Attend or defend? Sex differences in behavioral, autonomic, and respiratory response patterns to emotion–eliciting films

Fear facilitates utilitarian moral judgments: Evidence from a moral judgment task

Previous research on moral judgment (MJ) has focused on understanding the cognitive processes and emotional factors that influence different types of moral judgment tasks, such as personal and impersonal dilemmas. However, few studies have distinguished between the emotions related to cognition and the complex emotions specifically caused by MJ tasks. This gap in knowledge is important to address to have a better understanding of how emotions influence moral judgment. The aim of this study was to investigate the influence of fear and the role of moral emotions on MJ. Data were collected from 145 participants through jsPsych and analyzed using mixed-model analysis of variance (ANOVA) and correlation analysis. The study found that individuals who were triggered by the fear increased the number of utilitarian moral judgments in personal moral scenarios and lengthened the cognitive process, but not in impersonal moral dilemmas. Hence, we speculate that fear may play a cognitive role in personal moral dilemmas and an emotional role in impersonal moral dilemmas. Another finding is that the complex moral emotions arising from the moral decision-making process may affect the effectiveness of fear and potentially influence moral judgments. However, this study adopts a cautious attitude toward these discoveries, and further verification of this hypothesis should be conducted in the future.

Non-invasive assessment of positive affective state using infra-red thermography in rats

With recent increased focus on positive welfare in animal welfare science, there is demand for objective positive welfare indicators. It is unclear whether changes in body surface temperature can be used to non-invasively identify and quantify positive states in mammals. We recorded continuous measurements of tail surface temperature using infra-red thermography (IRT) and concurrent behavioural observations in male and female Wistar rats (Rattus norvegicus). If tail surface temperature can differentiate between positive and negative experiences, we expect a qualitatively different response compared to negative experiences. Three groups of rats were presented with increasing magnitudes of food rewards (neutral/none, one and three rewards). The rats were placed in an arena to which they were habituated and filmed for 30 s before and 30 min after exposure to different rewards. Tail temperature initially decreased from the pre-reward baseline and subsequently returned towards baseline temperature. The overall pattern of the change was the same as for rats subjected to negative stimuli in previous studies. Nevertheless, dynamic changes in tail temperature, specifically the rate of recovery and the behavioural response (exploration), differed between neutral and rewarded rats but failed to distinguish reward magnitude. Sex differences were found in both thermal and behavioural responses, unrelated to reward magnitudes. Female rats exhibited a greater initial response with a slower recovery than male rats, emphasising the value of using of both sexes in animal welfare research. This study improves our understanding of the effects of positive emotions induced by food reward on peripheral body temperature and behaviour.

Postural threat increases sample entropy of postural control

Introduction

Postural threat elicits modifications to standing balance. However, the underlying neural mechanism(s) responsible remain unclear. Shifts in attention focus including directing more attention to balance when threatened may contribute to the balance changes. Sample entropy, a measure of postural sway regularity with lower values reflecting less automatic and more conscious control of balance, may support attention to balance as a mechanism to explain threat-induced balance changes. The main objectives were to investigate the effects of postural threat on sample entropy, and the relationships between threat-induced changes in physiological arousal, perceived anxiety, attention focus, sample entropy, and traditional balance measures. A secondary objective was to explore if biological sex influenced these relationships.

Methods

Healthy young adults (63 females, 42 males) stood quietly on a force plate without (No Threat) and with (Threat) the expectation of receiving a postural perturbation (i.e., forward/backward support surface translation). Mean electrodermal activity and anterior-posterior centre of pressure (COP) sample entropy, mean position, root mean square, mean power frequency, and power within low (0-0.05 Hz), medium (0.5-1.8 Hz), and high-frequency (1.8-5 Hz) components were calculated for each trial. Perceived anxiety and attention focus to balance, task objectives, threat-related stimuli, self-regulatory strategies, and task-irrelevant information were rated after each trial.

Results and Discussion

Significant threat effects were observed for all measures, except low-frequency sway. Participants were more physiologically aroused, more anxious, and directed more attention to balance, task objectives, threat-related stimuli, and self-regulatory strategies, and less to task-irrelevant information in the Threat compared to No Threat condition. Participants also increased sample entropy, leaned further forward, and increased the amplitude and frequency of COP displacements, including medium and high-frequency sway, when threatened. Males and females responded in the same way when threatened, except males had significantly larger threat-induced increases in attention to balance and high-frequency sway. A combination of sex and threat-induced changes in physiological arousal, perceived anxiety, and attention focus accounted for threat-induced changes in specific traditional balance measures, but not sample entropy. Increased sample entropy when threatened may reflect a shift to more automatic control. Directing more conscious control to balance when threatened may act to constrain these threat-induced automatic changes to balance.

