prospect of using the obtained results for the targeted effect in order to improve human cognitive abilities. This review describes DNA methylation, histone acetylation, expression of specific noncoding RNAs during brain functioning, and the development of individual differences in cognitive abilities. The revealed epigenetic mechanisms suggest the methods of reversible correction of cognitive functioning both in nonclinical forms and pathological states.

To date, multiple efforts have been made to use genome-wide association studies (GWAS) to untangle the genetic basis for SARS-CoV-2 infection susceptibility and severe COVID-19. However, data on the genetic-related effects of SARS-CoV-2 infection on the presence of accompanying and long-term post-COVID-19 neurological symptoms in younger individuals remain absent. We aimed to examine the possible association between SNPs found in a GWAS of COVID-19 outcomes and three phenotypes: SARS-CoV-2 infection, neurological complications during disease progression, and long-term neurological complications in young adults with a mild-to-moderate disease course. University students (N = 336, age 18–25 years, European ancestry) with or without COVID-19 and neurological symptoms in anamnesis comprised the study sample. Logistic regression was performed with COVID-19-related phenotypes as outcomes, and the top 25 SNPs from GWAS meta-analyses and an MR study linking COVID-19 and cognitive deficits were found. We replicated previously reported associations of the FURIN and SLC6A20 gene variants (OR = 2.36, 95% CI 1.31–4.24) and OR = 1.94, 95% CI 1.08–3.49, respectively) and remaining neurological complications (OR = 2.12, 95% CI 1.10–4.35 for SLC6A20), while NR1H2 (OR = 2.99, 95% CI 1.39–6.69) and TMPRSS2 (OR = 2.03, 95% CI 1.19–3.50) SNPs were associated with neurological symptoms accompanying COVID-19. Our findings indicate that genetic variants related to a severe COVID-19 course in adults may contribute to the occurrence of neurological repercussions in individuals at a young age.

