The effect of masks on cognitive performance.

The use of face masks has been a key response to the COVID-19 pandemic in almost every country. However, despite widespread use of masks in classrooms and offices around the world, almost nothing is known about their effects on cognitive performance. Using a natural experiment, I show that mandatory mask wearing has a negative causal effect on the cognitive performance of competitive chess players. I analyzed the quality of almost 3 million chess moves played by 8,531 individuals (ages 5-98 y) in 18 countries before and during the pandemic. Wearing a mask decreased the quality of players' decisions-a measure of their cognitive performance-by approximately one-third of an SD. However, the disruptive effect of masks is relatively short-lived, gradually weakening such that there is no measurable disadvantage from wearing a mask after roughly 4 h of play. The mask effect is driven by a large, negative effect for experts, with minimal change in performance at lower levels, and is stronger in high-incentive competitions. I provide support for a distraction mechanism whereby masks interfere with performance when working memory load is high.

Cultural transmission of move choice in chess.

The study of cultural evolution benefits from detailed analysis of cultural transmission in specific human domains. Chess provides a platform for understanding the transmission of knowledge due to its active community of players, precise behaviours and long-term records of high-quality data. In this paper, we perform an analysis of chess in the context of cultural evolution, describing multiple cultural factors that affect move choice. We then build a population-level statistical model of move choice in chess, based on the Dirichlet-multinomial likelihood, to analyse cultural transmission over decades of recorded games played by leading players. For moves made in specific positions, we evaluate the relative effects of frequency-dependent bias, success bias and prestige bias on the dynamics of move frequencies. We observe that negative frequency-dependent bias plays a role in the dynamics of certain moves, and that other moves are compatible with transmission under prestige bias or success bias. These apparent biases may reflect recent changes, namely the introduction of computer chess engines and online tournament broadcasts. Our analysis of chess provides insights into broader questions concerning how social learning biases affect cultural evolution.

The Gender-Equality Paradox in Chess Participation Is Partially Explained by the Generational-Shift Account but Fully Inconsistent With Existing Alternative Accounts: A Partial Concession and Reply to Napp and Breda (2023).

Napp and Breda (2023) raised three arguments against the generational-shift account of the gender-equality paradox (GEP) in chess participation. First, using finer operationalizations of the age structure of players, they showed that it partially but not fully accounts for the GEP in chess participation. I find merit in these analyses and conclusion. Second, they argued that the country-level age structure is unrelated to the GEP in chess participation, which undermines the generational-shift account of the GEP. In contrast, I provide new analyses to show that the two are related after adjusting for the U-shaped relation between gender equality and female chess participation. Finally, they argued that previous explanations of the GEP are viable for explaining the GEP in chess participation. In contrast, I argue that the global increase in the proportion of female players is incompatible with previous explanations of the GEP, and I provide new analyses to support this.

On the Value of Chess Squares.

We propose a neural network-based approach to calculate the value of a chess square-piece combination. Our model takes a triplet (color, piece, square) as the input and calculates a value that measures the advantage/disadvantage of having this piece on this square. Our methods build on recent advances in chess AI, and can accurately assess the worth of positions in a game of chess. The conventional approach assigns fixed values to pieces (= ∞, = 9, = 5, = 3, = 3, = 1). We enhance this analysis by introducing marginal valuations. We use deep Q-learning to estimate the parameters of our model. We demonstrate our method by examining the positioning of knights and bishops, and also provide valuable insights into the valuation of pawns. Finally, we conclude by suggesting potential avenues for future research.

[Origin, development, and modern application value of Chinese herbal lozenges].

Lozenge is one of the traditional dosage forms of Chinese medicine. It has been recorded in traditional Chinese medical classics of all dynasties since the Eastern Han Dynasty and has been developing and evolving continuously. The unique pharmaceutical methods and application scope are the driving force of its emergence, existence, and development. Up to now, lozenge has been included in the Chinese Pharmacopoeia as an independent dosage form. Lozenge has been endowed with new meaning by modern Chinese medicine pharmaceutics, which is worth tracing origin and exploring value. The present study reviewed the origin and development of lozenge, compared lozenge with other similar dosage forms, analyzed the characteristics of modern and ancient dosage forms of lozenge, and discussed the development prospect and potential of lozenge in combination with the demand development of modern Chinese medicine preparation, so as to provide references for expanding the modern application of lozenge.

