Cold pressor stress effects on cardiac repolarization.

The cold pressor test (CPT) elicits strong cardiovascular reactions via activation of the sympathetic nervous system (SNS), yielding subsequent increases in heart rate (HR) and blood pressure (BP). However, little is known on how exposure to the CPT affects cardiac ventricular repolarization. Twenty-eight healthy males underwent both a bilateral feet CPT and a warm water (WW) control condition on two separate days, one week apart. During pre-stress baseline and stress induction cardiovascular signals (ECG lead II, Finometer BP) were monitored continuously. Salivary cortisol and subjective stress ratings were assessed intermittently. Corrected QT (QTc) interval length and T-wave amplitude (TWA) were assessed for each heartbeat and subsequently aggregated individually over baseline and stress phases, respectively. CPT increases QTc interval length and elevates the TWA. Stress-induced changes in cardiac repolarization are only in part and weakly correlated with cardiovascular and cortisol stress-reactivity. Besides its already well-established effects on cardiovascular, endocrine, and subjective responses, CPT also impacts on cardiac repolarization by elongation of QTc interval length and elevation of TWA. CPT effects on cardiac repolarization share little variance with the other indices of stress reactivity, suggesting a potentially incremental value of this parameter for understanding psychobiological adaptation to acute CPT stress.

Inhibitory control and its modification in spider phobia - Study protocol for an antisaccade training trial.

OBJECTIVES: Inhibitory control deficits are considered a key pathogenic factor in anxiety disorders. To assess inhibitory control, the antisaccade task is a well-established measure that assesses antisaccade performance via latencies and error rates. The present study follows three aims: (1) to investigate inhibitory control via antisaccade latencies and errors in an antisaccade task, and their associations with multiple measures of fear in patients with spider phobia (SP) versus healthy controls (HC), (2) to investigate the modifiability of antisaccade performance via a fear-specific antisaccade training in patients with SP and HC, and (3) to explore associations between putative training-induced changes in antisaccade performance in SPs and changes in diverse measures of fear. METHODS: Towards aim 1, we assess antisaccade latencies (primary outcome) and error rates (secondary outcome) in an emotional antisaccade task. Further, the baseline assessment includes assessments of psychophysiological, behavioral, and psychometric indices of fear in patients with SP and HCs. To address aim 2, we compare effects of a fear-specific antisaccade training with effects of a prosaccade training as a control condition. The primary and secondary outcomes are reassessed at a post-1-assessment in both SPs and HCs. Aim 3 employs a cross-over design and is piloted in patients with SP, only. Towards this aim, primary and secondary outcomes, as well as psychophysiological, behavioral, and psychometric measures of fear are reassessed at a post-2-assessment after the second training block. CONCLUSION: This study aims to better understand inhibitory control processes and their modifiability in spider phobia. If successful, antisaccade training may assist in the treatment of specific phobia by directly targeting the putative underlying inhibitory control deficits. This study has been preregistered with ISRCTN (ID: ISRCTN12918583) on 28th February 2022.

Repressive and vigilant coping styles in stress and relaxation: evidence for physiological and subjective differences at baseline, but not for differential stress or relaxation responses.