The present review describes longitudinal studies of cognitive traits and functions determining the causes of their variations and their possible correction to prevent cognitive impairment. The present study reviews the involvement of such environmental factors as nutrition, prenatal maternal stress, social isolation and others in cognitive functioning. The role of epigenetic factors in the implementation of environmental effects in cognitive characteristics is revealed. Considering the epigenome significance, several studies were focused on the design of substances affecting methylation and histone modification, which can be used for the treatment of cognitive disorders. The appropriate correction of epigenetic factors related to environmental differences in cognitive abilities requires to determine the mechanisms of chromatin modifications and variations in DNA methylation. Transposons representing stress-sensitive DNA elements appeared to mediate the environmental influence on epigenetic modifications. They can explain the mechanism of transgenerational transfer of information on cognitive abilities. Recently, large-scale meta-analyses based on the results of studies, which identified genetic associations with various cognitive traits, were carried out. As a result, the role of genes actively expressed in the brain, such as BDNF, COMT, CADM2, CYP2D6, APBA1, CHRNA7, PDE1C, PDE4B, and PDE4D in cognitive abilities was revealed. The association between cognitive functioning and genes, which have been previously involved in developing psychiatric disorders (MEF2C, CYP2D6, FAM109B, SEPT3, NAGA, TCF20, NDUFA6 genes), was revealed, thus indicating the role of the similar mechanisms of genetic and neural networks in both normal cognition and cognitive impairment. An important role in both processes belongs to common epigenetic factors. The genes involved in DNA methylation (DNMT1, DNMT3B, and FTO), histone modifications (CREBBP, CUL4B, EHMT1, EP300, EZH2, HLCS, HUWE1, KAT6B, KMT2A, KMT2D, KMT2C, NSD1, WHSC1, and UBE2A) and chromatin remodeling (ACTB, ARID1A, ARID1B, ATRX, CHD2, CHD7, CHD8, SMARCA2, SMARCA4, SMARCB1, SMARCE1, SRCAP, and SS18L1) are associated with increased risk of psychiatric diseases with cognitive deficiency together with normal cognitive functioning. The data on the correlation between transgenerational epigenetic inheritance of cognitive abilities and the insert of transposable elements in intergenic regions is discussed. Transposons regulate genes functioning in the brain due to the processing of their transcripts into non-coding RNAs. The content, quantity and arrangement of transposable elements in human genome, which do not affect changes in nucleotide sequences of protein encoding genes, but affect their expression, can be transmitted to the next generation.Рассмотрена роль лонгитюдных исследований когнитивных характеристик в определении причин, влияющих на познание, с целью возможной их коррекции для улучшения познавательных навыков. В данных исследованиях показано, что на развитие когнитивных функций влияют такие средовые факторы, как качество нутриентов, стресс во время гестации и характер социального окружения. Выявлены специфические эпигенетические изменения, выступающие в качестве посредников между генотипом и средой в реализации когнитивных функций. В связи с важным значением эпигенома перспективна разработка методов терапии когнитивных расстройств с использованием агентов, влияющих на метилирование и модификации гистонов. Развивающимся направлением в этой области является изучение некодирующих РНК, которые способны модифицировать эпи- генетические факторы. За последние годы проведены широкомасштабные метаанализы результатов исследова- ний роли генетических ассоциаций с различными когнитивными характеристиками. Показано значение активно экспрессирующихся в головном мозге генов, таких как BDNF, COMT, CADM2, CYP2D6, APBA1, CHRNA7, PDE1C, PDE4B, PDE4D. С физиологическим познанием оказались ассоциированы гены, вовлеченные в развитие психических заболеваний (MEF2C, CYP2D6, FAM109B, SEPT3, NAGA, TCF20, NDUFA6). В развитие психических заболеваний с ког- нитивным дефицитом вовлечены гены, участвующие в метилировании ДНК (DNMT1, DNMT3B, FTO), модификации гистонов (CREBBP, CUL4B, EHMT1, EP300, EZH2, HLCS, HUWE1, KAT6B, KMT2A, KMT2D, KMT2C, NSD1, WHSC1, UBE2A) и моделировании хроматина (ACTB, ARID1A, ARID1B, ATRX, CHD2, CHD7, CHD8, SMARCA2, SMARCA4, SMARCB1, SMARCE1, SRCAP, SS18L1), которые имеют значение в регуляции когнитивных функций у здоровых людей. Приведены дан- ные, позволяющие предположить, что трансгенерационное наследование когнитивных характеристик связано с некодирующими РНК, а также со способностью мобильных элементов, инсертированных в межгенные области, влиять на регуляцию функционирующих в головном мозге генов за счет процессинга транскриптов транспозо- нов в некодирующие РНК. Особенности состава, количества и распределения в геноме мобильных элементов, которые не изменяют нуклеотидные последовательности белок-кодирующих генов, но влияют на их экспрес- сию, могут передаваться из поколения в поколение.

The difficulties frequently caused by increased stress sensitivity while performing mathematical operations (mathematical anxiety, MA) represent an important problem for individual success. To date, no molecular-genetic studies have been published with respect to variations in math anxiety. According to “generalist genes hypothesis,” the genes involved in regulation of cognitive functioning and stress-associated component, including SNAP25, ARC, and GRIK1 genes, might be of interest to unravel the genetic nature of MA. Considering the necessity to include stress-related environmental factors in the analysis, the present study estimated both the main effect of SNAP25 (rs1051312, rs363050), ARC (rs2234911), and GRIK1 (rs2832407) gene polymorphisms and G × E interactions in individual differences in MA in 523 healthy individuals without cognitive decline with consideration of sex- and ethnicity-related differences. The association of SNAP25 rs363050*G allele with higher MA was observed in Tatars (P = 0.014, PFDR = 0.041, r2 = 0.044). As a result of multiple regression analysis, the G × E model including ARC (rs2234911)* order of birth affecting MA level was established (βST = 0.17, r2 = 0.017, Р = 0.049). The data obtained indicate the involvement of the SNAP25 and ARC genes

