The current study examined the subjective and physiological reactivity to body image stimuli among females engaging in a social comparison task. Study I was conducted to select images of thin and average size models and neutral objects for Study II. For Study II, fifty-six female undergraduate students had their skin conductance and startle reflex responses recorded while comparing themselves to images featuring thin models, average size models, and neutral objects. Following the visual presentation, participants rated every image using the Self-Assessment Manikin (SAM) rating scale. Analysis from the SAM ratings scale revealed a significant picture type effect for arousal, dominance, and body satisfaction, indicating that participants reported greater arousal, more body dissatisfaction, and less control after viewing images of thin models than after viewing images of normal models and neutral objects. With regards to the psychophysiological data, results indicated that startle reflex responses were inhibited during the presentation of thin models in comparison to average size models and neutral objects. Moreover, startle reflex responses were inhibited for average size models in comparison to neutral objects. The finding that startle reactivity to model images was inhibited with respect to neutral images suggests pictures of models were processed affectively as pleasant, positive stimuli. The finding that startle reactivity to thin models was inhibited with respect to average size models suggests that thin model images elicited differentially greater positive affect than average size models. For skin conductance, analysis revealed no significant picture type effect. Taken together, the results of this study highlight the influence of social comparison processes on affectivity reactivity to body image. Future research directions are discussed.

Stress is a concept that can be studied using a variety of theoretical approaches, with a focus on the individual’s perceptions, the external stressor, or the physiological reactions of stress responding. However these approaches are often used independently, when they can be used complementarily to understand the nuanced relationship between the individual and the situation when appraising stressors as challenges or threats. The current study examined the relationship between individual differences in perceptions, situational strength (both as a categorical and a continuous predictor), and physiological reactions in a leadership task. Situational strength and leadership self-efficacy were found to interact, such that those high is LSE reported more appraisals of challenge as situational strength increased. / Master of Science / Stress is a widely known concept that has been studied in various ways (individual perceptions, situational characteristics, physiology, etc.). However these approaches are often used independently, when they can be used together to more fully understand the process of how individuals appraise stressors. The current study examined the relationship between the previously mentioned approaches within a leadership task. Situational strength and leadership self-efficacy (LSE), or one’s perceived capabilities to perform leadership duties, were found to interact, such that those high is LSE reported more appraisals of challenge as situational strength increased.

No description available.

Although existing research has evaluated physiological and environmental risk factors for depression, these processes are often examined in isolation without considering the dynamic relationships in risk for depression. The present study evaluated physiological markers of resting and stress-reactive respiratory sinus arrhythmia (RSA and RSA reactivity) as predictors of depressive symptoms and interpersonal stress generation, a mutable and potent vulnerability for depression. Further, we examined whether stress generation predicted subsequent depressive symptoms. In a sample of late adolescents (N = 105; 18-22 years; 76% female), individuals who screened in for a history of clinical and subclinical depression participated in a micro-longitudinal assessment with a diagnostic interview, in-laboratory socio-evaluative stressor task, and two weeks of daily assessments of stressful events and depressive symptoms. First, results indicated that there were no clinical or physiological differences between individuals with a clinical or subclinical depression history. Our multilevel modeling analyses revealed that: 1) only lower levels of resting RSA predicted depressive symptoms over the two-week period; 2) only lower RSA reactivity predicted greater interpersonal stress generation, but not independent stressors; 3) interpersonal stress generation mediated the relationship between RSA reactivity and depressive symptoms, but not resting RSA and depressive symptoms; 4) sex differences only occurred in the relationship between resting RSA and depressive symptoms; and 5) there were no interactive effects of resting RSA and RSA reactivity on depression or interpersonal stress generation. These findings highlight the importance of assessing both resting RSA and RSA reactivity in the examination of depression and depression-related processes. / Psychology

