Acute dissociation as part of the defense cascade: Associations with behavioral, autonomic, and experiential threat responses in posttraumatic stress disorder.

Dissociative symptoms, such as depersonalization and derealization, are experienced by about half of individuals with posttraumatic stress disorder (PTSD). Theoretical models propose that acute dissociation is accompanied by specific behavioral, physiological, and experiential alterations and contributes to unfavorable PTSD symptom course. Yet, empirical evidence is scarce. Here, we explored associations between dissociative and behavioral, physiological, and experiential threat responses as well as effects of dissociative responding on PTSD symptom course. Individuals with PTSD (N = 71) participated in a preregistered script-driven imagery study including exposure to standardized, detail-enriched trauma, and neutral scripts. Stabilometry, eye-tracking, facial electromyography, autonomic psychophysiology, and self-report data were collected. Moreover, PTSD symptoms were assessed before and 3 months after testing. Analyses did not link acute dissociation to bodily and facial immobility or staring in response to trauma scripts. However, dissociation displayed an inverted U-shaped relationship with heart rate and was linked to higher nonspecific skin conductance fluctuation and higher high-frequency heart rate variability in response to trauma scripts. Moreover, acute dissociation was linked to higher self-reported negative affect responses to trauma scripts and displayed a U-shaped relationship with unfavorable PTSD symptom course. While results did not confirm hypothesized behavioral markers of dissociation, they do support defense-cascade model assumptions of an inverted U-shaped relationship between dissociation and psychophysiological arousal resulting from a progression of parasympathetic versus sympathetic dominance with increasing dissociation. On an experiential level, results did not confirm posttraumatic dissociation-induced emotional numbing, questioning theoretical notions. The observed nonlinear associations may help explain the heterogeneity of prior findings and might inform an updated conceptualization of posttraumatic dissociation. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Psychometric properties of the dissociative subtype of posttraumatic stress disorder scale: replication and extension in two German-speaking samples.

Background: The fifth version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) introduced the dissociative subtype of posttraumatic stress disorder (D-PTSD). To assess this subtype, the Dissociative Subtype of PTSD Scale (DSPS), a 15-item self-report measure to identify lifetime and current dissociative symptoms of D-PTSD, was developed. However, so far, the scale has only been validated in war veterans. Moreover, criterion validity and diagnostic utility have not been examined yet.Objective: We aimed to validate the DSPS in two samples of civilian trauma-exposed German-speaking participants.Methods: In Study 1, a pre-registered online study, participants with and without PTSD symptoms (N = 558) answered questionnaires about traumatic experiences, dissociation, PTSD, depression, generalized anxiety disorder, somatic symptom disorder, alcohol use disorder, absorption, and dissociative responding to trauma-related questionnaires. In Study 2, which used secondary data of a pre-registered clinical study, participants with a PTSD diagnosis (N = 71) answered questionnaires about traumatic experiences, dissociation, PTSD, depression, generalized anxiety disorder, somatic symptom disorder, and dissociative responding to standardized trauma exposure. Moreover, PTSD, D-PTSD, and other diagnoses were assessed with structured clinical interviews.Results: Analyses confirmed a three-factor structure as well as high internal consistency, and high convergent, discriminant, and criterion validity of the DSPS. Moreover, the scale was able to identify a latent D-PTSD group and individuals with D-PTSD diagnosis.Conclusions: The DSPS constitutes a reliable and valid tool to assess D-PTSD symptoms in clinical practice and research and thereby may contribute to a better understanding of these debilitating symptoms.

Many individuals with posttraumatic stress disorder (PTSD) suffer from dissociative symptoms which can be assessed with the Dissociative Subtype of PTSD Scale (DSPS; Wolf et al., 2017).The DSPS demonstrated good psychometric properties in two German-speaking trauma-exposed samples and hence might be used to assess D-PTSD symptoms in research and clinical practice.Complementing the original English version, a German version of the DSPS is provided in the Supplements.

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.

Estradiol during (analogue-)trauma: Risk- or protective factor for intrusive re-experiencing?

