Updating freeze: Aligning animal and human research

Geraniol mitigates anxiety-like behaviors in rats by reducing oxidative stress, repairing impaired hippocampal neurotransmission, and normalizing brain cortical-EEG wave patterns after a single electric foot-shock exposure

Anxiety-like conditions can interfere with daily activities as the adaptive mechanism fails to cope with stress. These conditions are often linked with increased oxidative stress, and abrupt neurotransmission and electroencephalography (EEG) wave pattern. Geraniol, a monoterpenoid, has antioxidant and anti-inflammatory activities, as well as brain-calming effects. Therefore, in this study, geraniol was tested for the potential anxiolytic effects in a rat model of anxiety. The rats were exposed to an electric foot shock (1 mA for 1 s) to develop anxiety-like symptoms. Treatment was carried out using geraniol (10 and 30 mg/kg) and the standard diazepam drug. The behavior of the rats was analyzed using the open field test, light-dark test, and social interaction test. Afterward, the rats were decapitated to collect samples for neurochemical and biochemical analyses. The cortical-EEG wave pattern was also obtained. The study revealed that the electric foot shock induced anxiety-like symptoms, increased oxidative stress, and altered hippocampal neurotransmitter levels. The power of low-beta and high-beta was amplified with the increased coupling of delta-beta waves in anxiety group. However, the treatment with geraniol and diazepam normalized cortical-EEG wave pattern and hippocampal serotonin and catecholamines profile which was also reflected by reduced anxious behavior and normalized antioxidant levels. The study reports an anxiolytic potential of geraniol, which can be further explored in future.

Heart rate variability and psychological health: The key role of trait emotional awareness

Studies have shown that Trait Emotional Awareness (TEA) - the ability to recognize one's emotions - and Heart Rate Variability (HRV) are both negatively associated with psychological disorders. Although these studies imply that TEA is related to HRV and may explain the association between HRV and psychological disorders, there is limited research investigating this implication. Such investigation is essential to illuminate the psychophysiological processes linked to psychological disorders. The present study aims to investigate a) the association between TEA and HRV, b) the association between HRV and psychological disorders, and c) whether TEA explains the association between HRV and psychological disorders. A sample of 41 German students completed self-report questionnaires as indicators of psychological disorders, including the Hospital Anxiety and Depression Scale (HADS; Snaith & Zigmond, 1983) for anxiousness and depressiveness, as well as the somatization scale of the Hopkins Symptom Checklist (HSCL; Derogatis et al., 1976) for physical complaints. HRV was measured at baseline (resting HRV) and during exposure to a fear-provoking movie clip (reactive HRV). As hypothesized, a) TEA showed a positive association with reactive HRV, b) HRV showed negative associations with anxiousness and physical complaints, and c) TEA explained the relationships between reactive HRV and anxiousness, as well as physical complaints. Contrary to our hypothesis, we did not find any association between HRV and depressiveness. We discussed the contribution of TEA to psychophysiological health, limited generalizability of the current study, and direct future research to explore the underlying mechanisms linking TEA to health.

Pre-trauma memory contextualization as predictor for PTSD-like behavior in male rats

While many people experience potentially threatening events during their life, only a minority develops posttraumatic stress disorder (PTSD). The identification of individuals at risk among those exposed to trauma is crucial for PTSD prevention in the future. Since re-experiencing trauma elements outside of the original trauma-context is a core feature of PTSD, we investigate if the ability to bind memories to their original encoding context (i.e. memory contextualization) predicts PTSD vulnerability. We hypothesize that pre-trauma neutral memory contextualization (under stress) negatively relates to PTSD-like behavior, in a prospective design using the cut-off behavioral criteria rat model for PTSD. 72 male Sprague Dawley rats were divided in two experimental groups to assess the predictive value of 1) memory contextualization without acute stress (NS-group) and 2) memory contextualization during the recovery phase of the acute stress-response (S-group) for susceptibility to PTSD-like behavior. A powerful extension to regression analysis -path analysis-was used to test this specific hypothesis, together with secondary research questions. Following traumatic predator scent stress, 19.4% of the rats displayed PTSD-like behavior. Results showed a negative relation between pre-trauma memory contextualization and PTSD-like behavior, but only in the NS-group. Pre-trauma memory contextualization was positively related to fear association in the trauma environment, again only in the NS group. If the predictive value of pre-trauma contextualization of neutral information under non-stressful conditions for PTSD susceptibility is replicated in prospective studies in humans, this factor would supplement already known vulnerability factors for PTSD and improve the identification of individuals at risk among the trauma exposed, especially those at high trauma risk such as soldiers deployed on a mission.

The impact of attention bias modification training on behavioral and physiological responses

Attention bias modification training aims to alter attentional deployment to symptom-relevant emotionally salient stimuli. Such training has therapeutic applications in the management of disorders including anxiety, depression, addiction and chronic pain. In emotional reactions, attentional biases interact with autonomically-mediated changes in bodily arousal putatively underpinning affective feeling states. Here we examined the impact of attention bias modification training on behavioral and autonomic reactivity. Fifty-eight participants were divided into two groups. A training group (TR) received attention bias modification training to enhance attention to pleasant visual information, while a control group (CT) performed a procedure that did not modify attentional bias. After training, participants performed an evaluation task in which pairs of emotional and neutral images (unpleasant-neutral, pleasant-neutral, neutral-neutral) were presented, while behavioral (eye movements) and autonomic (skin conductance; heart rate) responses were recorded. At the behavioral level, trained participants were faster to orientate attention to pleasant images, and slower to orientate to unpleasant images. At the autonomic level, trained participants showed attenuated skin conductance responses to unpleasant images, while stronger skin conductance responses were generally associated with higher anxiety. These data argue for the use of attentional training to address both the attentional and the physiological sides of emotional responses, appropriate for anxious and depressive symptomatology, characterized by atypical attentional deployment and autonomic reactivity.

Task-related modulation of motor response to emotional bodies: A TMS motor-evoked potential study

Exposure to emotional body postures during perceptual decision-making tasks has been linked to transient suppression of motor reactivity, supporting the monitoring of emotionally relevant information. However, it remains unclear whether this effect occurs implicitly, i.e., when emotional information is irrelevant to the task. To investigate this issue, we used single-pulse transcranial magnetic stimulation (TMS) to assess motor excitability while healthy participants were asked to categorize pictures of body expressions as emotional or neutral (emotion recognition task) or as belonging to a male or a female actor (gender recognition task) while receiving TMS over the motor cortex at 100 and 125 ms after picture onset. Results demonstrated that motor-evoked potentials (MEPs) were reduced for emotional body postures relative to neutral postures during the emotion recognition task. Conversely, MEPs increased for emotional body postures relative to neutral postures during the gender recognition task. These findings indicate that motor inhibition, contingent upon observing emotional body postures, is selectively associated with actively monitoring emotional features. In contrast, observing emotional body postures prompts motor facilitation when task-relevant features are non-emotional. These findings contribute to embodied cognition models that link emotion perception and action tendencies.