Experimental induction of peritraumatic dissociation: The role of negative affect and pain and their psychophysiological and neural correlates

While research has elucidated processes underlying dissociative symptoms in patients with posttraumatic stress disorder, little is known about the circumstances under which trauma-related dissociation initially arises. To experimentally investigate causes and concomitants of peritraumatic dissociation, we subjected sixty-nine healthy women to aversive-audiovisual and painful-electrical stimulation in a 2(aversive/neutral film) x 2(pain/no pain) within-subject design while recording psychophysiological and fMRI-BOLD responses. Afterwards, participants rated negative-affect, pain, and dissociation for each condition. Using Bayesian multilevel regression models, we examined (1) whether aversive-audiovisual and painful-electrical stimulation elicit higher dissociation-levels than control conditions and (2) whether stronger negative-affect and pain responses (operationalized via self-report, psychophysiological, and neural markers) correlate with higher dissociation-levels. Several key findings emerged: Both aversive-audiovisual and painful-electrical stimulation elicited dissociation. Dissociation was linked to higher self-reported negative-affect, but we did not find enough evidence linking it to psychophysiological and neural negative-affect markers. However, dissociation was associated with higher levels of self-reported pain, a skin-conductance-response-based pain marker, and the fMRI-BOLD-based Neurologic-Pain-Signature. Results indicate that both aversive-audiovisual and painful stimuli can independently cause dissociation. Critically, pain responses captured via self-report, psychophysiological, and neural markers were consistently linked to higher dissociation-levels suggesting a specific, evolutionary meaningful, contribution of pain to the rise of dissociation.

Sedentary behaviour, but not moderate-to-vigorous physical activity, is associated with respiratory responses to acute psychological stress

BACKGROUND

Acute psychological stress induces respiratory responses, and stress-induced respiratory changes can be used to non-invasively reflect metabolic regulation. Respiratory and cardiovascular responses to stress are both driven by sympathetic mechanisms. Higher volumes of sedentary behaviour and lower volumes of physical activity are associated with elevated sympathetic tone and larger cardiovascular responses to stress. The aim of this study was to test whether these associations translate to measures of respiratory stress reactivity.

METHODS

Daily hours of sedentary behaviour (thigh-mounted activPAL) and moderate-to-vigorous physical activity (MVPA; wrist-mounted ActiGraph) were assessed across seven days. Breath-by-breath respiratory (e.g., breathing frequency [BF], end-tidal carbon dioxide partial pressure [PetCO₂], carbon dioxide output [V̇CO₂] and respiratory exchange ratio [RER]) responses to an 8-min Paced Auditory Serial Addition Test were then measured using a Cortex MetaLyzer3B.

RESULTS

Healthy participants (N = 61, mean age ± SD = 25.7 ± 8.9 years) recorded high volumes of sedentary behaviour (9.96 ± 1.48 h/day) and MVPA (1.70 ± 0.71 h/day). In adjusted models (with the inclusion of sedentary behaviour, MVPA, and other a priori selected covariates) hours of daily sedentary behaviour were associated with baseline to stress changes in BF (Β = 0.695, 95% CI = 0.281 - 1.109, p = .014), V_T (Β = -0.042, 95% CI = -0.058 - -0.026, p = .014), PetCO₂ (Β = -0.537, 95% CI = -0.829 - -0.245, p = .014), V̇CO₂ (Β = -0.008, 95% CI = -0.014 - -0.003, p = .030), and RER (Β = -0.013, 95% CI = -0.021 - -0.005, p = .022). Daily hours of MVPA were not linked with respiratory responses to stress.

DISCUSSION

Sedentary behaviour, but not MVPA, is associated with respiratory stress reactivity. Future work should untangle the underlying mechanisms of these findings and explore the consequences for cardiometabolic disease.