Introduction: Previous research suggested differential stress reactivity depending on individuals' coping style, e.g., as classified by the model of coping modes. Specifically, stronger physiological reactivity and weaker subjective stress ratings were found for repressors than for sensitizers. However, it remains to be investigated (i) whether these findings, which are largely based on social stress induction protocols, also generalize to other stressors, (ii) whether repressors vs. sensitizers also exhibit differential stress recovery following the application of a relaxation method, and (iii) which stress reactivity and recovery patterns are seen for the two remaining coping styles, i.e., fluctuating, and non-defensive copers. The current study thus examines stress reactivity in physiology and subjective ratings to a non-social stressor and the subsequent ability to relax for the four coping groups of repressors, sensitizers, fluctuating, and non-defensive copers. Methods: A total of 96 healthy participants took part in a stress induction (Mannheim Multicomponent Stress Test) and a subsequent relaxation intervention. Subjective ratings of stress and relaxation, heart rate (HR), heart rate variability (HRV), and blood pressure were assessed during the experiment. HR and blood pressure are markers of the sympathetic stress response that can be regulated by relaxation, while HRV should increase with relaxation. To investigate long-term relaxation effects, subjective ratings were also assessed on the evening of testing. Results: Despite successful stress induction, no differential responses (baseline to stress, stress to relaxation) were observed between the different coping groups on any of the measures. In contrast, a strong baseline effect was observed that persisted throughout the experiment: In general, fluctuating copers showed lower HR and higher HRV than non-defensive copers, whereas repressors reported lower subjective stress levels and higher levels of relaxation during all study phases. No differences in subjective ratings were observed in the evening of testing. Conclusion: Contrary to previous research, no differential stress reactivity pattern was observed between coping groups, which could be due to the non-social type of stressor employed in this study. The novel finding of physiological baseline differences between fluctuating and non-defensive individuals is of interest and should be further investigated in other stressor types in future research.

Close(d) to you? Avoidant attachment is associated with attenuated pupil responsivity to social stimuli.

Insecure attachment is thought to impair romantic relationships, presumably also contributing to mental health problems. Previous research has suggested a link to biased automatic processing of social information, potentially reflected in pupil dilation responses. To address this hypothesis, 37 adults were presented with attachment-related, emotional pictures of erotic couples, everyday couples, or interpersonal violence after assessment with the Experiences in Close Relationships Scale. Considerable variation in self-reported attachment behaviors regarding both attachment anxiety and avoidance was observed in our sample. Overall, pupil dilation was most pronounced during viewing of erotica and violence-related pictures. Relative to nature pictures as control, attachment avoidance was associated with attenuated pupillary responses to social content. However, this was not significant with erotica. For pictures of violence, this avoidant bias was also evident in reduced subjective arousal. In contrast, attachment anxiety was unrelated to differential pupil dilation. Our findings, although preliminary, suggest that previous attachment-related experiences may bias the processing of social stimuli, which in turn may be reflected in altered patterns of pupillary responses.

Optimal timing of oral metyrapone intake for the suppression of cold-pressor stress-induced cortisol release.

BACKGROUND: Pharmacological manipulation of cortisol levels is instrumental in elucidating mechanisms underlying acute stress effects and for distinguishing the physiological and behavioral effects of cortisol from those of the adrenergic system. Administration (oral or IV) of hydrocortisone is a direct and efficient method to elevate cortisol, and thus, frequently used in psychobiological stress research. However, lowering of cortisol (i.e. blockade of stress cortisol) requires a more sophisticated approach, such as the administration of the corticostatic compound metyrapone (MET). However, there is insufficient knowledge about the temporal dynamics of MET for the blocking of stress-induced cortisol reactivity. Thus, the present study aimed to build up an experimental protocol suitable to suppress acute behavioral stress-induced cortisol secretion by MET. METHODS: 50 healthy young men were randomly assigned to one of five treatment groups. They received 750 mg oral MET either 30 (n = 9), 45 (n = 11), or 60 (n = 10) minutes before exposure to a combined cold pressor and mental arithmetic test (stress induction), or were subjected to two different control treatments (placebo 60 min before stress (n = 10) or MET 30 min before non-stressful warm-water condition (n = 10)). Salivary cortisol concentration, hemodynamics, and subjective ratings were assessed. RESULTS: Suppression of cold stress-induced cortisol release was strongest when MET intake was scheduled 30 min prior to stress onset. Cardiovascular stress-responses and subjective ratings remained unaffected by MET. CONCLUSION: In healthy young males, 750 mg of MET efficiently block cold stress-induced cortisol release when oral administration is scheduled 30 min prior to stress onset. This finding may guide future research in improving timing of suppression of stress-induced cortisol secretion.

Pupil dilation tracks divergent learning processes in aware versus unaware Pavlovian conditioning.