Social dominance is an inherent component of human social organization (Hawley, 1999, Ryff & Singer, 2000; Uchino, Cacioppo, & Kiecolt-Glaser, 1996). Some behaviors typically associated with gaining dominance (e.g., bullying, aggression), have been linked with maladaptive outcomes (Hawley, 2016). However, Resource Control Theory (RCT) highlights the adaptive role of the prosocial (e.g., sharing, cooperating) and the coercive (e.g., taking, threatening) strategies that youth use to gain resources within their peer group (Hawley, 2003a). These behaviors may have important implications for individuals’ physiological stress reactivity, particularly during middle childhood when youth are undergoing rapid cognitive and social development (Parker et al., 2006). The overall goal of the current study was to examine whether patterns of prosocial and coercive resource control strategy use were associated with autonomic nervous system reactivity in a sample of 9-12 year old children. Specifically, this study used person-centered analyses to investigate whether membership in groups based on resource control strategy use was associated with measures of autonomic nervous system reactivity (i.e., skin conductance [SCL-R], heart rate [HR-R], and systolic and diastolic blood pressure [SBP-R, DBP-R, respectively]). This study also utilized variable-centered analyses to investigate whether coercive resource control strategies were associated with these measures of autonomic nervous system reactivity, and whether this relationship was moderated by prosocial resource control strategies. This study also investigated whether these associations were present in the context of social and non-social stressor tasks. One hundred children (50% female, Mage = 10.47 years) and one of their parents participated in the current study and were recruited from the community in a small northeastern city. Participants’ SCL-R, HR-R, SBP-R, and DBP-R were assessed using a stress protocol during which they discussed an experience of relational victimization (e.g., being left out), played an online ball-tossing game designed to mimic social exclusion experiences, and completed a mirror-tracing task. Levels of prosocial and coercive resource control strategy use were gathered using parent report. Findings suggested that, during the discussion of a relational victimization experience, the association between coercive control strategies and HR-R was moderated by prosocial control strategies. Specifically, for those low in prosocial control strategies, lower coercive control strategies were associated with increased HR-R. In contrast, in the context of the online ball-tossing game, the associations between coercive control strategies and both SBP-R and DBP-R, respectively, were moderated by prosocial control strategies. Specifically, for those low in prosocial control strategies, higher coercive control strategies were associated with both increased SBP-R and DBP-R. No other outcome measures were associated with main effects of resource control strategies or an interaction between coercive and prosocial control strategies. These patterns suggest that resource control strategy use may be differentially related to HR-R and blood pressure reactivity. Additionally, this pattern may have resulted from differences in the characteristics of the social stressor tasks. Though more research is needed, this study provides the first step in investigating the associations between resource control strategies and long-term physical health in children. This may have important implications for the development of intervention and prevention programs that will help improve the physical health of youth.

hostility has been found to be a risk factor for cardiovascular disease. One proposed pathway between hostility and cardiovascular disease is an increase in cardiovascular reactivity among hostile individuals when faced with challenging, competitive situations, in which interpersonal stressors are present. A potential situation that may elicit this exaggerated reactivity is found in cardiac rehabilitation exercise programs. Such factors may be competition and feedback regarding their performance. This study sought to find out how hostile individuals would respond physiologically, behaviorally, and affectively when presented with negative and positive performance feedback, while exercising in a challenging, competitive setting. It was found that the three groups (positive feedback, negative feedback, no feedback) did not differ on physiological reactivity, exercise behavior, or affect as a result of the type of feedback they received. Limitations of the study are discussed and improvements for future studies are suggested.

No description available.