Psychophysiological reactions during the trauma-film paradigm and their predictive value for intrusions

Background: Adequate adaptation of the autonomic nervous system (ANS) is crucial in potentially life-threatening situations. The defence cascade provides a descriptive model of progressing dominant physiological reactions in such situations, including cardiovascular parameters and body mobility. The empirical evidence for this model is scarce, and the influence of physiological reactions in this model for predicting trauma-induced intrusions is unresolved.Objectives: Using a trauma-film paradigm, we aimed to test physiological reactions to a highly stressful film as an analogue to a traumatic event along the defence cascade model. We also aimed to examine the predictive power of physiological activity for subsequent intrusive symptoms.Method: Forty-seven healthy female participants watched a stressful and a neutral film in randomized order. Heart rate (HR), heart rate variability (HRV), and body sway were measured. Participants tracked frequency, distress, and quality of subsequent intrusions in a diary for 7 consecutive days.Results: For the stressful film, we observed an initial decrease in HR, followed by an increase, before the HR stabilized at a high level, which was not found during the neutral film. No differences in HRV were observed between the two films. Body sway and trembling frequency were heightened during the stressful film. Neither HR nor HRV predicted subsequent intrusions, whereas perceived distress during the stressful film did.Conclusions: Our results suggest that the physiological trauma-analogue response is characterized by an orientation response and subsequent hyperarousal, reaching a high physiological plateau. In contrast to the assumptions of the defence cascade model, the hyperarousal was not followed by downregulation. Potential explanations are discussed. For trauma-associated intrusions in the subsequent week, psychological distress during the film seems to be more important than physiological distress. Understanding the interaction between physiological and psychological responses during threat informs the study of ANS imbalances in mental disorders such as post-traumatic stress disorder.

Attenuation of visual exploration following stress

When we explore our surroundings, we frequently move our gaze to collect visual information. Studies have extensively examined gaze behavior in response to different visual scenes. Here, we examined how differences in an individual's state may affect visual exploration, for example, following acute stress. In this study, participants were exposed to either a psychosocial stressor-performing a public speaking task in front of a two-person committee-or a control condition absent stress induction. Elicitation of stress responses was validated using cortisol levels and subjective reports. Stress also led to an extended increase in pupil diameter (a proxy of arousal responses), suggesting it may also affect eye movements. Gaze behavior measures were taken prior and following the stress or control tasks. Acute stress attenuated visual exploration, reflected by fewer saccades and a smaller scanned area. Stress did not have a significant effect on either the tendency to look at social features or at salient regions of the images. These findings diverge from theoretical predictions suggesting that acute stress may facilitate social affiliative behaviors (e.g., Tend-and-Befriend theory). Reduced saccades and a smaller scanned area may be a possible mechanism explaining previous reports showing stress-related effects on various cognitive processes (e.g., visual working memory) that rely on visual exploration.

Threat gates visual aversion via theta activity in Tachykinergic neurons

Animals must adapt sensory responses to an ever-changing environment for survival. Such sensory modulation is especially critical in a threatening situation, in which animals often promote aversive responses to, among others, visual stimuli. Recently, threatened Drosophila has been shown to exhibit a defensive internal state. Whether and how threatened Drosophila promotes visual aversion, however, remains elusive. Here we report that mechanical threats to Drosophila transiently gate aversion from an otherwise neutral visual object. We further identified the neuropeptide tachykinin, and a single cluster of neurons expressing it ("Tk-GAL42 ∩ Vglut neurons"), that are responsible for gating visual aversion. Calcium imaging analysis revealed that mechanical threats are encoded in Tk-GAL42 ∩ Vglut neurons as elevated activity. Remarkably, we also discovered that a visual object is encoded in Tk-GAL42 ∩ Vglut neurons as θ oscillation, which is causally linked to visual aversion. Our data reveal how a single cluster of neurons adapt organismal sensory response to a threatening situation through a neuropeptide and a combination of rate/temporal coding schemes.

The relationship between tonic immobility and the development, severity, and course of posttraumatic stress disorder: Systematic and meta-analytic literature review

BACKGROUND

Tonic immobility (TI) is a reflexive, involuntary response that causes motor inhibition, vocal suppression, and analgesia. TI is elicited by extreme fear and perception of entrapment in a life-threatening situation. Research suggests that TI is a frequent peritraumatic response and may be related to subsequent posttraumatic stress disorder (PTSD). However, findings are mixed and, as of yet, no systematic or meta-analytic review examining associations between TI and PTSD has been published.

OBJECTIVE

We systematically and meta-analytically reviewed the literature and investigated whether TI is associated with the development, severity, and course of PTSD. Additionally, we evaluated whether different types of traumatic events are differentially associated with TI, and whether TI severity differs according to sex.

METHODS

A systematic literature search was conducted using Embase, PubMed, PsycINFO, and Scopus. Meta-analyses were performed on the included articles.

RESULTS

We identified 27 eligible articles. We found a significant association between TI and PTSD symptom severity (r = 0.39, 95% CI: 0.34-0.44; p < .0001). TI was more severe among females (Cohen's d=0.37, 95% CI: 0.25-0.48; p < .0001) and was more often elicited in situations involving interpersonal violence. We found limited longitudinal data to perform a meta-analysis of the association between TI and the development and/or course of PTSD. However, the literature available seems to support the role of TI in both the development and course of PTSD.

CONCLUSIONS

Peritraumatic TI is associated with PTSD symptom severity, occurs more often during interpersonal violence, and is more severe among females. More longitudinal research is needed to investigate the role of TI in psychopathology development and course.

Exploring hazard anticipation and stress while driving in light of defensive behavior theory

In driving, poor hazard anticipation would provide drivers less time to prepare an appropriate response, increasing the urgency of the situation and generating more stress. Assuming this, the current study seeks to determine whether a predictable road hazard triggers hazard anticipation in drivers that can mitigate the ensuing stress response, and whether the stress response is influenced by driving experience. In a simulated road environment, a cue was used to trigger hazard anticipation, and a road hazard to induce a stress response. Heart rate, pupil diameter, driving speed, subjective stress, arousal, and negative emotions, were retrieved from 36 drivers who all faced the cue followed by the hazard (i.e. a predictable hazard), the cue only, and the hazard only. In the light of work on defensive behaviors, the findings indicate that a predictable hazard triggers hazard anticipation detectable via (1) freezing behavior-characterized by cardiac deceleration-(2) anticipatory pupil dilation and (3) anticipatory speed deceleration. The results also point to a beneficial role for hazard anticipation in reducing driver stress, as evidenced by reductions in peak heart rate levels, as well as in reported levels of stress and negative emotions. Finally, the findings showed an influence of driving experience on reported levels of stress. Overall, this study shows how previous work on defensive behaviors can be used to gain insight into the processes and driving behaviors involved in hazard anticipation and stress.

Association between baseline dissociation levels and stress-induced state dissociation in patients with posttraumatic-stress disorder, borderline personality disorder, and major depressive disorder

INTRODUCTION

Dissociative symptoms are highly prevalent in patients with trauma-related disorders such as borderline personality disorder (BPD) and posttraumatic-stress disorder (PTSD), and also occur in patients with depressive disorders. Acute dissociative states are theorized to be stress-related, and some individuals experience recurring patterns of dissociation. The relationship between the intensity of dissociative episodes (trait-like dissociation) and acute dissociative states, however, is incompletely understood. In the present study, we investigated how levels of baseline (trait-like) dissociation relate to changes in dissociative states during a laboratory stress induction.

METHODS

Our female sample comprised 65 patients with BPD and/or PTSD, 84 patients with major depressive disorder (MDD) and 44 non-clinical controls (NCC). Baseline dissociation was assessed at the start of the study using the Dissociation Tension Scale past week version (DSS-7). All participants underwent the Trier Social Stress Test (TSST) and a placebo version (P-TSST). Before and after the TSST or P-TSST, state dissociation was assessed using the Dissociation Tension Scale acute (DSS-4). We used structural equation models to estimate changes in state dissociation items (somatoform dissociation, derealization, depersonalization, analgesia), and to test whether these changes relate to levels of baseline dissociation.