Queen's Gambit Declined: The Gender-Equality Paradox in Chess Participation Across 160 Countries.

The gender-equality paradox refers to the puzzling finding that societies with more gender equality demonstrate larger gender differences across a range of phenomena, most notably in the proportion of women who pursue degrees in science, technology, engineering, and math. The present investigation demonstrates across two different measures of gender equality that this paradox extends to chess participation (N = 803,485 across 160 countries; age range: 3-100 years), specifically that women participate more often in countries with less gender equality. Previous explanations for the paradox fail to account for this finding. Instead, consistent with the notion that gender equality reflects a generational shift, mediation analyses suggest that the gender-equality paradox in chess is driven by the greater participation of younger players in countries with less gender equality. A curvilinear effect of gender equality on the participation of female players was also found, demonstrating that gender differences in chess participation are largest at the highest and lowest ends of the gender-equality spectrum.

The joint influence of intelligence and practice on skill development throughout the life span.

The relative importance of different factors in the development of human skills has been extensively discussed. Research on expertise indicates that focused practice may be the sole determinant of skill, while intelligence researchers underline the relative importance of abilities at even the highest level of skill. There is indeed a large body of research that acknowledges the role of both factors in skill development and retention. It is, however, unknown how intelligence and practice come together to enable the acquisition and retention of complex skills across the life span. Instead of focusing on the 2 factors, intelligence and practice, in isolation, here we look at their interplay throughout development. In a longitudinal study that tracked chess players throughout their careers, we show that both intelligence and practice positively affect the acquisition and retention of chess skill. Importantly, the nonlinear interaction between the 2 factors revealed that more intelligent individuals benefited more from practice. With the same amount of practice, they acquired chess skill more quickly than less intelligent players, reached a higher peak performance, and arrested decline in older age. Our research demonstrates the futility of scrutinizing the relative importance of highly intertwined factors in human development.

Chess AI: Competing Paradigms for Machine Intelligence.

Endgame studies have long served as a tool for testing human creativity and intelligence. We find that they can serve as a tool for testing machine ability as well. Two of the leading chess engines, Stockfish and Leela Chess Zero (LCZero), employ significantly different methods during play. We use Plaskett's Puzzle, a famous endgame study from the late 1970s, to compare the two engines. Our experiments show that Stockfish outperforms LCZero on the puzzle. We examine the algorithmic differences between the engines and use our observations as a basis for carefully interpreting the test results. Drawing inspiration from how humans solve chess problems, we ask whether machines can possess a form of imagination. On the theoretical side, we describe how Bellman's equation may be applied to optimize the probability of winning. To conclude, we discuss the implications of our work on artificial intelligence (AI) and artificial general intelligence (AGI), suggesting possible avenues for future research.

Reduced Thalamus Volume and Enhanced Thalamus and Fronto-Parietal Network Integration in the Chess Experts.

The ability of chess experts depends to a large extent on spatial visual processing, attention, and working memory, all of which are thought to be mediated by the thalamus. This study explored whether continued practice and rehearsal over a long period of time results in structural changes in the thalamic region. We found smaller gray matter volume regions in the thalami of expert Chinese chess players in comparison with novice players. We then used these regions as seeds for resting-state functional connectivity analysis and observed significantly strengthened integration between the thalamus and fronto-parietal network in expert Chinese chess players. This strengthened integration that includes a group of brain regions showing an increase in activation to external stimulation, particularly during tasks relying on working memory and attention. Our findings demonstrate structural changes in the thalamus caused by a wide range of engagement in chess problem solving, and that this strengthened functional integration with widely distributed circuitry better supports high-level cognitive control of behavior.

Are the advantages of chess expertise on visuo-spatial working-memory capacity domain specific or domain general?

