Tonic immobility as an evolved predator defense: Implications for sexual assault survivors

Tonic Immobility as a Defensive Trauma Response to Rape: Bridging Public Health and Law

There is widespread scientific evidence that validates tonic immobility (TI) as part of the trauma response in victims of rape, and criminal justice practitioners are increasingly trained in trauma-informed approaches. Yet, legal and policy definitions of consent do not fully recognize TI during the incident as evidence of nonconsent. Using a systematic review of U.S. law and policy regarding sexual violence and consent, this paper analyzes the substantial legal reform of rape law and definitions of consent, suggesting ways to further integrate TI into existing law and legal practices to improve public health approaches and justice responses for victims.

Using shame to extend Martin Conway's self-memory system

We extend Conway's self-memory system by adding theory and data from shame, an emotion that disrupts the internalised ideals of society needed for a positive self-concept. The event that caused 273 undergraduates their greatest amount of shame was analyzed; 66% were not very negative except for producing shame. Ratings of post-event effects, including two measure of self (self-perceived weakness, and centrality to identity) and four clinical symptoms (intrusions, avoidance, anxiety, and depression), were attributed separately to the remembered event, behaviour during the event, and shame from the event. The effects of shame were generally as large as the those of the event and larger than those of the behaviour, demonstrating the importance of shame's effects. The Tonic Immobility Scale (TIS), which measures tonic immobility (i.e., freezing), was obtained for the event that produced the most tonic immobility but that was not the event that caused the most shame. The post-event symptoms measured on the event that caused the most shame and the TIS correlated highly, suggesting that shame and tonic immobility may belong to a cluster of phylogenetically conserved submissive defensive mechanisms that could account for effects currently attributed to goals in self-memory systems.

The Reality of Tonic Immobility in Victims of Sexual Violence: "I was Paralyzed, I Couldn't Move"

Tonic immobility (TI) is a state of temporary, involuntary motor inhibition that occurs in states of intense fear and has been studied among victims of sexual violence. Studies on TI are scarce and mainly focus on rape victims. The present study is a literature review of research that has examined TI in women victims of sexual violence. A database search was carried out using the Preferred data elements for systematic reviews and meta-analyses (PRISMA) method. In order to be included in the analysis, the manuscripts had to deal exclusively with research involving samples of subjects and the study analyzed TI in victims of sexual violence. In all, 11 manuscripts met the above criteria and were included in the review. Research describes that TI is characterized by two factors: fear and immobility. Quantitative research was conclusive in affirming the presence of a state of paralysis and fear in TI. The immobility factor is the determining factor in explaining the victim's lack of defense or resistance and causes effects such as trembling, physical and mental paralysis, inability to vocalize, and eye closure. In addition, TI has been correlated with long-term negative clinical manifestations as victims are more likely to suffer from post-traumatic stress disorder. These findings contribute to an understanding of TI in victims of sexual violence. Therefore, legal and care practitioners must be able to recognize TI to understand the victim's behavior, differentiate it from consent, and to be able to assist in their recovery.

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.

Why We Need a Developmentally Appropriate Trauma Diagnosis for Children: a 10-Year Update on Developmental Trauma Disorder

Developmental Trauma Disorder (DTD) was proposed almost two decades ago as a psychiatric diagnosis for children who have been traumatically victimized and whose attachment bonding with primary caregivers has been compromised. DTD was designed to complement and extend post-traumatic stress disorder (PTSD) by addressing forms of trauma-related biopsychosocial dysregulation not included in PTSD, many of which are attributed to other psychiatric disorders. In the past decade, evidence from clinician surveys and research field trial studies has provided evidence of DTD's validity and potential clinical utility. The growing evidence base for DTD is summarized and clinical rationales for the proposed DTD symptoms are described. DTD shows promise as a developmentally-attuned traumatic stress diagnosis for traumatized children.