The paper presents result of the development of the open digital platform (DigitalPsyTools.ru), which provides support for conducting the large-scale psychological research. Development of the dedicated information and data analysis instrument has a goal to consolidate the efforts of the professional interdisciplinary specialists in the area of psychological research on a single platform. Digital psychological platform is built as an evolving information environment with the toolset for conducting psychological studies of all levels. The paper describes the key functional capabilities, tasks solved and requirements implied for the software implementation and target environment conditions. The scalability, variability of the target execution environments of the software components and local specifics provide the foundation for crystallization of the platform development principles. Internal standard of the psychological test representation in a semi-structured form, corresponding domain-specific programming language and its interpreter software were developed. These components provide means for automatic questionnaire web-interface generation for the study participants. The results of the web-interface testing using varying devices are presented.

Multiple studies demonstrating the association of aggressive behavior with allelic variants of neurotransmitter system genes appear to be controversial, while “risk” alleles have no effect on impaired gene expression and functioning of encoded proteins. To explain these associations, we suggested the role of deregulated epigenetic processes caused by the changes in the spatial configuration of transcribed proteins owing to the impaired interaction with noncoding RNAs, which results in modified functioning of genetic networks. Stressful life events occurring during the pre- and postnatal period causing changes in DNA methylation and histone modifications, which disrupt expression of neurotransmitter genes with a long-lasting effect, represent the key factors causing the manifestation of aggressive behavior. The role of stressful life events in epigenome modifications is assumed to be caused by stress-sensitive transposable elements (TEs), whose processing results in the formation of noncoding RNAs probably affecting histone modifications and methylation of certain genomic loci. Transposable elements represent the key sources of sites of binding to transcription factors and regulate genome expression, while their ability to locus-specific transpositions under the stress and self-regulation by noncoding RNAs can explain both the long-term effect of behavioral impairments and their transgenerational transfer. Prevention of behavioral impairments and phenotypic manifestations of genetic liability to aggressive behavior requires the examination of the individual nature of epigenetic modifications for the further targeted action and their correction.

The paper presents a review of the results of molecular genetic studies of cognitive abilities. To date, a small number of genes responsible for normal cognitive functioning have been detected despite numerous studies based on the approach of candidate genes, genome-wide association studies, and linkage analyses. It should be considered that, even when the genetic variants were significantly associated with cognitive phenotypes, the sizes of the effect were usually very low (1–2%). However, large-scale genetic studies performed in the last few years significantly expanded the knowledge on the molecular basis of human cognitive abilities and made it possible to explain up to 20% of the 50% inheritance of intelligence.

The extent to which the approximate number sense is based on the estimation of continuous visual properties has been widely discussed. Some investigators have hypothesized that humans are able to estimate numerosity directly and independently of visual cues. Other investigators have posited that numerosity can be processed only via the estimation of non-numeric visual properties. The latter theory is confirmed by the existence of the congruency effect, that is, greater accuracy in congruent trials where visual properties were positively correlated with numerosity compared with that in incongruent trials. In this study, we tested the assumption that the congruency effect, reflecting the bias in numerosity estimation due to the estimation of visual cues, varies depending on the format of the stimulus presentation and object heterogeneity. The study involved a sample of pupils in Grades 5-9 from Kyrgyzstan (N = 764; 48% girls; mean age = 13.06 years), whereby participants performed a nonsymbolic comparison test in four formats of stimulus presentation: paired/homogeneous, paired/heterogeneous, mixed/homogeneous, and mixed/heterogeneous. Compared arrays of figures might be congruent or incongruent for one visual parameter (convex hull or cumulative area), whereas another visual parameter was held constant for two arrays. The results of generalized linear mixed-effect models demonstrated that the largest congruency effect occurred in a paired format with homogeneous figures. The congruency effect was insignificant in the mixed/heterogeneous format. The results also revealed that the effects of the convex hull and cumulative area varied in different formats of stimulus presentations.