Neuroscientific evidence for pain being a classically conditioned response to trauma- and pain-related cues in humans

ABSTRACT

Psychological trauma is typically accompanied by physical pain, and posttraumatic stress disorder (PTSD) often co-occurs with chronic pain. Clinical reports suggest that pain after trauma may be part of a re-experiencing symptomatology. Classical conditioning can underlie visual re-experiencing since intrusions can occur as conditioned responses (CRs) to trauma-related cues. If individuals also experience pain to cues previously paired with, but not anymore inflicting nociceptive stimulation (CSs), conditioning could also explain re-experiencing of pain. Sixty-five participants underwent classical conditioning, where painful electrocutaneous stimulation and aversive film-clips served as unconditioned stimuli (USs) in a 2(pain/no pain)×2(aversive/neutral film) design. CSs were neutral pictures depicting contextual details from the films. One day later, participants were re-exposed to CSs during a memory-triggering-task (MTT). We assessed pain-CRs by self-report and an fMRI-based marker of nociceptive pain, the neurologic pain signature (NPS); and recorded spontaneous daily-life pain-intrusions with an e-diary. During conditioning, pain-signaling CSs elicited more self-reported-pain and NPS-responses than no-pain-signaling CSs. Possibly because the aversive-film masked differences in participants' responses to pain-signaling vs. no-pain-signaling CSs, pain-CRs during acquisition only emerged within the neutral-film condition. When participants were re-exposed to CSs during MTT, self-reported-pain-CRs during the neutral-film condition and, though more uncertain, NPS-CRs during the aversive-film condition persisted. Importantly, participants with stronger pain-CRs showed a greater probability and severity of experiencing spontaneous pain intrusions during daily-life. Our data support that pain can emerge as a CR with emotional and sensory components. Classical conditioning presents a possible mechanism explaining pain-intrusions, and more broadly, pain experienced without nociceptive input.

Autonomic Nervous System Activity During Positive Emotions: A Meta-Analytic Review

Autonomic nervous system (ANS) activity is a fundamental component of emotional responding. It is not clear, however, whether positive emotional states are associated with differential ANS reactivity. To address this issue, we conducted a meta-analytic review of 120 articles (686 effect sizes, total N = 6,546), measuring ANS activity during 11 elicited positive emotions, namely amusement, attachment love, awe, contentment, craving, excitement, gratitude, joy, nurturant love, pride, and sexual desire. We identified a widely dispersed collection of studies. Univariate results indicated that positive emotions produce no or weak and highly variable increases in ANS reactivity. However, the limitations of work to date – which we discuss – mean that our conclusions should be treated as empirically grounded hypotheses that future research should validate.

Verification of the Psychometric Characteristics of the Nijmegen Questionnaire for the Diagnosis of Dysfunctional Breathing During the COVID-19 Pandemic on a Russian Sample

The purpose of the study was to check the psychometric properties of the Nijmegen questionnaire (NQ) (Van Dixhoorn, Duivenvoorden, 1985), aimed at diagnosing the presence of signs of dysfunctional breathing (DВ) according to self–reports of respondents in the conditions of the COVID-19 pandemic in a Russian-speaking sample. The study sample consisted of 1 362 respondents (1 153 women and 209 men) aged 18 to 88 years (mean age 38.3±11.4) who filled out an online questionnaire from April to December 2020 during the COVID-19 pandemic. The following methods were used to test the construct validity of the Russian version of the NQ: 1) Perceived Stress Scale-10 (PSS-10; Ababkov et al., 2016); 2) State-Trait Anxiety Inventory (STAI, Khanin, 1976), the scales of which were modified to measure the level of anxiety during a pandemic (State anxiety) and before the pandemic (Trait anxiety) (Pervichko et al., 2020); 3) The Symptom Check List-32 (SCL-32) (Mitina, Gorbunova, 2011); (4) An abridged version of the Six-Factor Personality Inventory HEXACO-24 (Egorova et al, 2019). The study participants also completed a socio-demographic questionnaire (Pervichko et al., 2020). The results of checking the Russian-language version of the NQ for reliability are presented: the value of the internal consistency coefficient α-Cronbach for the integral indicator = 0.877. Four subscales were identified, the indicators of which improved when the questionnaire was reduced to 10 points. Internal convergent and discriminant validity has been verified for the abridged version. The external constructive validity of the questionnaire is proved. High rates of correlation with stress, situational and personal anxiety, as well as other symptoms of psychological distress were revealed. In addition, a high correlation with emotionality has been established. The problem of the "threshold" value of NQ required to identify the formed symptom complex of DB is discussed. The prevalence of DB symptoms before and during the pandemic was compared. A significant difference in the indicators on the scale for men and women was established. Using the obtained Russian-language version of NQ, it was shown that in the conditions of the COVID-19 pandemic, 27.7% of the study participants who were not sick with COVID-19 showed signs of a formed DB symptom complex, which is more than twice higher than the population indicators in the pre-pandemic period. The frequency of occurrence of the holistic symptom complex of DB in women is three times higher than in men: 31.0% vs 9.1% (p<0.001). The results of the study allow us to conclude that NQ is a reliable and valid tool for diagnosing the severity of DB symptoms, which can be recommended for use as an express diagnostic tool for the presence of psychogenically caused respiratory disorders in persons complaining of "difficulty breathing" in the absence of objective grounds.