Le stress augmente le risque de développer des maladies cardiovasculaires (CV) ainsi que de mourir de ces maladies. Selon certaines hypothèses, ce phénomène se produirait par le biais de réponses répétés de réactivité physiologique élevée ou de récupération physiologique prolongée, suite à un épisode de stress. La stabilité à long terme des réponses physiologiques face au stress a reçu peu d’attention. Objectifs: (1) Évaluer la stabilité temporelle de la réactivité et de la récupération physiologique suite au stress, à travers l’évaluation des systèmes cardiovasculaires et nerveux autonome, et ce sur un intervalle de 3 ans. (2) Déterminer si le sexe et l'âge agissent comme des variables modératrices. Méthodologie: Un total de 134 hommes et femmes en santé ont été recrutés au sein de la communauté et ont pris part à 2 séances en laboratoire. Quatre tâches, d’une durée de 5 minutes chacune et composée d’un élément de stress interpersonnel différent, ont été administrées. Chaque tâche était suivie d’une période de récupération de 5 min. Des mesures de la fréquence cardiaque (FC), de la pression artérielle (PA) et de la variabilité de la fréquence cardiaque (VFC : HF, LF et VLF) ont été obtenues. Des corrélations de Spearman et des régressions linéaires ont été effectuées. Résultats: Des corrélations test-retest significatives ont été obtenues pour toutes les mesures physiologiques, sauf pour la PA diastolique et la VLF, lors de la période de récupération. Aucune différence significative quant à la stabilité des réponses face au stress en fonction du sexe ou de l’âge des participants, n’a été trouvée. Conclusion: Les réponses physiologiques face au stress représentent des caractéristiques individuelles stables sur trois ans, peu affectées par le sexe et l’âge. / It is known that stress increases the risk of cardiovascular disease and mortality associated with these diseases. It is hypothesized that this may occur through chronically heightened physiological reactivity to or delayed recovery from stress. The long-term stability of physiological stress responses has received little attention. Objectives: To evaluate the 3-year stability of reactivity and recovery change scores across CV and autonomic parameters and assess whether sex and age moderate stability. Methodology: A total of 134 healthy participants underwent 2 laboratory stress protocols, including four 5-minute interpersonal stressors, each followed by a 5-minute recovery period. Heart rate (HR), blood pressure (BP), and HR variability (HF, LF, VLF) were obtained. Spearman rank correlations and linear regressions were performed. Results: Significant test-retest correlations emerged for all physiological measures except diastolic BP recovery and VLF recovery. No significant sex or age differences in the stability of stress reactivity or recovery emerged. Conclusion: Stress responses represent stable individual traits, little affected by sex and age.