RESULTS

We found significant increases in all state dissociation items in response to the TSST in patients with BPD and/or PTSD and patients with MDD, but not in NCCs. Increases in somatoform dissociation and derealization during the TSST were significantly related to higher levels of baseline dissociation in patients with BPD and/or PTSD, but not in patients with MDD or NCCs. Results indicate no significant changes in state dissociation during the P-TSST.

CONCLUSION

Our results replicate earlier findings that patients with BPD and/or PTSD report higher levels of stress-related state dissociation than NCC and extend them to patients with MDD. In addition, our findings indicate that baseline levels of dissociation relate to stress-induced changes in state dissociation among patients with BPD and PTSD, but not patients with MDD. In clinical applications, measures of baseline dissociation could be used to facilitate the prediction and treatment of stress-related dissociative states in patients with BPD and/or PTSD.

Integrated cardio-behavioral responses to threat define defensive states

Fear and anxiety are brain states that evolved to mediate defensive responses to threats. The defense reaction includes multiple interacting behavioral, autonomic and endocrine adjustments, but their integrative nature is poorly understood. In particular, although threat has been associated with various cardiac changes, there is no clear consensus regarding the relevance of these changes for the integrated defense reaction. Here we identify rapid microstates that are associated with specific behaviors and heart rate dynamics, which are affected by long-lasting macrostates and reflect context-dependent threat levels. In addition, we demonstrate that one of the most commonly used defensive behavioral responses-freezing as measured by immobility-is part of an integrated cardio-behavioral microstate mediated by Chx10⁺ neurons in the periaqueductal gray. Our framework for systematic integration of cardiac and behavioral readouts presents the basis for a better understanding of complex neural defensive states and their associated systemic functions.

Physical and social trauma: Towards an integrative transdiagnostic perspective on psychological trauma that involves threats to status and belonging

Current theories of psychological trauma assume that posttraumatic symptoms originate from stress reactions caused by extremely adverse life experiences. Since the diagnosis of PTSD is restricted to events that involve threats to the physical or sexual integrity of a person, such as accidents and physical and sexual violence, these theories are not well suited to explain the psychopathological consequences of severe violations of one's social integrity, such as emotional abuse and bullying. However, it is evident that social threats contribute to a broad range of mental disorders and increase symptom severity in patients with posttraumatic stress disorder. The aim of the Physical and Social Trauma (PAST) framework is to extend current memory theories of psychological trauma to incorporate threats to a person's social integrity. Within this perspective, the harmful effects of events that involve social threats result from violations of core social motives such as the need for status and belonging that bring about intense affective reactions, including despair and defeat. Within associative threat structures, these emotions are tied to the stimulus characteristics of the experiences and can be re-activated in social situations. The resulting psychopathology transcends PTSD criteria and other current classifications and suggests a transdiagnostic perspective of psychological trauma. Implications for treatment and further directions for research are discussed.

Dissociation as a Distinct Peritraumatic Coping Response: A Preliminary Analysis

Research examining physiological responses to trauma cues in PTSD has identified a subset of "nonresponders" showing suppressed physiological reactivity. The defense cascade model posits that individuals respond to stressors by progressing through a series of defensive reactions, with nonresponders having advanced to a shutdown response. It remains unclear whether dissociation is at the end of a continuum of passive behavior, indicating full shutdown, or if it comprises a distinct response. The present study aimed to address this uncertainty, using EFA to compare a two-factor (active, passive) and three-factor (active, passive, dissociative) model of defensive responding. Eighty-nine female physical and sexual assault survivors reported their peritraumatic reactions within 1 month of their assault, which were entered into the EFA. The three-factor model was superior, suggesting dissociation is a distinct category of peritraumatic coping. Peritraumatic use of both passive and dissociative coping strategies were each significantly associated with ongoing use of passive coping and increased PTSD symptoms 1-month posttrauma; surprisingly, the use of passive peritraumatic coping strategies was a better indicator than peritraumatic dissociation. The inclusion of depression as a covariate removed the association of passive (but not dissociative) coping with PTSD symptom severity. Active coping use was not significantly associated with any outcome, suggesting that the presence of shutdown responses is more informative than the presence or absence of any active coping. These findings highlight the importance of differentiating peritraumatic coping responses and the need for increased attention to the comparatively neglected topic of passive coping.

Embodying the avatar of an omnipotent agent modulates the perception of one's own abilities and enhances feelings of invulnerability

Immersive virtual reality can give people the illusion of owning artificial bodies (i.e., avatars) and controlling their actions. Tellingly, people appear to adhere to the newly embodied entities not just on the basis of physical traits but also behaving accordingly with the hallmarks of the represented characters. In two studies we pushed the limits of this process by testing if one's own sense of power could be affected by embodying the anthropomorphic representation of the Christian God, that is considered an omnipotent entity. A human Muscled and a Normotype avatar were used as controls. Results showed that participants embodying the God-avatar: (i) reacted to a threatening event compromising their physical safety by exhibiting a lower skin conductance response and heart rate deceleration compared to the Normotype-control avatar (Study 1); (ii) estimated they had more physical abilities compared to both the Normotype-control and the Muscled-control avatars (Study 2). Taken together, our findings suggest that embodying an omnipotent agent may exert an influence on people's perception of their own limits and capabilities, nourishing feelings of physical invulnerability and strength. Our study indicates that effectively embodying virtual role models may boost achievements and have translational implications in the field of empowerment.

Understanding the roles of central and autonomic activity during sleep in the improvement of working memory and episodic memory

The last decade has seen significant progress in identifying sleep mechanisms that support cognition. Most of these studies focus on the link between electrophysiological events of the central nervous system during sleep and improvements in different cognitive domains, while the dynamic shifts of the autonomic nervous system across sleep have been largely overlooked. Recent studies, however, have identified significant contributions of autonomic inputs during sleep to cognition. Yet, there remain considerable gaps in understanding how central and autonomic systems work together during sleep to facilitate cognitive improvement. In this article we examine the evidence for the independent and interactive roles of central and autonomic activities during sleep and wake in cognitive processing. We specifically focus on the prefrontal-subcortical structures supporting working memory and mechanisms underlying the formation of hippocampal-dependent episodic memory. Our Slow Oscillation Switch Model identifies separate and competing underlying mechanisms supporting the two memory domains at the synaptic, systems, and behavioral levels. We propose that sleep is a competitive arena in which both memory domains vie for limited resources, experimentally demonstrated when boosting one system leads to a functional trade-off in electrophysiological and behavioral outcomes. As these findings inevitably lead to further questions, we suggest areas of future research to better understand how the brain and body interact to support a wide range of cognitive domains during a single sleep episode.

Don't Panic: Remaining El Capitan While Navigating Unpreparedness in Response to Extreme Events

Company leaders are frequently confronted with highly uncertain and risky situations for which they are often ill-prepared, and consequently, in which they often panic. Based on an exploratory case study of extreme rock climber Alexander Honnold, we have developed propositions that help decision-makers to learn to avoid panic in crises. Our findings suggest that gradual exposure to incrementally more challenging tasks by adjusting individual learning goals allows decision-makers to leverage existing skills, and to develop their physical, mental and emotional states simultaneously. Deliberate confrontation with the challenges that may trigger panic through real-life simulation and imagination helps decision-makers to retrain and transform triggers for panic responses, and to build systemic confidence. This organic and holistic growth provides decision-makers with the simultaneous preparation and mastery of their physical, mental, and emotional states to ensure the lightness and calmness necessary not to panic when facing a crisis.