Evidence regarding unaware differential fear conditioning in humans is mixed and even less is known about the effects of contingency awareness on appetitive conditioning. Phasic pupil dilation responses (PDR) might be more sensitive for capturing implicit learning than other measures, such as skin conductance responses (SCR). Here, we report data from two delay conditioning experiments utilizing PDR (alongside SCR and subjective assessments) to investigate the role of contingency awareness in aversive and appetitive conditioning. In both experiments, valence of unconditioned stimuli (UCS) was varied within participants by administering aversive (mild electric shocks) and appetitive UCSs (monetary rewards). Preceding visual stimuli (CSs) predicted either the reward, the shock (65% reinforcement), or neither UCS. In Exp. 1, participants were fully instructed about CS-UCS contingencies, whereas in Exp. 2, no such information was given. PDR and SCR demonstrated successful differential conditioning in Exp. 1 and in (learned) aware participants in Exp. 2. In non-instructed participants who remained fully unaware of contingencies (Exp. 2), differential modulation of early PDR (immediately after CS onset) by appetitive cues emerged. Associations with model-derived learning parameters further suggest that early PDR in unaware participants mainly reflect implicit learning of expected outcome value, whereas early PDR in aware (instructed/learned-aware) participants presumably index attentional processes (related to uncertainty/prediction error processing). Similar, but less clear results emerged for later PDR (preceding UCS onset). Our data argue in favor of a dual-process account of associative learning, suggesting that value-related processing can take place irrespective of mechanisms involved in conscious memory formation.

Associations between hair cortisol and subjective stress measures in a large occupational sample.

BACKGROUND: Hair cortisol concentrations (HCC) are commonly used to capture long-term cumulative cortisol secretion in stress research. However, data on associations between HCC and subjective stress measures have been inconsistent. This may partly be due to bias introduced by smaller-sized academic samples. Here, we investigate associations between HCC and (work-) stress-related measures in a large occupational, predominantly male, sample. METHODS: Demographic, anthropometric, and self-reported data were collected as part of an occupational health assessment for employees of an airplane manufacturing company (N = 1258). Hair samples (3 cm) were obtained and glucocorticoid concentrations (HCC and hair cortisone, HairE) were analyzed using liquid chromatography-tandem mass spectrometry. RESULTS: HCC and HairE were unrelated to self-report measures of perceived stress, work-related stress (effort-reward imbalance, overcommitment), and other stress-related constructs. Group-based analyses concerning associations with job strain revealed a small effect of individuals with high job strain (n = 281) exhibiting higher HCC than the remaining sample (n = 811). CONCLUSIONS: Our data replicate previous findings of no consistent associations between hair glucocorticoids and subjective stress-related questionnaire data, besides evidence for elevated HCC in a high job strain group. Further research addressing open methodological questions regarding HCC by means of advanced stress assessment methods is needed.

Increased pupil and heart-rate responses to sexual stimuli in men after physical exertion.

Physical stress has been found to enhance arousability by visual sexual stimuli on a short-term basis, as reflected in higher phasic pupil dilation responses, probably mediated by sympathetic nervous system (SNS)-related processes. However, previous research has not addressed the specificity of this effect in terms of emotional valence, that is, whether it reflects an instance of general excitation transfer or a more specific mechanism. Thus, to further investigate changes in sexual processing after acute stress exposure, 40 male participants underwent either a predominantly sympathetic stressor (3 min sustained handgrip) or similar control procedure. After stress induction, pictures varying in valence as well as sexual versus non-sexual arousal were presented (for 5000 ms each). Using principal component analysis, pupillary responses during picture viewing were dissociated into fast and slow components (early vs. late response phases). In addition, startle eyeblink responses were elicited by bursts of white noise (50 ms, 105 dB) in half of the trials and recorded at the orbicularis oculi via electromyography. Skin conductance and heart rate were co-registered, as well. While affective startle modulation and skin conductance responses to emotional stimuli were unaffected by previous stress exposure, both evoked heart-rate deceleration (but not acceleration) and pupil responses were specifically enhanced with sexually arousing stimuli in stressed participants, and this effect was mediated by blood pressure reactivity as an index of preceding SNS activation. Taken together, our findings provide strong evidence for enhancement of sexual processing by acute stress exposure in men and suggest differential involvement of parasympathetic versus sympathetic mechanisms.