Intrusions, a key symptom of posttraumatic stress disorder (PTSD), can occur in the form of images but also as pain sensations. Similar to audiovisual intrusions, the frequency and persistence of pain intrusions varies greatly between individuals. In the current study, we examined whether peritraumatic circulating 17ß-estradiol (E2) levels are a biologic factor associated with subsequent audiovisual (i.e., film) and pain intrusion development, and whether peritraumatic stress levels modulate this relationship. Forty-one free-cycling women participated in an ecologically informed trauma-pain-conditioning (TPC) paradigm, using trauma-films and pain as unconditioned stimuli. Independent variables were salivary peritraumatic E2 levels and stress indexed by salivary cortisol and self-reported state-anxiety during TPC. Outcomes were film- and pain-intrusions occurring during daily-life in the week following TPC and a Memory-Triggering-Task in response to conditioned stimuli 24 h after TPC. In the week after analogue-trauma, higher peritraumatic E2 levels were associated with a greater probability of experiencing film-intrusions in the beginning of the week, which switched to a lower probability toward the end of the week. This time-dependent relationship between E2 and film-intrusions only held for higher state-anxious women. In contrast, results indicated a consistent inverse relationship between peritraumatic E2 levels and pain-intrusions during daily-life and Memory-Triggering-Task. Together, these data suggest that higher peritraumatic E2 levels could be associated with lower long-term visual trauma intrusions, as well as lower pain-intrusions, and thereby possibly constitute a protective biologic factor for PTSD and potentially also for chronic pain.

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 cooccurs with chronic pain. Clinical reports suggest that pain after trauma may be part of re-experiencing symptomatology. Classical conditioning can underlie visual re-experiencing because intrusions can occur as conditioned responses (CRs) to trauma-related cues. If individuals also experience pain to cues previously paired with, but not inflicting nociceptive stimulation anymore (ie, conditioned stimuli, CS), 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 (US) in a 2 (pain/no pain) × 2 (aversive/neutral film) design. Conditioned stimuli were neutral pictures depicting contextual details from the films. One day later, participants were re-exposed to CS during a memory-triggering task (MTT). We assessed pain-CRs by self-report and an fMRI-based marker of nociceptive pain, the neurological pain signature (NPS), and recorded spontaneous daily-life pain intrusions with an e-diary. During conditioning, pain-signaling CS elicited more self-reported pain and NPS responses than no-pain-signaling CS. Possibly because the aversive film masked differences in participants' responses to pain-signaling CS vs no pain-signaling CS, pain-CRs during acquisition were most evident within the neutral film condition. When participants were re-exposed to CS during MTT, self-reported pain-CRs during the neutral film condition and, although more uncertain, NPS-CRs during the aversive film condition persisted. Of importance, participants with stronger pain-CRs showed a greater probability and severity of experiencing spontaneous pain intrusions during daily life. Our data support that spatiotemporally associating innocuous cues with pain (CS) endows these cues to elicit conditioned pain responses in the absence of noxious stimulation. In this way 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 a nociceptive input.

Lifetime adversity interacts with peritraumatic data-driven processing to predict intrusive memories.

BACKGROUND AND OBJECTIVES: Although most trauma survivors experience some intrusive recollections of the traumatic event, only few subsequently develop posttraumatic stress disorder (PTSD). A well-established proximal risk-factor predictive of post-trauma psychopathology is peritraumatic cognitive processing. Another, more distal risk-factor is pre-trauma lifetime adversity. The present experimental analogue study tested the hypothesis that pre-trauma lifetime adversity interacts with peritraumatic perceptual (i.e., data-driven) processing to predict intrusive memory development. METHODS: Fifty-three young adult women (non-clinical sample) indicated how much data-driven and conceptual processing they had engaged in while watching aversive film-clips (i.e., analogue trauma). On the subsequent three days, they reported intrusions of those clips. Moderation analyses tested for an interaction effect between lifetime adversity and data-driven processing in predicting intrusion load (number of intrusions weighted for their overall distress). RESULTS: Increased data-driven processing predicted intrusion load primarily in individuals reporting more than three lifetime adversities, explaining 55% of variance. No such relationship was found for conceptual processing. LIMITATIONS: Present analogue findings have yet to be replicated in a clinical population. Moreover, the conceptual processing scale was restricted by low internal consistency. CONCLUSION: Present findings support the idea that intrusions are the result of poorly elaborated and primarily perceptually-formed memory traces; however, this was primarily the case in vulnerable individuals reporting several lifetime adversities. Results replicate the importance of peritraumatic processing in intrusion development but additionally point to a moderating effect of lifetime adversity.

Peritraumatic dissociation revisited: associations with autonomic activation, facial movements, staring, and intrusion formation.