Web-surveys are one of the most popular forms of primary data collection used for various researches. However, mass surveys involve some challenges. It is required to consider different platforms and browsers, as well as different data transfer rates using connections in different regions of the country. Ensuring guaranteed data delivery in these conditions should determine the right choice of technologies for implementing web-surveys. The paper describes the solution to transfer a questionnaire to the client side in the form of an archive. This technological solution ensures independence from the data transfer rate and the stability of the communication connection with significant survey filling time. The conducted survey benefited the service of education psychologists under the federal Ministry of Education. School psychologists consciously took part in the survey, realizing the importance of their opinion for organizing and improving their professional activities. The desire to answer open-ended questions in detail created a part of the answers in the dataset, where there were several sentences about different aspects of professional activity. An important challenge of the problem is the Russian language, for which there are not as many tools as for the languages more widespread in the world. The survey involved 20,443 school psychologists from all regions of the Russian Federation, both from urban and rural areas. The answers did not contain spam, runaround answers, and so on as evidenced by the average response time. For the surveys, an authoring development tool DigitalPsyTools.ru was used.

The relationship between cognitive abilities and academic achievement across schooling from the first to the eleventh grade was analyzed. Information processing speed, visuospatial working memory, number sense, and fluid intelligence were considered predictors of general academic achievement, which was derived from grades in mathematics, language, and biology. This cross-sectional study involved 1560 pupils who were in grades 1&ndash, 11 at general education schools and were aged from 6.8 to 19.1 years (50.4% were boys). Information processing speed, visuospatial working memory, and number sense were measured using the Choice Reaction Time, Corsi Block-Tapping, and Number Sense computerized tests, respectively. Fluid intelligence was measured using the paper-and-pencil version of the Standard Progressive Matrices test. Correlation analysis and structural equation modeling were carried out. It was shown that it is possible to describe the structure of the relationship between cognitive abilities and academic achievement for all levels of schooling with a single model. In this model, information processing speed is the key predictor of fluid intelligence, working memory, and number sense, which in turn contribute to individual differences in academic success. Additionally, the specificity of the relationship between individual indicators of cognitive abilities and academic achievement at each level of schooling was revealed.

The main aim of this study was to analyze the patterns of changes in Approximate Number Sense (ANS) precision from grade 1 (mean age: 7.84 years) to grade 9 (mean age: 15.82 years) in a sample of Russian schoolchildren. To fulfill this aim, the data from a longitudinal study of two cohorts of children were used. The first cohort was assessed at grades 1–5 (elementary school education plus the first year of secondary education), and the second cohort was assessed at grades 5–9 (secondary school education). ANS precision was assessed by accuracy and reaction time (RT) in a non-symbolic comparison test (“blue-yellow dots” test). The patterns of change were estimated via mixed-effect growth models. The results revealed that in the first cohort, the average accuracy increased from grade 1 to grade 5 following a non-linear pattern and that the rate of growth slowed after grade 3 (7–9 years old). The non-linear pattern of changes in the second cohort indicated that accuracy started to increase from grade 7 to grade 9 (13–15 years old), while there were no changes from grade 5 to grade 7. However, the RT in the non-symbolic comparison test decreased evenly from grade 1 to grade 7 (7–13 years old), and the rate of processing non-symbolic information tended to stabilize from grade 7 to grade 9. Moreover, the changes in the rate of processing non-symbolic information were not explained by the changes in general processing speed. The results also demonstrated that accuracy and RT were positively correlated across all grades. These results indicate that accuracy and the rate of non-symbolic processing reflect two different processes, namely, the maturation and development of a non-symbolic representation system.

