Defense mechanisms and physiological reactivity to stress

The relation between the use of defense mechanisms and autonomic nervous system reactivity, under conditions of laboratory stress, was studied in 78 men and women. Both diastolic blood pressure (DBP) and skin conductance level (SCL) were monitored during exposure to ten stress tasks; concurrently, the use of three defense mechanisms was assessed by coding Thematic Apperception Test stories. Autonomic reactivity was found to be related to defenses; the nature of that relation differed across the defenses. DBP, typically found to be associated with cognitive work, was higher in those individuals who used more Identification, a defense that requires greater cognitive activity. The use of Projection, on the other hand, was associated with lower DBP. In addition, the use of Identification showed a tendency to be associated with lower SCL.     

Touch attenuates infants’ physiological reactivity to stress

Animal studies demonstrate that maternal touch and contact regulate infant stress, and handling during periods of maternal deprivation attenuates the stress response. To measure the effects of touch on infant stress reactivity during simulated maternal deprivation, 53 dyads were tested in two paradigms: still‐face (SF) and still‐face with maternal touch (SF+T). Maternal and infant cortisol levels were sampled at baseline, reactivity, and recovery and mother’s and infant’s cardiac vagal tone were measured during the free play, still‐face, and reunion episodes of the procedure. Cortisol reactivity was higher among infants in the SF condition and while cortisol decreased at recovery for infants in the SF+T, it further increased for those in the SF. Vagal tone showed a greater suppression when SF was not accompanied by maternal touch. Touch synchrony during free play was associated with higher infant vagal tone, whereas touch myssynchrony – maternal tactile stimulation while the infant gaze averts – correlated with higher maternal and infant cortisol. In humans, as in mammals, the provision of touch during moments of maternal unavailability reduces infants’ physiological reactivity to stress.     

Subjective, behavioral, and physiological reactivity to ethnically matched and ethnically mismatched film clips

This study examined whether individuals from 4 major ethnic groups within the United States (African American, Chinese American, European American, and Mexican American) showed greater subjective, behavioral, and physiological responses to emotional film clips (amusement, sadness, and disgust) with actors from their own ethnic group (ethnically matched) compared with actors from the other 3 ethnic groups (ethnically mismatched). Evidence showed greater responsivity to ethnically matched films for African Americans and European Americans, with the largest effect for African Americans. These findings were consistent across both sex and level of cultural identification. Findings of ethnic difference notwithstanding, there were many areas in which ethnic differences were not found (e.g., little or no evidence was found of greater response to ethnically matched films in Chinese-American or Mexican- American participants). These findings indicate that the emotional response system clearly reacts to stimuli of diverse ethnic content; however, the system is also amenable to subtle "tuning" that allows for incrementally enhanced responding to members of one's own ethnic or cultural group.     

Future anhedonia and time discounting

The temporal location of an event influences the way people mentally represent that event. We suggest (a) that such representational differences can produce an affective forecasting error that we call future anhedonia, which is the belief that hedonic states will be less intense in the future than in the present, and (b) that future anhedonia plays a role in time discounting (i.e., the tendency to place a smaller present value on present events than on future events). Experiments 1a and 1b demonstrated that people are prone to future anhedonia, Experiments 2a and 2b ruled out artifactual alternatives, and Experiments 3a and 3b demonstrated that future anhedonia plays a role in time discounting. These studies suggest that one reason why people prefer to enjoy benefits in the present and pay costs in the future is that they do not realize how they will feel when those costs and benefits are actually experienced.     

Utility of virtual reality environments to examine physiological reactivity and subjective distress in adults who stutter

PurposeVirtual reality environments (VREs) allow for immersion in speaking environments that mimic real-life interactions while maintaining researcher control. VREs have been used successfully to engender arousal in other disorders. The purpose of this study was to investigate the utility of virtual reality environments to examine physiological reactivity and subjective ratings of distress in persons who stutter (PWS).MethodSubjective and objective measures of arousal were collected from 10 PWS during four-minute speeches to a virtual audience and to a virtual empty room.ResultsStuttering frequency and physiological measures (skin conductance level and heart rate) did not differ across speaking conditions, but subjective ratings of distress were significantly higher in the virtual audience condition compared to the virtual empty room.ConclusionVREs have utility in elevating subjective ratings of distress in PWS. VREs have the potential to be useful tools for practicing treatment targets in a safe, controlled, and systematic manner.     

Social stimuli increase physiological reactivity but not defensive responses

Emotional reactions are crucial in survival because they provide approach and withdrawal behaviors. However, an unsolved question is whether the social content of the affective stimuli has a specific effect on emotional responses. We studied whether the social content of affective pictures influenced the defensive response and response mobilization. For this purpose, we recorded startle blink reflex (a defensive response) and skin conductance responses (a measure of unspecific physiological reactivity or arousal) in 73 participants while they viewed a series of 81 pictures of varying affective valence and social content. Our results revealed that defense response, as indicated by increases in the magnitude of the startle blink reflex, was mainly dependent on threatening or unpleasant cues, but was unrelated to the social content of the pictures. The social content, however, had an influence on pleasant stimuli, provoking an increase in resource mobilization, as reflected by changes in electrodermal activity. Hence, the social content of the affective stimuli may increase the physiological arousal elicited by pleasant stimuli, and it appears to be unrelated to the defense reactivity provoked by unpleasant stimuli.     

