Non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) has attracted increasing interest as a neurostimulation tool with potential applications in modulating cognitive processes such as attention and memory, possibly through the modulation of the locus-coeruleus noradrenaline system. Studies examining the P300 brain-related component as a correlate of noradrenergic activity, however, have yielded inconsistent findings, possibly due to differences in stimulation parameters, thus necessitating further investigation. In this event-related potential study involving 61 participants, therefore, we examined how changes in taVNS parameters, specifically stimulation type (interval vs. continuous stimulation) and duration, influence P300 amplitudes during a visual novelty oddball task. Although no effects of stimulation were found over the whole cluster and time window of the P300, cluster-based permutation tests revealed a distinct impact of taVNS on the P300 response for a small electrode cluster, characterized by larger amplitudes observed for easy targets (i.e., stimuli that are easily discernible from standards) following taVNS compared to sham stimulation. Notably, our findings suggested that the type of stimulation significantly modulated taVNS effects on the P300, with continuous stimulation showing larger P300 differences (taVNS vs. sham) for hard targets and standards compared to interval stimulation. We observed no interaction effects of stimulation duration on the target-related P300. While our findings align with previous research, further investigation is warranted to fully elucidate the influence of taVNS on the P300 component and its potential utility as a reliable marker for neuromodulation in this field.

OBJECTIVE: Previous research has suggested beneficial effects of music in reducing stress levels. However, there is no consistent conclusion demonstrating that music can contribute to stress recovery, primarily due to limitations in stress measurement, and inconsistent methodology within existing studies. Our study explores whether relaxing music, especially when self-selected, outperforms non-music acoustic, and silence conditions, fostering both subjective and biological stress recovery.
METHODS: One hundred and five healthy female participants underwent the Trier Social Stress Test (TSST) before being randomly allocated to one of four conditions: condition 1 (n = 25) listened to researcher-selected relaxing music; condition 2 (n = 27) listened to self-selected relaxing music; condition 3 (n = 26) listened to the sound of rippling water; and condition 4 (n = 27) remained in silence. Stress parameters were repeatedly measured nine times before and after the TSST. Saliva samples were collected for cortisol and saliva alpha-amylase (sAA) analysis, Movisens equipment was used to measure heart rate (HR) and skin conductance levels (SCL), and Visual Analogue Scales (VAS) were used for subjective stress measurement.
RESULTS: The examination of SCL, and VAS scores revealed no significant changes following the four relaxation interventions. Although sAA displayed a significant main effect of condition, post hoc tests did not pinpoint specific differences. HR recovery patterns varied among the four relaxation interventions, with the sound of rippling water condition exhibiting a later significant decrease compared to the other conditions. Exploratory analyses revealed that cortisol levels continued increase in all conditions during intervention phase except the researcher-selected music condition.
CONCLUSIONS: The subjective and biological stress markers did not exhibit better recovery after the music stimulus, except for a tendency in the researcher-selected music condition to mitigate the continued increase in cortisol levels after the stress test. Our study provides the first evidence comparing the impact of researcher- and participant-selected music with silence and a non-music acoustic stimulus, on both subjective and biological stress recovery. Our findings contribute to a more nuanced understanding of the impact of music on stress recovery.

暂无摘要。

Saliva facilitates food oral processing, bolus formation, swallowing, and sensory perception, in addition to contributing to oral health and phonation. Ageing, health affections, and polymedication are among many causes altering salivary production, modifying the mastication process, the food impregnation ratio, and in turn altering the characteristics of the bolus, swallowing, and digestion. In this in vitro work, using the AM2 masticator apparatus, which replicates the mechanical actions taking place while chewing solid foods and produces realistic food bolus in various oral conditions, we investigated the effect of salivary fluid characteristics, i.e., composition, quantity (from absence to hypersalivation), temperature, and enzymatic action, on the physical characteristics (i.e., particle size distribution (PSD), bolus mass, salivary fluid content) of in vitro boluses of Traditional French baguette. A ready-to-swallow bolus of baguette displayed on average a d50 value (median particle size by mass) of 4.1 ± 0.4 mm, with saliva fluid constituting ∼ 35 % of the final bolus mass. The absence of saliva in mouth led to a deficient oral processing, forming bread boluses constituted by extremely big particles (ca. 80 % of particles had a size > 7.1 mm) that likely cannot be swallowed safely. On the contrary, an excess of saliva favoured an excessive breaking down of bread, leading to bread boluses constituted by smaller particles than those formed under healthy salivary conditions (d50 decreased from 4.1 mm to 3.1 mm), having a higher salivary fluid content (+10 %). On the other hand, the salivary fluid temperature did not affect PSD, d50, bolus mass, or salivary fluid content of in vitro bread boluses, however, the addition of human salivary α-amylase did, favouring particle size reduction (d50 decreased to 2.6 mm). Therefore, beyond the correlation between bolus hydration by saliva and food properties such as hardness and moisture content, our findings indicate that the quantity of salivary fluid present in the oral cavity and the enzymatic activity of salivary α-amylase during bread mastication significantly influence both the particle size distribution and the fluid content of bread boluses, ultimately determining the physical properties of the bolus and, therefore, potentially impacting the subsequent swallowing process.