Chess experts have repeatedly demonstrated exceptional recall of chessboards, which is weakened by disruption of the chessboard. However, chess experts still perform better than novices when recalling such disrupted chessboards, suggesting a somewhat generalized expertise effect. In the current study, we examined the extent of this generalized expertise effect on early processing of visuo-spatial working memory (VSWM), by comparing 14 chess experts (Elo rating > 2000) and 15 novices on a change-detection paradigm using disrupted chessboards, where attention had to be selectively deployed to either visual or spatial features, or divided across both features. The paradigm differed in the stimuli used (domain-specific chess pieces vs. novel visual shapes) to evaluate domain-general effects of chess expertise. Both experts and novices had greater memory discriminability for chess stimuli than for the unfamiliar stimuli, suggesting a salience advantage for familiar stimuli. Experts, however, demonstrated better memory discriminability than novices not only for chess stimuli presented on these disrupted chessboards, but also for novel, domain-general stimuli, particularly when detecting spatial changes. This expertise advantage was greater for chessboards with supra-capacity set sizes. For set sizes within the working-memory capacity, the expertise advantage was driven by enhanced selective attention to spatial features by chess experts when compared to visual features. However, any expertise-related VSWM advantage disappeared in the absence of the 8 × 8 chessboard display, which implicates the chessboard display as an essential perceptual aspect facilitating the "expert memory effect" in chess, albeit one that might generalize beyond strictly domain-relevant stimuli.

Online cheating amid COVID-19.

We present evidence of cheating that took place in online examinations during COVID-19 lockdowns and propose two solutions with and without a camera for the cheating problem based on the experience accumulated by online chess communities over the past two decades. The best implementable solution is a uniform online exam policy where a camera capturing each students computer screen and room is a requirement. We recommend avoiding grading on a curve and giving students less time but simpler questions on tests.

Effectiveness of a chess-training program for improving cognition, mood, and quality of life in older adults: A pilot study.

BACKGROUND: Regular practice of a cognitively stimulating activity, such as chess, can help maintain a healthy cognitive, social, and psychological state during the aging process. OBJECTIVE: To evaluate the effects of a chess-training program on cognitive status, mood, and quality of life (QoL) in a sample of institutionalized and semi-institutionalized older adults. METHOD: A nonrandomized, controlled pilot study with repeated measures (pre- and post-intervention) was conducted. RESULTS: Analyses revealed a positive impact of the chess program on general cognitive status (p < 0.001) and promising evidence (p < 0.043) of an impact on attention, processing speed, and executive functions. The participants in the intervention group also showed significant improvement in QoL scores (p < 0.021). CONCLUSIONS: A 12-week chess-training protocol with two 60-minute sessions per week improved cognition and QoL in a sample of institutionalized and semi-institutionalized older adults. Further research with larger samples is needed to explore its effects in depth.

Predicting care intensity in geriatric home care patients: a comparison of different measures.

BACKGROUND: Dependency in older ages is increasing. Many older persons receive care while living in the community. We aimed to identify the predictive value of four clinical measurements to predict home care intensity in older patients following discharge from hospital to home care over 90 days. METHODS: We included 425 inpatients from the "Frailty Department-Local Palliative Care Network" of the local social health authority (ASST) Lecco, Italy (mean age 75.4 years, SD 14.5; female 75.5%). Changes in Health, End-stage disease, and Signs and Symptoms, light version (CHESS-Lite), activities of daily living (ADL), frailty, and the Service Urgency Algorithm. Receiver operative curves were used to calculate the area under the curve (AUC) for predicting Home Care Intensity coefficient (ratio of the number of days when any home care was provided 90 days post-discharge). The interRAI Contact Assessment Instrument was used to calculate these measures. RESULTS: Analysis was stratified using six different home care intensity score cut-offs. CHESS-Lite had a higher AUC for predicting home care intensity at all cut-off levels but was best for predicting the highest level of home care intensity (≥ 0.8) where the AUC was 0.71 (0.64-0.79). The frailty index also had an acceptable AUC. ADL had the lowest AUC. CONCLUSIONS: Health instability measured with CHESS-Lite has a high predictive value for identifying home care intensity in geriatric patients after discharge from hospital to home, especially in persons with higher home care intensity scores. Geriatric patients with high health instability should be focused on at discharge to prioritize assessment and initiate timely services for home care support.

