Sergey B. Malykh

Background. In recent years, experimental studies concerning the role of the cerebellum in cognitive functions and a variety of language deficits have been conducted.

Objective. To evaluate the impact of posterior fossa tumors (PFT) on spatial working memory and eye-movement behavior during reading in children and to compare the system-level organization of working memory and gaze-related parameters between patients and typically developing peers.

Design. This retrospective cohort study applied advanced analytical methods, including Drift Diffusion Modeling (DDM) and Recurrence Quantification Analysis (RQA), to capture the temporal dynamics of cognitive processing and oculomotor control. The study included 119 children aged 8 to 17 years: 59 survivors of posterior fossa tumors and 60 healthy controls. Working memory was assessed using the Spatial Span task from the CANTAB battery, modeled using DDM parameters, while eye movements during reading were recorded with eye tracking and analyzed using RQA. Network analysis was conducted to characterize cross-domain integration between working memory dynamics and gaze behavior.

Results. Our findings indicate that cerebellar disruption due to tumor and treatment affects not only isolated aspects of reading or eye-movement behavior, but also the functional coordination between working memory and oculomotor control. Stronger working memory capacity was associated with more organized and predictable gaze dynamics in controls, whereas patients showed reduced flexibility and altered connectivity patterns. RQA parameters captured a unified dynamical system, linking cognitive control and motor implementation during reading.

Conclusion. These findings highlight the importance of considering subtle, system-level disruptions in posterior fossa tumor patients and underscore the relevance of using multimodal, temporally sensitive approaches when designing rehabilitation protocols.

Background. Visuospatial working memory (VSWM) is critical for academic achievement, particularly in mathematics. The Corsi Block-Tapping Test (CBTT) is one of the most widely used tools to assess VSWM, traditionally relying on span length as the primary performance indicator. However, recent research suggests that additional metrics, such as accuracy and reaction time (RT), may offer complementary insights. Despite this, RT remains underexplored in studies examining VSWM development and its links to academic outcomes such as math performance.

Objective. To investigate age- and sex-related changes in VSWM using CBTT accuracy, span, and RT, and to examine how these metrics relate to math achievement across school grades and sexes.

Design. Data were collected from 2,749 Russian pupils (53% girls), aged 10 to 18 years (M = 13.89, SD = 2.08), enrolled in grades 5 to 11 in two regions (Nizhny Novgorod and Irkutsk). Regression analysis was applied to three indicators of CBTT and math achievement that was measured by average school grades.

Results. CBTT accuracy increased and RT decreased from grades 5 to 8, then both increased post-grade 9, suggesting a developmental shift. Accuracy predicted math grades in grades 5–9 but not later; RT was a stable negative predictor across all grades. Sex did not moderate VSWM–math associations, though girls showed greater RT efficiency in late adolescence.

Conclusion. VSWM develops along non-linear trajectories that differ by metric. Multi-indicator assessment is essential, and school grades should be interpreted with caution as proxies for math ability.

Background. The quality of sleep significantly impacts children’s day-to-day performance, with at least 20% reporting issues with sleepiness. Valid tools for assessing the quality of sleep are needed.

Objective. In this study, we assessed the psychometric properties of the Russian version of the Pediatric Daytime Sleepiness Scale (PDSS). The initial adaptation of the PDSS was conducted on a sample from the Arctic regions of Russia. This location may have influenced the scale's generalizability due to variations in natural daylight across different areas of the country.

Design. To rectify this, we gathered a comprehensive, geographically diverse sample from Russia. This combined dataset comprised 3772 participants between 10 to 18 years of age, from nine different regions of Russia.

Results. We confirmed the unifactorial structure of the PDSS, which showed no regional effects. The psychometric analysis indicated that one item from the 8-item PDSS could be removed, thereby improving the scale's model fit. We also observed gender and age impacts on sleep quality: boys reported fewer sleep-related issues than girls, and younger children reported fewer problems than older children.

Conclusion. This study validates the usefulness and reliability of the Russian version of the PDSS, thereby enhancing its general applicability. Furthermore, we replicated previously reported age and sex effects on the sleep quality of school-aged children.