Evaluation and update of the expert consensus guidelines for the assessment of the cortisol awakening response (CAR).

The cortisol awakening response (CAR) is frequently assessed in psychobiological (stress) research. Obtaining reliable CAR data, however, requires careful attention to methodological detail. To promote best practice, expert consensus guidelines on the assessment of the CAR were published (Stalder et al., 2016, PNEC). However, it is unclear whether these highly cited guidelines have resulted in actual methodological improvements. To explore this, the PNEC editorial board invited the present authors to conduct a critical evaluation and update of current CAR methodology, which is reported here. (i) A quantitative evaluation of methodological quality of CAR research published in PNEC before and after the guidelines (2013-2015 vs. 2018-2020) was conducted. Disappointingly, results reveal little improvement in the implementation of central recommendations (especially objective time verification) in recent research. (ii) To enable an update of guidelines, evidence on recent developments in CAR assessment is reviewed, which mostly confirms the accuracy of the majority of the original guidelines. Moreover, recent technological advances, particularly regarding methods for the verification of awakening and sampling times, have emerged and may help to reduce costs in future research. (iii) To aid researchers and increase accessibility, an updated and streamlined version of the CAR consensus guidelines is presented. (iv) Finally, the response of the PNEC editorial board to the present results is described: potential authors of future CAR research to be published in PNEC will be required to submit a methodological checklist (based on the current guidelines) alongside their article. This will increase transparency and enable reviewers to readily assess the quality of the respective CAR data. Combined, it is hoped that these steps will assist researchers and reviewers in assuring higher quality CAR assessments in future research, thus yielding more reliable and reproducible results and helping to further advance this field of study.

Stress effects on the top-down control of visuospatial attention: Evidence from cue-dependent alpha oscillations.

Stress is assumed to inhibit the top-down control of attention and to facilitate bottom-up processing. Evidence from human experiments, however, remains scarce. Previous studies have addressed how stress affects the interplay of bottom-up and top-down mechanisms of attention. A key open question is in how far such effects can actually be attributed to a stress-induced modulation of top-down attention control. We sought to isolate top-down from bottom-up effects by assessing stress effects on anticipatory changes in alpha oscillations that precede stimulus processing. Participants performed in a cued target detection task in which a cue prompted them to covertly shift their attention to left or right screen positions, 20 min after being exposed to the bilateral feet cold pressor test or a warm water control procedure. The stressor led to a substantial increase in cortisol, peaking 20 min post stressor, along with rises in heart rate, blood pressure, and subjective ratings of stress and arousal. As expected, cued attention deployment led to higher alpha power over posterior electrodes contralateral versus ipsilateral to the attended hemifield during the cue-target interval. Importantly, this purely endogenous effect was potentiated by stress, however, significant differences were restricted to the middle of the cue-target interval and thus temporally separated from the appearance of the target. These results indicate that stress does not impair top-down attentional control per se but may introduce a qualitative change modulating the way attention is deployed to meet action goals.

Stressed in afterthought: Neuroendocrine effects of social self-threat during physical effort are counteracted by performance feedback after stress exposure.

