Decrease in Salivary Serotonin in Response to Probiotic Supplementation With Saccharomyces boulardii in Healthy Volunteers Under Psychological Stress: Secondary Analysis of a Randomized, Double-Blind, Placebo-Controlled Trial

BackgroundBacterial probiotics are thought to exert a serotonergic effect relevant to their potential antidepressant and pro-cognitive action, but yeast probiotics have not been tested. The aim of the present study was to determine whether 30-day supplementation with Saccharomyces boulardii affects the level of salivary serotonin under psychological stress and identify the factors associated with it.MethodsHealthy medical students were randomized to ingest Saccharomyces boulardii CNCM I-1079 or placebo before a stressful event. Salivary serotonin concentration was assessed before and at the end of supplementation. Moreover, obtained results were compared to psychological, biochemical, physiological and sociodemographic study participants data.ResultsData of thirty-two participants (22.8 ± 1.7 years of age, 16 males) was available for the main analysis. Supplementation with Saccharomyces boulardii decreased salivary serotonin concentration under psychological stress by 3.13 (95% CI 0.20 to 6.07) ng/mL, p = 0.037, as compared to placebo. Salivary serotonin was positively correlated with salivary metanephrine (β = 0.27, 95% CI 0.02 to 0.52, p = 0.031) and pulse rate (β = 0.28, 95% CI 0.05 to 0.50, p = 0.018), but insignificantly with anxiety, depression, eating attitudes and information retrieval.ConclusionsSaccharomyces boulardii CNCM I-1079 may be distinct from bacterial probiotics in its salivary serotonergic effect, which appears positively linked to symapathoadrenal markers. The study requires cautious interpretation, and further investigation.

Impaired dynamics of prefrontal beta-band networks during cognitive action control in Parkinson's disease

Among the cognitive symptoms that are associated with Parkinson's disease (PD), alterations in cognitive action control (CAC) are commonly reported in patients. CAC enables the suppression of an automatic action, in favor of a goal-directed one. The implementation of CAC is time-resolved and arguably associated with dynamic changes in functional brain networks. However, the electrophysiological functional networks involved, their dynamic changes, and how these changes are affected by PD, still remain unknown. In this study, to address this gap of knowledge, 21 PD patients and 10 healthy controls (HC) underwent a Simon task while high-density electroencephalography (HD-EEG) was recorded. Source-level dynamic connectivity matrices were estimated using the phase-locking value in the beta (12-25 Hz) and gamma (30-45 Hz) frequency bands. Temporal independent component analyses were used as a dimension reduction tool to isolate the group-specific brain network states that were dominant during the task. Typical microstate metrics were quantified to investigate the presence of these states at the subject-level. Our results first confirmed that PD patients experienced difficulties in inhibiting automatic responses during the task. At the group-level, HC displayed a significant functional network state that involved typical CAC-related prefrontal and cingulate nodes (e.g., inferior frontal cortex). Both group- and subject-level analyses showed that this network was less present in PD to the benefit of other networks involving lateralized temporal and insular components. The presence of this prefrontal network was associated with decreased reaction time. In the gamma band, two networks (fronto-cingulate and fronto-temporal) followed one another in HC, while 3 partially overlapping networks that included fronto-temporal, fronto-occipital and cross-hemispheric temporal connections were found in PD. At the subject-level, differences between PD and HC were less marked. Altogether, this study showed that the functional brain networks observed during CAC and their temporal changes were different in PD patients as compared to HC, and that these differences partially relate to behavioral changes. This study also highlights that task-based dynamic functional connectivity is a promising approach in understanding the cognitive dysfunctions observed in PD and beyond.

The Instuments for the Development of Universal Logical Skills of Analysis and the Culture of the Transmission of These Skills in the Process of Professional Training of Mathimatics Teachers

General logical universal learning activities (analysis, synthesis, comparison, etc.) in studies of the theory of development of universal learning activities are often represented by generalized formulations such as «text analysis», «analysis of the formulation of a theorem», «synthesis of information», etc. This approach does not allow to evaluate the level of complexity of a cognitive action, to determine its specificity, and to distinguish the levels of possession of this cognitive action. The article deals with the approach to forming the general logical action of analysis, which is based on the concept of funding, developed by E.I. Smirnov, V.D. Shadrikov. The methodological principle of the research is associated with various aspects of the system-activity and competence-based approaches to the organization of teaching students of pedagogical specialties. The aim of the article is to develop an approach to the design of teaching tools aimed at the formation of the general logical action of analysis. Results. The article describes the preparatory stage of the implementation of the concept of funding general logical cognitive actions in the training of students of pedagogical direction. The approach to the level differentiation of cognitive action of analysis is proposed. The types of analysis and their manifestations in mathematical and socio-humanitarian disciplines are considered. In conclusion, the necessity of differentiating the analysis in the organization of funding of this action is justified.