Effects of a Novel Gel Formulation of Dog Appeasing Pheromone (DAP) on Behavioral and Physiological Stress Responses in Dogs Undergoing Clinical Examination

Simple Summary

Safeguarding the health of dogs presupposes undergoing regular veterinary visits (VVs). However, the VV can be emotionally challenging, thus impairing the welfare of the patient, also reducing dog and owner compliance. The fear and anxiety experienced by the dogs evokes behavioral and physiological stress responses for adaptive purposes. It is therefore desirable to lower the stress from the visit. With this intent, we tested a gel formulation of a synthetic analogue of the appeasing pheromone secreted by bitches, the dog appeasing pheromone (DAP), as a situational support to improve the perception of the stay in the waiting room and the physical examination. In the waiting room, the dogs exposed to DAP exhibited changes in their behavior, namely significant decrease in lip licking, increase in panting, and nearly significant reduction of low body postures. On the examination table, neither behavioral nor physiological differences were found. DAP did not alter markedly the stress behavior and physiology of dogs during a VV, maybe due to a stress level exceeding the potential efficacy of the product. However, the change of a few stress-associated behaviors suggests that DAP could contribute to improving the welfare of dogs staying in the waiting room before the physical examination.

Abstract

The veterinary visit is necessary for safeguarding the health of dogs, but it can be stressful and threaten both the welfare of the patient and the accuracy of the examination. This randomized, triple-blind, placebo-controlled, crossover study aims at evaluating how dog appeasing pheromone (DAP) in a novel gel formulation influences the behavioral and physiological stress responses of 28 dogs undergoing a standardized clinical examination, while staying in the waiting room (WR) and visited in the examination room (ER). Behavioral responses were studied through behavioral categories and subjective scales (WR and ER). Autonomic response considered heart rate (WR and ER), blood pressure (WR and ER), respiratory rate (ER), and rectal temperature (ER). Neuroendocrine response considered salivary cortisol (WR and ER). In the waiting room, the use of DAP was associated with a significant reduction of lip licking (p = 0.0189), an increase in panting (p = 0.0276), and a reduction close to significance (p = 0.0584) of low body postures. No significant differences were observed within the physiological responses. In the examination room, neither behavioral nor physiological differences were found.

Socioeconomic status in early adolescence predicts blunted stress responses in adulthood

Individuals who grow up in families with lower socioeconomic status (SES) tend to experience disproportionate rates of chronic stress. The “freeze” response, characterized by blunted cardiovascular reactivity and reduced engagement with the environment, is associated with chronic stress and may be utilized when an individual is unable to escape or overcome environmental stressors. Using a diverse community sample of 184 adolescents followed from the age of 13 to 29 years, along with their friends and romantic partners, this study examined links between family SES and stress responses in adulthood. Low family SES at the age of 13 years directly predicted blunted heart rate responding and fewer attempts to answer math problems during a modified version of the Trier Social Stress Task at the age of 29 years. Indirect effects were found from low family SES to blunted respiratory sinus arrhythmia responding and the number of words spoken during a speech task. SES at the age of 29 years mediated many of these relations. Findings held after accounting for a number of potential confounds, including adolescent academic and attachment functioning and body mass index. We interpret these findings as evidence that low familial SES may predict freezing‐type responses in adulthood.

Acute stress affects peripersonal space representation in cortisol stress responders

Peripersonal space is the representation of the space near the body. It is implemented by a dedicated multisensory-motor network, whose purpose is to predict and plan interactions with the environment, and which can vary depending on environmental circumstances. Here, we investigated the effect on the PPS representation of an experimentally induced stress response and compared it to a control, non-stressful, manipulation. We assessed PPS representation in healthy humans, before and after a stressful manipulation, by quantifying visuotactile interactions as a function of the distance from the body, while monitoring salivary cortisol concentration. While PPS representation was not significantly different between the control and experimental group, a relation between cortisol response and changes in PPS emerged within the experimental group. Participants who showed a cortisol stress response presented enhanced visuotactile integration for stimuli close to the body and reduced for far stimuli. Conversely, individuals with a less pronounced cortisol response showed a reduced difference in visuotactile integration between the near and the far space. In our interpretation, physiological stress resulted in a freezing-like response, where multisensory-motor resources are allocated only to the area immediately surrounding the body.

The gene environment aetiology of freezing and its relationship with internalizing symptoms during adolescence

Background

The freezing response is a universal response to threat, linked to attentive immobility and action preparation. It is relevant for acute stress coping in animals and humans, and subtle deviations in toddler freezing duration (absence of, or excessively long reactions) have been linked to higher risk for internalizing symptoms in adolescence. Yet, while individual freezing tendencies are relatively stable throughout life, little is known about their gene-environment aetiology.

Methods

We investigated the heritability of toddler freezing in the Quebec Newborn Twin Study (QNTS; n=508 twins) by fitting behavioural genetic models to video-coded freezing responses during a robot confrontation. Furthermore, we examined the predictive associations between toddler freezing and internalizing symptoms (anxiety and depressive symptoms), as they unfold during adolescence (ages 12–19 years) using linear mixed-effects models.

Findings

Freezing was found to be moderately heritable (45% of the variance accounted for by genetic factors). The remaining variance was explained by unique environmental factors, including measurement error. No significant contribution of shared environmental factors was noted. Additionally, shorter freezing was associated with more internalizing symptoms in adolescence at trend level, a pattern that was significant for depressive but not anxiety symptoms.

Interpretation

Freezing is an adaptive coping mechanism in early childhood, which is partly driven by genetic factors. Crucially, the absence or shorter duration of these behaviours may signal vulnerability to depressive problems later in life.

Funding

Canadian Institutes of Health Research and Research Fund of Quebec–Health and Society and Culture. Consolidator grant from the European Research Council (ERC_CoG-2017_772337).

Freezing revisited: coordinated autonomic and central optimization of threat coping

Animals have sophisticated mechanisms for coping with danger. Freezing is a unique state that, upon threat detection, allows evidence to be gathered, response possibilities to be previsioned and preparations to be made for worst-case fight or flight. We propose that - rather than reflecting a passive fear state - the particular somatic and cognitive characteristics of freezing help to conceal overt responses, while optimizing sensory processing and action preparation. Critical for these functions are the neurotransmitters noradrenaline and acetylcholine, which modulate neural information processing and also control the sympathetic and parasympathetic branches of the autonomic nervous system. However, the interactions between autonomic systems and the brain during freezing, and the way in which they jointly coordinate responses, remain incompletely explored. We review the joint actions of these systems and offer a novel computational framework to describe their temporally harmonized integration. This reconceptualization of freezing has implications for its role in decision-making under threat and for psychopathology.