Social self-threat during physical stress, such as exposure to the cold pressor test and isometric handgrip test, has been shown to induce activation of the HPA axis, in addition to autonomic responses. However, previous research has suggested that dysfunctional post-event processing may play a major role in neuroendocrine reactivity at initial as well as subsequent social stress exposure. In the present study, we investigated how the interplay of context (i.e. performance feedback) with state (i.e., self-esteem) as well as trait-like factors (i.e., ruminative tendencies) affects stress responses to repeated, short bouts of physical activity. On two sessions, 1 week apart, 53 participants (27 women) performed an isometric handgrip task for 3 min, during which they were exposed to social-evaluative threat. In addition, participants received fake feedback on their performance immediately after the task, labeling it as either 'above' (positive) or 'below average' (negative). In addition to neuroendocrine (cortisol), cardiovascular (heart rate, blood pressure) and subjective stress reactivity, performance-related and social dimensions of state self-esteem were assessed before and after stress induction. Substantial increases in cardiovascular parameters were found on both days, regardless of feedback condition. However, positive feedback led to significantly diminished neuroendocrine responses on day 1, whereas baseline cortisol on session 2 was significantly higher in the negative feedback group. Conversely, social self-esteem decreased after stress induction on both days only for participants who had received negative feedback. Changes in self-esteem reported on day 1 were associated with increased baseline cortisol at the second session, while interindividual differences in self-reported (trait) rumination were associated with cortisol reactivity at session 1. Taken together, the results suggest that effects of social evaluation during short periods of physical stress rely on post-event processing and might be counteracted by positive appraisal directly after stress exposure. Post-hoc framing (in terms of success vs. failure) may predict subsequent stress-related hormonal effects better than task demands per se, which should be considered as a potential moderator in future acute stress research, but might also be relevant to many practical applications in fields ranging from sports/performance to health psychology.

Pupil dilation as an index of Pavlovian conditioning. A systematic review and meta-analysis.

The use of pupillometry to track emotional learning processes in humans is generating an increasing interest. Here, we provide a first systematic review and meta-analysis on the value of pupil dilation as a marker of Pavlovian conditioning, focusing on the roles of UCS valence (aversive vs. appetitive), the time course across trials and response intervals within trials. Based on data from 39 independent samples (total n = 1303), our results revealed strong evidence for the overall validity of conditioned pupil responses, with a trend for larger effects in aversive (average g = 0.73) vs. appetitive conditioning (g = 0.39). Response differentiation increased over the course of acquisition. Substantial differentiation effects were found in both early and late response windows. Moderator analyses revealed a consistent influence of UCS modality on differential conditioning, while evidence for moderation by contingency instructions and length of acquisition phase was mixed. The results highlight pupil dilation as a sensitive and reliable index of Pavlovian conditioning across valence categories and stimulus modalities. Important implications regarding methodological considerations and research goals are discussed.

Combining mental and physical stress: Synergy or interference?

Both cognitive stressors (such as mental arithmetic tasks) and physical stressors (such as the cold pressor test, CP) are among the most widely employed tools in acute stress research, and there is growing evidence for a high degree of stimulus-response specificity, rather than uniformity, in the human stress response. However, little is known about potential synergistic or interfering effects during concurrent administration. While cognitive tasks have been hypothesized to attenuate pain perception during CP, they are also thought to enhance physiological reactivity. Conversely, physical stress might interfere with effective stress induction by cognitive challenges. To address these questions, 56 participants underwent either the CP (3-min ice-water immersion of feet) or a warm-water control condition. In half of the sample, the Paced Auditory Serial Addition Task (PASAT) was performed simultaneously (fully crossed interventions). Salivary cortisol, cardiovascular parameters, and subjective ratings as well as voice pitch (F0) were assessed. Results show that cortisol responses, self-reported pain and subjective arousal were mainly driven by cold exposure, which also led to increased F0. The PASAT incrementally enhanced cardiovascular reactions, but did not affect pain ratings nor cortisol responses to the CP. However, intra-individual concordance between elevated blood pressure and other reactivity measures was enhanced by PASAT administration during the CP. Importantly, performance decrements in the mental-arithmetic task were not associated with diminished stress responses. In conclusion, our results speak against any strong interference when administering cognitive and painful physical stressors simultaneously, pointing rather to specific additive effects, particularly regarding cardiovascular reactivity.

Central Sympathetic Nervous System Effects on Cognitive-Motor Performance.