Dynamics of the Prefrontal Cortex during Chess-Based Problem-Solving Tasks in Competition-Experienced Chess Players: An fNIR Study.

This study aimed to compare the dynamics of the prefrontal cortex (PFC), between adult and adolescent chess players, during chess-based problem-solving tasks of increasing level of difficulty, relying on the identification of changes in oxygenated hemoglobin (HbO2) and hemoglobin (HHb) through the functional near-infrared spectroscopy (fNIRS) method. Thirty male federated chess players (mean age: 24.15 ± 12.84 years), divided into adults and adolescents, participated in this cross-sectional study. Participants were asked to solve three chess problems with different difficulties (low, medium, and high) while changes in HbO2 and HHb were measured over the PFC in real-time with an fNIRS system. Results indicated that the left prefrontal cortex (L-PFC) increased its activation with the difficulty of the task in both adolescents and adults. Interestingly, differences in the PFC dynamics but not in the overall performance were found between adults and adolescents. Our findings contributed to a better understanding of the PFC resources mobilized during complex tasks in both adults and adolescents.

The influence of context on information processing.

The main research question of this study is how the processing of information relates to different contextual characteristics. More specifically, how the context is associated with efficiency of information processing (success and speed), size of chunks, speed of chunk processing and the recall of a chunk. The research domain was the game of chess. The efficiency of information processing and the chunk characteristics were defined with the reconstruction of sequences of chess moves. Context variables were defined using a slightly adapted chess program. Variables on information dispersion, deviation, complexity and positivity were extracted in each chess position. Overall, the results showed that higher dispersion and complexity and lower positivity of information in a context lead to less efficient information processing. The results support the assumptions of the cognitive load theory about the negative effects of external factors burden on information processing and working memory. Our results also support the ACT-R theory, which suggests that more frequent information has a higher activation level and can therefore be retrieved more easily and quickly. The results are also congruent with the positivity effect, which proposes that it is easier to remember positive information than negative information. The findings of our study can be beneficial for the development of intelligent tutoring systems and the design of human-computer interaction systems.

A network view on brain regions involved in experts' object and pattern recognition: Implications for the neural mechanisms of skilled visual perception.

Skilled visual object and pattern recognition form the basis of many everyday behaviours. The game of chess has often been used as a model case for studying how long-term experience aides in perceiving objects and their spatio-functional interrelations. Earlier research revealed two brain regions, posterior middle temporal gyrus (pMTG) and collateral sulcus (CoS), to be linked to chess experts' superior object and pattern recognition, respectively. Here we elucidated the brain networks these two expertise-related regions are embedded in, employing resting-state functional connectivity analysis and meta-analytic connectivity modelling with the BrainMap database. pMTG was preferentially connected with dorsal visual stream areas and a parieto-prefrontal network for action planning, while CoS was preferentially connected with posterior medial cortex and hippocampus, linked to scene perception, perspective-taking and navigation. Functional profiling using BrainMap meta-data revealed that pMTG was linked to semantic processing as well as inhibition and attention, while CoS was linked to face and shape perception as well as passive viewing. Our findings suggest that pMTG subserves skilled object recognition by mediating the link between object identity and object affordances, while CoS subserves skilled pattern recognition by linking the position of individual objects with typical spatio-functional layouts of their environment stored in memory.

[Improvement of Brain Contrast Using Spin Echo T1-weighted Image at 3 T MRI].