Background: Peritraumatic dissociation is purported to emerge together with attenuated autonomic arousal, immobility, and staring. However, empirical evidence is scarce and heterogeneous. Moreover, it is still a matter of debate whether these responses predict intrusion formation. Objective: The present trauma-analogue study examined associations between peritraumatic dissociation, autonomic activation, facial movements, staring, and intrusion formation. Method: Seventy-one healthy women watched a highly aversive film, while autonomic activation (heart rate, respiratory sinus arrhythmia, skin conductance level), facial movements (temporal variations in corrugator electromyography), and staring (fixation duration, tracklength) were assessed. Afterwards, participants rated the intensity of dissociation during film viewing and reported intrusions and associated distress in a smartphone application for 24 hours. Results: Peritraumatic dissociation was linked to higher autonomic arousal (higher heart rate and, on a trend-level, lower respiratory sinus arrhythmia), increased facial movements, and staring (lower tracklength). Peritraumatic dissociation, higher autonomic arousal (higher heart rate and lower respiratory sinus arrhythmia), staring (higher fixation duration), and, on a trend-level, more facial movements were linked to higher intrusion load (number x distress of intrusions) and together explained 59% of variance. Skin conductance level was neither linked to peritraumatic dissociation nor intrusion load. Conclusions: Our results suggest that, at low-dissociation-levels observed in trauma-analogue studies, peritraumatic dissociation may occur together with heightened autonomic arousal and facial movements, indexing increased negative affect. Staring might, irrespectively of dissociation-levels, serve as objective marker for dissociation. Together, peritraumatic dissociation and its psychophysiological correlates might set the stage for later intrusion formation.

Antecedentes: Se supone que la disociación peritraumática surge junto con la activación autonómica atenuada, la inmovilidad y la mirada fija. Sin embargo, la evidencia empírica es escasa y heterogénea. Además, sigue siendo objeto de debate si estas respuestas predicen la formación de intrusiones.Objetivo: El presente estudio análogo al trauma examinó las asociaciones entre la disociación peritraumática, la activación autonómica, los movimientos faciales, la mirada fija y la formación de intrusiones.Método: Setenta y una mujeres sanas vieron una película altamente aversiva mientras se evaluaba la activación autonómica (frecuencia cardíaca, arritmia sinusal respiratoria, nivel de conductancia de la piel), los movimientos faciales (variaciones temporales en la electromiografía del corrugador) y la mirada fija (duración de la fijación, longitud del seguimiento). Posteriormente, las participantes calificaron la intensidad de la disociación durante la visualización de la película e informaron sobre las intrusiones y la angustia asociada en una aplicación para teléfonos inteligentes durante 24 horas.Resultados: La disociación peritraumática se relacionó con una mayor activación autonómica (mayor frecuencia cardíaca y, a nivel de tendencia, menor arritmia sinusal respiratoria), mayores movimientos faciales y mirada fija (menor duración del seguimiento). La disociación peritraumática, la mayor activación autonómica (mayor frecuencia cardíaca y menor arritmia sinusal respiratoria), la mirada fija (mayor duración de la fijación) y, en un nivel de tendencia, más movimientos faciales estaban vinculados a una mayor carga de intrusiones (número x angustia de intrusiones) y juntos explicaban el 59% de la varianza. El nivel de conductancia de la piel no se relacionó con la disociación peritraumática ni con la carga de intrusión.Conclusiones: Nuestros resultados sugieren que, a niveles bajos de disociación observados en estudios de trauma análogos, la disociación peritraumática puede ocurrir junto con una mayor activación autonómica y movimientos faciales, lo que indica un aumento del afecto negativo. La mirada fija, independientemente de los niveles de disociación, podría servir como marcador objetivo de disociación. En conjunto, la disociación peritraumática y sus correlatos psicofisiológicos podrían sentar las bases para la formación posterior de intrusiones.

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.

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.

Frequency of Intrusions and Appraisal of Related Distress After Analogue Trauma: A Comparative Ecological Momentary Assessment Methods Study.

