Correction to: An Anti-hyperventilation Instruction Decreases the Drop in End-tidal CO 2 and Symptoms of Hyperventilation During Breathing at 0.1 Hz The original version of this article unfortunately contained an error in abstract section. The number of participants should be “Forty-six participants” instead of “Thirty-six participants”. The correct sentence is as follows: Forty-six participants were randomly assigned to one of two groups: a group given an anti-hyperventilation instruction and a control group without such an instruction. The original article has been corrected.

The Analysis of Electroencephalography Changes Before and After a Single Neurofeedback Alpha/Theta Training Session in University Students Abstract The underlying mechanisms of alpha/theta neurofeedback training have not been fully determined. Therefore, this study aimed to test the changes in the brain state feedback during the alpha/theta training. Twenty-seven healthy participants were trained during a single session of the alpha/theta protocol, and the resting quantitative electroencephalography (QEEG) was assessed before and after training. QEEG was recorded at eight scalp locations (F3, F4, C3, C4, T3, T4, O1, and O2), and the absolute power, relative power, ratio of sensory-motor rhythm beta (SMR) to theta (RST), ratio of SMR-mid beta to theta (RSMT), ratio of mid beta to theta (RMT), ratio of alpha to high beta (RAHB), and scaling exponent of detrended fluctuation analysis by each band were measured. The results indicated a significant increase of absolute alpha power, especially the slow alpha band, at all electrodes except T3 and T4. Moreover, the relative alpha power, especially the slow alpha band, showed a significant increase at all electrodes. The relative theta power showed a significant decrease at all electrodes, except T3. A significant decrease in relative beta power, relative lower beta power and relative mid beta power was observed at O1. RST (at C4, O1, and O2), RSMT and RMT (at F4, C4, O1 and O2), and RAHB (at all electrodes) showed significant increase. Scaling exponents at all electrodes except T3 showed a significant decrease. These findings indicate that a one-time session of alpha/theta training might have the possibility to enhance both vigilance and concentration, thus stabilizing the overall brain function.

Higher levels of Depressive Symptoms are Associated with Increased Resting-State Heart Rate Variability and Blunted Reactivity to a Laboratory Stress Task among Healthy Adults Abstract Laboratory stress tasks induce strong changes in linear and non-linear indices of heart rate variability (HRV) among healthy adults, due to a task-induced parasympathetic withdrawal. Previous findings suggested that negative affectivity and its correlates (i.e., depressive symptoms, anxiety, hostility, type D personality, and situational stress) could profoundly affect autonomic activity. However, to date no studies considered these psychological dimensions simultaneously while trying to disentangle their acute effects on HRV during a laboratory stress task. A total of 65 healthy participants completed a battery of questionnaires and later underwent a psychosocial stress protocol, which involves a stressful and a non-stressful mental arithmetic task, with the latter serving as a control condition for the former. During the entire procedure, autonomic activity was recorded through a portable ECG device. We analysed longitudinal changes in HRV indices using Mixed Models, taking into account respiration rates and the associations between psychophysiological variables through bivariate Pearson’s r (partial) correlation indices. We found significant changes in linear (e.g., HF power, RMSSD) and non-linear (e.g., Poincaré Plot and Correlation Dimension D2) HRV indices during the procedure, with the lowest point reached during the stressful mental arithmetic task. Interestingly, only depressive symptomatology was significantly and positively related to a higher resting-state HRV and to a blunted reactivity to the stress task, even after controlling for baseline values. Results suggest that healthy individuals with higher levels of depressive symptoms could experience atypical cardiovascular responses to stressful events: several speculative interpretations, considering autonomic, behavioral, and motivational dysregulations, are discussed.