Brain Reactions to Opening and Closing the Eyes: Salivary Cortisol and Functional Connectivity

This study empirically assessed the strength and duration of short-term effects induced by brain reactions to closing/opening the eyes on a few well-known resting-state networks. We also examined the association between these reactions and subjects’ cortisol levels. A total of 55 young adults underwent 8-min resting-state fMRI (rs-fMRI) scans under 4-min eyes-closed and 4-min eyes-open conditions. Saliva samples were collected from 25 of the 55 subjects before and after the fMRI sessions and assayed for cortisol levels. Our empirical results indicate that when the subjects were relaxed with their eyes closed, the effect of opening the eyes on conventional resting-state networks (e.g., default-mode, frontal-parietal, and saliency networks) lasted for roughly 60-s, during which we observed a short-term increase in activity in rs-fMRI time courses. Moreover, brain reactions to opening the eyes had a pronounced effect on time courses in the temporo-parietal lobes and limbic structures, both of which presented a prolonged decrease in activity. After controlling for demographic factors, we observed a significantly positive correlation between pre-scan cortisol levels and connectivity in the limbic structures under both conditions. Under the eyes-closed condition, the temporo-parietal lobes presented significant connectivity to limbic structures and a significantly positive correlation with pre-scan cortisol levels. Future research on rs-fMRI could consider the eyes-closed condition when probing resting-state connectivity and its neuroendocrine correlates, such as cortisol levels. It also appears that abrupt instructions to open the eyes while the subject is resting quietly with eyes closed could be used to probe brain reactivity to aversive stimuli in the ventral hippocampus and other limbic structures.

Adaptation of Threat Responses Within the Negative Valence Framework

External threats are a major source of our experience of negatively valanced emotion. As a threat becomes closer and more real, our specific behavior patterns and our experiences of negative affect change in response to the perceived imminence of threat. Recognizing this, the National Institute of Mental Health's Research Domain Criteria (RDoC) Negative Valence system is largely based around different levels of threat imminence. This perspective describes the correspondence between the RDoC Negative Valence System and a particular neurobiological/neuroecological model of reactions to threat, the Predatory Imminence Continuum (PIC) Theory. Using the COVID-19 pandemic as an illustration, we describe both adaptive and maladaptive behavior patterns from this perspective to illustrate how behavior in response to a crisis may get shaped. We end with suggestions on how further consideration of the PIC suggests potential modifications of the negative valence systems RDoC.

Involvement of nitric oxide in the neurobiology of fear-like behavior

Fear is an emotional reaction that arises in dangerous situations, inducing the adaptation to an existing condition. This behavior was conserved in all vertebrates throughout evolution and is observed in mammals, birds, fish, amphibians, and reptiles. The neurocircuitry of fear involves areas of the limbic system, cortical regions, midbrain, and brainstem. These areas communicate with each other so that there is an expression of fear and memory formation to deal with the same situation at another time. The effect of nitric oxide (NO) on fear modulation has been explored. NO is a gaseous compound that easily diffuses through the cell membrane and is produced through the oxidation reaction of l-Arginine to l-citrulline catalyzed by nitric oxide synthase (NOS). Activating the intracellular NO receptor (soluble guanylyl cyclase enzyme - sGC) triggers an enzymatic cascade that can culminate in plastic events in the neuron. NOS inhibitors induce anxiolytic-like responses in fear modulation, whereas NO donors promote fear- and anxiety-like behaviors. This review describes the neurobiology of fear in mammals and non-mammals, how NO is produced in the central nervous system, and how NO acts in fear-like behavior.

The Embodiment of Insult: A Theory of Biobehavioral Response to Workplace Incivility

This article builds a broad theory to explain how people respond, both biologically and behaviorally, when targeted with incivility in organizations. Central to our theorizing is a multifaceted framework that yields four quadrants of target response: reciprocation, retreat, relationship repair, and recruitment of support. We advance the novel argument that these behaviors not only stem from biological change within the body but also stimulate such change. Behavioral responses that revolve around affiliation and produce positive social connections are most likely to bring biological benefits. However, social and cultural features of an organization can stand in the way of affiliation, especially for employees holding marginalized identities. When incivility persists over time and employees lack access to the resources needed to recover, we theorize, downstream consequences can include harms to their physical health. Like other aspects of organizational life, this biobehavioral theory of incivility response is anything but simple. But it may help explain how seemingly "small" insults can sometimes have large effects, ultimately undermining workforce well-being. It may also suggest novel sites for incivility intervention, focusing on the relational and inclusive side of work. The overarching goal of this article is to motivate new science on workplace incivility, new knowledge, and ultimately, new solutions.

When ancestry haunts – can evolutionary links to ancestors affect vulnerability of Australian prey to introduced predators? A preliminary study

The high extinction risk of Australian marsupials has been attributed to their failure to recognise novel predators, the application of inappropriate antipredator responses, and advanced hunting strategies of novel predators. This study is a preliminary attempt to explore whether the Lumholtz’ tree-kangaroo (Dendrolagus lumholtzi) (a) is able to recognise odour cues from different predators as threats, and (b) possesses predator-archetype specific antipredator responses. A small number of available captive tree-kangaroos were exposed to faecal odours from two extant predators of different archetypes (python, dingo), a regionally extinct predator which closely matches past terrestrial predators (Tasmanian devil), and a novel predator (domestic dog). Lavender oil was used as non-predator novel odour and water as control. Results suggest that all subjects associated the presented odours with a threat, albeit to different degrees, but did not display predator-archetype specific responses. It appears that this species applies an ancestral antipredator response of flight-on-the ground when encountering predators, including novel predators. Although the results need to be confirmed with more animals, further studies on the vulnerability of Australian prey to novel predators should take the ancestral history of Australian prey species into account.

Trauma-related dissociation and the autonomic nervous system: a systematic literature review of psychophysiological correlates of dissociative experiencing in PTSD patients

Background: Neurophysiological models link dissociation (e.g. feeling detached during or after a traumatic event) to hypoarousal. It is currently assumed that the initial passive reaction to a threat may coincide with a blunted autonomic response, which constitutes the dissociative subtype of post-traumatic stress disorder (PTSD). Objective: Within this systematic review we summarize research which evaluates autonomic nervous system activation (e.g. heart rate, blood pressure) and dissociation in PTSD patients to discern the validity of current neurophysiological models of trauma-related hypoarousal. Method: Of 553 screened articles, 28 studies (N = 1300 subjects) investigating the physiological response to stress provocation or trauma-related interventions were included in the final analysis. Results: No clear trend exists across all measured physiological markers in trauma-related dissociation. Extracted results are inconsistent, in part due to high heterogeneity in experimental methodology. Conclusion: The current review is unable to provide robust evidence that peri- and post-traumatic dissociation are associated with hypoarousal, questioning the validity of distinct psychophysiological profiles in PTSD.

Postural freezing relates to startle potentiation in a human fear-conditioning paradigm

Freezing to impending threat is a core defensive response. It has been studied primarily using fear conditioning in non-human animals, thwarting advances in translational human anxiety research that has used other indices, such as skin conductance responses. Here we examine postural freezing as a human conditioning index for translational anxiety research. We employed a mixed cued/contextual fear-conditioning paradigm where one context signals the occurrence of the US upon the presentation of the CS, and another context signals that the CS is not followed by the US. Critically, during the following generalization phase, the CS is presented in a third and novel context. We show that human freezing is highly sensitive to fear conditioning, generalizes to ambiguous contexts, and amplifies with threat imminence. Intriguingly, stronger parasympathetically driven freezing under threat, but not sympathetically mediated skin conductance, predicts subsequent startle magnitude. These results demonstrate that humans show fear-conditioned animal-like freezing responses, known to aid in active preparation for unexpected attack, and that freezing captures real-life anxiety expression. Conditioned freezing offers a promising new, non-invasive, and continuous, readout for human fear conditioning, paving the way for future translational studies into human fear and anxiety.

Fear balance is maintained by bodily feedback to the insular cortex in mice

[Figure: see text].