Intrusive thoughts, images, and their appraisal remain difficult to study despite their clinical relevance. Clinical studies typically used time-based (frequency and distress per observation period), while analogue studies mainly used event-based (report upon occurrence) assessment. A comparison of intrusion frequency, distress appraisal, compliance, and reactivity across different assessments is mostly lacking, particularly with regard to analogue research. Here, intrusions were induced via aversive films and assessed by a smart phone application for 4 days. Three sampling modes were compared by randomizing participants to one of three conditions: either one, or five time-based daily prompts, or event-based assessment. At the end of the study, all participants reported intrusions once again in a retrospective summary assessment. Results indicate that intrusions and their distress decayed over a few days. The three assessments did not differ in intrusion frequency, distress appraisal, compliance (generally high), reactivity (generally low), or retrospective summary assessment. Across groups, the more aversive and arousing participants rated the film clips and the more reactivity to the electronic-diary assessment they reported, the more intrusive memories they had; assessment modes did not differ on this. Thus, no general differences were found between electronic-diary assessment modes for analogue intrusions, giving researchers flexibility for tailoring ecological momentary assessment to specific study aims.

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.

Suppressing images of desire: Neural correlates of chocolate-related thoughts in high and low trait chocolate cravers.

Chocolate is the most often craved food in Western societies and many individuals try to resist its temptation due to weight concerns. Suppressing chocolate-related thoughts might, however, lead to paradoxical enhancements of these thoughts and this effect might be more pronounced in individuals with frequent chocolate cravings. In the current study, neural and cognitive correlates of chocolate thought suppression were investigated as a function of trait chocolate craving. Specifically, 20 high and 20 low trait chocolate cravers followed suppression vs. free thinking instructions after being exposed to chocolate and neutral images. Enhanced cue reactivity was evident in high trait chocolate cravers in that they reported more chocolate-related thoughts selectively after chocolate images compared to their low trait craving counterparts. This cue reactivity was mirrored neurally by higher activation in the ventral and dorsal striatum, demonstrating enhanced reward system activity. Unexpectedly, high trait chocolate cravers successfully reduced their elevated chocolate thoughts in the suppression condition. This lends support for the use of thought suppression as a means of regulating unwanted thoughts, cravings and imagery. Whether this thought manipulation is able to curb the elevated cue reactivity and the underlying reward sensitivity in chocolate cravers in applied settings remains to be shown.

Neural activity during traumatic film viewing is linked to endogenous estradiol and hormonal contraception.

Women are at higher risk for Posttraumatic Stress Disorder (PTSD) and recent research has highlighted a modulating role of female sex hormones for cognitive and emotional processes potentially underlying PTSD symptoms. However, studies combining fMRI recordings of brain activity during trauma film viewing with assessment of female sex hormones are missing. The trauma film paradigm - a widely used experimental analogue for trauma exposure - confronts healthy participants with traumatic film clips and thus allows studying peritraumatic processing under laboratory conditions. Following this paradigm, the current fMRI study examined the role of endogenous estradiol and synthetic sex hormones for the neural processing of traumatic (i.e., depicting interpersonal violence) vs. neutral films in 53 healthy women (mean age 22.3 years; 23 using hormonal contraception, HC). As predicted, traumatic films strongly activated areas of the fear processing network, such as amygdala, insula, and dorsal anterior cingulate cortex. Estradiol levels in women not using HC were positively correlated with ventromedial prefrontal activity. Furthermore, women using HC as compared to women without HC demonstrated heightened insula and dorsal anterior cingulate cortex activity during traumatic film viewing. These experimental results highlight the effects of both gonadal hormone status and HC intake on peritraumatic processing in neural regions relevant for emotion generation and regulation that have been found to be abnormal in PTSD.

Higher threat avoidance costs reduce avoidance behaviour which in turn promotes fear extinction in humans.

Theoretical models specifying the underlying mechanisms of the development and maintenance of anxiety and related disorders state that fear responses acquired through classical Pavlovian conditioning are maintained by repeated avoidance behaviour; thus, it is assumed that avoidance prevents fear extinction. The present study investigated behavioural avoidance decisions as a function of avoidance costs in a naturalistic fear conditioning paradigm. Ecologically valid avoidance costs - manipulated between participant groups - were represented via time-delays during a detour in a gamified computer task. After differential acquisitions of shock-expectancy to a predictive conditioned stimulus (CS+), participants underwent extinction where they could either take a risky shortcut, while anticipating shock signaled by the CS+, or choose a costly avoidance option (lengthy detour); thus, they were faced with an approach-avoidance conflict. Groups with higher avoidance costs (longer detours) showed lower proportions of avoiders. Avoiders gave heightened shock-expectancy ratings post-extinction, demonstrating 'protecting from extinction', i.e. failure to extinguish. Moreover, there was an indirect effect of avoidance costs on protection from extinction through avoidance behaviour. No moderating role of trait-anxiety was found. Theoretical implications of avoidance behaviour are discussed, considering the involvement of instrumental learning in the maintenance of fear responses.

