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An acute stress response is a complex interaction of central and peripheral psychophysiological systems with unique temporal characteristics. Interestingly, the interaction represents a unique temporal characteristic. Investigating the dynamics of both brain and body signals during and after an encounter with a stressor allows us to understand the underlying principle of the acute stress response, which has been shown to be atypical in various psychiatric disorders. However, a detailed understanding of stress response is rarely investigated. Therefore, this thesis investigates two major approaches for understanding the acute stress response dynamics using simultaneous electroencephalography (EEG)-photoplethysmography-functional magnetic resonance imaging experiments in 39 subjects before and after the ScanStress task. The EEG-derived vigilance indexes reveal a continuous decline at rest. Given the role of alertness in an efficient stress response, the effects of acute stress induction on EEG-derived vigilance metrics are of interest. Therefore, the first approach uses the dynamic analysis of psychophysiological stress responses after the acute psychosocial stress induction. The first study investigates the carry-over effect of acute psychosocial stress on vigilance and its modulation by the multicomponent over-the-counter drug neurexan, which has been shown to modulate the neuroendocrine stress response. By using dynamic analysis, six vigilance scores were calculated every two minutes before and after the stress induction during the resting state. The study revealed that stress delays the continuous decline of vigilance at rest. In addition, the stress-induced increase in mean vigilance levels at rest was correlated positively with the levels of perceived stress during the last month. In addition, the mean vigilance level exhibited a decrease after neurexan treatment compared to placebo intake. Heart rate variability (HRV) can be viewed as an indicator of how well the adaptive regulation system in the brain reacts the peripheral environment. However, the relationship between the HRV and functional connectivity patterns in the brain networks in stressful situations is rarely investigated. Therefore, the second approach uses the multimodal approach to examine the interaction between different stress response systems. The study investigated the temporal association between HRV and FC between the three core brain networks, namely the central executive network, salience network, and default mode network at baseline and after the psychosocial stress induction. In this study, the functional connectivity between three core brain networks and the HRV was examined by taking 60s window length. Furthermore, the temporal association between HRV and functional connectivity was investigated. A significant association was found between HRV and default mode network-central executive network functional connectivity at rest, which was significantly reduced after acute stress induction compared to baseline. These findings suggest that HRV co-fluctuates with the core brain networks selectively depending on the stress conditions. In summary, acute psychological stress affects brain dynamics by exhibiting a delay in the continuously declining vigilance and keeping the brain in a more alert state even after the stressor disappears. Furthermore, the results suggest that EEG-derived vigilance metrics index not only stress-response but also the temporal dynamics of vigilance regulation. It can serve as a potential biomarker for the diagnosis and prognosis for stress-related disorders disrupting temporal characteristics of stress response dynamics and showing atypical stress response. In addition, the study revealed that stress affects the interactions among the core large-scale functional networks and physiological dynamics of the heart. The dynamic adaptation of the resources is crucial in a stressful situation; therefore, the stress alters the interaction between the brain and heart. The perturbation in this interaction may play an important role in developing and maintaining stress-related disorders. The thesis work provides novel insights and an understanding of the central and peripheral stress response dynamics, which show a huge potential for the diagnosis, prognosis, and therapeutic planning of individuals with neuropsychiatric disorders.

International audience; Initiatives such as the UK Biobank provide joint cardiac and brain imaging information for thousands of individuals, representing a unique opportunity to study the relationship between heart and brain. Most of research on large multimodal databases has been focusing on studying the associations among the available measurements by means of univariate and multivariate association models. However, these approaches do not provide insights about the underlying mechanisms and are often hampered by the lack of prior knowledge on the physiological relationships between measurements. For instance, important indices of the cardiovascular function, such as cardiac contractility, cannot be measured in-vivo. While these non-observable parameters can be estimated by means of biophysical models, their personalisation is generally an ill-posed problem, often lacking critical data and only applied to small datasets. Therefore, to jointly study brain and heart, we propose an approach in which the parameter personalisation of a lumped cardiovascular model is constrained by the statistical relationships observed between model parameters and brain-volumetric indices extracted from imaging, i.e. ventricles or white matter hyperintensities volumes, and clinical information such as age or body surface area. We explored the plausibility of the learnt relationships by inferring the model parameters conditioned on the absence of part of the target clinical features, applying this framework in a cohort of more than 3 000 subjects and in a pathological subgroup of 59 subjects diagnosed with atrial fibrillation. Our results demonstrate the impact of such external features in the cardiovascular model personalisation by learning more informative parameter-space constraints. Moreover, physiologically plausible mechanisms are captured through these personalised models as well as significant differences associated to specific clinical conditions.

The brain continuously receives input from the internal and external environment. Using this information, the brain exerts its influence on both itself and the body to facilitate an appropriate response. The dynamic interplay between the brain and the heart and how external conditions modulate this relationship deserves attention. In high-stress situations, synchrony between various brain regions such as the prefrontal cortex and the heart may alter. This flexibility is believed to facilitate transitions between functional states related to cognitive, emotional, and especially autonomic activity. This study examined the dynamic temporal functional association of heart rate variability (HRV) with the interaction between three main canonical brain networks in 38 healthy male subjects at rest and directly after a psychosocial stress task. A sliding window approach was used to estimate the functional connectivity (FC) among the salience network (SN), central executive network (CEN), and default mode network (DMN) in 60-s windows on time series of blood-oxygen-level dependent (BOLD) signal. FC between brain networks was calculated by Pearson correlation. A multilevel linear mixed model was conducted to examine the window-by-window association between the root mean square of successive differences between normal heartbeats (RMSSD) and FC of network-pairs across sessions. Our findings showed that the minute-by-minute correlation between the FC and RMSSD was significantly stronger between DMN and CEN than for SN and CEN in the baseline session [b = 4.36, t(5025) = 3.20, p = 0.006]. Additionally, this differential relationship between network pairs and RMSSD disappeared after the stress task; FC between DMN and CEN showed a weaker correlation with RMSSD in comparison to baseline [b = −3.35, t(5025) = −3.47, p = 0.006]. These results suggest a dynamic functional interplay between HRV and the functional association between brain networks that varies depending on the needs created by changing conditions.

