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Neurophysiological and autonomic responses of high and low level chess players during difficult and easy chess endgames – A quantitative EEG and HRV study
Abstract
The aim of the present study was to analyze the heart rate variability (HRV) and the electroencephalographic (EEG) power spectrum in low and high performance chess players during easy and difficult chess endgames. A total of 28 chess players participated in this cross-sectional study. Participants were divided into two groups according to their ELO level (rating system used by the international chess federation): 1) high level chess players (more than 1600 of ELO score); and 2) low level chess players (ELO less than 1599 of ELO score). Chess players had to complete two easy and two difficult endgames while the electroencephalographic activity and heart rate variability were assessed. High level chess players exhibit more alpha EEG power spectrums (p-value>0.05) during difficult than during easy chess endgames in the occipital area (O1 and O2 electrodes). Moreover, high performance players showed a reduced autonomic modulation (p-value>0.05) during the difficult chess endgames which low performance players did not reach. These results could suggest that high level chess players adapt their neurophysiological response to the task demand.
... In this regard, previous studies showed that theta power spectrum (4-7 Hz), which has been related to mental effort [13][14][15][16][17], was increased when the level of difficulty increased [10][11][12]. In the same line, chess players exhibit a higher Alpha power spectrum (8)(9)(10)(11)(12) during difficult chess endgames [12] and higher-skilled opponents [18]. Furthermore, beta power spectrum (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) has been suggested to be behavioral arousal and attentional process biomarker [19]. ...
... In the same line, chess players exhibit a higher Alpha power spectrum (8)(9)(10)(11)(12) during difficult chess endgames [12] and higher-skilled opponents [18]. Furthermore, beta power spectrum (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) has been suggested to be behavioral arousal and attentional process biomarker [19]. ...
... In this regard, expert chess players showed higher task-related functional integration of the cortical areas [3], superior pattern recognition, and memory retrieval of chunks [22] when compared with novices. Similarly, high-level chess players exhibit greater values of Alpha power spectrum than low-level chess players during high demanding tasks [18]. ...
The study of mental load is an emerging research topic in the field of sport sciences. In the sport of chess, there is a need to understand the mental demands of the sport of chess in order to manage training loads. The present study aimed to analyze the electrical brain pattern of an elite chess player during different chess games: 15 + 10, blindfold 15 + 10, lightning game, and problem-solving chess tasks. The participant was a male 33-year-old chess player with 2562 points of ELO and more than 26 years of chess experience, training between 3 and 4 h a day. The 15 + 10 game consisted of 15 minutes + 10 seconds increment per move. In the blindfold game, the participant cannot see the positions of the pieces and does not touch them. In the lightning game, the participant played four consecutive one minute game. In addition, two high-level, two low-level, and two medium-level chess problems were performed. Electroencephalographic (EEG) and heart rate variability (HRV) responses were measured to assess the electrical brain pattern and autonomic modulation respectively. The participant won both games at 15 + 10 (normal and blindfold), lost three and drew one of the four lightning games, solved the two low-level and the two medium-level problems and solved one of the two high-level problems. Although in both games the player achieved victory the average player move quality measured with both pure analysis and analysis with additional limitations were lower in 15 + 10 blindfold game than in 15 + 10 game. Increments in theta and alpha power spectrums can be observed during the most demanding chess games (blindfold chess, lightning game, and the chess problem at difficult- level). Furthermore, the highest alpha power spectrum values can be observed during blindfold chess. In conclusion, this is the first study investigating the EEG pattern of a International Chess Grandmaster during a blindfold chess game. We found that in the chess games where lower performance is exhibited, theta and alpha power spectrums increased.
... Since HRV can serve as an indicator of brainstem activity and thus ANS function, a promising method has become available to complement EEG measurements with the goal of maintaining autonomic homeostasis during general anesthesia [16][17][18]. However, the pioneering studies of the level of concordance between EEG and HRV have mostly been performed on awake patients [19][20][21], under experimental conditions [22] or have been performed during induction of general anesthesia [17,18]. To our knowledge, the level of concordance between EEG and HRV during general anesthesia has not been adequately studied yet. ...
... Filipovic, et al. [51] showed that a preoperative LF/HF ratio below two served as the best predictor for two-year allcause mortality in 167 patients with coronary artery disease. Based on the results of this study, HRV not only provides clinically relevant orientation concerning the activity of the CNS but also enables the assessment of homeostasis of the the level of concordance of EEG and HRV has been tested on awake patients [19][20][21], under experimental conditions [22] or performed during the induction of general anesthesia [16][17][18]. But it has not been adequately studied throughout general anesthesia. ...
The aim of the proof-of-concept study is to investigate the level of concordance between the heart rate variability (HRV), the EEG-based Narcotrend Index as a surrogate marker for the depth of hypnosis, and the minimal alveolar concentration (MAC) of the inhalation anesthetic sevoflurane across the entire course of a surgical procedure. This non-blinded cross-sectional study recorded intraoperative HRV, Narcotrend Index, and MAC in 31 male patients during radical prostatectomy using the Da-Vinci robotic-assisted surgical system at Mannheim University Medical Center. The degree of concordance was calculated using repeated measures correlation with the R package (rmcorr) and presented using the rmcorr coefficient (rrm). The Narcotrend Index correlates significantly across all measures with the time-dependent parameter of HRV, the standard deviation of the means of RR intervals (SDNN) (rrm = 0.2; p < 0.001), the frequency-dependent parameters low frequency (LF) (rrm = 0.09; p = 0.04) and the low frequency/high frequency ratio (LF/HF ratio) (rrm = 0.11; p = 0.002). MAC correlated significantly negatively with the time-dependent parameter of heart rate variability, SDNN (rrm = -0.28; p < 0.001), the frequency-dependent parameter LF (rrm = -0.06; p < 0.001) and the LF/HF ratio (rrm = -0.18; p < 0.001) and the Narcotrend Index (rrm = -0.49; p < 0.001) across all measures. HRV mirrors the trend of the Narcotrend Index used to monitor depth of hypnosis and the inhibitory influence of the anesthetic sevoflurane on the autonomic nervous system. Therefore, HRV can provide essential information about the homeostasis of the autonomic nervous system during general anesthesia. DRKS00024696, March 9th, 2021.
... EEG recordings of high-performance players revealed that during rapid and lightning chess games, the right hemisphere had greater activity than the left hemisphere. This asymmetry can be attributed to the involvement of visuospatial processing (Villafaina et al., 2021). Positron emission tomography (PET) was used to examine chess players with an average of 37 years of experience. ...
... Additionally, players must possess cognitive reflection and employ planned actions in order to achieve success or emerge as winners in complex games (de Groot, 1978;Ericsson & Charness, 1994;Cumming et al., 2005;Gobet & Charness, 2006) (Campitelli & Gobet, 2005). The outcome is also consistent with neuropsychological findings that emphasize the significance of analytical cognitive processes in chess playing and expertise (Villafaina et al., 2021;Saarilouma et al., 2004). The absence of significance in the predictive role of self-efficacy may be attributed to the assessment scale's characteristics, which primarily evaluated general self-efficacy and may have a low sensitivity in detecting the variability among A+ level chess players. ...