The intriguing interplay between acute stress physiology and cognitive processes has long been noted. However, while stress-induced release of glucocorticoids has repeatedly been shown to impact brain mechanisms underlying cognition and memory, less experimental research addressed the effects of stress-induced central sympathetic nervous system (SNS) activation on cognitive performance. Moreover, despite the long-standing notion that the way performance is modulated by arousal may crucially depend on task complexity, mechanistic research demonstrating a direct, causal influence of altered SNS activity is scarce. Twelve healthy men participated in a placebo-controlled, pharmacologic dose-response study involving three within-subject assessments (1-week intervals). Subjective and objective indices of SNS activity as well as reaction time (RT) in three different tasks varying in cognitive demand (simple RT, choice RT, and verbal RT in complex mental arithmetic) were assessed during modulation of central SNS tone by intravenous infusions of dexmedetomidine (alpha2-agonist), yohimbine (alpha2-antagonist), and placebo. Cognitive performance was negatively affected by alpha2-agonism in all task conditions. By contrast, administration of yohimbine improved simple RT, while diminishing complex RT, supporting the assumption of a nonlinear way of action depending on task characteristics. Our results highlight the consequences of central (noradrenergic) SNS activation for cognitive-motor performance in RT tasks of varying complexity.

Modulation of startle and heart rate responses by fear of physical activity in patients with heart failure and in healthy adults.

Fear of physical activity (FoPA) has been suggested as a barrier to physical activity in patients with heart failure and might be associated with low adherence to exercise regimen despite medical guideline recommendations. The present study examined physiological indicators of FoPA by assessing startle modulation (via EMG at the orbicularis oculi muscle) and heart rate responses (derived from ECG) after affective priming with lexical stimuli of positive, neutral, and negative valence, as well as words related to physical activity as potentially phobic cues. After screening for FoPA in patients with heart failure and healthy adults, twenty participants each were assigned to one of three subsamples: a healthy control group and two cardiac patient groups scoring either low or high on FoPA. The high-FoPA group showed startle potentiation and more pronounced heart rate acceleration (than did controls) in the phobic prime condition, indicating defensive response mobilization. Among the patients, higher FoPA accounted for 30% of the startle potentiation by phobic priming, whereas general anxiety, depression, and disease severity were no significant predictors of startle modulation. These findings suggest that FoPA in patients with heart failure is associated with defensive responses on a physiological level that might be indicative of avoidance behavior, thereby contributing to low adherence to exercise regimen. Thus, FoPA presents a significant target for psychological interventions to foster physical activity in cardiac patients.

Disentangling sensorimotor and cognitive cardioafferent effects: A cardiac-cycle-time study on spatial stimulus-response compatibility.

Cardiac-cycle-time effects are attributed to variations in baroreceptor (BR) activity and have been shown to impinge on subcortical as well as cortical processes. However, cognitive and sensorimotor processes mediating voluntary responses seem to be differentially affected. We sought to disentangle cardiac-cycle-time effects on subcortical and cortical levels as well as sensorimotor and cognitive processes within a spatial stimulus-response-compatibility paradigm employing startling stimuli of different modalities. Air-puffs and white noise-bursts were presented unilaterally during either cardiac systole or diastole while bilateral startle EMG responses were recorded. Modality, laterality and cardiac-cycle-time were randomly varied within-subjects. Cognitive and sensorimotor stimulus-response-compatibility was orthogonally varied between-subjects: Participants (N = 80) responded to the stimuli via left/right button-push made with either the contra- or ipsilateral hand (sensorimotor compatibility) on either the ipsi- or contralateral button (cognitive compatibility). We found that sensorimotor compatible reactions were speeded during systole whereas sensorimotor incompatible ones were prolonged. This effect was independent of cognitive compatibility and restricted to auditory stimuli. Startle was inhibited during systole irrespective of modality or compatibility. Our results demonstrate how differential cardiac-cycle-time effects influence performance in conflict tasks and further suggest that stimulus-response-compatibility paradigms offer a viable method to uncover the complex interactions underlying behavioral BR effects.

Test-retest reproducibility of a combined physical and cognitive stressor.