Background. The cognitive predictors of academic achievement are associated both with basic cognitive abilities such as the information processing speed, number sense and visuospatial working memory, as well as with general ability including nonverbal intelligence. However, the ratio between cognitive development and school achievement can depend on sociocultural conditions.

Objective. The results of a cross-cultural analysis of the relationship between cognitive development and academic achievement during primary education are presented. The analysis was conducted sampling schoolchildren from Russia and Kyrgyzstan, two countries that have a similar organization of the national education system but differ in the level of socioeconomic development.

Design. The study involved 732 schoolchildren aged 7.7 to 11.8 years studying in Russia and Kyrgyzstan. Information processing speed, visuospatial working memory, and number sense were assessed using each of “Choice Reaction Time,” “Corsi Block-Tapping Test,” and “Number Sense” computerized tests.

Results. According to the results, empirical data in both samples show that a model where in information processing speed signifies basic cognitive ability is a key predictor of nonverbal intelligence, working memory, and number sense, and each of these may contribute to individual differences in academic achievement. Notwithstanding the universality of this model, cross-cultural differences were seen to engender a reduction of schoolchildren’s academic achievements, given possible impacts of less favorable educational conditions.

Conclusion. In the relationship between cognitive abilities and academic success at the primary school education, there are both similarities and differences between schoolchildren studying in Russia and Kyrgyzstan.  

Background. Visuospatial working memory changes across years of schooling. According to data from the cross-sectional and longitudinal studies available in the literature, conclusions about the linear or nonlinear nature of changes in visuospatial working memory depend on the period of time analyzed and the frequency of the measurements. However, which of the two nonlinear models of functional dependence (e.g., quadratic or cubic) best describes the developmental trajectories of visuospatial memory across schooling is still an open question. 

Objective. The results of statistical analysis of the development of visuospatial working memory in girls and boys across school years from Grade 1 to Grade 11 are presented. Additionally, the relationship between age and years of schooling is investigated, as is the influence of these factors on the developmental trajectory of visuospatial working memory.

Design. This cross-sectional study involved 1,246 pupils who were in Grades 1 to 11 at one public school; their ages ranged from 6.8 to 19.1 years (50.4% were boys). The students’ visuospatial working memory was measured using the computerized “Sequences” test, which is based on the “Corsi block-tapping task” and has been adapted for Russian schoolchildren. Correlations, dispersion analysis, and polynomial regression were carried out, and both linear and nonlinear models of the functional dependence of working memory on years of schooling were tested. 

Results. The results of the multiple regression analysis suggest that number of years of schooling is a more important factor than age with regard to temporal changes in visuospatial working memory. When we introduced “years of schooling” and “age” predictors into a single model, we found the year of schooling  to be the most significant predictor of visuospatial working memory (β = 1.07;p = 0.000).While age remained a statistically significant predictor (β = -0.52;p = 0.008), it did not significantly improve the model characteristics (corrected R² = 0.30; F(2) = 253.9; p<0.01).

The results of the polynomial regression showed that during schooling, the developmental trajectories of visuospatial working memory are nonlinear for both genders. In girls, both the quadratic and cubic models explained 36% of the variance in visuospatial working memory, but the quadratic model had the least number of parameters and the best fit to data. In boys, despite all theoretical models being suitable, the largest percentage of the variance in visuospatial working memory values was explained using the cubic model (R²= 0.31; p = 0.000). Thus, the characteristic of change in visuospatial working memory for girls had a quadratic relationship that stabilized after Grade 8, while for boys, the relationship was cubic, with the period of stabilization between Grades 5 and 6, and then further growth. 

Conclusion. We concluded that the number of years of study is an important factor in the development of visuospatial working memory during the schooling period, but that there are other factors involved as well. 

Background. The COVID-19 pandemic has subjected people around the world to severe stress, evoking a variety of coping responses. Coping responses can be broadly classified into four strategies: 1) problem-focused coping; 2) emotion-focused coping; 3) socially supported coping; and 4) avoidance. While there is a wide variability of individual coping responses, to some extent they are also culturally specific.

Objective. This study aimed to compare the differences in the prevalence and factor structure of coping responses during COVID-19 pandemic in three countries: Russia, Kyrgyzstan, and Peru.