"Literature is scarce regarding the psychological predictors of chess expertise and A-level chess performance. Methods: A cross-sectional study was designed and conducted on a total number of 90 Hungarian and Romanian competitive chess players. More than half were males, the average age was 32.07 (SD=12.99). The study aimed to explore the predictive influence of age, gender, number of hours spent practicing, preferences for rational and intuitive thinking styles, self-efficacy, and emotionality on the likelihood of obtaining a publicly accessible ELO rating within the range of 1800-2500 (indicating at least A-level expertise or higher). Binary logistic regression was applied to examine the weight of each predictor. Results: The data evinced the statistically significant role of gender, and rational thinking style on A-level chess expertise and from all the conclusive predictors the most determinant was the rational thinking style which raised the chance of high expertise more than 60 times. Conclusions: Practice contributes positively to the development of A-level competence. However, the most crucial factor in predicting high chess expertise and performance is the preference for rational thinking style. Keywords: chess expertise, ELO rating, A-level, emotionality, self-efficacy, rational thinking, intuitive thinking, practice, adults"
... [15] Since HRV can serve as an indicator of brainstem activity and thus ANS function, a promising method has become available to complement EEG measurements with the goal of maintaining autonomic homeostasis during general anesthesia.[16-18] However, the pioneering studies of the level of concordance between EEG and HRV have mostly been performed on awake patients [19][20][21], under experimental conditions [22] or have been performed during induction of general anesthesia. [17,18] To our knowledge, the level of concordance between EEG and HRV during general anesthesia has not been adequately studied yet. ...
... [18,32] In a pilot study, Zhan, et al. [5] showed that the time and frequency parameters of HRV facilitate the assessment of anesthesia across a wide ranges of levels. So far, the level of concordance of EEG and HRV has been tested on awake patients [19][20][21], under experimental conditions [22] or performed during the induction of general anesthesia. [17,18] But it has not been adequately studied throughout general anesthesia. ...
Purpose
The aim of the proof-of-concept study is to investigate the level of concordance between the heart rate variability (HRV), the EEG-based Narcotrend Index as a surrogate marker for the depth of anesthesia, and the minimal alveolar concentration (MAC) of the inhalation anesthetic sevoflurane across the entire course of a surgical procedure.
Methods
This non-blinded cross-sectional study recorded intraoperative HRV, Narcotrend Index, and MAC in 31 male patients during radical prostatectomy using the Da-Vinci robotic-assisted surgical system at Mannheim University Medical Center. The degree of concordance was calculated using repeated measures correlation with the R package (rmcorr) and presented using the rmcorr coefficient (rrm).
Results
The Narcotrend Index correlates significantly across all measures with the time-dependent parameter of HRV, the standard deviation of the means of RR intervals (SDNN) (rrm = 0.2; p < 0.001), the frequency-dependent parameters low frequency (LF) (rrm = 0.09; p = 0.04) and the low frequency/high frequency ratio (LF/HF ratio) (rrm = 0.11; p = 0.002). MAC correlated significantly negatively with the time-dependent parameter of heart rate variability, SDNN (rrm = -0.28; p < 0.001), the frequency-dependent parameter LF (rrm = -0.06; p < 0.001) and the LF/HF ratio (rrm = -0.18; p < 0.001) and the Narcotrend Index (rrm = -0.49; p < 0.001) across all measures.
Conclusion
HRV mirrors the trend of the Narcotrend Index used to monitor depth of anesthesia and the inhibitory influence of the anesthetic sevoflurane on the autonomic nervous system. Therefore, HRV can provide essential information about the homeostasis of the autonomic nervous system during general anesthesia.
Trial registration number
DRKS00024696, March 9th, 2021
... For example, professional chess players employ more advanced visual search strategies when judging the board [11,12], with stronger pattern recognition ability [13]. Advanced chess players have a higher alpha EEG (electroencephalogram) power spectrum when completing difficult ends than novice players [14]. In 2 tennis players, the ERP (event-related potential) component of the expert group activated earlier and more strongly in motion-in-depth perception of the tennis ball [15]. ...
... For instance, research in other domains, such as chess, has shown that professional players employ more sophisticated visual search strategies and exhibit enhanced pattern recognition abilities [14][15][16]. Advanced chess players also show heightened alpha EEG (electroencephalogram) activity during complex tasks, compared to novices [17]. Similarly, in tennis, experts display faster and stronger activation of ERP (event-related potential) components during motion perception tasks [18]. ...
Objectives: Teachers’ intention understanding ability reflects their professional insight, which is the basis for effective classroom teaching activities. However, the cognitive process and brain mechanism of how teachers understand students’ action intention in class are still unclear. Methods: This study used event-related potential (ERP) technology to explore the cognitive neural differences in intention understanding ability among teachers with different levels of knowledge and experience. The experiment used the comic strips paradigm to examine the ability of expert and novice teachers to understand students’ normative and non-normative classroom actions under different text prompts (“how” and “why”). Results: The results revealed that in the late time window, expert teachers induced larger P300 and LPC amplitudes when they understood students’ classroom action intentions, while the N250 amplitudes induced by novice teachers in the early time window were significantly larger. In addition, for both types of teachers, when understanding the intentions behind students’ normative actions, the N250 amplitude was the most significant, while the P300 and LPC amplitudes were more significant for non-normative actions. Conclusions: This study found that teachers at varying professional development stages had different time processing processes in intention understanding ability, which supported teachers’ brain electrophysiological activities related to social ability.
... with a lower global efficiency in people performing high in a linguistic task, presumably because of their greater capacity to recruit non-linguistic cognitive networks (between-subnetwork connectivity), and an efficient use of language networks (within-subnetwork connectivity) (Gonzalez-Burgos et al., 2020;Mohanty et al., 2021). This hypothesis would be further supported by rs-fMRI, electroencephalography (EEG), or single photon emission computerized tomography (SPECT) studies that showed an increased brain activation in posterior brain regions, the non-dominant hemisphere, and subcortical structures in response to a high cognitive demand or difficulty level (Onofrj et al., 1995;Duan et al., 2012;Villafaina et al., 2019Villafaina et al., , 2021Song et al., 2020). Hence, we suggest that the high local efficiency in the cognitive connectome of chess players may be at the cost of a low global efficiency, possibly resulting in a higher specialized performance. ...
Objectives
We aimed to advance our understanding of the effect of chess on cognition by expanding previous univariate studies with the use of graph theory on cognitive data. Specifically, we investigated the cognitive connectome of adult chess players.
Method
We included 19 chess players and 19 controls with ages between 39 and 69 years. Univariate analysis and graph theory included 27 cognitive measures representing multiple cognitive domains and subdomains. Graph analysis included global and nodal measures of integration, segregation, and centrality. We also performed an analysis of community structures to gain an additional understanding of the cognitive architecture of chess players.
Results
The analysis of global graph measures showed that chess players had a higher local efficiency than controls at the cost of a lower global efficiency, which did not permeate segregation aspects of their connectome. The nodal graph measures showed that executive/attention/processing speed and visuoconstructive nodes had a central role in the connectome of chess players. The analysis of communities showed that chess players had a slightly reorganized cognitive architecture into three modules. These graph theory findings were in the context of better cognitive performance in chess players than controls in visuospatial abilities.
Conclusion
We conclude that the cognitive architecture of chess players is slightly reorganized into functionally and anatomically coherent modules reflecting a distinction between visual, verbal, and executive/attention/processing speed-related functions, perhaps reminiscent of right hemisphere and left hemisphere subnetworks orchestrated by the frontal lobe and its white matter connections.
... Convergent cross mapping analysis demonstrated the correlation between IMF envelop of EEG and HRV, and surrogate data analysis confirmed the statistical significance of nonlinear metrics estimated from them [4]. HRV and EEG N. Bahador spectral measures were compared in some studies [5]. Relationship between sample entropy extracted from HRV and Wiener entropy extracted from EEG was also investigated [6]. ...