Tonic immobility (freezing) during sexual and physical assaults produces stronger memory effects than other characteristics of the assaults

Tonic immobility (TI) is a phylogenetically conserved, passive, obligatory defense mechanism commonly engaged during sexual and physical assaults. During TI, people become immobile while remaining conscious and later reexperience intrusive memories of both their assault and of its accompanying immobility. Here we show that this well-studied biological process has powerful effects on memory and other processes. Participants had experienced either a serious sexual (n = 234) or physical (n = 137) assault. For both the assault and its accompanying immobility, the standard measure of the peritraumatic severity of TI correlated between .40 and .65 with post-assault effects on memory, including memory of the assault and memory of the immobility, the two memory-based self-concept measures of self-blame and event centrality, and post-assault anxiety and depression. The correlations with TI were much higher than other peritraumatic characteristics commonly used to predict and describe posttraumatic effects in assaults and other traumas. The results suggest that TI should be considered for a broader, more biologically based and ecologically valid understanding of the effects of trauma on memory and memory-based reactions.

Induced Coma, Death, and Organ Transplantation: A Physiologic, Genetic, and Theological Perspective

In the clinic, the death certificate is issued if brain electrical activity is no longer detectable. However, recent research has shown that in model organisms and humans, gene activity continues for at least 96 h postmortem. The discovery that many genes are still working up to 48 h after death questions our definition of death and has implications for organ transplants and forensics. If genes can be active up to 48 h after death, is the person technically still alive at that point? We discovered a very interesting parallel between genes that were upregulated in the brain after death and genes upregulated in the brains that were subjected to medically-induced coma, including transcripts involved in neurotransmission, proteasomal degradation, apoptosis, inflammation, and most interestingly, cancer. Since these genes are involved in cellular proliferation, their activation after death could represent the cellular reaction to escape mortality and raises the question of organ viability and genetics used for transplantation after death. One factor limiting the organ availability for transplantation is religious belief. However, more recently, organ donation for the benefit of humans in need has been seen as “posthumous giving of organs and tissues can be a manifestation of love spreading also to the other side of death”.

Peri-Traumatic Dissociation and Tonic Immobility as Severity Predictors of Posttraumatic Stress Disorder After Rape

Some individuals show abnormal reactions to extreme fear and life-threatening situations, including tonic immobility (TI) and peri-traumatic dissociation (PTD). We aimed to investigate the association of TI and PTD with posttraumatic stress disorder (PTSD) in women who experienced sexual violence and the risk factors for PTD occurrence. We compared PTSD severity in 86 young adult women with PTSD after a sexual violence exposure grouped according to the presence of PTD and TI. In addition, we investigated whether PTD is associated with depression and anxiety symptoms and assessed potential risk factors for PTD reaction. We found a significant positive correlation between PTSD severity and PTD occurrence (R² = .132; p = .001). PTD was also positively correlated with all clusters of PTSD symptoms except the Clinician-Administered PTSD Scale avoidance cluster (p = .058). PTD was strongly correlated with anxiety (R² = .619; p < .001) and depressive symptoms (R² = .547; p < .001). Multiple logistic regression showed that history of physical abuse (odds ratio [OR]: 1.386; p = .011) and sexual abuse (OR: 1.947; p = .004) during childhood were associated with PTD occurrence. Other risk factors for PTD were having less years of study (OR: 0.216; p = .016) and lower income (OR: 7.403; p = .028). TI measures were available for a subsample of 29 women. We found no association between TI and PTSD severity. PTD, but not TI, is significantly associated with more severe PTSD, depressive, and anxiety symptoms. Less-educated women with a history of childhood abuse and a lower income are at risk of PTD occurrence during a sexual violence episode.