Context-specific freezing and associated physiological reactivity as a dysregulated fear response

The putative association between fear-related behaviors and peripheral sympathetic and neuroendocrine reactivity has not been replicated consistently. This inconsistency was addressed in a reexamination of the characterization of children with extreme fearful reactions by focusing on the match between distress behaviors and the eliciting context. Eighty 24-month-old children were observed in 4 mildly threatening contexts, and the relations among different measures of fear-related behaviors, reactive and basal cortisol levels, and baseline cardiac measures of heart rate, respiratory sinus arrhythmia, and preejection period (PEP) were examined. The hypothesis that only behaviors under the less threatening context would be associated with higher cortisol and sympathetic cardiac activity was confirmed; only task-specific freezing behavior predicted higher reactive and basal cortisol levels and resting PEP measured 1 week later. Implications for the conceptualization of dysregulated fear behaviors in the classification of extremely fearful children are discussed.     

Essentializing race: implications for bicultural individuals' cognition and physiological reactivity

It is a widely held belief that racial groups have underlying essences. We hypothesized that bicultural individuals who hold this essentialist belief about race are oriented to perceive rigid interracial boundaries and experience difficulty passing between their ethnic culture and the host culture. As predicted, we found that the more strongly Chinese American participants endorsed an essentialist belief about race, the less effective they were in switching rapidly between Chinese and American cultural frames in a reaction time task (Study 1), and the greater emotional reactivity they exhibited (reflected in heightened skin conductance) while they talked about their Chinese and American cultural experiences (Study 2). Taken together, these findings suggest that essentialist beliefs about race set up a mind-set that influences how bicultural individuals navigate between their ethnic and host cultures.     

Listening to music and physiological and psychological functioning: the mediating role of emotion regulation and stress reactivity

Music listening has been suggested to have short-term beneficial effects. The aim of this study was to investigate the association and potential mediating mechanisms between various aspects of habitual music-listening behaviour and physiological and psychological functioning. An internet-based survey was conducted in university students, measuring habitual music-listening behaviour, emotion regulation, stress reactivity, as well as physiological and psychological functioning. A total of 1230 individuals (mean?=?24.89?±?5.34 years, 55.3% women) completed the questionnaire. Quantitative aspects of habitual music-listening behaviour, i.e. average duration of music listening and subjective relevance of music, were not associated with physiological and psychological functioning. In contrast, qualitative aspects, i.e. reasons for listening (especially 'reducing loneliness and aggression', and 'arousing or intensifying specific emotions') were significantly related to physiological and psychological functioning (all p?=?0.001). These direct effects were mediated by distress-augmenting emotion regulation and individual stress reactivity. The habitual music-listening behaviour appears to be a multifaceted behaviour that is further influenced by dispositions that are usually not related to music listening. Consequently, habitual music-listening behaviour is not obviously linked to physiological and psychological functioning.     

Effects of worry on physiological and subjective reactivity to emotional stimuli in generalized anxiety disorder and nonanxious control participants

The present study examined the effect of worry versus relaxation and neutral thought activity on both physiological and subjective responding to positive and negative emotional stimuli. Thirty-eight participants with generalized anxiety disorder (GAD) and 35 nonanxious control participants were randomly assigned to engage in worry, relaxation, or neutral inductions prior to sequential exposure to each of four emotion-inducing film clips. The clips were designed to elicit fear, sadness, happiness, and calm emotions. Self reported negative and positive affect was assessed following each induction and exposure, and vagal activity was measured throughout. Results indicate that worry (vs. relaxation) led to reduced vagal tone for the GAD group, as well as higher negative affect levels for both groups. Additionally, prior worry resulted in less physiological and subjective responding to the fearful film clip, and reduced negative affect in response to the sad clip. This suggests that worry may facilitate avoidance of processing negative emotions by way of preventing a negative emotional contrast. Implications for the role of worry in emotion avoidance are discussed.     

Appraisals of marital conflict and children's adjustment, health, and physiological reactivity.

Children's appraisals of marital conflict were examined as moderators and mediators of conflict and children's adjustment, physical health, and physiological reactivity. Mothers completed measures of marital conflict and children's adjustment and physical health, and elementary school children provided information on their parents' marital conflict, appraisals of perceived threat and self-blame in relation to parents' conflicts, and their internalizing symptomatology. Children's heart rate, systolic and diastolic blood pressure, and skin conductance response and level were examined during both a baseline and an interadult argument. Higher levels of both self-blame and perceived threat functioned as robust vulnerability factors for children exposed to higher levels of marital conflict in relation to internalizing behaviors, health problems, and higher levels of cardiovascular reactivity to the argument. Further, a higher level of perceived threat was a vulnerability factor for externalizing problems associated with exposure to marital conflict.     

Habitual reappraisal in context: peer victimisation moderates its association with physiological reactivity to social stress

Although the emotion regulation strategy of reappraisal has been associated with adaptive outcomes, there is a growing evidence that it may not be adaptive in all contexts. In the present study, adolescents reported their use of habitual reappraisal and their experiences with peer victimisation, a chronic stressor that is associated with reduced well-being in this population. We examined how these variables predicted physiological reactivity (vagal withdrawal and changes in pre-ejection period) during a social stressor (i.e., Trier Social Stress Task). In line with previous research, at high levels of victimisation, habitual reappraisal predicted adaptive physiological reactivity (i.e., greater vagal withdrawal). Conversely, at low levels of victimisation, habitual reappraisal predicted maladaptive physiological reactivity (i.e., blunted vagal withdrawal). These findings were specific to parasympathetic reactivity. They suggest that habitual reappraisal may exert different effects on parasympathetic reactivity depending on the presence of stressors, and highlight the importance of examining the role of contextual factors in determining the adaptiveness of emotion regulation strategies.