Supplemental information captured from HRV can provide deeper insight into nervous system function and consequently improve evaluation of brain function. Therefore, it is of interest to combine both EEG and HRV. However, irregular nature of time spans between adjacent heartbeats makes the HRV hard to be directly fused with EEG timeseries. Current study performed a pioneering work in integrating EEG-HRV information in a single marker called cumulant ratio, quantifying how far EEG dynamics deviate from self-similarity compared to HRV dynamics. Experimental data recorded using BrainStatus device with single ECG and 10 EEG channels from healthy-brain patients undergoing operation (N = 20) were used for the validation of the proposed method. Our analyses show that the EEG to HRV ratio of first, second and third cumulants gets systematically closer to zero with increase in depth of anesthesia, respectively 29.09%, 65.0% and 98.41%. Furthermore, extracting multifractality properties of both heart and brain activities and encoding them into a 3-sample numeric code of relative cumulants does not only encapsulates the comparison of two evenly and unevenly spaced variables of EEG and HRV into a concise unitless quantity, but also reduces the impact of outlying data points.
... Regarding the performance in sports, the analysis of the cortical electrical activity through the electroencephalographic (EEG) signal may be a useful alternative to assess the activation of professional female soccer players before a competition [1] and to monitor stress or cognitive load in chess players while playing games at different paces or solving chess problems or endgames with different difficulty levels [2,3,4]. Similarly, in the military context, this tool can be considered for training purposes during takeoff, landing, air-air attacks, and air-ground attack maneuvers [5]. ...
BACKGROUND
Heart rate variability (HRV) was shown to be affected by performing religious activities.
AIM
To examine the relationship between the level of Quran (the holy book of Muslims) memorisation and HRV among teenagers.
METHODS
This experimental study included 16 Tahfiz students and 16 non-Tahfiz students (n = 32). The HRV was measured in three tasks: Recalling familiar verses, memorising new verses, and recalling the newly memorised verses of the Quran. HRV analysis was done using these parameters: Standard deviation of N-N (heartbeat peak) interval; low frequency (LF); high frequency (HF) and LF/HF ratio.
RESULTS
There were significant differences between tasks for all parameters (P < 0.05). However, between the groups, only the LF/HF ratio had significant differences, with F = 5.04, P < 0.05. Pearson correlation showed a moderate positive correlation between the number of pages memorised and the LF/HF ratio (r = 0.61, P < 0.05).
CONCLUSION
Quran memorisation increased the HRV and our results suggested that this activity could be developed as an effective sympathovagal modulation training activity.
The aim of this study was to monitor the mental activation training during match pressure imageries using a protocol with (MT) and without mental training (wMT) performed in the office and on the tennis court based on the analysis of heart rate, brain waves and subjective ratings in a professional tennis player with high imagery experience. Results showed that both in the office (MTo/wMTo) and on the court (MTc/wMTc) the tennis player’s heart rate increased in the match pressure imagery (I.3-8), being higher in the MTo. It decreased in the pressure imagery using mental tools (I.8-13) in the MT. In the case of brainwaves, beta and gamma waves increased in the match pressure imagery (I.3-8); while beta, gamma, delta and theta waves decreased in the pressure imagery using mental tools (I.8-13), being higher in the office. Entropy decreased in the match pressure imagery (I.3-8), being higher in the MTo. It increased in the pressure imagery using mental tools (I.8-13), being higher in the MTo. Regarding subjective ratings, the tennis player felt the pressure in the match pressure imagery, being higher in MT. In the pressure imagery using mental tools he regulated the activation to feel it at an optimal level (7). In the imagery reality, the olfactory and gustatory dimensions were the most difficult to feel in both imageries.
Keywords
EEG monitoring, mental activation training, pressure, imagery, EEG, tennis
The aim of this study was to monitor the activation during a neutral situation imagery (NSI) and a pressure situation imagery (PSI), based on the analysis of heart rate, brain waves and subjective ratings in athletes. The sample was made up of sixteen professional tennis players. Imagery protocols consisted of 3 phases; the first and the third involved being focused on their deep breathing (2 min.); the second, in the NSI, first service routine (17 sec.-1 min. 21 sec.) and in the PSI, a match pressure situation (2 min. 10 sec.). Results showed that both NSI and PSI increased heart rate. This increase was higher in the PSI and its highest point was at the maximum pressure moment: interval 5-6. In the case of brain waves, both NSI and PSI caused a decrease in gamma wave activity (intervals 3-8). In the PSI, there was also an increase in gamma waves in interval 5-6, the maximum pressure moment. Entropy was lower in the NSI. In regard to subjective ratings, in the psychological skills there were only significant differences in the PSI between pre- and post-activation at the during moment (pressure). In the imagery reality, olfactory and gustatory dimensions were the most difficult to perceive as real in the NSI and only the olfactory in the PSI.
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.
Multidisciplinary approaches have demonstrated that the brain is potentially modulated by the long-term acquisition and practice of specific skills. Chess playing can be considered a paradigm for shaping brain function, with complex interactions among brain networks possibly enhancing cognitive processing. Dynamic network analysis based on resting-state magnetic resonance imaging (rs-fMRI) can be useful to explore the effect of chess playing on whole-brain fluidity/dynamism (the chronnectome). Dynamic connectivity parameters of 18 professional chess players and 20 beginner chess players were evaluated applying spatial independent component analysis (sICA), sliding-time window correlation, and meta-state approaches to rs-fMRI data. Four indexes of meta-state dynamic fluidity were studied: i) the number of distinct meta-states a subject pass through, ii) the number of switches from one meta-state to another, iii) the span of the realized meta-states (the largest distance between two meta-states that subjects occupied), and iv) the total distance travelled in the state space. Professional chess players exhibited an increased dynamic fluidity, expressed as a higher number of occupied meta-states (meta-state numbers, 75.8 ± 7.9 vs 68.8 ± 12.0, p = 0.043 FDR-corrected) and changes from one meta-state to another (meta-state changes, 77.1 ± 7.3 vs 71.2 ± 11.0, p = 0.043 FDR-corrected) than beginner chess players. Furthermore, professional chess players exhibited an increased dynamic range, with increased traveling between successive meta-states (meta-state total distance, 131.7 ± 17.8 vs 108.7 ± 19.7, p = 0.0004 FDR-corrected). Chess playing may induce changes in brain activity through the modulation of the chronnectome. Future studies are warranted to evaluate if these potential effects lead to enhanced cognitive processing and if “gaming” might be used as a treatment in clinical practice.
The aim of the present study was to investigate how the heart and the brain react to playing chess with a computer versus in a real context in chess players. We also aim to investigate if familiarization with simulated practice leads to changes in heart rate variability (HRV) and the electroencephalographic (EEG) power spectrum. We designed a cross-sectional study, enrolling 27 chess players. They were randomly assigned to 3 minutes plus 2-second chess games: one with a computer (simulated scenario), and another in a real context. Additionally, participants were divided into two groups according to their level of familiarization of playing chess in a computer context. While they were playing, HRV and EEG were continuously recorded. Differences in HRV and EEG theta power spectrum between playing chess in a real or a simulated scenario were not found in chess players (p-value > 0.05). When participants were divided into groups (familiarized and unfamiliarized with simulated chess practice), significant differences were observed in HRV and EEG (p-value < 0.05). The EEG theta power spectrum was significantly lower, and HRV was higher in unfamiliarized players during the simulated scenario, which could indicate that they were less focused in a simulated environment than in a real context. Therefore, familiarization with simulated environments should be taken into account during the training process to achieve the best performance.