UNASSIGNED: Video games affect the stress system and cognitive abilities in different ways. Here, we evaluated electrophysiological and biochemical indicators of stress and assessed their effects on cognition and behavioral indexes after playing a scary video game.
UNASSIGNED: Thirty volunteers were recruited into two groups as control and experimental. The saliva and blood samples were collected before and after intervention (watching/playing the scary game for control and experimental groups respectively). To measure cortisol and salivary alpha-amylase (sAA) levels, oxytocin (OT), and brain-derived neurotrophic factor (BDNF) plasma levels, dedicated ELISA kits were used. Electroencephalography recording was done before and after interventions for electroencephalogram (EEG)-based emotion and stress recognition. Then, the feature extraction (for mental stress, arousal, and valence) was done. Matrix laboratory (MATLAB) software, version 7.0.1 was used for processing EEG-acquired data. The repeated measures were applied to determine the intragroup significance level of difference.
UNASSIGNED: Scary gameplay increases mental stress (P<0.001) and arousal (P<0.001) features and decreases the valence (P<0.001) one. The salivary cortisol and alpha-amylase levels were significantly higher after the gameplay (P<0.001 for both). OT and BDNF plasma levels decreased after playing the scary game (P<0.05 for both).
UNASSIGNED: We conclude that perceived stress considerably elevates among players of scary video games, which adversely affects the emotional and cognitive capabilities, possibly via the strength of synaptic connections, and dendritic thorn construction of the brain neurons among players.
UNASSIGNED: The mental stress level increases in players of scary video games.The salivary cortisol and alpha-amylase levels are significantly higher after the scary gameplay.Plasma levels of oxytocin and brain-derived neurotrophic factor decrease after the scary gameplay.The arousal and valence features increase in players of scary video game.Cognitive capabilities are adversely affected by the scary gameplay.
UNASSIGNED: Nowadays, video games have become an important part of human life at different ages. Therefore, assessing their effects (improving and/or damaging) on cognition and behavior is important for understanding how they affect the nervous system. The results of such studies can be used to design a variety of games in the future in a way that minimizes the harmful side effects of video games on human cognitive functions and maximizes their beneficial effects.

Psychologically aggressive parenting (PAP) exposure negatively affects children\'s development of aggression. Nevertheless, not all children exposed to PAP display aggressive behaviors. Sympathetic nervous system (SNS) activity may influence the impact of early adversity on aggression. This study examines whether SNS reactivity and sex moderate the link between psychologically aggressive parenting (PAP) during childhood and later aggression. Emerging adults (N = 182, mean age = 19.03 years, 53 % female) retrospectively reported on their childhood PAP and current aggression. Salivary alpha-amylase (sAA) collected from a social stress task indexed SNS reactivity to stress. Childhood PAP was associated with emerging adulthood anger, hostility, physical, and verbal aggression. Moreover, males were more likely to exhibit anger, verbal, and physical aggression and had higher levels of sAA reactivity than females. A significant three-way interaction between childhood PAP, sAA reactivity, and sex accounted for participants\' current verbal aggression. The link between childhood PAP and later verbal aggression was stronger for males at higher levels of sAA reactivity. Females with higher levels of sAA reactivity displayed lower levels of verbal aggression regardless of PAP exposure. Males and females with lower levels of sAA reactivity were at elevated risk for verbal aggression regardless of PAP exposure. Moreover, we found a significant two-way interaction between PAP and sex on anger, such that higher levels of PAP exposure were associated with more anger among males, but not females. These findings highlight the importance of examining interactions between biological and environmental factors and sex in accounting for later aggression.