Peritraumatic physical symptoms and the clinical trajectory of PTSD after a terrorist attack: a network model approach

Introduction: Following a mass casualty event, such as the Paris terrorist attacks of 13 November 2015, first responders need to identify individuals at risk of PTSD. Physical peritraumatic symptoms involving the autonomic nervous system may be useful in this task.Objective: We sought to determine the trajectory of physical response intensity in individuals exposed to the Paris terrorist attacks using repeated measures, and to examine its associations with PTSD. Using network modelling, we examined whether peritraumatic physical symptom associations differed by PTSD status.Methods: Physical reactions were assessed using the Subjective Physical Reactions Scale at three time points: peritraumatic by retrospective recall, then current at one year (8-18 months) and three years (30-42 months) after the attacks. Interaction networks between peritraumatic physical reactions were compared according to PTSD status.Results: On the one hand, the reported intensity of physical reactions was significantly higher in the PTSD group at all time points. On the other hand, using the dynamic approach, more robust positive interactions between peritraumatic physical reactions were found in the PTSD group one and three years after the attacks. Negative interactions were found in the no-PTSD group at one year. Peritraumatic physical numbness was found to be the most central network symptom in the PTSD group, whereas it was least central in the no-PTSD group.Discussion: Network analysis of the interaction between peritraumatic physical subjective responses, particularly physical numbness, may provide insight into the clinical course of PTSD. Our knowledge of the brain regions involved in dissociation supports the hypothesis that the periaqueductal grey may contribute to the process leading to physical numbing.Conclusions: Our findings highlight the role of peritraumatic somatic symptoms in the course of PTSD. Peritraumatic physical numbness appears to be a key marker of PTSD and its identification may help to improve early triage.

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.

What Stops Unwanted Sexual and Social Advances Made by Heavy Drinking College Men?

Although rates of sexual aggression are high among college men who engage in heavy drinking, little is known regarding how often heavy drinking college men initiate unwanted sexual advances towards women that could lead to a potential sexual assault or the reasons why these advances stop or proceed. The present study describes heavy drinking college men's (N = 210) initiation of unwanted sexual and social advances towards women, as well as outcomes of these interactions, including how often these behaviors continue, and men's perception of what stopped the behavior over a 3-month period. Men indicated whether they were in a situation where a sexual partner noted that she does not want sexual activity to proceed further, initiated unwanted sexual contact, initiated unwanted sexual intercourse, attempted to give a woman alcohol when she did not appear to want to drink, or attempted to take a woman to an isolated location when she did not appear to want to go. These unwanted sexual and social advances most often stopped because of women's verbal resistance (i.e., saying "stop" or "no"), or because men engaged in a discussion regarding the women's limits or choices. Given that none of the unwanted sexual or social advances stopped because of bystander intervention, the present study highlights the importance of raising awareness of the effectiveness of women's resistance tactics and continuing to train bystanders to notice and take action to address risky situations.

The brain-body disconnect: A somatic sensory basis for trauma-related disorders

Although the manifestation of trauma in the body is a phenomenon well-endorsed by clinicians and traumatized individuals, the neurobiological underpinnings of this manifestation remain unclear. The notion of somatic sensory processing, which encompasses vestibular and somatosensory processing and relates to the sensory systems concerned with how the physical body exists in and relates to physical space, is introduced as a major contributor to overall regulatory, social-emotional, and self-referential functioning. From a phylogenetically and ontogenetically informed perspective, trauma-related symptomology is conceptualized to be grounded in brainstem-level somatic sensory processing dysfunction and its cascading influences on physiological arousal modulation, affect regulation, and higher-order capacities. Lastly, we introduce a novel hierarchical model bridging somatic sensory processes with limbic and neocortical mechanisms regulating an individual's emotional experience and sense of a relational, agentive self. This model provides a working framework for the neurobiologically informed assessment and treatment of trauma-related conditions from a somatic sensory processing perspective.