The ICLabel dataset is comprised of training and test sets of a set of spatiotemporal features of electroencephalographic (EEG) independent components (IC). The ICLabel training set feature sets were computed for over 200,000 EEG ICs from more than 6,000 existing EEG recordings. More than 8,000 of these ICs have accompanying crowdsourced IC labels across seven IC categories: Brain, Muscle, Eye, Heart, Line Nosie, Channel Noise, and Other. The feature-sets included in the ICLabel dataset are scalp topography images, channel-based scalp topography measures, power spectral densities (PSD) measures (median, variance and kurtosis) and autocorrelation functions, equivalent current dipole (ECD) model fits for single and bilaterally symmetric dipole models, plus features used in several published IC classifier approaches. The ICLabel test set is comprised of 130 ICs from 10 datasets not included in the training set. Each of the test set ICs has an associated IC label estimated based on labels provided by six ICA-EEG experts. Files necessary for adding to and amending the dataset are also included, plus a python class containing useful methods for interacting with the dataset, and IC classifications produced by several existing IC classifiers. These data are linked to the article, "ICLabel: An automated electroencephalographic independent component classifier, dataset, and website" [1]. An active tutorial and crowdsourcing website is available: iclabel.ucsd.edu/tutorial/overview.
Variations in alpha rhythm have a significant role in perception and attention. Recently, alpha decrease has been associated with externally directed attention, especially in the visual domain, whereas alpha increase has been related to internal processing such as mental arithmetic. However, the role of alpha oscillations and how the different components of a task (processing of external stimuli, internal manipulation/representation, and task demand) interact to affect alpha power are still unclear. Here, we investigate how alpha power is differently modulated by attentional tasks depending both on task difficulty (less/more demanding task) and direction of attention (internal/external). To this aim, we designed two experiments that differently manipulated these aspects. Experiment 1, outside Virtual Reality (VR), involved two tasks both requiring internal and external attentional components (intake of visual items for their internal manipulation) but with different internal task demands (arithmetic vs. reading). Experiment 2 took advantage of the VR (mimicking an aircraft cabin interior) to manipulate attention direction: it included a condition of VR immersion only, characterized by visual external attention, and a condition of a purely mental arithmetic task during VR immersion, requiring neglect of sensory stimuli. Results show that: (1) In line with previous studies, visual external attention caused a significant alpha decrease, especially in parieto-occipital regions; (2) Alpha decrease was significantly larger during the more demanding arithmetic task, when the task was driven by external visual stimuli; (3) Alpha dramatically increased during the purely mental task in VR immersion, whereby the external stimuli had no relation with the task. Our results suggest that alpha power is crucial to isolate a subject from the environment, and move attention from external to internal cues. Moreover, they emphasize that the emerging use of VR associated with EEG may have important implications to study brain rhythms and support the design of artificial systems.
This article reports on an investigation of the use of convolutional neural networks to predict the visual attention of chess players. The visual attention model described in this article has been created to generate saliency maps that capture hierarchical and spatial features of chessboard, in order to predict the probability fixation for individual pixels Using a skip-layer architecture of an autoencoder, with a unified decoder, we are able to use multiscale features to predict saliency of part of the board at different scales, showing multiple relations between pieces. We have used scan path and fixation data from players engaged in solving chess problems, to compute 6600 saliency maps associated to the corresponding chess piece configurations. This corpus is completed with synthetically generated data from actual games gathered from an online chess platform. Experiments realized using both scan-paths from chess players and the CAT2000 saliency dataset of natural images, highlights several results. Deep features, pretrained on natural images, were found to be helpful in training visual attention prediction for chess. The proposed neural network architecture is able to generate meaningful saliency maps on unseen chess configurations with good scores on standard metrics. This work provides a baseline for future work on visual attention prediction in similar contexts.
Background: Heart rate variability (HRV) has been considered as a measure of heart-brain interaction and autonomic modulation, and it is modified by cognitive and attentional tasks. In cognitive tasks, HRV was reduced in participants who achieved worse results. This could indicate the possibility of HRV predicting cognitive performance, but this association is still unclear in a high cognitive load sport such as chess.
Objective: To analyze modifications on HRV and subjective perception of stress, difficulty and complexity in different chess problem tasks.
Design: HRV was assessed at baseline. During the chess problems, HRV was also monitored, and immediately after chess problems the subjective stress, difficulty and complexity were also registered.
Methods: A total of 16 male chess players, age: 35.19 (13.44) and ELO: 1927.69 (167.78) were analyzed while six chess problem solving tasks with different level of difficulty were conducted (two low level, two medium level and two high level chess problems). Participants were classified according to their results into two groups: high performance or low performance.
Results: Friedman test showed a significant effect of tasks in HRV indexes and perceived difficulty, stress and complexity in both high and low performance groups. A decrease in HRV was observed in both groups when chess problems difficulty increased. In addition, HRV was significantly higher in the high performance group than in the low performance group during chess problems.
Conclusion: An increase in autonomic modulation was observed to meet the cognitive demands of the problems, being higher while the difficulty of the tasks increased. Non-linear HRV indexes seem to be more reactive to tasks difficulty, being an interesting and useful tool in chess training.
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.
To explore the perceptual component of chess expertise, we monitored the eye movements of expert and novice chess players during a chess-related visual search task that tested anecdotal reports that a key differentiator of chess skill is the ability to visualize the complex moves of the knight piece. Specifically, chess players viewed an array of four minimized chessboards, and they rapidly searched for the target board that allowed a knight piece to reach a target square in three moves. On each trial, there was only one target board (i.e., the "Yes" board), and for the remaining "lure" boards, the knight's path was blocked on either the first move (the "Easy No" board) or the second move (i.e., "the Difficult No" board). As evidence that chess experts can rapidly differentiate complex chess-related visual patterns, the experts (but not the novices) showed longer first-fixation durations on the "Yes" board relative to the "Difficult No" board. Moreover, as hypothesized, the task strongly differentiated chess skill: Reaction times were more than four times faster for the experts relative to novices, and reaction times were correlated with within-group measures of expertise (i.e., official chess ratings, number of hours of practice). These results indicate that a key component of chess expertise is the ability to rapidly recognize complex visual patterns.
Chess is thought to be a game demanding high cognitive abilities to be played well. Although many studies proved the link between mastery in chess and high degree of intelligence, just few studies proved that chess practice can enhance cognitive abilities. Starting from these considerations, the main purpose of the present research was to investigate the potential benefits of in-presence chess lessons and on-line training on mathematical problem-solving ability in young pupils (8 to 11 years old). Five hundred sixty students were divided into two groups, experimental (which had chess course and on-line training) and control (which had normal school activities), and tested on their mathematical and chess abilities. Results show a strong correlation between chess and math scores, and a higher improvement in math in the experimental group compared with the control group. These results foster the hypothesis that even a short-time practice of chess in children can be a useful tool to enhance their mathematical abilities.
Nonlinear parameters of heart rate variability (HRV) have proven their prognostic value in clinical settings, but their physiological background is not very well established. We assessed the effects of low intensity isometric (ISO) and dynamic (DYN) exercise of the lower limbs on heart rate matched intensity on traditional and entropy measures of HRV. Due to changes of afferent feedback under DYN and ISO a distinct autonomic response, mirrored by HRV measures, was hypothesized. Five-minute inter-beat interval measurements of 43 healthy males (26.0 ± 3.1 years) were performed during rest, DYN and ISO in a randomized order. Blood pressures and rate pressure product were higher during ISO vs. DYN (p < 0.001). HRV indicators SDNN as well as low and high frequency power were significantly higher during ISO (p < 0.001 for all measures). Compared to DYN, sample entropy (SampEn) was lower during ISO (p < 0.001). Concluding, contraction mode itself is a significant modulator of the autonomic cardiovascular response to exercise. Compared to DYN, ISO evokes a stronger blood pressure response and an enhanced interplay between both autonomic branches. Non-linear HRV measures indicate a more regular behavior under ISO. Results support the view of the reciprocal antagonism being only one of many modes of autonomic heart rate control. Under different conditions; the identical “end product” heart rate might be achieved by other modes such as sympathovagal co-activation as well.