Intrusive memories as conditioned responses to trauma cues: An empirically supported concept?

Intrusions in posttraumatic stress disorder (PTSD) are clinically understood as conditioned responses (CRs) to trauma-cues; however, experimental evidence for this is limited. We subjected 84 healthy participants to a differential conditioned-intrusion paradigm, where neutral faces served as conditioned stimuli (CSs) and aversive film clips as unconditioned stimuli (USs). While one group only completed acquisition, another group additionally received extinction. Subsequently, participants provided detailed e-diary intrusion reports. Several key findings emerged: First, participants in both groups re-experienced not only USs but also CSs as content of their intrusions. Second, intrusions were elicited by cues resembling CSs, USs, and experimental context. Third, extinction reduced probability and severity of US intrusions, and accelerated their decay, and this was particularly the case in participants showing greater cognitive (US-expectancy) and physiological (SCR) differential responding to CS+ vs. CS- at end of acquisition (i.e., conditionability). Similarly, extinction reduced CS-intrusion probability and severity, but only in participants with greater cognitive conditionability. These results support conditioning's role in re-experiencing in two critical ways: (1) Conditioning during trauma provides cues that not only function as reminder cues, but also as content of intrusions; (2) After strong conditioning, weakening the original CS-US relationship via extinction reduces intrusion formation after analogue-trauma.

Sensation seeking and neuroticism in fear conditioning and extinction: The role of avoidance behaviour

Maladaptive avoidance behaviour, a key symptom of anxiety-related disorders, prevents extinction learning and maintains anxiety. Individual personality traits likely influence avoidance propensity: high sensation-seeking may decrease avoidance, thereby increasing extinction, and neuroticism may have the reverse effect. However, research on this is scarce. Using a naturalistic conditioned avoidance paradigm, 163 women underwent differential fear acquisition to a conditioned stimulus (CSplus). Next, during extinction, participants could either choose a risky shortcut, anticipating shock signalled by CSplus, or a time-consuming avoidance option (lengthy detour). Across participants, increased skin conductance (SCR) acquisition learning predicted subsequent instrumental avoidance. Avoidance, in turn, predicted elevated post-extinction SCR and shock-expectancy, i.e., 'protection-from-extinction'. Mediation analyses revealed that sensation seeking decreased protection-from-extinction-both for shock-expectancy and SCR-via attenuating avoidance. Neither sensation seeking nor neuroticism were related to acquisition learning and neuroticism was neither related to avoidance nor extinction. Transcranial direct currentstimulation administered before extinction did not influence present results. Results highlight the important role of elevated avoidance propensity in fear maintenance. Results moreover provide evidence for reduced sensation-seeking and increased acquisition learning to be avoidance-driving mechanisms. Since approach-avoidance conflicts are faced by anxiety patients on a daily basis, strengthening sensation-seeking-congruent attitudes and approach behaviours may optimize individualized treatment.

Cardiac defensive reactions and orienting responses correspond to virtual withdrawal behavior choices in a virtual T-maze

Trait or stimulus valence related differences in heart rate change have often been investigated in psychophysiological research. However, the influence of different behavioral responses during motivational contexts on cardiac response patterns has been neglected so far. In this manuscript, HR change during movement via joystick during the negatively valent motivational condition of a virtual T-maze was investigated in two studies. Concerning the behavior, two specific avoidance response types could be identified in previous studies: a backwards withdrawal and an approach to safety. HR change and skin conductance response were hypothesized to be differentially related to these response patterns. For HR changes, the proposed difference was found. Participants facing the safety zone during their avoidance showed cardiac responses associated with the defensive response. In contrast, participants facing the negative entity of the virtual T-maze during their backwards withdrawal yielded cardiac responses associated with orienting reactions. Interestingly, these differences were found independently of the stimuli used in the two paradigms (monster vs. man). These findings lead to the conclusion that the execution of different behavioral responses during motivational conditions is an important factor in analyzing psychophysiological patterns, because they change according to the executed behavior and the linked visual and motivational properties.