This work reports the results of an evaluation study to assess the efficacy of the Early HeartSmarts (EHS) program in schools of the Salt Lake City, Utah, School District. The EHS program is designed to guide teachers with methods that support young children (3-6 y old) in learning emotion self-regulation and key age-appropriate socioemotional competencies with the goal of facilitating their emotional, social, and cognitive development. The study was conducted over one school year using a quasiexperimental longitudinal field research design with 3 measurement points (baseline, preintervention, and postintervention) using The Creative Curriculum Assessment (TCCA), a teacher-scored, 50-item instrument measuring students growth in 4 areas of development: social/emotional, physical, cognitive, and language development. Children in 19 preschool classrooms in the Salt Lake City School District were divided into intervention and control group samples (n = 66 and n = 309, respectively; mean age = 3.6 y). The intervention classes were specifically selected to target children of lower socioeconomic and ethnic minority backgrounds. Overall, there is compelling evidence of the efficacy of the EHS program in increasing total psychosocial development and each of the 4 development areas measured by the TCCA: the results of a series of analyses of covariance found a strong, consistent pattern of large, significant differences on the development measures favoring preschool children who received the EHS program over those in the control group.研究人员在犹他州盐湖城学区进 行了一项名为Early HeartSmarts （EHS）的项目，本文对该项目有 效性评估研究的结果进行了报 告。EHS项目的目的是对教师进行 方法指导，帮助幼儿（3~6岁）学 习自我调节情绪以及关键的与年 龄相适应的社会情绪能力，其目 的是促进幼儿情感、社交能力和 认识能力的发展。该研究采用半 验证纵向研究设计，在一学年内 实施，并设置了三个测量点（基 线，干预前和干预后），使用创 造性课程评估（TCCA）——教师 计分，包含50道题的测量工具， 对学生发展的4个方面进行测量： 社交/情感，身体状况，认知能力 以及语言能力开发。研究人员将 盐湖城学区19个学前班教室的儿 童划分为干预组和对照组样本（ 分别n=66和n=309；平均年龄=3.6 岁）。本研究特别选择针对具有 较低的社会经济地位和少数民族 背景的儿童进行干预。从整体上 来说， 有显著的证据能够证 明，EHS项目在促进儿童的整体社 会心理发展和TCCA测量的4个开发 领域方面具有有效性：对两个组 之间的差异进行的一系列分析结 果发现，接受EHS项目的学前儿童 组与对照组相比，在各项能力开 发的测量指标上具有显著优势。Este trabajo informa los resultados de un estudio de evaluación de la eficacia del programa Early Heartsmarts (EHS) en las escuelas del Distrito Escolar de Salt Lake City, Utah. El programa EHS está diseñado para orientar a los maestros respecto de métodos de asistencia a niños pequeños (entre 3 y 6 años de edad) en el aprendizaje de técnicas de autorregulación emocional y competencias socioemocionales fundamentales, adecuadas para su edad, con el fin de favorecer su desarrollo emocional, social y cognitivo. Este estudio se realizó durante un año escolar, conforme un diseño de investigación de campo cuasi experimental y longitudinal, diseñada con tres puntos de medición (punto de partida, intervención previa e intervención posterior), en la que se utilizó una Evaluación del Currículo Creativo (TCCA, por sus siglas en inglés), un instrumento calificado por el maestro de 50 puntos para medir el crecimiento de los estudiantes en 4 áreas del desarrollo: social y emocional, físico, cognitivo y desarrollo del lenguaje. Los niños de los 19 salones de clase de nivel preescolar en el Distrito Escolar de Salt Lake City, se analizaron de manera fraccionada según muestras de intervención y de control de grupo (n=66 y n=309, respectivamente; edad promedio=3 a 6 años). Las clases de intervención fueron seleccionadas específicamente para examinar a niños de bajo nivel socioeconómico y pertenecientes a minorías étnicas. En general, existen pruebas convincentes de la eficacia del programa EHS para fomentar el desarrollo psicosocial total. Respecto de cada una de las 4 áreas de desarrollo que fueron medidas por la TCCA: los resultados de una serie de análisis de la covarianza mostraron un patrón sólido y consistente de diferencias notorias y significativas en las medidas de desarrollo que favorecen a los niños de preescolar que recibieron el programa EHS, respecto de aquellos del grupo de control.

International audience; Strong emotions and mental stress have been linked to potentially deadly arrhythmias. Music evokes strong emotion through the regulation of tension and release and the modulation of changes and transitions. We exploit this in a novel study involving patients with implanted cardiac defibrillators to study the impact of live music performance on cardiac electrophysiology. The patients' heart rates are artificially fixed with pacing at the higher of 80 beats per minute or 10 above the heart's intrinsic rate. We make continuous recordings directly from the heart muscle whilst the patients are listening to a short classical music concert, which is concurrently recorded in a separate stream. The participants provide annotations of perceived boundaries/transitions and felt tension. The recorded cardiac and music information is further processed to extract relevant features. Here, we describe the experiment design, and the mathematical and computing techniques used to represent and abstract the features from the recorded data. Cardiac reaction is measured by the action potential duration (APD), approximated using the action recovery interval (ARI). The expressive parameters extracted from the music include the time varying loudness, tempo, and harmonic tension. The synchronized information layers allow for detailed analysis of immediate cardiac response to dynamically varying expressive nuances in performed music.