Criticism hurts everybody, praise only some: Common and specific neural responses to approving and disapproving social-evaluative videos.

Social evaluation is a ubiquitous feature of daily interpersonal interactions and can produce strong positive or negative emotional reactions. While previous research has highlighted neural correlates of static or dynamic facial expressions, little is known about neural processing of more naturalistic social interaction simulations or the modulating role of inter-individual differences such as trait fear of negative/positive evaluation. The present fMRI study investigated neural activity of 37 (21 female) healthy participants while watching videos of posers expressing a range of positive, negative, and neutral statements tapping into several basic and social emotions. Unpleasantness ratings linearly increased in response to positive to neutral to negative videos whereas arousal ratings were elevated in both emotional video conditions. At the whole brain level, medial prefrontal and rostral anterior cingulate cortex activated strongly in both emotional conditions which may be attributed to the cognitive processing demands of responding to complex social evaluation. Region of interest analysis for basic emotion processing areas revealed enhanced amygdala activation in both emotional conditions, whereas anterior and posterior insula showed stronger activity during negative evaluations only. Individuals with high fear of positive evaluation were characterized by increased posterior insula activity during positive videos, suggesting heightened interoception. Taken together, these results replicate and extend studies that used facial expression stimuli and reveal neurobiological systems involved in processing of more complex social-evaluative videos. Results also point to vulnerability factors for social-interaction related psychopathologies.

To eat or not to eat: Effects of food availability on reward system activity during food picture viewing.

Neuroimaging studies have started to explore the role of food characteristics (e.g., calorie-content) and psychological factors (e.g., restrained eating, craving) for the human appetitive system, motivated by the significant health implications of food-choice, overeating and overweight/obesity. However, one key aspect of modern food environments, food availability, especially of high energy foods, has not been adequately modeled in experimental research. Food that is immediately available for consumption could elicit stronger reward system activity and associated cognitive control than food that is not currently available for consumption and this could vary as a function of energy density. To examine this question, 32 healthy participants (16 women) underwent functional magnetic resonance imaging while passively viewing available foods - i.e. foods that could be eaten during and after the experiment - and unavailable foods of either high or low-caloric density in a 2 × 2 design. Available compared to unavailable foods elicited higher palatability ratings as well as stronger neural activation in the orbitofrontal cortex (OFC), amygdala, and left caudate nucleus as well as in the anterior cingulate cortex (ACC) - and thus structures implicated in reward and appetitive motivation as well as cognitive control, respectively. Availability effects in the caudate were mainly attributable to the high calorie condition (availability × calorie density interaction). These neuroimaging results support the contention that foods are particularly rewarding when immediately available and particularly so when high in caloric density. Thus, our results are consistent with health promoting interventions utilizing a nudging approach, i.e. aiming at decreasing accessibility of high calorie and increasing accessibility of low calorie foods in daily life. Results also imply that controlling/manipulating food availability may be an important methodological aspect in neuroscientific eating research.

Intertemporal choice behavior is constrained by brain structure in healthy participants and pathological gamblers.

The steepness of the delay discounting function shows considerable interindividual differences. Moreover, faster devaluation of future rewards has been consistently observed in pathological gamblers (PGs). Here, we asked whether variability in delay discounting is at least partially driven by differences in the anatomy of gray and white matter. For 40 healthy young subjects (study 1) as well as 15 PG and 15 age-matched healthy controls (HCs, study 2), the individual discounting parameter k was obtained. Based on 3D T1-weighted high-resolution magnetic resonance scans and diffusion tensor imaging, we performed voxel-based morphometry and tract-based spatial statistics, respectively, to examine the relation of gray matter volume (GMV) and white matter properties (as indicated by fractional anisotropy, FA) to k. Healthy groups from both studies showed a negative correlation between k and FA for the superior longitudinal fascicle and inferior longitudinal fascicle, whereas a positive correlation was found in the PG group for the inferior longitudinal fascicle and left inferior fronto-occipital fascicle. The latter also was significantly different between HC and PG in the group statistics (albeit on the right side), thus suggesting that this is a significant structure for the development of pathological gambling. GMV of the right frontal orbital cortex, left insular cortex and right lateral occipital cortex showed a positive correlation to k HC (studies 1 and 2) and PG, whereas a negative correlation was found for the left frontal pole in all three groups. Group comparison of GMV (study 2) revealed a decrease in PG for several cortical and subcortical areas.