Heart rate variability (HRV), the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operate on different time scales to adapt to challenges and achieve optimal performance. This article briefly reviews neural regulation of the heart, and its basic anatomy, the cardiac cycle, and the sinoatrial and atrioventricular pacemakers. The cardiovascular regulation center in the medulla integrates sensory information and input from higher brain centers, and afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. This article reviews sympathetic and parasympathetic influences on the heart, and examines the interpretation of HRV and the association between reduced HRV, risk of disease and mortality, and the loss of regulatory capacity. This article also discusses the intrinsic cardiac nervous system and the heart-brain connection, through which afferent information can influence activity in the subcortical and frontocortical areas, and motor cortex. It also considers new perspectives on the putative underlying physiological mechanisms and properties of the ultra-low-frequency (ULF), very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) bands. Additionally, it reviews the most common time and frequency domain measurements as well as standardized data collection protocols. In its final section, this article integrates Porges' polyvagal theory, Thayer and colleagues' neurovisceral integration model, Lehrer et al.'s resonance frequency model, and the Institute of HeartMath's coherence model. The authors conclude that a coherent heart is not a metronome because its rhythms are characterized by both complexity and stability over longer time scales. Future research should expand understanding of how the heart and its intrinsic nervous system influence the brain.
Cardiac mortality and electrophysiologic dysfunction both increase with age. Heart rate variability (HRV) provides indices of autonomic function and electrophysiology that are associated with cardiac risk. How habitual physical activity (PA) among older adults prospectively relates to HRV, including nonlinear indices of erratic sinus patterns, is not established. We hypothesized that increasing levels of both total leisure-time activity and walking would be prospectively associated with more favorable time-domain, frequency-domain, and nonlinear HRV measures in older adults.
We evaluated serial longitudinal measures of both PA and 24-hour Holter HRV over 5 years among 985 older US adults in the community-based Cardiovascular Health Study. After multivariable adjustment, greater total leisure-time activity, walking distance, and walking pace were each prospectively associated with specific, more favorable HRV indices, including higher 24-hour standard-deviation-of-all-normal-to-normal-intervals (SDNN, p-trend=0.009, 0.02, 0.06, respectively) and ultra-low-frequency-power (p-trend=0.02, 0.008, 0.16, respectively). Greater walking pace was also associated with higher short-term-fractal-scaling-exponent (p-trend=0.003) and lower Poincare ratio (p-trend=0.02), markers of less erratic sinus patterns.
Greater total leisure-time activity, as well as walking alone, were prospectively associated with more favorable and specific indices of autonomic function in older adults, including several suggestive of more normal circadian fluctuations and less erratic sinoatrial firing. Our results suggest potential mechanisms that might contribute to lower cardiovascular mortality with habitual PA later in life.
The aim of this study was to analyze the effect of learning of chess play on developing meta-cognitive ability and mathematical problem-solving capability of students at various levels of schooling. To this end, 86 school-boy students were randomly selected and they taught chess for six months, and another group of 94 students randomly selected for control group. The subjects were assessed via meta-cognitive questionnaire of Panaoura, Philippou, and Christou (2003) and mathematics exams. The results indicated that chess player students showed more achievement in both meta-cognitive abilities and mathematical problem solving capabilities than other non-chess player students. In addition, a positive and significant relationship was found between students’ meta-cognitive ability and their mathematical problem-solving power. These results suggest that we can use chess as an effective tool for developing higher order thinking skills.
ERP experiments were conducted to analyze the underlying neural events when chess players make simple judgments of a board position. Fourteen expert players and 14 age-matched novices viewed, for each of four tasks, 128 unique positions on a mini (4 × 4) chess board each presented for 0.5 s. The tasks were to respond: (a) if white king was in check, (b) if black knight was present, (c) if white king was not in check, and (d) if no black knight was present. Experts showed an enhanced N2 with check targets and a larger P3 with knight targets, relative to novices. Expert-novice differences in posterior N2 began as early as 240 ms on check-related searches. Results were consistent with the view that prolonged N2 components reflect matching of current perceptual input to memory, and thus are sensitive to experts' superior pattern recognition and memory retrieval of chunks.
Systems Engineering often involves computer modelling the behaviour of proposed systems and their components. Where a component is human, fallibility must be modelled by a stochastic agent. The identification of a model of decision-making over quantifiable options is investigated using the game-domain of Chess. Bayesian methods are used to infer the distribution of players' skill levels from the moves they play rather than from their competitive results. The approach is used on large sets of games by players across a broad FIDE Elo range, and is in principle applicable to any scenario where high-value decisions are being made under pressure.
The common approach to the multiplicity problem calls for controlling the familywise error rate (FWER). This approach, though, has faults, and we point out a few. A different approach to problems of multiple significance testing is presented. It calls for controlling the expected proportion of falsely rejected hypotheses – the false discovery rate. This error rate is equivalent to the FWER when all hypotheses are true but is smaller otherwise. Therefore, in problems where the control of the false discovery rate rather than that of the FWER is desired, there is potential for a gain in power. A simple sequential Bonferroni-type procedure is proved to control the false discovery rate for independent test statistics, and a simulation study shows that the gain in power is substantial. The use of the new procedure and the appropriateness of the criterion are illustrated with examples.
The Publication Manual of the American Psychological Association (American Psychological Association, 2001, American Psychological Association, 2010) calls for the reporting of effect sizes and their confidence intervals. Estimates of effect size are useful for determining the practical or theoretical importance of an effect, the relative contributions of factors, and the power of an analysis. We surveyed articles published in 2009 and 2010 in the Journal of Experimental Psychology: General, noting the statistical analyses reported and the associated reporting of effect size estimates. Effect sizes were reported for fewer than half of the analyses; no article reported a confidence interval for an effect size. The most often reported analysis was analysis of variance, and almost half of these reports were not accompanied by effect sizes. Partial η2 was the most commonly reported effect size estimate for analysis of variance. For t tests, 2/3 of the articles did not report an associated effect size estimate; Cohen's d was the most often reported. We provide a straightforward guide to understanding, selecting, calculating, and interpreting effect sizes for many types of data and to methods for calculating effect size confidence intervals and power analysis.
To determine (1) whether heart rate variability (HRV) was a sensitive and reliable measure in mental effort tasks carried out by healthy seniors and (2) whether non-linear approaches to HRV analysis, in addition to traditional time and frequency domain approaches were useful to study such effects.
Forty healthy seniors performed two visual working memory tasks requiring different levels of mental effort, while ECG was recorded. They underwent the same tasks and recordings 2 weeks later. Traditional and 13 non-linear indices of HRV including Poincaré, entropy and detrended fluctuation analysis (DFA) were determined.
Time domain, especially mean R-R interval (RRI), frequency domain and, among non-linear parameters - Poincaré and DFA were the most reliable indices. Mean RRI, time domain and Poincaré were also the most sensitive to different mental effort task loads and had the largest effect size.
Overall, linear measures were the most sensitive and reliable indices to mental effort. In non-linear measures, Poincaré was the most reliable and sensitive, suggesting possible usefulness as an independent marker in cognitive function tasks in healthy seniors.
A large number of HRV parameters was both reliable as well as sensitive indices of mental effort, although the simple linear methods were the most sensitive.