Gender Equitable Attitudes, Rape Myth Acceptance, and Perceived Peer Approval of Violence as Correlates of High School Boys' Intention to Garner Sexual Consent

The current study examines correlates of high school boys' intentions to garner consent in a future sexual encounter (N = 816). Bivariate correlation analyses demonstrated that increased intention to garner sexual consent was negatively correlated with rape myth acceptance and perceived peer acceptance of violence, and positively correlated with gender equitable attitudes. In multivariate linear regression analyses, perceived peer acceptance of violence and gender equitable attitudes remained significant in relation to intentions to garner sexual consent. Specifically, boys who reported a greater likelihood of perceiving their peers as accepting of violence and a lower likelihood of holding gender equitable attitudes also reported a lower likelihood to garner sexual consent. These findings highlight the importance of developing sexual assault prevention programs for high school boys that address the complex relationships between perceived peer norms, harmful gender role expectancies, and risk for sexual aggression. Results from this study also add to the existing literature on sexual consent communication in adolescents.

A Qualitative Analysis of Sexual Consent among Heavy-drinking College Men

The current study sought to examine how heavy-drinking college men describe communication of sexual interest and sexual consent. Thematic analysis of semi-structured interviews with 12 heavy-drinking college men identified three themes. Themes included: (a) expectations about parties and sexual activity, (b) observing and communicating sexual interest, and (c) communication of sexual consent. Men reported visiting drinking environments to locate women who they assumed would be open to sexual advances. In these environments, sexual interest was inferred indirectly through shared alcohol use. Anticipating token resistance men reported "trying and trying again" to pursue escalating types of sexual activity. Consent was inferred when participants did not hear "no" from a sexual partner, highlighting the importance of continued education on verbal consent in the context of sexual assault prevention programs.

"If Only I Could Have Stopped It": Reflections of Adult Child Sexual Abuse Survivors on Their Responses During the Abuse

Child sexual abuse (CSA) has received much research attention in recent years, leading to the considerable development of services provided for children worldwide. The literature in the field of trauma studies recognizes that responses to trauma are of central importance and mainly discusses the fight-flight-freeze model of automatic responses to traumatic events. For a variety of reasons, research on this specific subject in the field of CSA is sparse. The current study was designed to spotlight the way adults perceive their responses during incidents of CSA. Semistructured interviews were carried out with 20 survivors who described their responses. The results pointed to the irrelevance of "fight or flight" responses in the context of CSA and emphasized compliance, avoidance, and simply surviving the abuse. In addition, the survivors shared the thoughts they had had during the abusive incidents. Specifically, while they understood that what was being done to them was wrong, they also realized that there was little they could do other than try to survive. The survivors' reflections on how their responses to CSA affected their negative self-attributions and on the way they contend with difficult incidents in adulthood suggest the central role played by CSA responses. The findings point to the multifaceted nature of responses to CSA and to the urgent need to further examine them by exploring other relevant contexts and perceptions to develop a theoretical model that will address responses to child abuse and inform both prevention and intervention efforts.

Children's Responses to Maltreatment: Key Conclusions From a Systematic Literature Review

Child maltreatment (CM) has received much research attention in recent years, leading to the enormous development of services provided to children worldwide. However, although the literature in the field of trauma studies recognizes that responses to trauma are of central importance, for a variety of reasons, the research on this subject is sparse. The current systematic literature review was therefore designed to characterize and analyze the existing knowledge on children's responses to CM, while putting in focus all possible responses that will appear in the identified manuscripts. Key databases were explored using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and only six studies were identified as relevant to the focus of the current study. Utilizing thematic analysis, the results addressed four main themes: the studies' methodologies, the terminology and responses that were explored in these studies, the abuse-related factors and contexts that were taken into account, and the consequences for the children (of their responses to the maltreatment). A key conclusion from this review is that concepts in this area, as well as theory, are considerably lacking. Promoting the development of theory regarding children's responses to CM is urgently needed, as it will greatly impact clinical intervention, legal investigation, and the development of prevention programs.