The Paradox of Fiction Revisited-Improvised Fictional and Real-Life Social Rejections Evoke Associated and Relatively Similar Psychophysiological Responses

Theatre-based practices, such as improvisation, are frequently applied to simulate everyday social interactions. Although the improvisational context is acknowledged as fictional, realistic emotions may emerge, a phenomenon labelled the 'paradox of fiction'. This study investigated how manipulating the context (real-life versus fictional) modulates psychophysiological reactivity to social rejection during dyadic interactions. We measured psychophysiological responses elicited during real-life (interview) and fictional (improvisation exercises) social rejections. We analysed the heart rate (HR), skin conductance, facial muscle activity, and electrocortical activity (electroencephalographic (EEG) alpha asymmetry) of student teachers (N = 39) during various social rejections (devaluing, interrupting, nonverbal rejection). All social rejections evoked negative EEG alpha asymmetry, a measure reflecting behavioural withdrawal motivation. Psychophysiological responses during real-life and fictional rejections correlated, and rejection type modified the responses. When comparing responses across all rejection types, facial muscle activity and EEG alpha asymmetry did not differ between real-life and fictional rejections, whereas HR decelerated and skin conductance increased during fictional rejections. These findings demonstrate that regardless of cognitive awareness of fictionality, relatively subtle social rejections elicited psychophysiological reactivity indicating emotional arousal and negative valence. These findings provide novel, biological evidence for the application of theatre-based improvisation to studying experientially everyday social encounters.

Human defensive freezing: Associations with hair cortisol and trait anxiety

The anticipation of threat facilitates innate defensive behaviours including freezing reactions. Freezing in humans is characterised by reductions in body sway and heart rate. Limited evidence suggests that individual differences in freezing reactions are associated with predictors of anxiety-related psychopathology including trait anxiety and hypothalamic-pituitary-adrenal (HPA) axis activity. However, previous human studies focused on acutely circulating cortisol levels, leaving the link between freezing and more stable, individual trait markers of HPA axis activity unclear. We investigated whether individual differences in anticipatory freezing reactions are predicted by accumulated hair cortisol concentrations (HCC) and trait anxiety, in a well-powered mixed sample of police recruits at the start of the police training, and age, sex and education matched controls (total N = 419, mean age = 24, N_women = 106, N_{police recruits} = 337). Freezing-related reactions were assessed with posturographic and heart rate measurements during an active shooting task under threat of shock. The anticipation of threat of shock elicited the expected reductions in body sway and heart rate, indicative of human freezing. Individual differences in threat-related reductions in body sway, but not heart rate, were related to lower HCC and higher trait anxiety. The observed links between postural freezing and predictors of anxiety-related psychopathology suggest the potential value of defensive freezing as a somatic marker for individual differences in stress-vulnerability and resilience. DATA AVAILABILITY: The datasets analysed during the current study are available from the corresponding authors upon reasonable request.

Dissociation and emotion regulation strategies: A meta-analytic review

OBJECTIVE

Clinical and neurobiological models posited that dissociative mechanisms might affect processes involved in emotional generation and regulation. However, there is a lack of a comprehensive theoretical framework that systematically includes dissociation within emotional functioning.

METHODS

The current study aims at conducting a meta-analytic review on the relationship between dissociation and emotion regulation in order to empirically estimate to what extent dissociation is related to emotion regulation processes. The meta-analysis was based on r coefficient as effect size measure, using a random-effect approach.

RESULTS

The meta-analysis included 57 independent studies for a total of 11596 individuals. Findings showed an overall moderate relationship between dissociation and emotion regulation (r_w = .32; p < .05). The association between dissociation and emotion regulation was the same among clinical samples than non-clinical ones. Furthermore, dissociation showed moderate to large relationships with maladaptive domains of emotion regulation, namely disengagement (r_w = 0.34; p < .01) (i.e., behavioral avoidance, experiential avoidance, thought and emotional suppression) and aversive cognitive perseveration (r_w = 0.38; p < .001) (i.e., rumination, worry and nonacceptance). The analysis did not find significant relationship between dissociation and adaptive domain of emotional regulation (i.e., problem solving, mindfulness).

CONCLUSION

Dissociation in the context of emotion regulation might be viewed as a basic neuro-mental mechanism that automatically contribute to the over-modulation of emotional states through avoidance reactions from internal and external reality. Future longitudinal studies are needed to clarify the causal relationships between dissociation and emotion regulation.

Threat induces cardiac and metabolic changes that negatively impact survival in flies

Adjusting to a dynamic environment involves fast changes in the body’s internal state, characterized by coordinated alterations in brain activity and physiological and motor responses. Threat-induced defensive states are a classic case of coordinated adjustment of bodily responses, cardiac regulation being one of the best characterized examples in vertebrates. A great deal is known regarding the neural basis of invertebrate defensive behaviors, mainly in Drosophila melanogaster. However, whether physiological changes accompany these remains unknown. Here, we set out to describe the internal bodily state of fruit flies upon an inescapable threat and found cardiac acceleration during running and deceleration during freezing. In addition, we found that freezing leads to increased cardiac pumping from the abdomen toward the head-thorax, suggesting mobilization of energy resources. Concordantly, threat-triggered freezing reduces sugar levels in the hemolymph and renders flies less resistant to starvation. The cardiac responses observed during freezing were absent during spontaneous immobility, underscoring the active nature of freezing response. Finally, we show that baseline cardiac activity predicts the amount of freezing upon threat. This work reveals a remarkable similarity with the cardiac responses of vertebrates, suggesting an evolutionarily convergent defensive state in flies. Our findings are at odds with the widespread view that cardiac deceleration while freezing has first evolved in vertebrates and that it is energy sparing. Investigating the physiological changes coupled to defensive behaviors in the fruit fly has revealed that freezing is costly yet accompanied by cardiac deceleration and points to heart activity as a key modulator of defensive behaviors.

•

Flies show tight coupling between defensive behaviors and cardiac activity

•

Flies bias cardiac pumping toward the head and thorax during defensive behaviors

•

After prolonged freezing, sugar levels and resistance to starvation are decreased

•

Cardiac reversal rate and rate variability are predictive of freezing intensity

Human-Animal Interaction and Perinatal Mental Health: A Narrative Review of Selected Literature and Call for Research

There is a paucity of research exploring how relationships with household pets may impact maternal mental health. We are unaware of any study to date that has examined associations between individuals' relationships with their pets and psychological adjustment in the perinatal period. Using a biobehavioral lens, this paper provides a narrative overview of the literature on perinatal mental health and human-animal interaction (HAI). We focus on the role of social relationships, stress, and stress reduction in relation to perinatal mental health; the role of HAI in perceptions of social support, stressors, and stress reduction; and gaps in empirical knowledge concerning the role of HAI in perinatal mental health. Finally, we integrate contemporary biobehavioral models of perinatal mental health and HAI (i.e., Comprehensive Model of Mental Health during the Perinatal Period and the HAI-HPA Transactional Model) to propose a new conceptual framework that depicts ways in which HAI during the perinatal period may influence maternal and child health and wellbeing. To our knowledge, this is the first paper to consider the role of HAI in biobehavioral responses and mental health during the perinatal period. We conclude with recommendations for future research and improved perinatal care.

Binge ethanol consumption-associated behavioral impairments in male mice using a gelatin-based drinking-in-the dark model

BACKGROUND

Acute intoxication caused by binge ethanol drinking is linked to widespread impairments in brain functions. Various alcohol administration paradigms have been used in animals to model the heterogeneous clinical manifestation of intoxication in people. It is challenging to model a procedure that produces "visible intoxication" in rodents; however, manipulation of variables such as route of alcohol administration, time of availability, frequency, and duration and amount of ethanol exposure has achieved some success. In the current study, we employed a modified drinking-in-the-dark model to assess the validity of this model in producing "post-ethanol consumption intoxication" impairments following prolonged repeated daily voluntary "binge" ethanol consumption.