UNASSIGNED: Studies have suggested that listening to music can reduce psychological and biological responses to a stressor. However, it is unclear whether music has the same effect on stress recovery. According to field studies, people commonly use music in daily life for the specific purpose of relaxation. We explored whether individuals who generally use music for relaxation purposes show improved recovery from an acute stressor.
UNASSIGNED: In two independent studies, twenty-seven healthy female participants (Mage = 24.07) (Study 1) and twenty-one healthy male participants (Mage = 23.52) (Study 2) were separated into two groups based on their frequency of using music for relaxation purposes (low vs. high). All participants underwent a lab-based psychosocial stress test. Subjective stress levels were measured using visual analogue scales. Salivary cortisol and salivary alpha-amylase were measured to assess endocrine and autonomic stress responses, respectively. Subjective stress levels and saliva samples were measured nine times throughout the stress induction and recovery procedure. Chronic stress levels were assessed using the Perceived Stress Scale and the Screening Scale of Chronic Stress.
UNASSIGNED: No significant differences were observed in subjective stress levels, salivary alpha-amylase activity, or cortisol concentration between the two groups in either of the two studies. Further analyses revealed that among male participants, increased use of music for relaxation purposes was related to more chronic stress levels (t (10.46) = 2.45, p = 0.03, r = 0.60), whereas female participants exhibited a trend in the opposite direction (t (13.94) = -1.92, p = 0.07, r = 0.46).
UNASSIGNED: Contrary to our expectations, the results indicate that habitual music listening for relaxation purposes is not associated with improved recovery from a stressor. However, due to the small sample size, future exploration is necessary to enhance the statistical power of the results of the study.

Physical activity (PA) in the form of aerobic exercise (AE) preserves and improves neurocognitive function across the lifespan. However, a mechanistic understanding of the pathways by which aerobic exercise impacts brain health is still lacking, particularly with respect to stress-related pathways. One mechanistic hypothesis is that AE improves neurocognitive health in part by modifying circulating levels of stress-related hormones and signaling factors associated with the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS), as commonly measured by the biomarkers cortisol (CORT) and salivary α-amylase (sAA). Thus, this hypothesis predicts that changes in stress biomarkers, such as CORT and sAA, are possible explanatory pathways mediating the positive effects of AE on neurocognitive health. In the present review article, we provide a summary of available studies examining the possibility that exercise-induced changes to stress biomarkers could partly account for exercise-related improvements in neurocognitive health. Our review indicates that despite the intuitive appeal of this hypothesis, there is insufficient evidence available to conclude that chronic and habitual AE affects neurocognitive health by altering stress biomarker pathways. The cross-sectional nature of the majority of reviewed studies highlights the need for well-controlled studies to adequately test this hypothesis.

UNASSIGNED: In paediatric dentistry, pain is adversely influenced by a child\'s level of anxiety. Ironically, the most common form of pain control used in dentistry, local anaesthesia, can itself produce anxiety. One of the techniques to overcome a child\'s anxiety is using distraction. The aim of the present study was to evaluate the effectiveness of distraction techniques, i.e. audio distraction (AD) and audio-visual distraction (AVD) by measuring salivary stress biomarker (salivary cortisol and salivary alpha-amylase) levels in 3-5 year-old children.
UNASSIGNED: Forty children aged 3-5 years were divided randomly into two groups; (Group I = AD, Group II = AVD). Cotton pellets were placed in the lingual vestibule to collect a sample of saliva. Children were then asked to wear overhead phones in the AD group, connected to a phone, and rhymes were played. In AVD, a cartoon movie was shown to the children using AV glasses. Simultaneously, local anaesthesia was administrated to children, after which another saliva sample was collected. Biomarker estimation was done using ELISA. Fisher\'s exact test was used for statistical analysis.
UNASSIGNED: Statistically significant results were seen with Group II compared to Group I (cortisol-P = 0.009; salivary alpha-amylase-P = 0.03).
UNASSIGNED: Both distraction techniques are effective in reducing stress but compared to AD, AVD is more efficacious.

BACKGROUND: The main functions of healthcare professionals include training and health education. In this sense, we must be able to incorporate new technologies and serious game to the teaching cardiopulmonary resuscitation.
METHODS: a multicenter, comparative and cross-sectional study was carried out to assess the learning of resuscitation of a group that was trained with the use of serious gaming with virtual reality, as compared to a control group trained with conventional classroom teaching.
RESULTS: the mean quality obtained in chest compressions for the virtual reality group was 86.1 % (SD 9.3), and 74.8 % (SD 9.5) for the control group [mean difference 11.3 % (95 % CI 6.6-16.0), p < 0.001]. Salivary Alpha-Amylase was 218.882 (SD 177.621) IU/L for the virtual reality group and 155.190 (SD 116.746) IU/L for the control group [mean difference 63.691 (95 % CI 122.998-4.385), p = 0.037].
CONCLUSIONS: using virtual reality and serious games can improve the quality parameters of chest compressions as compared to traditional training.