Changes in oscillatory brain activity are strongly correlated with performance in cognitive tasks and modulations in specific frequency bands are associated with working memory tasks. Mesoscale network models allow the study of oscillations as an emergent feature of neuronal activity. Here we extend a previously developed attractor network model, shown to faithfully reproduce single-cell activity during retention and memory recall, with synaptic augmentation. This enables the network to function as a multi-item working memory by cyclic reactivation of up to six items. The reactivation happens at theta frequency, consistently with recent experimental findings, with increasing theta power for each additional item loaded in the network's memory. Furthermore, each memory reactivation is associated with gamma oscillations. Thus, single-cell spike trains as well as gamma oscillations in local groups are nested in the theta cycle. The network also exhibits an idling rhythm in the alpha/beta band associated with a noncoding global attractor. Put together, the resulting effect is increasing theta and gamma power and decreasing alpha/beta power with growing working memory load, rendering the network mechanisms involved a plausible explanation for this often reported behavior.
A novel descriptor (Complex Correlation Measure (CCM)) for measuring the variability in the temporal structure of Poincaré plot has been developed to characterize or distinguish between Poincaré plots with similar shapes.
This study was designed to assess the changes in temporal structure of the Poincaré plot using CCM during atropine infusion, 70° head-up tilt and scopolamine administration in healthy human subjects. CCM quantifies the point-to-point variation of the signal rather than gross description of the Poincaré plot. The physiological relevance of CCM was demonstrated by comparing the changes in CCM values with autonomic perturbation during all phases of the experiment. The sensitivities of short term variability (SD1), long term variability (SD2) and variability in temporal structure (CCM) were analyzed by changing the temporal structure by shuffling the sequences of points of the Poincaré plot. Surrogate analysis was used to show CCM as a measure of changes in temporal structure rather than random noise and sensitivity of CCM with changes in parasympathetic activity.
CCM was found to be most sensitive to changes in temporal structure of the Poincaré plot as compared to SD1 and SD2. The values of all descriptors decreased with decrease in parasympathetic activity during atropine infusion and 70° head-up tilt phase. In contrast, values of all descriptors increased with increase in parasympathetic activity during scopolamine administration.
The concordant reduction and enhancement in CCM values with parasympathetic activity indicates that the temporal variability of Poincaré plot is modulated by the parasympathetic activity which correlates with changes in CCM values. CCM is more sensitive than SD1 and SD2 to changes of parasympathetic activity.
Gamma-band activity (GBA) bursts have been viewed as a signature for ignitions in localized Hebbian cell assemblies and are thought to indicate active memory. Using whole-head magnetoencephalography, we recorded focal bursts of GBA during chess playing. Unlike highly skilled chess grandmasters, with amateur chess players focal gamma bursts prevailed in deeper structures in the region of the medial temporal lobes. This observation is consistent with the interpretation of memory formation in amateur chess players. For the frontal and parietal cortex the relationship was reversed, with more frequent gamma bursts found in chess grandmasters, indicating that the retrieval of chunks from expert memory is based on the recruitment of these neocortical areas. The results suggest the possibility that time-dependent reorganization during the formation of expert memory can be studied in humans and support the theory that the medial temporal lobe and hippocampal formation play a transitional role during the creation of expert memory in the neocortex.
We have studied the physiological consequences of the tension caused by playing chess in 20 male chess players, by following heart rate, heart rate variability, and respiratory variables. We observed significant increase in the heart rate (75-86 beats/min), in the ratio low frequency (LF)/high frequency (HF) of heart rate variability (1.3-3.0) and also a decrease in mean heart rate variability with no changes in HF throughout the game. These results suggest a stimulation of the sympathetic nervous system with no changes in the parasympathetic system. The respiratory exchange ratio was rather elevated (over 0.89) at the start and significantly decreased during the game (0.75 at the end), indicating that energy expenditure progressively switched from carbohydrate to lipid oxidation. The changes in substrate oxidation and the sympathetic system seem to be due to high cognitive demands and bring new insight into adaptations to mental strain.
Investigated the respiratory and heart rate (HR) components of attentive observation to external stimuli and to an internal stimulus (Ss' own HR). 48 male undergraduates were required to either estimate their HRs, estimate the rate of a series of intermittent tones, count light flashes, or watch a light flash. The various tasks produced no differential effects on respiration, but across tasks there were significant increases in frequency and decreases in amplitude of respiration. Mean HR decreased across trials, and all tasks except watching the light produced significant decreases in HR variance. The HR response pattern during the 1st 10 sec. of each trial differentiated between the groups: HR accelerated for internal observation and decelerated for external observation. (18 ref.)
Changes in the human neuromagnetic alpha rhythm were monitored during an object detection task to study the effects of visual shape processing on the parieto-occipital activity. Pictures of coherent meaningful objects, which the observers had to detect, and of disorganized meaningless non-objects were presented briefly between masks. The non-objects were systematically followed by a higher level of alpha than the objects, the difference emerging on average 400 msec after the stimulus, with a median delay of 130 msec after evoked response onsets in the occipital, temporal, and parietal cortices. Without attention to visual shape, the alpha levels did not differ between objects and non-objects. The alpha level was higher after non-objects than missed objects, and higher after missed than correctly detected objects, suggesting that the alpha level is inversely related to saliency or familiarity of the object and does not directly reflect visual awareness.
The reactive alpha rhythm was generated in the parieto-occipital sulcus, which in several primate species includes areas belonging to the dorsal visual pathway. According to current views, the parietal cortex produces attentional signals that filter out irrelevant information in the ventral visual stream. Our results reinforce the idea of bidirectional interaction: information derived from visual shape can rapidly modify activity in the parieto-occipital region. The synchronized alpha oscillations may reflect attenuation of occipito-parietal information transfer and disengagement of parietal cortex from object selection.
The electroencephalograms (EEGs) of the sleep onset period (SOP) of psychophysiogical insomniacs. psychiatric insomniacs, and controls were compared using power spectral analysis. We predicted that psychophysiological insomniacs would show elevated cortical arousal throughout their entry into sleep. Electroencephalograms, electrooculograms (EOGs), and electromyograms (EMGs) were recorded for two consecutive nights. Power spectral analysis of EEG from the sleep onset period was performed on all standard frequency bands. Psychophysiological insomniacs had less alpha during the first part of the SOP and did not show the dramatic drop in alpha across the SOP that characterizes normal sleep. They showed less delta in the last quartile of the chronological analysis of the SOP. Psychiatric insomniacs showed lower relative beta power values overall, while psychophysiological insomniacs showed higher relative beta power values during wakefulness. This microanalysis indicates that the SOP is generally similar for psychiatric insomniacs and normal sleepers but that clear differences in the SOP of psychophysiological insomniacs exist. They have higher cortical arousal during the SOP than do psychiatric insomniacs and controls. The dramatic changes in power values in the latter two groups as sleep begins are not seen in the psychophysiological insomniacs, which may help explain the difficulty that psychophysiological insomniacs have discriminating between wakefulness and sleep.
In the last decade, cardiac vagal tone has emerged as a psychophysiological marker of many aspects of behavioral functioning in both children and adults. Research efforts during this time have produced an extensive list of vagal tone correlates that includes temperamental variables as well as both anxious/internalizing and disruptive/externalizing behaviors. This potentially confusing state of affairs is compounded by developmental shifts in vagal tone behavior relations that to date have not been elucidated. In this paper, the vagal tone literature is reviewed, and discrepancies, including the lack of specificity of vagal tone as a psychophysiological marker, are clarified. Such clarification requires that we (a) view vagal tone-behavior relations in developmental context, (b) juxtapose vagal tone-behavior relations in typical and atypical samples, and (c) consider the parasympathetic underpinnings of vagal tone as but one component in a broader model of autonomic nervous system functioning. Such a model is provided by combining Gray's motivational theory with Porges's polyvagal theory. Together these models account for behavioral and emotional differences in a diverse range of psychological disorders that are not differentiated by either model alone. Moreover, use of the integrated model offers a theory-driven approach to the study of autonomic nervous system-behavior relations.