METHODS

Adult male C57BL/6J mice were allowed a daily 3-h access to non-alcoholic plain or ethanol-containing gel during the dark cycle for a total of 83 days. After the initial 2-month daily DID, ethanol intake patterns were intensely characterized during the next 3 weeks. Immediately following the last DID session (day 83), plain and ethanol gel-consuming mice were then subjected to behavioral tests of locomotor ability and/or anxiety (cylinder, wire grip, open field) followed by blood ethanol concentration measurement.

RESULT

Mice exhibited a relatively consistent ethanol consumption pattern during and across daily access periods. Ethanol intake of individual mice positively correlated with blood ethanol concentration that averaged 61.64 ± 2.84 mg/dL (n = 12). Compared to the plain gel-consuming control mice, ethanol gel mice exhibited significant locomotor impairment as well as anxiety-like behavior, with the magnitude of impairments of key indices well correlated with blood ethanol levels.

CONCLUSION

The gelatin vehicle-based voluntary ethanol drinking-in-the-dark model reliably produced post consumption acute movement impairments as well as anxiety-like behaviors even after 2 months of daily binge ethanol consumption in male mice. Taken together, this mouse binge ethanol model should facilitate the investigation of mechanisms of binge drinking in subjects chronically abusing ethanol and the search for effective novel treatment strategies.

Old Fears Die Hard: Return of Public Speaking Fear in a Virtual Reality Procedure

Exposure-based therapy is an effective treatment for social anxiety, but some patients relapse. We used a novel virtual reality procedure to examine spontaneous recovery (i.e., a return of fear over time) and fear renewal (i.e., the return of fear after a context switch) in individuals with fear of public speaking. On Day 1, 32 participants received exposure training before a virtual audience. On Day 8, participants completed a spontaneous recovery phase, followed by a fear renewal test, in which they gave a presentation in front of a new (context switch) or the same audience (no context switch). After exposure, participants exhibited a lower heart rate, subjective distress, negative valence, and arousal. One week later, participants showed spontaneous recovery of heart rate, and the context switch group showed renewal of subjective distress, negative valence, and arousal. Future studies can use this procedure to test interventions aimed at improving long-term exposure effects in individuals with public speaking fear.

On the physiology of interruption after unexpectedness

We tested whether surprise elicits similar physiological changes as those associated with orienting and freezing after threat, as surprise also involves a state of interruption and attention for effective action. Moreover, because surprise is primarily driven by the unexpectedness of an event, initial physiological responses were predicted to be similar for positive, neutral, and negative surprises. Results of repetition-change studies (4 + 1 in Supplemental Materials) showed that surprise lowers heart rate (Experiments 1-4) and increases blood pressure (Experiment 4). No effects on body movement (Experiment 2) or finger temperature (Experiment 4) were found. When unexpected stimuli were presented more often (making them less surprising) heart rate returned to baseline, while blood pressure remained high (Experiment 4). These effects were not influenced by stimulus valence. However, second-to-second analyses within the first (surprising) block showed a tendency for a stronger increase in systolic blood pressure after negative vs. positive surprise.

Saccadic scanpath length: an index for human threat conditioning

Threat-conditioned cues are thought to capture overt attention in a bottom-up process. Quantification of this phenomenon typically relies on cue competition paradigms. Here, we sought to exploit gaze patterns during exclusive presentation of a visual conditioned stimulus, in order to quantify human threat conditioning. To this end, we capitalized on a summary statistic of visual search during CS presentation, scanpath length. During a simple delayed threat conditioning paradigm with full-screen monochrome conditioned stimuli (CS), we observed shorter scanpath length during CS+ compared to CS- presentation. Retrodictive validity, i.e., effect size to distinguish CS+ and CS-, was maximized by considering a 2-s time window before US onset. Taking into account the shape of the scan speed response resulted in similar retrodictive validity. The mechanism underlying shorter scanpath length appeared to be longer fixation duration and more fixation on the screen center during CS+ relative to CS- presentation. These findings were replicated in a second experiment with similar setup, and further confirmed in a third experiment using full-screen patterns as CS. This experiment included an extinction session during which scanpath differences appeared to extinguish. In a fourth experiment with auditory CS and instruction to fixate screen center, no scanpath length differences were observed. In conclusion, our study suggests scanpath length as a visual search summary statistic, which may be used as complementary measure to quantify threat conditioning with retrodictive validity similar to that of skin conductance responses.

"I just became like a log of wood … I was paralyzed all over my body": women's lived experiences of tonic immobility following rape

Tonic immobility is considered the last involuntary self-protecting act/mechanism experienced by victims of rape when they are under attack. It is associated with trauma related mental health risks post-rape. Despite this, tonic immobility has not received priority as an area of research on Nigerian female victims of rape. As a result, little has been known about this phenomenon by nurses and other professionals who are involved in the care and management of rape survivors in Nigeria. The limited knowledge about tonic immobility as a phenomenon might have resulted in mismanagement and secondary victimization of rape victims experiencing manifestations suggestive of tonic immobility during or after rape. This study was a qualitative narrative inquiry that explored, analysed, and interpreted the lived experiences suggestive of tonic immobility, and the meaning attached to such experiences by victims. A sample of fourteen Nigerian women who self-identified as rape victims was utilized. Individual semi-structured, in-depth interviews were conducted to generate data. Thematic data analysis revealed four overarching themes: namely (i) Tonic immobility as an Altered Physical State, (ii) Tonic Immobility as Mental Paralysis, (iii) Painful Loss of Self-defence, and (iv) Constant Self-blame. The findings provided an insight into the traumatic experience of raped women and the psychological implication of tonic immobility as extreme defence mechanism. This study will prove invaluable to nurses and other professionals/stakeholders involved in the care and management of rape victims; to help them develop and use appropriate strategies for management and prevention of secondary victimisation.

Defensive freezing and its relation to approach-avoidance decision-making under threat

Successful responding to acutely threatening situations requires adequate approach-avoidance decisions. However, it is unclear how threat-induced states-like freezing-related bradycardia-impact the weighing of the potential outcomes of such value-based decisions. Insight into the underlying computations is essential, not only to improve our models of decision-making but also to improve interventions for maladaptive decisions, for instance in anxiety patients and first-responders who frequently have to make decisions under acute threat. Forty-two participants made passive and active approach-avoidance decisions under threat-of-shock when confronted with mixed outcome-prospects (i.e., varying money and shock amounts). Choice behavior was best predicted by a model including individual action-tendencies and bradycardia, beyond the subjective value of the outcome. Moreover, threat-related bradycardia (high-vs-low threat) interacted with subjective value, depending on the action-context (passive-vs-active). Specifically, in action-contexts incongruent with participants' intrinsic action-tendencies, stronger bradycardia related to diminished effects of subjective value on choice across participants. These findings illustrate the relevance of testing approach-avoidance decisions in relatively ecologically valid conditions of acute and primarily reinforced threat. These mechanistic insights into approach-avoidance conflict-resolution may inspire biofeedback-related techniques to optimize decision-making under threat. Critically, the findings demonstrate the relevance of incorporating internal psychophysiological states and external action-contexts into models of approach-avoidance decision-making.

