Facial expressions of emotion reveal neuroendocrine and cardiovascular stress responses

Hydrocortisone infusion exerts dose- and sex-dependent effects on attention to emotional stimuli

Glucocorticoid administration has been shown to exert complex effects on cognitive and emotional processing. In the current study we investigated the effects of glucocorticoid administration on attention towards emotional words, using an Affective Go/No-go task on which healthy humans have shown an attentional bias towards positive as compared to negative words. Healthy volunteers received placebo and either low-dose (0.15mg/kg) or high-dose (0.45mg/kg) hydrocortisone intravenously during two separate visits in a double-blind, randomized design. Seventy-five minutes post-infusion, the subjects performed tests of attention (Rapid Visual Information Processing [RVIP]), spatial working memory (Spatial Span) and emotional processing (Affective Go/No-go task [AGNG]). On the attention task, performance was impaired under both hydrocortisone doses relative to placebo, though the effect on error rate was not significant after controlling for age; Spatial Span performance was unaffected by hydrocortisone administration. On the AGNG task, relative to the placebo condition the low-dose hydrocortisone infusion decreased response time to emotional words while high-dose hydrocortisone increased response time. In the females specifically, both high and low dose hydrocortisone administration attenuated the normal attentional bias toward positively valenced words. These data suggest that, in healthy women, the modulation of attention by the emotional salience of stimuli is influenced by glucocorticoid hormone concentrations.

Affective signals of threat increase perceived proximity

Do stimuli appear to be closer when they are more threatening? We tested people's perceptions of distance to stimuli that they felt were threatening relative to perceptions of stimuli they felt were disgusting or neutral. Two studies demonstrated that stimuli that emitted affective signals of threat (e.g., an aggressive male student) were seen as physically closer than stimuli that emitted affective signals of disgust (e.g., a repulsive male student) or no affective signal. Even after controlling for the direct effects of physiological arousal, object familiarity, and intensity of the negative emotional reaction, we found that threatening stimuli appeared to be physically closer than did disgusting ones (Study 2). These findings highlight the links among biased perception, action regulation, and successful navigation of the environment.

Assisting couples to develop healthy relationships: effects of couples relationship education on cortisol

INTRODUCTION

Couple conflict in unhappy marriages is suggested to impair individual health via chronic psychophysiological stress reactions in couples' everyday lives. As a consequence, we hypothesized that standard couples relationship education (CRE) would decrease psychophysiological stress, namely salivary cortisol levels, during couple conflict in the laboratory as compared to a standard psychological stress paradigm. We considered cortisol to be of particular interest in this context, as it mediates endocrine and immune responses to stress, and thus might influence couples' health.

METHODS

Salivary cortisol was repeatedly investigated in 61 couples during (a) a standard psychological stress test with no relevance for the couples, and (b) a standard couple conflict discussion in the laboratory before and after CRE. In addition, increases in self-evaluated relationship quality were analyzed with regard to their influence on salivary cortisol. Data were analyzed using multilevel modeling.

RESULTS

Cortisol responses to the couple-external psychological stress test were unaffected by CRE, but specifically cortisol responses during the couple conflict discussion were significantly reduced following CRE compared to pre-intervention levels. Moreover, cortisol decreases during conflict were partially mediated by increases in self-reported relationship quality following CRE.

CONCLUSIONS

These data suggest that CRE might buffer the harmful effects of repeated conflict in close relationships. Rather than ameliorating overall stress resilience, CRE might thus specifically improve individual health through increased relationship quality and reduced HPA axis activity during couple conflict.

Physical proximity in anticipation of meeting someone with schizophrenia: the role of explicit evaluations, implicit evaluations and cortisol levels

It has been suggested that the study of the stigma of mental illness should include more behavioral measures and further investigation of the possible importance of implicit evaluations in predicting responses to those with such illness. In the current paper, we report a study testing the relationship of implicit and explicit evaluations to physical proximity and cortisol levels in anticipation of meeting someone with schizophrenia. The results showed that both explicit evaluations and cortisol levels independently predicted physical proximity. Implicit evaluations were not related to either physical proximity or cortisol levels. The findings suggest that there are aspects of emotional response to those with mental illness that are not reflected in explicit measures of evaluation and that these, as well as explicit responses, can contribute to the prediction of behavior.

Autonomic nervous system activity in emotion: a review

Autonomic nervous system (ANS) activity is viewed as a major component of the emotion response in many recent theories of emotion. Positions on the degree of specificity of ANS activation in emotion, however, greatly diverge, ranging from undifferentiated arousal, over acknowledgment of strong response idiosyncrasies, to highly specific predictions of autonomic response patterns for certain emotions. A review of 134 publications that report experimental investigations of emotional effects on peripheral physiological responding in healthy individuals suggests considerable ANS response specificity in emotion when considering subtypes of distinct emotions. The importance of sound terminology of investigated affective states as well as of choice of physiological measures in assessing ANS reactivity is discussed.

Intranasal oxytocin increases positive communication and reduces cortisol levels during couple conflict

BACKGROUND

In nonhuman mammals, the neuropeptide oxytocin has repeatedly been shown to increase social approach behavior and pair bonding. In particular, central nervous oxytocin reduces behavioral and neuroendocrine responses to social stress and is suggested to mediate the rewarding aspects of attachment in highly social species. However, to date there have been no studies investigating the effects of central oxytocin mechanisms on behavior and physiology in human couple interaction.