Salivary Serotonin Decrease in Response to Probiotic Supplementation with Saccharomyces boulardii in Healthy Volunteers under Psychological Stress: Secondary Analysis of a Randomized, Double-Blind, Placebo-Controlled Trial

(1) Background: Bacterial probiotics are thought to exert a serotonergic effect relevant to their potential antidepressant and pro-cognitive action, but yeast probiotics have not been tested. The aim of the present study was to determine whether 30-day supplementation with Saccharomyces boulardii affects the level of salivary serotonin under psychological stress and identify the factors associated with it. (2) Methods: Healthy medical students were randomized to ingest Saccharomyces boulardii CNCM I-1079 or placebo before a stressful event. Salivary serotonin concentration was assessed before and at the end of supplementation. Moreover, obtained results were compared to psychological, biochemical, physiological and sociodemographic study participants data. (3) Results: Data of thirty-two participants (22.8 ± 1.7 years of age, 16 males) was available for the main analysis. Supplementation with Saccharomyces boulardii decreased salivary serotonin concentration under psychological stress by 3.13 (95% CI 0.20 to 6.07) ng/mL, p = 0.037, as compared to placebo. Salivary serotonin was positively correlated with salivary metanephrine (β = 0.27, 95% CI 0.02 to 0.52, p = 0.031) and pulse rate (β = 0.28, 95% CI 0.05 to 0.50, p = 0.018), but insignificantly with anxiety, depression, eating attitudes and information retrieval. (4) Conclusions: Saccharomyces boulardii CNCM I-1079 may be distinct from bacterial probiotics in its salivary serotonergic effect, which appears positively linked to symapathoadrenal markers. The study requires cautious interpretation, and further investigation.

Efference information flow during skill acquisition mediates its interaction with medical simulation technology

Despite substantial progress towards establishing virtual reality (VR) simulators as a replacement for physical ones for skill training, its effect on the brain network during skill acquisition has not been well addressed. In this study, we employed portable optical neuroimaging technology and Granger causality approach to uncover the impact of the two medical simulation technologies on the directed functional brain network of the subjects with two different skill levels. The mobile brain-behavior relantionship was evaluated using functional near-infrared spectroscopy (fNIRS) while right-handed subjects performed well-established fundamentals of laparoscopic surgery (FLS) pattern cutting task. A multiple regression path analysis found that the cognitive-action information flow from the right prefrontal cortex to the supplementary motor area statistically significantly predicted the FLS task performance. Here, the skill level (expert vs novice) affected the cognitive-action information flow from the right prefrontal cortex and the efference copy information flow from the left primary motor cortex via supplementary motor area as hub to the cognitiveperception at the left prefrontal cortex, i.e., the action-preception link. The simulation technology (physical vs VR simulator) affected solely the cognitive-action information flow from the right prefrontal cortex to the left primary motor cortex; however, the interaction between the medical simulation technology) and the skill level affected the efference information flow from the left primary motor cortex to the right prefrontal cortex and from the supplementary motor area to the left prefrontal cortex. These discriminative findings are crucial since our VR simulator had face and construct validity. Therefore, our study highlighted the importance of efference information flow within the framework of the perception-action cycle when comparing medical simulation technology for visuomotor skill acquisition.

An Active Inference Model of Conscious Access with and without Report

Cognitive theories of consciousness, such as global workspace theory and higher-order theories, posit that frontoparietal circuits play a crucial role in conscious access. However, recent studies using no-report paradigms have posed a challenge to cognitive theories by demonstrating conscious accessibility in the apparent absence of prefrontal cortex (PFC) activation. To address this challenge, this paper presents a computational model of conscious access, based upon active inference, that treats working memory gating as a cognitive action. We simulate a visual masking task and show that late P3b-like event-related potentials (ERPs), and increased PFC activity, are induced by the working memory demands of report. When reporting demands are removed, these late ERPs vanish and PFC activity is reduced. These results therefore reproduce, and potentially explain, results from no-report paradigms. However, even without reporting demands, our model shows that simulated PFC activity on visible stimulus trials still crosses the threshold for reportability – maintaining the link between PFC and conscious access. Therefore, our simulations show that evidence provided by no-report paradigms does not necessarily contradict cognitive theories of consciousness.

Attitudes of course participants towards evaluation at the training courses of pedagogical staff

The article demonstrates some of the results identified in a comprehensive study of the assessment process for certification of training courses. The study focuses on the attitude of the course participants towards the assessment, based on which recommendations were developed to improve the effectiveness of the assessment. Based on the views of the course participants who passed the assessment procedures, the impact and opportunities of assessment to improve learning outcomes are discussed. As part of the study, a Likert-scale survey questionnaire was taken from 2445 course participants who were assessed on training programs in different regions of the Republic of Kazakhstan from 2012 to 2020. According to the results of the survey, the explanatory statistical analysis showed that the majority of course participants experienced a positive effect of the assessment. Based on the parametric-correlation analysis, cognitive-action and emotional-motivational components were identified as factors influencing the attitude of course participants towards the assessment, and the issues of concern to the course participants in terms of the assessment process are explained. Keywords: Teacher training courses, certification, assessment, assessment tools, objectivity, cognitive-action, emotional-motivational

Pre-trial predictors of conflict response efficacy in human dorsolateral prefrontal cortex

The ability to perform motor actions depends, in part, on the brain's initial state, that is the ensemble firing rate pattern prior to the initiation of action. We hypothesized that the same principle would apply to cognitive functions as well. To test this idea, we examined a unique set of single unit data collected in human dorsolateral prefrontal cortex (dlPFC). Data were collected in a conflict task that interleaves Simon (motor-type) and Eriksen (flanker-type) conflict trials. Variability in pre-trial firing rate predicted the ability to resolve conflict, as inferred from reaction times. Ensemble patterns that predicted faster Simon reaction times overlapped slightly with those predicting Eriksen performance, indicating that the two conflict types are associated with near-orthogonal initial states, and suggesting that there is a weak abstract or amodal conflict preparatory state in this region. These codes became fully orthogonalized in the response state. We interpret these results in light of the initial state and dual-mechanisms of control hypotheses, arguing that the firing patterns in dlPFC immediately preceding the start of the task predispose it for the efficient implementation of cognitive action.