The game of chess has been traditionally used to study basic cognitive processes. However, it has been poorly studied in adolescent chess players. The aim of the present study was to describe the psychophysiological response of adolescence, using electroencephalography (EEG) and heart rate variability (HRV) during problem-solving tasks. Thus, participants had to solve four chess problems with different level of difficulty (low and high). A total of 13 adolescent chess players (age: 15.45 [1.64] with a mean ELO score of 1403 [209.16]) participated in the study. EEG and HRV were recorded while participants solved the chess problems. Results indicated that HRV is reduced as well as EEG theta power spectrum increased during the high difficulty level. These results support the idea of HRV and EEG as useful tools to control stress or cognitive load during cognitive tasks even in adolescent. This characterization increases the knowledge about the psychophysiological response of adolescence to a cognitive task under time pressure.
The common approach to the multiplicity problem calls for controlling the familywise error rate (FWER). This approach, though, has faults, and we point out a few. A different approach to problems of multiple significance testing is presented. It calls for controlling the expected proportion of falsely rejected hypotheses — the false discovery rate. This error rate is equivalent to the FWER when all hypotheses are true but is smaller otherwise. Therefore, in problems where the control of the false discovery rate rather than that of the FWER is desired, there is potential for a gain in power. A simple sequential Bonferronitype procedure is proved to control the false discovery rate for independent test statistics, and a simulation study shows that the gain in power is substantial. The use of the new procedure and the appropriateness of the criterion are illustrated with examples.
The game of chess offers an enabling environment for the study of basic cognitive decision making processes
where different types of memories are involved. The aim of the present study was to describe and compare the
brain electrical activity pattern of chess players in two different situations under time pressure to make the
move: rapid, 15 min, plus 10 s additional time per move and lightning, a one-minute game. Thus, lightning game
offers an appropriate environment to isolate memory chunks and rapid game will offer the perspective of a
working memory task. Encephalogram (EEG) recordings were obtained while a total of 14 male chess players
(age: 35.36 ± 13.77 and ELO: 1921.07 ± 170.67) played lightning and rapid chess games. Results indicate
that different activity patterns between the rapid and the lightning games were found. Increments in theta power
during lightning game in posterior regions could indicate that theta power might be related with chunks retrieval.
Moreover, right hemisphere is more activated in chess games, probably caused by visuospatial processing.
These brain patterns characterizations could be useful for chess training or clinicians in the field of neuroscience.
Objectives:
This study sought to determine whether Holter-based parameters of heart rate variability (HRV) are independently associated with incident heart failure among older adults in the CHS (Cardiovascular Health Study) as evidenced by an improvement in the predictive power of the Health Aging and Body Composition Heart Failure (Health ABC) score.
Background:
Abnormal HRV, a marker of autonomic dysfunction, has been associated with multiple adverse cardiovascular outcomes but not the development of congestive heart failure (CHF).
Methods:
Asymptomatic CHS participants with interpretable 24-h baseline Holter recordings were included (n = 1,401). HRV measures and premature ventricular contraction (PVC) counts were compared between participants with (n = 260) and without (n = 1,141) incident CHF on follow-up. Significantly different parameters between groups were added to the components of the Health ABC score, a validated CHF prediction tool, using stepwise Cox regression.
Results:
The final model included components of the Health ABC score, In PVC counts (adjusted hazard ratio [aHR]: 1.12; 95% confidence interval [CI]: 1.07 to 1.19; p < 0.001) and the following HRV measures: abnormal heart rate turbulence onset (aHR: 1.52; 95% CI: 1.11 to 2.08; p = 0.009), short-term fractal scaling exponent (aHR: 0.27; 95% CI: 0.14 to 0.53; p < 0.001), in very low frequency power (aHR: 1.28; 95% CI: 1.02 to 1.60; p = 0.037), and coefficient of variance of N-N intervals (aHR: 0.94; 95% CI: 0.90 to 0.99; p = 0.009). The C-statistic for the final model was significantly improved over the Health ABC model alone (0.77 vs. 0.73; p = 0.0002).
Conclusions:
Abnormal HRV parameters were significantly and independently associated with incident CHF in asymptomatic, older adults. When combined with increased PVCs, HRV improved the predictive power of the Health ABC score.
The capacity of relational reasoning is to find relationships, comprehend implications, analyze novel problems and draw conclusions. This study has investigated brain behavior and dynamic neural activity during Raven's Advance Progressive Matrices (RAPM), which requires strong cognitive reasoning to select a solution, by using an electroencephalogram (EEG). The EEGs were recorded all over the scalps of eight healthy volunteers using the 128-channel Hydro-Cel Geodesic (EGI Inc.) system. Brain activation was dominant during the reasoning and problem solving process in the pre-frontal lobe and parietal lobe as compared to the baseline conditions in all of the subjects, consistently. The theta band (3.5-7.5Hz) was significantly (p<;0.025) higher during the reasoning process at the frontal lobe as compared to eye-closed and eye-open conditions. Results showed high frontal theta activity in problem solving, which requires substantial reasoning and thinking skills.
Kubios HRV is an advanced and easy to use software for heart rate variability (HRV) analysis. The software supports several input data formats for electrocardiogram (ECG) data and beat-to-beat RR interval data. It includes an adaptive QRS detection algorithm and tools for artifact correction, trend removal and analysis sample selection. The software computes all the commonly used time-domain and frequency-domain HRV parameters and several nonlinear parameters. There are several adjustable analysis settings through which the analysis methods can be optimized for different data. The ECG derived respiratory frequency is also computed, which is important for reliable interpretation of the analysis results. The analysis results can be saved as an ASCII text file (easy to import into MS Excel or SPSS), Matlab MAT-file, or as a PDF report. The software is easy to use through its compact graphical user interface. The software is available free of charge for Windows and Linux operating systems at http://kubios.uef.fi.
This paper develops a technique for isolating and studying the per- ceptual structures that chess players perceive. Three chess players of varying strength - from master to novice - were confronted with two tasks: ( 1) A perception task, where the player reproduces a chess position in plain view, and (2) de Groot's ( 1965) short-term recall task, where the player reproduces a chess position after viewing it for 5 sec. The successive glances at the position in the perceptual task and long pauses in tbe memory task were used to segment the structures in the reconstruction protocol. The size and nature of these structures were then analyzed as a function of chess skill. What does an experienced chess player "see" when he looks at a chess position? By analyzing an expert player's eye movements, it has been shown that, among other things, he is looking at how pieces attack and defend each other (Simon & Barenfeld, 1969). But we know from other considerations that he is seeing much more. Our work is concerned with just what ahe expert chess pIayer perceives.
The purpose of this study is to examine brain activities of participants solving mental math problems. The research investigated how problem difficulty affected the subjects' responses and electroencephalogram (EEG) in different brain regions. In general, it was found that solution latencies (SL) to the math problems increased with difficulty. The EEG results showed that across subjects, the right-central beta, left-parietal theta, left-occipital theta and alpha, right-parietal alpha and beta, medial-frontal beta and medial central theta power decreased as task difficulty increased. This study further explored the effects of problem-solving performance on the EEG. Slow solvers exhibited greater frontal theta activities in the right hemisphere, whereas an inverse pattern of hemispheric asymmetry was found in fast solvers. Furthermore, analyses of spatio-temporal brain dynamics during problem solving show progressively stronger alpha- and beta-power suppression and theta-power augmentation as subjects were reaching a solution. These findings provide a better understanding of cortical activities mediating math-based problem solving and knowledge acquisition that can ultimately benefit math learning and education.