Sympathetic arousal during the processing of dysphoric affect by youths at high and low familial risk for depression

Youths at high risk for depression have been shown to have problems in repairing their own sad mood. Given that sympathetic arousal has been implicated both in the experience and regulation of affect, an atypical pattern of arousal may be one of the factors that contribute to mood repair problems. In the current study, we measured sympathetic arousal of never-depressed youths at high (n = 56) and low (n = 67) familial risk for depression during sad mood induction and instructed mood repair. Sympathetic arousal was indexed by skin conductance level (SCL) and cardiac pre-ejection period (PEP); mood repair outcome was indexed by self-rated affect. High-risk youths demonstrated increased SCL during sadness induction, which persisted during mood repair; low-risk youths evidenced increased SCL only during mood repair. Shortened PEP was evident only among high-risk youths and only during mood repair. Furthermore, shortened PEP during mood induction predicted less successful mood repair in the low-risk but not in the high-risk group. The findings suggest that: (a) depression-prone youths differ from control peers in patterns of sympathetic responses to emotional stimuli, which may impair their ability to relieve sadness, and (b) activation patterns differ across subsystems (SCL vs. PEP) of sympathetic activity, in conjunction with depression risk status.

Neural Processing During Fear Extinction Predicts Intrusive Memories

BACKGROUND

Deficient extinction learning has been suggested as an important mechanism involved in the etiology of posttraumatic stress disorder. A key feature of posttraumatic stress disorder, reexperiencing the trauma in form of intrusions, may be linked to deficient extinction learning. This link is investigated in a novel, functional magnetic resonance imaging-compatible fear conditioning procedure that uses trauma films. Based on previous results, we expected deficient fear extinction indexed by exaggerated responding in the anterior insula and dorsal anterior cingulate cortex to predict subsequent intrusions.

METHODS

A total of 58 healthy participants underwent acquisition and extinction learning with faces as conditioned stimuli (CS) and highly aversive 16-second films depicting interpersonal violence as unconditioned stimuli. During the subsequent 3 days, participants reported intrusive memories on their smartphone.

RESULTS

Successful fear acquisition was evidenced by differential (CS+ > CS-) activity (threat cues associated with trauma films > cues paired only with neutral films) of a widespread network, including the anterior insula and dorsal anterior cingulate cortex, whereas extinction was characterized exclusively by differential anterior insula activity. Differential conditioned responding during late extinction in the anterior insula and dorsal anterior cingulate cortex was positively related to intrusive memory frequency independent of unconditioned stimuli responding. Exploratory analysis also revealed intrusion sensitivity of the hippocampus, rostral anterior cingulate cortex, and ventromedial prefrontal cortex, among others.

CONCLUSIONS

Results support the role of extinction learning in intrusive memory formation; a failure to uncouple conditioned emotional responding from external threat cues was associated with subsequent intrusive memories, representing a potential risk marker for developing posttraumatic stress disorder symptomatology after trauma.

Prenatal Exposure to PM2.5 and Cardiac Vagal Tone during Infancy: Findings from a Multiethnic Birth Cohort

BACKGROUND

The autonomic nervous system plays a key role in maintaining homeostasis and responding to external stimuli. In adults, exposure to fine particulate matter (PM2.5) has been associated with reduced heart rate variability (HRV), an indicator of cardiac autonomic control.

OBJECTIVES

Our goal was to investigate the associations of exposure to fine particulate matter (PM2.5) with HRV as an indicator of cardiac autonomic control during early development.

METHODS

We studied 237 maternal-infant pairs in a Boston-based birth cohort. We estimated daily residential PM2.5 using satellite data in combination with land-use regression predictors. In infants at 6 months of age, we measured parasympathetic nervous system (PNS) activity using continuous electrocardiogram monitoring during the Repeated Still-Face Paradigm, an experimental protocol designed to elicit autonomic reactivity in response to maternal interaction and disengagement. We used multivariable linear regression to examine average PM2.5 exposure across pregnancy in relation to PNS withdrawal and activation, indexed by changes in respiration-corrected respiratory sinus arrhythmia (RSAc)-an established metric of HRV that reflects cardiac vagal tone. We examined interactions with infant sex using cross-product terms.