METHODS

In a double-blind placebo-controlled design, 47 heterosexual couples (total n = 94) received oxytocin or placebo intranasally before a standard instructed couple conflict discussion in the laboratory. The conflict session was videotaped and coded for verbal and nonverbal interaction behavior (e.g., eye contact, nonverbal positive behavior, and self-disclosure). Salivary cortisol was repeatedly measured during the experiment.

RESULTS

Oxytocin significantly increased positive communication behavior in relation to negative behavior during the couple conflict discussion (F = 4.18, p = .047) and significantly reduced salivary cortisol levels after the conflict compared with placebo (F = 7.14, p = .011).

CONCLUSIONS

These results are in line with animal studies indicating that central oxytocin facilitates approach and pair bonding behavior. Our findings imply an involvement of oxytocin in couple interaction and close relationships in humans.

Multiple aspects of the stress response under social evaluative threat: an electrophysiological investigation

Affective traits and states may be important moderators of stress reactivity, providing insight into stress-related consequences on cognitive functioning. This study assessed cognitive control processes using response-related brain electrical activities-the error-related negativity (ERN) and error positivity (Pe)-that are sensitive to trait and state affect. To assess the role of cognitive control in affective and cortisol reactivity to social evaluative threat, 55 undergraduates first completed a standard task designed to elicit the ERN in order to index 'baseline' error monitoring. Participants then performed a difficult mathematical task designed to elicit the ERN under conditions of exposed failure and social evaluation. Baseline ERN amplitude predicted future cortisol reactivity to social evaluative threat in highly punishment-sensitive individuals (high self-reported Behavioral Inhibition System: Carver and White [1994. Behavioral inhibition, behavioral activation, and affective responses to impending reward and punishment: the BIS/BAS scales. J. Pers. Soc. Psych. 67, 319-333], although the presence of outliers suggest the need for replication. The math stress ERN amplitude was diminished in direct relationship to trait (punishment sensitivity) and state (fear and shame) negative affect. Individuals high in punishment sensitivity also showed specific deficits in task performance following error feedback under stress. High state affect related to a larger Pe amplitude. Results are interpreted as consequences of different motivational and affective reactivities under social evaluative threat.

Cardiovascular, electrodermal, and respiratory response patterns to fear- and sadness-inducing films

Responses to fear- and sadness-inducing films were assessed using a broad range of cardiovascular (heart rate, T-wave amplitude, low- and high-frequency heart rate variability, stroke volume, preejection period, left-ventricular ejection time, Heather index, blood pressure, pulse amplitude and transit time, and finger temperature), electrodermal (level, response rate, and response amplitude), and respiratory (rate, tidal volume and its variability, inspiratory flow rate, duty cycle, and end-tidal pCO(2)) measures. Subjective emotional experience and facial behavior (Corrugator Supercilii and Zygomaticus Major EMG) served as control measures. Results indicated robust differential physiological response patterns for fear, sadness, and neutral (mean classification accuracy 85%). Findings are discussed in terms of the fight-flight and conservation-withdrawal responses and possible limitations of a valence-arousal categorization of emotion in affective space.

Acute psychosocial challenge and cardiac autonomic response in women: the role of estrogens, corticosteroids, and behavioral coping styles

Theoretical statements, as well as clinical and experimental data, suggest that the amplitude of cardiovascular reactivity to acute stressors can be a good predictor of preclinical and clinical cardiovascular states. The aim of the present study is to investigate the role of estrogens, the hypothalamic-pituitary-adrenocortical activity, and the behavioral profile in individual cardiac autonomic reactivity to brief laboratory stressors in women. Thirty-six adult, healthy women were exposed to a stress interview and a mental task test, each lasting 5 min. They were assigned to two experimental groups: D4, i.e. 4 days after menses beginning (follicular phase, n=18), and D14, i.e. 14 days after menses beginning (ovulatory phase, n=18). The cardiac measurements in the baseline, stress and recovery periods consisted in heart rate (average R-R interval) and parasympathetic tone (r-MSSD) quantification, while the HPA axis activity and stress reactivity were assessed via plasma cortisol and dehydroepiandrosterone concentrations. The ethological profile during the interview was drawn by means of non-verbal behavior analysis. The cardiac, adrenocortical and behavioral responses to the two stressors were similar in groups D4 and D14, despite significantly higher estradiol levels in the latter. Subjects with higher pre-stress cortisol levels had higher heart rate and lower vagal activity in the baseline, stress and recovery phases. Women showing higher level of submission were characterized by higher heart rate acceleration and vagal withdrawal during both the interview and the recovery phase. In addition, the subjects that exhibited greater displacement during the interview were also characterized by lower heart rate increments and less pronounced vagal suppression during post-stress recovery. In conclusion, the present results do not support a clear buffering role of estrogens in cardiovascular response to acute stressors. However, they confirm that baseline HPA axis activity can be predictive of cardiac autonomic activity and stress responsiveness. They also highlight the modulating role of the individual style of behavioral coping in cardiac sympathovagal stress reactivity. Therefore, the objective assessment of the individual behavioral profile via the analysis of non-verbal communication patterns might represent a powerful tool for identifying subjects with higher risk of cardiac events.