Internal State: Dynamic, Interconnected Communication Loops Distributed Across Body, Brain, and Time

Internal state profoundly alters perception and behavior. For example, a starved fly may approach and consume foods that it would otherwise find undesirable. A socially engaged newt may remain engaged in the presence of a predator, whereas a solitary newt would otherwise attempt to escape. Yet, the definition of internal state is fluid and ill-defined. As an interdisciplinary group of scholars spanning five career stages (from undergraduate to full professor) and six academic institutions, we came together in an attempt to provide an operational definition of internal state that could be useful in understanding the behavior and the function of nervous systems, at timescales relevant to the individual. In this perspective, we propose to define internal state through an integrative framework centered on dynamic and interconnected communication loops within and between the body and the brain. This framework is informed by a synthesis of historical and contemporary paradigms used by neurobiologists, ethologists, physiologists, and endocrinologists. We view internal state as composed of both spatially distributed networks (body-brain communication loops), and temporally distributed mechanisms that weave together neural circuits, physiology, and behavior. Given the wide spatial and temporal scales at which internal state operates-and therefore the broad range of scales at which it could be defined-we choose to anchor our definition in the body. Here we focus on studies that highlight body-to-brain signaling; body represented in endocrine signaling, and brain represented in sensory signaling. This integrative framework of internal state potentially unites the disparate paradigms often used by scientists grappling with body-brain interactions. We invite others to join us as we examine approaches and question assumptions to study the underlying mechanisms and temporal dynamics of internal state.

The evolutionary origin of near-death experiences: a systematic investigation

Near-death experiences are known from all parts of the world, various times and numerous cultural backgrounds. This universality suggests that near-death experiences may have a biological origin and purpose. Adhering to a preregistered protocol, we investigate the hypothesis that thanatosis, aka death-feigning, a last-resort defense mechanism in animals, is the evolutionary origin of near-death experiences. We first show that thanatosis is a highly preserved survival strategy occurring at all major nodes in a cladogram ranging from insects to humans. We then show that humans under attack by animal, human and ‘modern’ predators can experience both thanatosis and near-death experiences, and we further show that the phenomenology and the effects of the two overlap. In summary, we build a line of evidence suggesting that thanatosis is the evolutionary foundation of near-death experiences and that their shared biological purpose is the benefit of survival. We propose that the acquisition of language enabled humans to transform these events from relatively stereotyped death-feigning under predatory attacks into the rich perceptions that form near-death experiences and extend to non-predatory situations.

Rape and social death

Rape that does not involve life-threatening physical violence, is committed by someone known to the victim, and is not reported to law enforcement (called, here, commonplace rape) raises two questions: “Why didn't she fight back or run away?” and “Why didn't she say anything at the time?” Recently, research on “tonic immobility,” based on animal predation studies, has provided a physiological explanation for experiences of immobilization during sexual assault. The juxtaposition of animal predation with commonplace sexual assault raises the question: How is it that a response reserved, in animals, for lethal, no-way-out scenarios is present in modes of violation where the victim does not report fear of death or extreme physical harm? Neither does this research help explain why women fail to report. This philosophical exploration of the meaning of tonic immobility in sexual assault helps to justify the juxtaposition of life-or-death scenarios with less-than-life-threatening violation, and sheds light on the reason for women's silence after sexual assault. Rape is accompanied by deep historical meanings that can be encapsulated in the notion of “social death,” associated in the U.S. with colonial conquest, enslavement, and impoverishment. The specter of social death haunts commonplace rape, producing life or death responses.

Beyond fight, flight, and freeze: Towards a new conceptualization of peritraumatic responses to child sexual abuse based on retrospective accounts of adult survivors

BACKGROUND

Child sexual abuse (CSA) studies have greatly contributed to theory, policy, and practice worldwide. Surprisingly, although trauma studies in particular have highlighted the importance of peritraumatic responses to trauma, this aspect is underdeveloped in the context of child abuse studies.