Brain T1-weighted images using spin echo (SE) sequence has poor contrast at 3.0 Tesla magnetic resonance imaging (3.0 T MRI) systems from the influence of crosstalk and magnetized transfer (MT) effect, and prolongation of the T1 value. Therefore, improving of scan parameters has been reported such as excitation flip angle (FA) and interleave data acquisition. The purpose of this study was to show the effects of alterations of presaturation pulse amplitude and chemical shift selective (CHESS) pulse amplitude. Gray-to-white matter contrast increased with decreasing amplitude of presaturation pulse in whole brain imaging. Presaturation and CHESS pulse consist of radio frequency pulse. Therefore, both pulses have a similar effect on MT pulse. Manual alteration of presaturation pulse amplitude for each scan lacks versatility on clinical use. However, decreasing amplitude of presaturation pulse is equal to decreasing thickness of presaturation pulse. About CHESS pulse, it requires no manual alteration for each scan. For example, switching fat suppression mode from strong to weak increase T1 contrast. Our study demonstrated that using not only low excitation FA and interleave date acquisition but also low amplitude of presaturation and CHESS pulse increase the contrast in T1 SE brain scans at 3.0 T MRI.

Chess knowledge predicts chess memory even after controlling for chess experience: Evidence for the role of high-level processes.

The expertise effect in memory for chess positions is one of the most robust effects in cognitive psychology. One explanation of this effect is that chess recall is based on the recognition of familiar patterns and that experts have learned more and larger patterns. Template theory and its instantiation as a computational model are based on this explanation. An alternative explanation is that the expertise effect is due, in part, to stronger players having better and more conceptual knowledge, with this knowledge facilitating memory performance. Our literature review supports the latter view. In our experiment, a sample of 79 chess players were given a test of memory for chess positions, a test of declarative chess knowledge, a test of fluid intelligence, and a questionnaire concerning the amount of time they had played nontournament chess and the amount of time they had studied chess. We determined the numbers of tournament games the players had played from chess databases. Chess knowledge correlated .67 with chess memory and accounted for 16% of the variance after controlling for chess experience. Fluid intelligence accounted for an additional 13% of the variance. These results support the conclusion that both high-level conceptual processing and low-level recognition of familiar patterns play important roles in memory for chess positions.

Use of Biotechnological Devices in the Quantification of Psychophysiological Workload of Professional Chess Players.

Psychophysiological requirements of chess players are poorly understood, and periodization of training is often made without any empirical basis. For this reason, the aim of the present study was to investigate the psychophysiological response and quantify the player internal load during, and after playing a chess game. The participant was an elite 33 year-old male chess player ranked among the 300 best chess players in the world. Thus, cortical arousal by critical flicker fusion threshold, electroencephalogram by the theta Fz/alpha Pz ratio and autonomic modulation by heart rate variability were analyzed. Data revealed that cortical arousal by critical flicker fusion threshold and theta Fz/alpha Pz ratio increased and heart rate variability decreased during chess game. All these changes indicated that internal load increased during the chess game. In addition, pre-activation was detected in pre-game measure, suggesting that the prefrontal cortex might be preparatory activated. For these reasons, electroencephalogram, critical flicker fusion threshold and heart rate variability analysis may be highly applicable tools to control and monitor workload in chess player.

Does chess instruction improve mathematical problem-solving ability? Two experimental studies with an active control group.

It has been proposed that playing chess enables children to improve their ability in mathematics. These claims have been recently evaluated in a meta-analysis (Sala & Gobet, 2016, Educational Research Review, 18, 46-57), which indicated a significant effect in favor of the groups playing chess. However, the meta-analysis also showed that most of the reviewed studies used a poor experimental design (in particular, they lacked an active control group). We ran two experiments that used a three-group design including both an active and a passive control group, with a focus on mathematical ability. In the first experiment (N = 233), a group of third and fourth graders was taught chess for 25 hours and tested on mathematical problem-solving tasks. Participants also filled in a questionnaire assessing their meta-cognitive ability for mathematics problems. The group playing chess was compared to an active control group (playing checkers) and a passive control group. The three groups showed no statistically significant difference in mathematical problem-solving or metacognitive abilities in the posttest. The second experiment (N = 52) broadly used the same design, but the Oriental game of Go replaced checkers in the active control group. While the chess-treated group and the passive control group slightly outperformed the active control group with mathematical problem solving, the differences were not statistically significant. No differences were found with respect to metacognitive ability. These results suggest that the effects (if any) of chess instruction, when rigorously tested, are modest and that such interventions should not replace the traditional curriculum in mathematics.