Kinematic changes in goal-directed movements in a fear-conditioning paradigm

In individuals with a musculoskeletal disorder, goal-directed reaching movements of the hand are distorted. Here, we investigated a pain-related fear-conditioning effect on motor control. Twenty healthy participants (11 women and 9 men, 21.7 ± 2.7 years) performed a hand-reaching movement task. In the acquisition phase, a painful electrocutaneous stimulus was applied on the reaching hand simultaneous with the completion of reaching. In the subsequent extinction phase, the task context was the same but the painful stimulus was omitted. We divided the kinematic data of the hand-reaching movements into acceleration and deceleration periods based on the movement-velocity characteristics, and the duration of each period indicated the degree of impairment in the feedforward and feedback motor controls. We assessed the wavelet coherence between electromyograms of the triceps and biceps brachii muscles. In the acquisition phase, the durations of painful movements were significantly longer in both the acceleration and deceleration periods. In the extinction phase, painful movements were longer only in the acceleration period and higher pain expectation and fear were maintained. Similarly, the wavelet coherence of muscles in both periods were decreased in both the acquisition and extinction phases. These results indicate that negative emotional modulations might explain the altered motor functions observed in pain patients.

Response Processes to Looming Appetitive and Aversive Cues in Euthymic Bipolar Patients and Their First-Degree Relatives: An Exploratory Study

BACKGROUND

Patients with bipolar disorder demonstrate increased sensitivity to appetitive/rewarding stimuli even during euthymia. On presentation of arousing pictures, they show a peculiar response, suggesting heightened vigilance. While responding to looming arousing cues, studies show subjects with anxiety spectrum disorders exhibit increased reaction time (RT), explained by the "looming-vulnerability model." This study aimed to investigate the responses to looming arousing cues in euthymic bipolar patients and their first-degree relatives, as compared to healthy controls.

METHOD

A looming appetitive and aversive cue paradigm was designed for assessing the RT of patients to process appetitive and aversive cues. The behavioral inhibition/activation and sensitivity to reward/punishment amongst the groups were also assessed.

RESULTS

The bipolar group showed significantly longer RT to process appetitive cues irrespective of the looming condition. Aversive cues elicited significantly longer RT in both the bipolar group and in first-degree relatives, but only when presented with the looming condition. Significant looming bias was elicited in the bipolar group which suggested a particular cognitive style to looming cues. A composite measure of RT along with sensitivity to reward/punishment distinguishes the bipolar group and their first-degree relatives from the healthy controls.

CONCLUSION

The looming vulnerability model may provide important insights for future exploration of cognitive endophenotypes in bipolar disorder.

Growing points in attachment disorganization: looking back to advance forward

In this special issue paper we reflect on the next generation of attachment research with a focus on disorganization, a central but still poorly understood topic in this area. We suggest that progress will be facilitated by a return to attachment theory's evolutionary roots, and to the emphasis on biological function that inspired Bowlby's original thinking. Increased interdisciplinary cross-fertilization and collaborations would enable novel and generative research on some of the long-standing questions surrounding attachment disorganization. Accordingly, we present an agenda for future research that encompasses contributions of modern ethology and neurobiology, novel hypotheses based on the concept of adaptive decanalization, connections with neurodevelopmental vulnerability and risk for mental disorders such as schizophrenia, and the possibility of sex differences in the behavioral manifestations of attachment disorganization. We believe that these avenues of theory and research offer exciting potential for innovative work in attachment disorganization in the years ahead.

The dissociative subtype of posttraumatic stress disorder is associated with subcortical white matter network alterations

Posttraumatic stress disorder (PTSD) is characterized by intrusions, avoidance, and hyperarousal while patients of the dissociative subtype (PTSD-D) experience additional dissociative symptoms. A neurobiological model proposes hyper-inhibition of limbic structures mediated by prefrontal cortices to underlie dissociation in PTSD. Here, we tested whether functional alterations in fronto-limbic circuits are underpinned by white matter network abnormalities on a network level. 23 women with PTSD-D and 19 women with classic PTSD participated. We employed deterministic diffusion tractography and graph theoretical analyses. Mean fractional anisotropy (FA) was chosen as a network weight and group differences assessed using network-based statistics. No significant white matter network alterations comprising both frontal and limbic structures in PTSD-D relative to classic PTSD were found. A subsequent whole brain exploratory analysis revealed relative FA alterations in PTSD-D in two subcortical networks, comprising connections between the left amygdala, hippocampus, and thalamus as well as links between the left ventral diencephalon, putamen, and pallidum, respectively. Dissociative symptom severity in the PTSD-D group correlated with FA values within both networks. Our findings suggest fronto-limbic inhibition in PTSD-D may present a dynamic neural process, which is not hard-wired via white matter tracts. Our exploratory results point towards altered fiber tract communication in a limbic-thalamic circuit, which may underlie (a) an initial strong emotional reaction to trauma reminders before conscious regulatory processes are enabled and (b) deficits in early sensory processing. In addition, aberrant structural connectivity in low-level motor regions may present neural correlates for dissociation as a passive threat-response.

Approach-Avoidance Decisions Under Threat: The Role of Autonomic Psychophysiological States

Acutely challenging or threatening situations frequently require approach-avoidance decisions. Acute threat triggers fast autonomic changes that prepare the body to freeze, fight or flee. However, such autonomic changes may also influence subsequent instrumental approach-avoidance decisions. Since defensive bodily states are often not considered in value-based decision-making models, it remains unclear how they influence the decision-making process. Here, we aim to bridge this gap by discussing the existing literature on the potential role of threat-induced bodily states on decision making and provide a new neurocomputational framework explaining how these effects can facilitate or bias approach-avoid decisions under threat. Theoretical accounts have stated that threat-induced parasympathetic activity is involved in information gathering and decision making. Parasympathetic dominance over sympathetic activity is particularly seen during threat-anticipatory freezing, an evolutionarily conserved response to threat demonstrated across species and characterized by immobility and bradycardia. Although this state of freezing has been linked to altered information processing and action preparation, a full theoretical treatment of the interactions with value-based decision making has not yet been achieved. Our neural framework, which we term the Threat State/Value Integration (TSI) Model, will illustrate how threat-induced bodily states may impact valuation of competing incentives at three stages of the decision-making process, namely at threat evaluation, integration of rewards and threats, and action initiation. Additionally, because altered parasympathetic activity and decision biases have been shown in anxious populations, we will end with discussing how biases in this system can lead to characteristic patterns of avoidance seen in anxiety-related disorders, motivating future pre-clinical and clinical research.

A Preliminary Exploration of Behaviours Associated with Negative Urgency in Individuals High and Low in Chronic Worry

While chronic worry is typically associated with cautious and harm-avoidant behaviours, there is evidence that people high in chronic worry are characterised by negative urgency (NU), that is, the propensity to act rashly when experiencing negative affect. The present study was a preliminary examination of how rash action and impulsive decision-making manifest for chronic worriers compared to individuals low in worry. In total, 93 participants who endorsed high and low worry and NU responded to open-ended questions about their experience of NU on Amazon Mechanical Turk. Themes were identified using a data-driven approach. Participants high in chronic worry endorsed significantly greater NU compared to those low in worry. However, the types of NU behaviours were similar across participants, with a majority of responses involving initiating interpersonal conflict. Other themes included spending money, excessive eating, alcohol use, and aggressive behaviours. The manifestations of NU were largely consistent with those described in the model of NU. Although individuals higher in chronic worry engaged in NU behaviours to a greater extent, the types of behaviours were similar to those reported by people lower in worry. More research is needed to understand the characteristics of NU-motivated behaviour in individuals high in chronic worry.