Give Me Five? Examining the Psychophysiological Effects of High-Fives in Athletes Abstract High-fives are a phenomenon that is frequently observed in sports. However, investigations on effects of high-fives are missing. Therefore, the aim of the present study was to examine psychophysiological effects of high-fives. From an embodied cognition perspective, dynamic, upward movements compared to downward movements should activate positive concepts that are represented by psychological as well as physiological states. Thirty-four athletes performed high- and low-fives (dynamic movements) as opposed to high and low static postures (control conditions) in a double-blind, within-subject design. Psychological states (i.e., feeling motivated, feeling strong) and physiological changes (i.e., cortisol, testosterone) due to the manipulation were measured. Results showed the predicted significant interaction effect for cortisol changes, but not for the other psychological (i.e., feeling motivated, feeling strong) and physiological (testosterone) state measures. In detail, a decrease in cortisol was found after athletes performed high-fives compared to low-fives. The observed effect on cortisol should be considered with caution and needs to be replicated, however, might add information to the current discussion about the crucial relevance of movement for embodied cognition effects. Future research could investigate the effects of high-fives with a partner and add performance parameters to provide more information on the effects of high-fives on performance in sport.

Item Roles Explored in a Modified P300-Based CTP Concealed Information Test Abstract In this study, we introduced familiarity-related inducer items (expressions referring to the participant’s self-related, familiar details: “mine,” “familiar”; and expressions referring to other, unfamiliar details, e.g., “other,” “irrelevant”) to the Complex Trial Protocol version of the P300-based Concealed Information Test (CIT), at the same time using different item categories with various levels of personal importance to the participants (forenames, birthdays, favorite animals). The inclusion of inducers did not significantly improve the overall efficiency of the method as we would have expected considering that these inducers should increase awareness of the denial of the recognition of the probes (the true details of the participants), and hence the subjective saliency of the items (Lukács in J Appl Res Mem Cognit, 6:283–284, 2017a). This may be explained by the visual similarity of inducers to the probe and irrelevant items and the consequent distracting influence of inducers on probe-task performance. On the other hand, the CIT effect (probe-irrelevant P300 differences) was always lower for less personally important (low-salient) and higher for more personally important (high-salient) items.

Is It Possible to Determine the Level of Spiritual Well-Being by Measuring Heart Rate Variability During the Reading of Heavenly Books? Abstract A previous study stated that reading holy books can make a meaningful change in heart rate variability (HRV). The purpose of this study was to test the effect of reading the Quran, the heavenly religious book of the Muslim people in the Arabic language, on the Farsi (Persian)-speaking Muslims with various levels of spiritual well-being (SWB). In addition, novel to this study was the assessment of whether or not it is possible to use HRV features to distinguish individuals with high SWB from those with medium SWB. First, a questionnaire was completed by 31 volunteers to measure their SWB. Baseline ECG measurements were recorded during the resting stage. The volunteers were then asked to read the Quran for 5 min while ECG was recorded again. HRV indexes were calculated and four features were extracted and analyzed based on their correlation with the different levels of SWB. Independent t-tests were conducted and the results established a significant difference in these four features between high SWB and medium SWB groups, during the reading stage. Subsequently, with the use of these four HRV features, an artificial neural network and a decision tree were designed to classify the levels of SWB in volunteers. The outcome of this study demonstrated that it is possible to evaluate the level of SWB in individuals while they are reading the Quran.

An Anti-hyperventilation Instruction Decreases the Drop in End-tidal CO 2 and Symptoms of Hyperventilation During Breathing at 0.1 Hz Abstract Breathing at a frequency of around 0.1 Hz is widely used in basic research and in applied psychophysiology because it strongly increases fluctuations in the cardiovascular system and affects psychological functioning. Volitional control of breathing often leads to hyperventilation among untrained individuals, which may produce aversive symptoms and alter the psychological and physiological effects of the paced breathing. The present study investigated the effectiveness of a brief anti-hyperventilation instruction during paced breathing at a frequency of 0.1 Hz. Forty-six participants were randomly assigned to one of two groups: a group given an anti-hyperventilation instruction and a control group without such an instruction. The instruction asked participants to avoid excessively deep breathing and to breathe shallowly and naturally. Participants performed the breathing task for 10 min. Hyperventilation was measured by partial pressure of end-tidal CO2 (PetCO2); furthermore, symptoms of hyperventilation, feeling of air hunger, task difficulty, and affective state were measured by self-report. The results showed that paced breathing without instruction decreased PetCO2 by 5.21 mmHg and that the use of the anti-hyperventilation instruction reduced the drop in PetCO2 to 2.7 mmHg. Symptoms of hyperventilation were lower in the group with the anti-hyperventilation instruction. Neither the feeling of air hunger nor task difficulty were affected by the instruction. There were no significant effects of the instruction on affective state. The present study indicates that a brief anti-hyperventilation instruction may be used to decrease drop in PetCO2 and symptoms of hyperventilation during breathing at 0.1 Hz and that the instruction is well tolerated.