1. Time domain summary statistics and frequency domain parameters can be used to measure heart rate variability. More recently, qualitative methods including the Poincaré plot have been used to evaluate heart rate variability. The aim of this study was to validate a novel method of quantitative analysis of the Poincaré plot using conventional statistical techniques.
2. Beat-to-beat heart rate variability was measured over a relatively short period of time (10–20 min) in 12 healthy subjects aged between 20 and 40 years (mean 30 ± 7 years) during (i) supine rest, (ii) head-up tilt (sympathetic activation, parasympathetic nervous system activity withdrawal), (iii) intravenous infusion of atropine (parasympathetic nervous system activity withdrawal), and (iv) after overnight administration of low-dose transdermal scopolamine (parasympathetic nervous system augmentation).
3. The ‘width’ of the Poincaré plot, as quantified by SD delta R—R (the difference between successive R—R intervals), was determined at rest (median 48.9, quartile range 20 ms) and found to be significantly reduced during tilt (median 19.1, quartile range 13.7 ms, P < 0.01) and atropine administration (median 7.1, quartile range 5.7 ms, P < 0.01) and increased by scopolamine (median 79.3, quartile range 33 ms, P < 0.01). Furthermore, log variance of delta R—R intervals correlated almost perfectly with log high-frequency (0.15–0.4 Hz) power (r = 0.99, P < 0.01).
4. These findings strongly suggest that the ‘width’ of the Poincaré plot is a measure of parasympathetic nervous system activity. The Poincaré plot is therefore a quantitative visual tool which can be applied to the analysis of R—R interval data gathered over relatively short time periods.
In a previous study of simulated vehicle performance we found that stationary visual attention and body movements alone produced selective effects on topographic EEG frequency patterns. In the present study we focus on an expanded set of these task components. EEG, EOG and ECG data were recorded from 21 subjects during instructed driving movements and during visual scanning tasks ranging from a stationary to a rapidly moving simulated driving display. Spectral analysis was calculated on ten 2-Hz, partially overlapped frequency bands between 6 and 17 Hz. Body movements produced a selective bilateral suppression of 11-15 Hz activity localized to medial somatosensory cortex, while both slow and rapid visual scanning tasks produced a similar bilateral suppression of 11-15 Hz activity localized to temporo-parietal sites. A generalized suppression of 7-11 Hz activity was also found during the fastest visual scanning task. There were no significant differences in ECG between tasks. Other human and animal findings consistent with these functional observations are discussed.
This article tries to integrate results in memory research from divergent disciplines such as cognitive psychology, neuroanatomy, and neurophysiology. The integrating link is seen in more recent findings that provide strong arguments for the assumption that oscillations are a basic form of communication between cortical cell assemblies. It is assumed that synchronous oscillations of large cell assemblies--termed type 1 synchronization--reflect a resting state or possibly even a state of functional inhibition. On the other hand, during mental activity, when different neuronal networks may start to oscillate with different frequencies, each network may still oscillate synchronously (this is termed type 2 synchronization), but as a consequence, the large scale type 1 oscillation disappears. It is argued that these different types of synchronization can be observed in the scalp EEG by calculating event-related power changes within comparatively narrow but individually adjusted frequency bands. Experimental findings are discussed which support the hypothesis that short-term (episodic) memory demands lead to a synchronization (increase in band power) in the theta band, whereas long-term (semantic) memory demands lead to a task-specific desynchronization (decrease or suppression of power) in the upper alpha band. Based on these and other findings, a new memory model is proposed that is described on three levels: cognitive, anatomical and neurophysiological. It is suggested that short-term (episodic) memory processes are reflected by oscillations in an anterior limbic system, whereas long-term (semantic) memory processes are reflected by oscillations in a posterior-thalamic system. Oscillations in these frequency bands possibly provide the basis for encoding, accessing, and retrieving cortical codes that are stored in the form of widely distributed but intensely interconnected cell assemblies.
Theta rhythm at the midline of the frontal area can be observed in normal subjects, during mental task performance, rest and sleep. Frontal midline theta rhythm (Fm theta) is a train of rhythmic waves at the frequency of 6- Hz and can be induced by various mental tasks. Fm theta is induced not only during mental tasks but also during nocturnal sleep in which it was most frequent during rapid eye movement (REM) and second most frequent during stage 1 of non-REM (NREM) sleep, and the relationship of Fm theta to dream images during sleep was found. It is concluded, therefore, that the appearance of Fm theta is related to mental activity even during sleep. Fm theta shows individual differences and is related to certain personality traits. High Fm theta groups showed the lowest anxiety score in the Manifest Anxiety Scale (MAS), the highest score in the extrovertive scale of the Maudsley Personality Inventory (MPI) and the lowest score in the neurotic scale of MPI. Low Fm theta groups showed the opposite correlation. Significant negative correlation was found between the amount of Fm theta and platelet monoamine oxidase (MAO) activity. Summarizing the above-mentioned results, it may be concluded that the appearance of Fm 0 is related to mental activity, personality traits and platelet MAO activity. Furthermore, the correlation of such markers as platelet MAO activity and Fm theta with personality traits as measured by various psychological tests may prove to be of great importance in the exploration of the biological bases of personality.
Electrical potentials produced by blinks and eye movements present serious problems for electroencephalographic (EEG) and event-related potential (ERP) data interpretation and analysis, particularly for analysis of data from some clinical populations. Often, all epochs contaminated by large eye artifacts are rejected as unusable, though this may prove unacceptable when blinks and eye movements occur frequently.
Frontal channels are often used as reference signals to regress out eye artifacts, but inevitably portions of relevant EEG signals also appearing in EOG channels are thereby eliminated or mixed into other scalp channels. A generally applicable adaptive method for removing artifacts from EEG records based on blind source separation by independent component analysis (ICA) (Neural Computation 7 (1995) 1129; Neural Computation 10(8) (1998) 2103; Neural Computation 11(2) (1999) 606) overcomes these limitations.
Results on EEG data collected from 28 normal controls and 22 clinical subjects performing a visual selective attention task show that ICA can be used to effectively detect, separate and remove ocular artifacts from even strongly contaminated EEG recordings. The results compare favorably to those obtained using rejection or regression methods.
The ICA method can preserve ERP contributions from all of the recorded trials and all the recorded data channels, even when none of the single trials are artifact-free.
Recent theoretical work has suggested that brain oscillations in the theta band are involved in active maintenance and recall of working memory representations. To test this theoretical framework we recorded neuromagnetic responses from 10 subjects performing the Sternberg task. Subjects were required to retain a list of 1, 3, 5 or 7 visually presented digits during a 3-s retention period. During the retention period we observed ongoing frontal theta activity in the 7-8.5-Hz band recorded by sensors over frontal brain areas. The activity in the theta band increased parametrically with the number of items retained in working memory. A time-frequency analysis revealed that the task-dependent theta was present during the retention period and during memory scanning. Following the memory task the theta activity was reduced. These results suggest that theta oscillations generated in frontal brain regions play an active role in memory maintenance.
An advanced, simple to use, detrending method to be used before heart rate variability analysis (HRV) is presented. The method is based on smoothness priors approach and operates like a time-varying finite-impulse response high-pass filter. The effect of the detrending on time- and frequency-domain analysis of HRV is studied.
Chess is a game that involves many aspects of high level cognition and requires sophisticated problem solving skills. However, there is little understanding of the neural basis of chess cognition. This study employed functional magnetic resonance imaging (fMRI) to identify cortical areas that are active during the analysis of chess positions compared with a spatial task with matched visual stimuli. Bilateral activation was revealed in the superior frontal lobes, the parietal lobes, and occipital lobes. Some small areas of activation were observed unilaterally in the left hemisphere. The left hemisphere showed more activation than the right. Results are discussed in relation to a similar brain imaging study on the game Go.