Background Multiple studies of depression indicated a significant role of gene-by-environment interactions; however, they are mainly limited to the examination of modulating effect of recent stressful life events. Other environmental factors occurring at different stages of ante- and postnatal development may affect the association between multiple genes and depression. The study aimed to analyze the main and haplotype-based effect of serotonergic system and HPA-axis gene polymorphisms on depression and to detect gene-by-environment interaction models explaining individual variance in depression in mentally healthy young adults from Russia. Methods Depression score was assessed using Beck Depression Inventory (BDI) in 623 healthy individuals (81% women; 17-25 years) of Caucasian origin (Russians, Tatars, Udmurts) from Russia. The main- and gene-based effects of 12 SNPs in SLC6A4 (5-HTTLPR, rs1042173), HTR2A (rs7322347), OXTR (rs7632287, rs2254298, rs13316193, rs53576, rs2228485, rs237911), AVPR1A (rs3803107, rs1042615), and AVPR1B (rs33911258) genes, and gene-by-environment interactions were tested with linear regression models (PLINK v.1.9) adjusted for multiple comparisons. Results We observed ethnicity-specific main effect of the AVPR1A rs3803107 (P = 0.003; PFDR = 0.047) and gene-based effect of the OXTR gene (Р = 0.005; Pperm = 0.034) on BDI-measured depression, and modifying effect of paternal care on OXTR rs53576 (P = 0.004; PFDR = 0.012) and birth order on OXTR rs237911 (P = 0.006; PFDR = 0.018) association with depression level. Limitations A hypothesis driven candidate gene approach, which examined a limited number of genetic variants in a moderately large sample, was used. Conclusions Our preliminary findings indicate that familial environment may play a permissive role modulating the manifestation of OXTR-based depression variance in mentally healthy subjects., oxytocin; arginine vasopressin; serotonin; Depression; family environment; GxE interaction; Behavioral Neuroscience; Molecular Neuroscience; Mental Disorder; Genomics; Polymerase Chain Reaction; Human Genetics; Biological Psychiatry; Mental Health; Psychological Disorders.

Background. Spatial ability (SA) has long been the focus of research in psychology, because it is associated with performance in science, technologies, engineering, and mathematics (STEM). Research has shown that males consistently outperform females in most aspects of SA, which may partially explain the observed overrepresentation of male students seeking STEM degrees. Objective. Tis study examines sex and feld of study (degree) diferences in diferent aspects of spatial ability and its structure. Design. We assessed SA by using an on-line gamifed battery, which included 10 spatial tests capturing 10 dimensions of spatial ability, among which were mental rotation, spatial visualization, spatial scanning, spatial reasoning, perspective-taking, and mechanical reasoning. Te sample consisted of 882 STEM (55% males) and Humanities (20% males) university students in Russia. Results. Males outperformed females on all assessed components of SA with a small efect size (1–11%). We also found that students from STEM felds outperformed Humanities students on all SA subtests (efect size ranged from 0.2 to 7%). Tese diferences by study choice were not fully explained by the observed over-representation of males in the STEM group. Te results of the study suggested no interaction between sex and degree. In other words, on average, males outperformed females, irrespective of whether they were STEM or humanities students; and the STEM advantage was observed for both males and females. Te same unifactorial structure of SA was observed in the STEM and Humanities groups. Conclusion. Our results are consistent with previous research, suggesting sex and study feld diferences in SA. Longitudinal research is needed to explore the causal mechanisms underscoring these diferences.

Background. Mental fatigue is a state of tiredness, decreased motivation, and increased aversion to performing a task. Mental fatigue is associated with the length of engagement in an activity (time-on-task) and the degree of cognitive efort required. In addition, mental fatigue can be afected by personality characteristics, such as trait or domain-specifc anxiety. Tere is a lack of research into associations between mental fatigue and trait anxiety, as well as specifc types of anxiety such as math anxiety. Objective. Tis study investigates whether the level of mental fatigue manifested in an EEG taken during the performance of a mixed problem-solving task, is associated with math and trait anxiety. Design. An EEG recording was performed on participants in a resting state with their eyes closed in two runs, both before and afer they performed a task. Te task consisted of three types of stimuli: arithmetic, algebraic, and lexical. Results. Te results showed that the EEG correlates of fatigue changed between the frst and second runs. Tese changes were not linked with mathematics anxiety. Some signifcant EEG efects were found for trait anxiety: people with high trait anxiety appeared more aroused and showed less fatigue efects. However, these results did not reach the level of signifcance afer correction for multiple comparisons. Conclusion. Overall, our results are in line with the motivational control theory, according to which mental fatigue “resets” when a person switches from one task to another. In our study, the experimental paradigm consisted of three types of tasks, a format which might have prevented fatigue. We discuss the implications of the study for further research into the links between anxiety and mental fatigue.