Towards a Pragmatic Approach to a Psychophysiological Unit of Analysis for Mental and Brain Disorders: An EEG-Copeia for Neurofeedback Abstract This article proposes what we call an “EEG-Copeia” for neurofeedback, like the “Pharmacopeia” for psychopharmacology. This paper proposes to define an “EEG-Copeia” as an organized list of scientifically validated EEG markers, characterized by a specific association with an identified cognitive process, that define a psychophysiological unit of analysis useful for mental or brain disorder evaluation and treatment. A characteristic of EEG neurofeedback for mental and brain disorders is that it targets a EEG markers related to a supposed cognitive process, whereas conventional treatments target clinical manifestations. This could explain why EEG neurofeedback studies encounter difficulty in achieving reproducibility and validation. The present paper suggests that a first step to optimize EEG neurofeedback protocols and future research is to target a valid EEG marker. The specificity of the cognitive skills trained and learned during real time feedback of the EEG marker could be enhanced and both the reliability of neurofeedback training and the therapeutic impact optimized. However, several of the most well-known EEG markers have seldom been applied for neurofeedback. Moreover, we lack a reliable and valid EEG targets library for further RCT to evaluate the efficacy of neurofeedback in mental and brain disorders. With the present manuscript, our aim is to foster dialogues between cognitive neuroscience and EEG neurofeedback according to a psychophysiological perspective. The primary objective of this review was to identify the most robust EEG target. EEG markers linked with one or several clearly identified cognitive-related processes will be identified. The secondary objective was to organize these EEG markers and related cognitive process in a psychophysiological unit of analysis matrix inspired by the Research Domain Criteria (RDoC) project.

Effect of Complexity on Frontal Event Related Desynchronisation in Mental Rotation Task Abstract A complexity (orientation and shape of stimuli) in the mental rotation (MR) task often affects reaction time (RT) and response accuracy, but the nature of such reflections in neuroscientific research is commonly undocumented. A number of studies have explored the effect of complexity and subsequently noted down the differences in performance. However, a few studies explored complexity (in the term of angular disparity) and cognitive strategies with respect to correct responses only. In contrast, the present study investigated frontal alpha desynchronization with reference to the complexity and proportions of correct and incorrect responses. Behavioral and neurophysiological responses were investigated to understand the switching between strategies (Analytic vs. Holistic). Results showed longer response time with respect to increased complexity. Frontal alpha desynchronization increased for difficult trials and incorrect responses, suggesting a higher utilization of cognitive resources at the frontal region during the MR task. Higher left frontal desynchronization reflected a trading off between strategies for difficult trials. Taken together, these findings suggest that the effect of stimuli complexity is more nuanced than implied by a simple hemispheric dichotomy for frontal cortex and discuss possible future directions to better understand the multitudinous brain mechanisms involved in MR.

Social Context and Sex Moderate the Association Between Type D Personality and Cardiovascular Reactivity Abstract Type D personality has been consistently associated with adverse cardiovascular health with atypical cardiovascular reactions to psychological stress one plausible underlying mechanism. However, whether this varies by sex and social context has received little attention. This study examined the interaction between Type D personality, sex and social context on cardiovascular reactivity to acute stress. A sample of 76 healthy undergraduate students (47 female) completed the DS14 Type D measure, before undergoing a traditional cardiovascular reactivity protocol. The social context of the laboratory environment was manipulated to create a social and non-social context using a between-subjects design. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were monitored throughout. No associations were evident for blood pressure. However, a significant personality × sex × social context interaction on HR reactivity was found; here Type D was associated with a higher HR response to the social task amongst males but not females, while Type D females typically exhibited blunted reactions. While these atypical reactions indicate a possible psychophysiological pathway leading to adverse cardiovascular events amongst Type Ds, it appears that Type D males are particularly vulnerable to socially based stressors, exhibiting exaggerated cardiovascular reactions.