RESULTS

In adjusted models we found that a 1-unit increase in PM2.5 (in micrograms per cubic meter) was associated with a 3.53% decrease in baseline RSAc (95% CI: -6.96, 0.02). In models examining RSAc change between episodes, higher PM2.5 was generally associated with reduced PNS withdrawal during stress and reduced PNS activation during recovery; however, these associations were not statistically significant. We did not observe a significant interaction between PM2.5 and sex.

DISCUSSION

Prenatal exposure to PM2.5 may disrupt cardiac vagal tone during infancy. Future research is needed to replicate these preliminary findings. https://doi.org/10.1289/EHP4434.

Facial Affect and Interpersonal Affiliation: Displays of Emotion During Relationship Formation in Social Anxiety Disorder

Social anxiety disorder (SAD) often involves difficulty developing relationships. Facial expressions are important in relationship formation, but data are limited regarding facial display production among persons with SAD during social interaction. The current study compared facial displays of individuals diagnosed with SAD (n=41) to control participants (n=24) as they interacted with a confederate; confederates and observers then rated their desire for future interaction with participants. Automated software used the Facial Action Coding System (FACS; Ekman & Friesen, 1978) to classify displays. During portions of the interaction that involved listening to partners, the SAD group smiled less frequently and less intensely than controls, and lower smiling was associated with others' lower desire for future interaction with participants. Diminished positive facial affect in response to interaction partners may disrupt relationship formation in SAD and may serve as an effective treatment target.

Detecting Moments of Stress from Measurements of Wearable Physiological Sensors

There is a rich repertoire of methods for stress detection using various physiological signals and algorithms. However, there is still a gap in research efforts moving from laboratory studies to real-world settings. A small number of research has verified when a physiological response is a reaction to an extrinsic stimulus of the participant's environment in real-world settings. Typically, physiological signals are correlated with the spatial characteristics of the physical environment, supported by video records or interviews. The present research aims to bridge the gap between laboratory settings and real-world field studies by introducing a new algorithm that leverages the capabilities of wearable physiological sensors to detect moments of stress (MOS). We propose a rule-based algorithm based on galvanic skin response and skin temperature, combing empirical findings with expert knowledge to ensure transferability between laboratory settings and real-world field studies. To verify our algorithm, we carried out a laboratory experiment to create a "gold standard" of physiological responses to stressors. We validated the algorithm in real-world field studies using a mixed-method approach by spatially correlating the participant's perceived stress, geo-located questionnaires, and the corresponding real-world situation from the video. Results show that the algorithm detects MOS with 84% accuracy, showing high correlations between measured (by wearable sensors), reported (by questionnaires and eDiary entries), and recorded (by video) stress events. The urban stressors that were identified in the real-world studies originate from traffic congestion, dangerous driving situations, and crowded areas such as tourist attractions. The presented research can enhance stress detection in real life and may thus foster a better understanding of circumstances that bring about physiological stress in humans.

Peritraumatic Neural Processing and Intrusive Memories: The Role of Lifetime Adversity

BACKGROUND

Pathological peritraumatic encoding is proposed as a proximal risk factor for the development of posttraumatic stress disorder (PTSD), with trauma-analog studies linking increased neural processing of trauma films to intrusive trauma recollections, a core symptom of PTSD. Cumulative lifetime adversity is proposed as a more distal risk factor, with research indicating a tipping point at about five events with regard to PTSD development following re-exposure to trauma. Thus, within a diathesis × stress framework, increased peritraumatic neural processing may constitute a specific risk factor for PTSD, particularly in individuals with several lifetime adversities.

METHODS

Fifty-three healthy women watched highly aversive films depicting severe interpersonal violence versus neutral films during functional magnetic resonance imaging, and they reported involuntary recollections during subsequent days. Moderation analyses tested the interactive relationship between peritraumatic neural processing and lifetime adversity in predicting intrusion load, i.e., the total number of intrusions weighted for their average distress.

RESULTS

Increased processing of aversive versus neutral films in the amygdala, anterior insula, dorsal and rostral anterior cingulate cortices, and hippocampus predicted increased intrusion load only in participants reporting above five lifetime adversities; for participants reporting few to none, no such relationship was found. This interactive relationship explained ≤59% of variance. Conditioned stimuli preceding film viewing mirrored this pattern.