Design. The sample included 501 participants from Russia, 456 participants from Kyrgyzstan, and 354 participants from Peru. The mean age of participants was 28 years in Russia (SD = 13.5); 24 years in Kyrgyzstan (SD = 10.0); and 30 years in Peru (SD = 12.3). In Russia and Kyrgyzstan, coping strategies were assessed with an abbreviated Russian adaptation of the COPE (Coping Orientations to Problems Experienced) questionnaire. In Peru, coping responses were assessed using the Spanish version of the Brief COPE questionnaire. The average scores from fifteen COPE scales were used as the input data for linear modelling and factor analysis.

Results. The coping scores varied substantially within each country. Differences between countries accounted for 17.7% of the total variability in religious coping; 15.8% in acceptance; 13.9% in mental disengagement; and less than 7% in the other coping strategies. No difference in the prevalence of coping responses was found between Russian and Kyrgyz participants after accounting for age and gender. In all three countries the coping responses were associated with the same four coping domains: problem-focused coping, socially supported coping, avoidance, and emotion-focused coping. Four factors explained up to 44% of the total variation in the COPE scores. Religious coping and mental disengagement were classified into different coping domains in the three countries.

Conclusion. The results suggest that during the COVID-19 pandemic, people from different countries apply the full range of coping responses within the four universal coping strategies. Religious coping and mental disengagement differed the most across the countries, suggesting that some coping behaviors can take on different roles within the system of coping responses to stressful events. We attribute these differences to differing cultural and socioeconomic characteristics, and the different measures taken by governments in response to COVID-19.

Background. The search for cognitive predictors of success in language learning is associated both with basic cognitive characteristics (processing speed and spatial working memory) and with general characteristics (intelligence). However, the ratio between cognitive functioning and success in language learning can change during the period of school education and depends on the socioeconomic level of the society and the effectiveness of the national educational system.

Objective. To analyze the cognitive predictors of Russian language learning samples of Russian-speaking 11th graders from Russia, Kyrgyzstan, and Moldova, three countries with a similar organization of the educational system, but differing in the functional effectiveness of that educational system and in their socioeconomic levels.

Design. The sample comprised 545 Russian-speaking 11th graders (average age = 17.42 + 0.59; 36.1% male) studying Russian throughout their public-school education in Russia, Kyrgyzstan, and Moldova. The statistical methods of one-way analysis of variance, correlation, and multiple regression analysis were used.

Results. Among the indicators of cognitive development we analyzed, the functioning of the national educational system is the one most associated with the development of fluid intelligence of 11th graders, which is directly proportional to the quality of education in the country; to a lesser extent, it is associated with the development of working memory. In Kyrgyzstan (with an average level of socioeconomic development) and Moldova (with a high level of socioeconomical development), only fluid intelligence was associated with the score on the state exam on the Russian language. In Russia, which has a very high level of socioeconomic development, fluid intelligence and spatial working memory were updated.

Conclusion. Differences in the relationship between cognitive functioning and success in Russian-language learning are associated both with the objectives of the state exam (identification of pupils ready to attend university versus testing of what was learned in school), and, in conditions of low educational effectiveness, with a greater cognitive load during the exam.

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. This study examines sex and field of study (degree) differences in different aspects of spatial ability and its structure.

Design. We assessed SA by using an on-line gamified 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. The 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 effect size (1–11%). We also found that students from STEM fields outperformed Humanities students on all SA subtests (effect size ranged from 0.2 to 7%). These differences by study choice were not fully explained by the observed over-representation of males in the STEM group. The 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. The 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 field differences in SA. Longitudinal research is needed to explore the causal mechanisms underscoring these differences.

This article presents the results of a study of mathematical fluency in high school students. We provide a definition of mathematical fluency and illustrate the relevance of the research by presenting an overview of studies examining mathematical fluency development and its relationship with success in mathematical disciplines.

A computerized test “Problem Verification Task” (Tosto et al., 2013) was administered to 692 high school students from one public secondary school (grades 9/10/11: n = 336/210/146) in the Moscow region. The stimuli consisted of 48 elementary arithmetic equations along with answer options. To indicate a correct answer, participants were instructed to press the corresponding key on the keyboard as quickly as possible.

Two-way ANOVA was used to estimate grade and sex similarities and differences in mathematical fluency at the high school level.