La peur est une émotion essentielle à la survie. Cependant, lorsqu'elle devient excessive, comme lors d'un événement traumatique, elle peut entraîner le développement d'un trouble de stress post-traumatique (TSPT), une psychopathologie pour laquelle le risque des femmes est doublé comparativement aux hommes. Le TSPT se caractérise par une altération des mécanismes de la peur. La thérapie d'exposition est recommandée pour le traitement de cette psychopathologie. Elle vise à diminuer la peur, en misant sur les processus d’apprentissage de l’extinction. Néanmoins, certains individus demeurent symptomatiques après cette thérapie, ce qui souligne la nécessité de mieux comprendre les mécanismes qui régissent l’apprentissage initial de la peur et de sa régulation et d’identifier des facteurs qui influencent ces processus. Des études ont démontré que la réactivité physiologique ainsi que l’exposition au stress et la réactivité hormonale qui en découle modulent l’acquisition et la régulation de la peur. De plus, étant donné la différence sexuelle marquée dans le diagnostic de TSPT, le rôle du statut hormonal sexuel a été suggéré comme un modulateur de ces processus. En effet, la rétention de l’extinction est meilleure chez les femmes en milieu de cycle qui ont des niveaux élevés de 17-βestradiol et chez les hommes comparativement aux femmes en début de phase folliculaire qui ont des niveaux faibles de 17-βestradiol et aux femmes qui utilisent un contraceptif oral. Les études antérieures ont montré que les hormones de stress et sexuelles agissent sur les structures cérébrales impliquées dans les mécanismes de la peur. Cependant, la grande majorité de ces études ont exploré les effets de chaque modulateur de façon individuelle, sans tenir compte de leurs potentiels effets combinés. L'objectif principal de cette thèse est d'examiner l’influence de la réactivité physiologique et du stress avant l'acquisition et l'extinction de la peur sur les mécanismes de la peur et ce, en fonction du statut hormonal sexuel. La première étude visait à déterminer si la réactivité physiologique en réponse au stimulus aversif prédisait l’acquisition de la peur, l’extinction et la rétention de l’extinction différemment selon le statut hormonal sexuel. Les participants ont été exposés à un protocole de conditionnement et d’extinction de peur. La réactivité physiologique durant l’acquisition de la peur ainsi que les réponses conditionnées de peur tout au long du protocole ont été évaluées par la réponse électrodermale. La réactivité physiologique au stimulus aversif lors du conditionnement semble prédire l’acquisition et la consolidation de la peur chez les femmes, mais pas chez les hommes. Quant à la rétention de l’extinction de la peur, elle semble également être prédite par la réactivité physiologique lors de l’acquisition de la peur mais uniquement chez les femmes étant en début de phase folliculaire. L’objectif de la deuxième étude était de déterminer l’effet d’un stresseur non-lié à la tâche de peur lorsque celui-ci est administré avant le conditionnement sur l’acquisition de la peur et son extinction selon le statut hormonal sexuel. Une revue exhaustive de la littérature a été réalisée pour répondre à cet objectif. Celle-ci a permis de révéler que le stress avant l'acquisition de la peur tend à entraîner une résistance à l'apprentissage de l'extinction et ce, indépendamment du statut hormonal sexuel. Enfin, dans la troisième étude, les effets d’un stresseur administré avant l'extinction sur son acquisition et sa rétention ont été examinés en tenant compte du statut hormonal. Dans cette étude, les participants ont effectué un protocole de conditionnement de peur et d’extinction, et la moitié d’entre eux a été exposée à un stress psychosocial avant l'apprentissage de l'extinction. Les résultats indiquent que l’exposition au stress n'affecte pas l'apprentissage de l’extinction, mais qu’elle nuit à la rétention de l’extinction chez les hommes, alors qu’elle l’améliore chez les femmes utilisant un contraceptif oral. Chez les femmes naturellement cyclées en début de cycle ou en milieu de cycle, le patron de résultats de rétention de l’extinction ne change pas sous l’effet du stress. En effet, les femmes en phase folliculaire continuent de présenter des difficultés de rétention d’extinction tandis que celles en milieu de cycle présentent une bonne rétention. Les conclusions générales de cette thèse indiquent que la réactivité physiologique et le stress avant l'acquisition de la peur et l'extinction influencent les mécanismes de la peur, particulièrement la régulation de la peur, avec des variations selon le statut hormonal sexuel. / Fear is an essential emotion for survival. However, when fear becomes excessive, particularly in a context of traumatic event, it can lead to the development of post-traumatic stress disorder (PTSD), a psychopathology that affects women twice as often as men. PTSD is characterized by altered fear mechanisms. One of the main therapeutic approaches for this psychopathology is exposure therapy, which aims to reduce fear by relying on extinction learning processes. However, some individuals remain symptomatic after this therapy, highlighting the need for a better understanding of the mechanisms underpinning initial fear acquisition and its regulation, while identifying the factors that influence these processes. Studies have shown that physiological reactivity, as well as exposure to stress and subsequent hormonal reactivity, modulate the acquisition and regulation of fear. Moreover, the pronounced sex difference in the diagnosis of PTSD has prompted exploration of the potential influence of sex hormone status as a modulating factor in these complex processes. In fact, compared to women in early follicular phase with low 17-βestradiol levels and women using oral contraceptives, extinction retention is better in women in mid-cycle with high 17-βestradiol levels and men. Previous studies have shown that stress and sex hormones affect fear-related brain structures. However, most of these studies have examined the effects of each modulator individually, without considering their potential combined effects. The primary goal of this thesis was to examine the influence of physiological reactivity and stress prior to fear acquisition and extinction on fear mechanisms as a function of sex hormone status. The first study aimed to determine whether physiological reactivity in response to the aversive stimulus predicted fear acquisition, extinction, and extinction retention differently according to sex hormone status. Participants were exposed to a fear conditioning and extinction protocol. Physiological reactivity to the aversive stimulus during fear acquisition as well as conditioned fear responses throughout the protocol were assessed by electrodermal responses. Results indicate that physiological reactivity predicts fear acquisition and consolidation in women, but not in men. Physiological reactivity during conditioning also predicts fear extinction recall only in women in the early follicular phase. The aim of the second study was to determine the effect of a stressor unrelated to the fear task, when administered prior to conditioning, on fear acquisition and extinction as a function of sex hormone status. A comprehensive review of the literature was conducted to accomplish this goal. This review revealed that stress prior to fear acquisition tends results in resistance to extinction learning, regardless of sex hormone status. Finally, the third study examined the effects of a pre-extinction stressor on extinction learning and retention, considering hormonal status. In this study, participants completed a fear conditioning and extinction protocol, and half of them were exposed to a psychosocial stressor prior to extinction acquisition. Results indicate that stress exposure does not affect extinction learning, but impairs extinction retention in men, while improving it in oral contraceptive users. In women in the early or mid-cycle phases of their menstrual cycle, the pattern of extinction retention scores does not change under stress. Indeed, women in the early follicular phase continue to show difficulties with extinction retention, while those in the mid-cycle show good retention. The overall conclusions of this thesis suggest that physiological reactivity and stress prior to fear acquisition and extinction influence fear mechanisms, particularly fear regulation, with variations according to sexual hormonal status.