CONCLUSIONS

Peritraumatic neural processing in multiple salience network regions and cumulative lifetime adversity interactively predicted PTSD-like symptomatology, representing a diathesis × stress framework that might guide identification of at-risk individuals and potential targets for symptom prevention after traumatic incidents.

Peritraumatic unconditioned and conditioned responding explains sex differences in intrusions after analogue trauma

Higher prevalence of posttraumatic stress disorder (PTSD) in women than men may be explained by sex differences in fear learning processes. Initial evidence points to elevated unconditioned and conditioned fear responding as well as to elevated state anxiety in women as potential peritraumatic mechanisms. Using the "conditioned-intrusion-paradigm", which combines differential fear conditioning with the trauma-film paradigm, neutral sounds were presented as predictors of the occurrence (CS+) or non-occurrence (CS-) of highly aversive films. Intrusions were elicited by these sounds in the laboratory after conditioning and naturalistic intrusions were assessed in daily-life on subsequent days. Compared to men (n = 62), women (n = 60) reported more intrusions and associated distress following analogue trauma. Sex differences in intrusive symptoms were mediated by a) higher unconditioned trauma responding, b) slowed extinction of differential CS valence ratings, and c) elevated state anxiety increase across conditioning in women. Secondary analyses revealed that state anxiety was the strongest mediator, followed by slowed extinction learning. Mediation models were unrelated to sex differences in trait anxiety or depressive symptoms. Thus, associative (extinction learning) and non-associative (state anxiety, trauma responding) mechanisms contribute to sex differences in intrusive symptoms after analogue trauma and might add to the heightened vulnerability to PTSD in women.

EVALUATION OF SIGNAL PROCESSING TECHNIQUES IN DISCRIMINATING ECG SIGNALS OF MEN AND WOMEN DURING REST CONDITION AND EMOTIONAL STATES

Great range of electrocardiogram (ECG) signal processing methods can be found in the literature. In addition, the importance of gender differences in physiological activities was also identified in various conditions. This article aims to provide a comprehensive evaluation of linear and nonlinear ECG parameters to indicate suitable signal processing approaches which can show significant differences between men and women. These differences were investigated in two conditions: (i) during rest condition, and (ii) during the affective image inducements. A wide range of parameters from time-, frequency-, wavelet-, and nonlinear-techniques were examined. Applying the Wilcoxon rank sum test, significant differences between two genders were inspected. The analysis was performed on 47 college students at rest condition and while subjects watching four types of affective pictures, including sadness, happiness, fear, and peacefulness. The impact of these emotions on the results was also investigated. The results indicated that 72.95% and 72.61% of all features were significantly different between male and female in rest condition and affective inducements, respectively. In addition, the highest percentage of the significant difference between ECG parameters of men and women was achieved using nonlinear characteristics. Considering all features together, the highest significant difference between two genders was achieved for negative emotions, including sadness and fear. In conclusion, the results of this study emphasized the importance of gender role in cardiac responses during rest condition and different emotional states. Since these gender differences are well manifested by nonlinear signal processing techniques, dynamical gender-specific ECG system may improve the automatic emotion recognition accuracies.

Assessing the antecedents and consequences of threat appraisal of an acute psychosocial stressor: the role of optimism, displacement behavior, and physiological responses

The feeling of stress is increasing in today's societies, particularly in young adults subjected to social evaluative situations in highly competitive academic and work contexts. Threat appraisal is a primary and fundamental reaction when people face a stressful situation. The aim of this study was to investigate the role of dispositional optimism as an antecedent and displacement behavior as a consequence of threat appraisal of a social-evaluative situation of stress. A second objective was to verify the moderating role of physiological responses to stress (heart rate and cortisol reactivity) in the relationship between threat appraisal and displacement behavior. To do this, we combined the Trier Social Stress Test (TSST) with ethological analysis, self-report questionnaires, and physiological data. As expected, people who scored higher on dispositional optimism perceived stress as less threatening, and a higher perception of threat was positively related to displacement behavior patterns. Moreover, the results showed that threat appraisal fully mediates the relationship between dispositional optimism and displacement behavior, and that only heart rate reactivity (not cortisol) moderates the relationship between threat appraisal and displacement behavior.