The current study has two primary findings: (1) students differed in math fluency across grades, and (2) there were no sex differences in mathematical fluency at the high school level. ANOVA exhibited significant differences in mathematical fluency among all three groups of students at grades 9, 10 and 11 with a 19% effect size. These results may be associated with the accumulating effects of the educational process: high school students in each subsequent year of schooling demonstrate a higher level of mathematical fluency on average compared to the previous year. At the same time, we observed no sex differences in mathematical fluency at the high school level. The results are discussed in terms of educational effects.

This study examines the role of cognitive characteristics in the success in learning Russian, assessed through teachers’ grades and test scores on standardized state exams.

This paper examines the relationship between cognitive characteristics, such as nonverbal intelligence, working memory and speed of information processing, and the results of the Unified State Exam for 11^th grade students, the Basic State Exam for 9^th grade students and the traditional assessment of Russian language learning.

This study involved students in the 9^th and 11^th grades from four educational institutions in the Moscow and St. Petersburg regions; 427 students were studying in the 9th grade (50.3% were boys) and 398 students were studying in the 11^th grade (44.8% were boys).

This study concluded that expert assessment of Russian language learning is more associated with successful test scores on the Unified State Exam (r = 0.71, p < 0.01) than with the results of the Basic State Exam (r = 0.46, р < 0.01).

This study showed that at the lower and upper levels of secondary education, nonverbal intelligence is a significant predictor of success in learning the Russian language according to expert estimates. In addition, we found differences in the relationship between cognitive performance and success in learning the Russian language as assessed by tests. Nonverbal intelligence contributes significantly to individual differences in scores for the Unified State Exam in Russian, while the contribution of cognitive characteristics on the Basic State Exam is not statistically significant.

The Influence of genetic and environmental factors on liability to depression in Russian teenage sample was investigated. 196 twin pairs aged 13 to 17 (M=15,2) from Moscow, Izhevsk and Bishkek took part in the survey. We have found out that genetic factors had an effect on individual difference in depressiveness among Russian teenagers: more than 50% of variance was explained by additive genetic factors which correspond to international results. The biggest genetic influence was obtained for such scales as negative emotions, negative self esteem and externalization which are the most replicable factor scales in CDI structure worldwide.

The article is devoted to individual differences in psychological characteristics, the influence of genotype and environment on individual differences in evoked potential of brain related to the execution of motor action, the role of genetic and environmental factors in individual characteristics of the parameters of sensorimotor activity, genetic and environmental factors in development of psychological traits.

Gene-environment correlations have been studied in behavior genetics since the beginning of the 1980s, including genetic effect on the perceived family environment; however, the majority of studies have been based on retrospective self-reports. The current study is meant to analyze the sources of variance (complementary genetic factors, shared and non-shared environmental variance) in perceived family environment with Russian adolescent twins. Perception of family environment was measured with the Russian version of Family Environment Scale (Moos & Moos, 1981). The structural equation model in "Mx"(Neale, Boker, Xie, & Maes, 2004) was employed to estimate the influence of genetic and environmental factors on adolescents' self-reports. The environmental variance components are prevalent for most FES scales (6 of 10). The shared environment was significant for 3 primary grades and the Organization factor, the complementary genetic variance was revealed for 2 primary grades and the Expressiveness-Control super-order factor. These results are generally consistent with previously reported moderate heritability of FES scales, although the heritabilities for the Conflict scale and the Structure super-order factor appear to be relatively high. The gene-environment correlation might be a possible explanation for these findings.

This study, which is a part of a Moscow longitudinal twin project, aims to explore genetic and environmental contributions to inter-individual variability of temperamental traits in adolescence on the basis of a Russian sample. 85 monozygotic (MZ) and 64 same-sex dizygotic (DZ) twin pairs aged 12 – 14 years completed the children version of Rusalov Structure of Temperament Questionnaire (C-STQ). The results of model-fitting analyses indicate considerable hereditary determination of individual differences in 3 out of the 8 C-STQ dimensions - social tempo, objectrelated emotional sensitivity, and social emotional sensitivity. Non-shared environmental effects explained the rest of the total variance in these dimensions. Individual differences in the other STQ dimensions were due to environmental factors.