OBJECTIVE

The current study profiles the peritraumatic responses of children to abuse, based on adults' retrospective accounts of their childhood experiences.

PARTICIPANTS & METHODS

180 adults who retrospectively reported having been sexually abused in childhood completed a questionnaire that included four categories of common peritraumatic responses to CSA: automatic, behavioral, cognitive and affective.

RESULTS

Latent class analysis revealed a number of classes in each of the questionnaire's four categories. Within each, classes were identified and the relationships within and between them, as well as with abuse characteristics were explored.

CONCLUSIONS

Existing theory with respect to peritraumatic responses to trauma, and to CSA in particular, should be reconsidered based on the multifaceted model proposed in the current study. The findings point to a previously unrecognized peritraumatic response to trauma: numbness and seeking ways to survive ongoing abuse. Finally, recommendations are provided for incorporating the current model in both prevention and intervention efforts in the CSA field.

Are memories of sexual trauma fragmented?

Alarmingly high rates of sexual assault on campus have motivated American colleges and universities to take steps to address this serious problem. Yet university administrators have often felt ill-equipped to assess allegations of sexual assault. Unsurprisingly, they have sought the expertise of psychologists who can educate administrative staff about the complexities of traumatic memory. Dr. Rebecca Campbell is among the most influential figures teaching university administrators about sexual trauma and memory. The purpose of this article is to review research pertinent to her views on fragmentation of traumatic memories, and the possible roles of tonic immobility and alcohol consumption on how survivors of sexual assault recall their experience.

Feelings, Thoughts, and Behaviors During Disaster

Thoughts, feelings, and behaviors during traumatic events, that is, peritraumatic reactions, are key to post-trauma psychopathology development. Qualitative research is required to investigate whether existing quantitative methods capture the range and complexity of peritraumatic reactions as described by survivors. Semi-structured interviews were conducted with 104 earthquake survivors. Participants reported experiencing various peritraumatic reactions (M = 21, range = 6-43). The survivors' accounts confirmed presence and overall phenomenological characteristics of commonly studied peritraumatic reactions such as dissociation, distress, mental defeat, and immobility. In addition, novel and understudied reactions were identified: cognitive overload, hyperfocus, and emotion regulation, as well as positive affect. Finally, a number of cross-cutting phenomena were identified such as the social nature of many reactions and survivors evaluating their reactions as difficult to put into words. These findings have implications for the conceptualization of peritraumatic reactions, for trauma-focused psychotherapeutic interventions, and for the wellbeing of disaster survivors.

Coronavirus Anxiety Scale: A New Instrument to Measure Anxiety Symptoms Associated with COVID-19

Background: The purpose of this study was to adapt and validate the Coronavirus Anxiety Scale in a sample of Hispanic residents in Puerto Rico. This instrument is a brief mental health screening to identify anxiety symptoms associated with COVID-19. Method: An availability sampling and a sample of 327 Spanish-speaking participants were used. Results: Psychometric analyses confirmed that the scale has a one-dimensional structure and solid reliability (Ω = .93) and validity. The five items met fair discrimination values, demonstrating that the instrument can distinguish between people with anxiety symptoms associated with COVID-19 and those without symptoms. According to the analyses performed, the cut-off points to identify significant symptoms of coronavirus anxiety was ≥ 10. The prevalence of significant symptoms of coronavirus anxiety was 15.29% (n = 50). Conclusions: These results support the scale as a useful and valid tool for clinical research and practice.

Maladaptive Alterations of Defensive Response Following Developmental Complex Stress in Rats

Objective

Despite the etiological significance of complex developmental trauma in adult personality disorders and treatment-resistant depression, neurobiological studies have been rare due to the lack of useful animal models. As a first step, we devised an animal model to investigate the effects of multiple trauma-like stress during different developmental periods.