When studying the factors which influence stress reactivity in within-subject designs, test-retest reproducibility data is needed to estimate power and sample size. We report such data regarding a new experimental stress protocol, based on simultaneous application of the socially evaluated, bilateral feet Cold Pressor Test (CPT) and the Paced Auditory Serial Addition Task (PASAT). Cardiovascular, neuroendocrine, and subjective (affective) stress responses of 32 healthy males were measured twice, at an interval of one week. The novel protocol induced substantial stress reactivity in all parameters at both test and retest. Cardiovascular reactivity remained unchanged, but cortisol and subjective responses were lower at second stress exposure, with high test-retest stability of neuroendocrine (r>.7) and cardiovascular measures (r = .5 to r = .9). PASAT performance improved. Response attenuation suggests habituation-like and/or learning effects. Data provided by our study demonstrate feasibility and power of this stress protocol for investigating changes in stress reactivity in repeated, within-subject designs.

The role of physiological arousal for self-reported emotional empathy.

The capacity to represent the emotional and mental states of others is referred to by the concept of empathy. Empathy further differentiates into an emotional and a cognitive subcomponent, which in turn is known to require a tacit perspective-taking process. However, whether the empathizer by himself needs to enter an affective state as a necessary precondition for emotional empathy remains a matter of debate. If empathy would require a vicarious emotional reaction, specific physiological markers of affective responding should be detectable in the empathizing person. In the present study, we investigated the relationship between self-reported empathy and psychophysiological responses in young, healthy participants. We assessed emotional and cognitive empathy with the Multifaceted Empathy Test on the one hand and the corresponding heart rate and skin conductance responses (SCR), affective startle modulation and heart rate variability on the other. We found a negative relationship between SCR and self-reported emotional empathy: higher SCR to emotional stimuli predicted lower empathy ratings. We conclude that physiological arousal is not necessary and might even diminish empathy for others.

Acute stress enhances pupillary responses to erotic nudes: Evidence for differential effects of sympathetic activation and cortisol.

Chronic stress attenuates reproductive behavior in many species, but evidence regarding the impact of acute stress on human sexual arousability is insufficient. Stressor-specific effects might result from divergent roles of both stress response systems. Social self-threat, linked to affiliation-oriented coping, might also influence sexual responsivity. To investigate stress-induced modulation of the processing of sexual cues and its relationship with cortisol, 58 participants underwent either a predominantly sympathetic stressor (3 min sustained handgrip) or similar control procedure. In both conditions, half of the sample was monitored by an opposite-sex person (social evaluation). Pupillary responses to erotic nudes were recorded and dissociated into fast and slow PCA components. Physically stressed participants showed enhanced (slow) dilation to explicit pictures. Cortisol levels after stress negatively predicted rapid responses to opposite-sex and (marginally) explicit stimuli. Our results suggest that acute sympathetic stress exposure facilitates cognitive sexual processing, whereas subsequent HPA-axis activation may induce counteracting effects.

Blunted endocrine response to a combined physical-cognitive stressor in adults with early life adversity.

The negative health effects of early life adversity (ELA) continue long into adulthood. Changes in the physiological response to psychosocial stressors have been proposed to mediate this effect. However, many previous studies have come to contradicting conclusions as to whether ELA induces a long-term increase or decrease in stress reactivity. Therefore, we tested the association of ELA exposure and adult stress reactivity in a sample of early life adoptees and controls. Two previously validated stressful elements (bilateral feet CPT and the Paced Auditory Serial Addition Task (PASAT)) were combined in an extended Cold Pressor Test (CPT). This test was performed on 22 participants who had experienced severe ELA (separation from biological parents, institutionalization, and adoption in early childhood), and in 22 age-matched control participants. A prior history of ELA was associated with blunted reactivity of the hypothalamic-pituitary-adrenal (HPA) axis (Cohen´s d = 0.680). Cardiovascular reactivity remained unchanged, and affective reactivity (self-report ratings) were increased in participants exposed to ELA compared to the control group (range Cohen´s d: 0.642-0.879). Our results suggest that the activity of the HPA axis reactivity was inhibited in ELA participants. Importantly, cardiovascular stress responsiveness was not affected by ELA. This separation of the HPA axis and cardiovascular stress responses may best be explained by ELA selectively enhancing central feedback-sensitivity to glucocorticoids, but preserving cardiovascular/ autonomic stress reactivity.