Methods

Twenty-one male Sprague-Dawley rats were classified into 3 groups based on the stress protocol: fear conditioning control (FCC, n = 6), complex stress (ComS, n = 9), and control (n = 6). While the ComS experienced three types of stress (maternal separation, juvenile isolation, electric foot shock), the FCC only experienced an electric foot shock stress and the control never experienced any. We compared fear responses at postnatal day (PND) 29 and PND 56 through freezing time per episode (FTpE), total freezing time (TFT), total freezing episodes (TFE), and ultrasonic vocalization (USV).

Results

ComS showed the longest FTpE in the conditioned fear response test. ComS and FCC exhibited the longer TFT and these two groups only displayed USV. ComS show difference TFE between PND 29 and PND 56.

Conclusion

The results of this investigation show that complex stress may affect not quantity of fear response but characteristics of fear response. Longer FTpE may be associated with tonic immobility which could be considered as a failed self-protective reaction and might be analogous to a sign of inappropriate coping strategy and self-dysregulation in complex trauma patients.

Acute and Post-Traumatic Stress Disorders: A biased nervous system

Acute stress disorder and post-traumatic stress disorder are generally triggered by an exceptionally intense threat. The consequences of this traumatogenic situation are explored here in chronological order, from exposure to the threat to development of symptoms. Such a situation may disrupt the equilibrium between two fundamental brain circuits, referred to as the "defensive" and "cognitive". The defensive circuit triggers the stress response as well as the formation of implicit memory. The cognitive circuit triggers the voluntary response and the formation of explicit autobiographical memory. During a traumatogenic situation, the defensive circuit could be over-activated while cognitive circuit is under-activated. In the most severe cases, overactivation of the defensive circuit may cause its brutal deactivation, resulting in dissociation. Here, we address the underlying neurobiological mechanisms at every scale: from neurons to behaviors, providing a detailed explanatory model of trauma.

No way to run or hide: Children's perceptions of their responses during intrafamilial child sexual abuse

BACKGROUND

Child maltreatment (CM) has received much research attention in recent years, leading to substantial development of relevant child services worldwide. The literature on posttraumatic stress accentuates the long-term mental and physical ramifications of peritraumatic responses. However, although CM is considered a traumatic experience, examinations of child responses to CM have rarely been attempted.

OBJECTIVE

The current study spotlights children's responses during intrafamilial child sexual abuse (IFCSA), as conveyed by them during forensic interviews.

PARTICIPANTS AND SETTING

The sample is comprised of 40 transcripts of forensic interviews with children aged 4-14, who have been sexually abused by their fathers.

METHODS

The exploration of the children's responses to the abuse was guided by the grounded theory approach and their narratives were thematically analyzed.

RESULTS

Indicate that when children contend with ongoing and severe IFCSA, they tend to develop alternative survival strategies, understanding that fight, flight, or disclosure are not relevant options for them.

CONCLUSION

The discussion stresses the multifaceted nature of the way children respond during IFCSA, which should be understood through holistic observation of the children and various aspects of their lives. The children's responses profoundly shape their abuse experiences and require further exploration so as to promote both intervention and prevention efforts.

The Neurology of Death and the Dying Brain: A Pictorial Essay

As neurologists earn their living with the preservation and restoration of brain function, they are also well-positioned to address the science behind the transition from life to death. This essay in pictures highlights areas of neurological expertise needed for brain death determination; shows pitfalls to avoid during the clinical examination and interpretation of confirmatory laboratory tests in brain death protocols; illustrates the great variability of brain death legislations around the world; discusses arguments for the implementation of donation after circulatory death (DCD); points to unresolved questions related to DCD and the time between cardiac standstill and organ procurement (“hands-off period”); provides an overview of the epidemiology and semiology of near-death experiences, including their importance for religion, literature, and the visual arts; suggests biological mechanisms for near-death experiences such as dysfunction of temporoparietal cortex, N-methyl-D-aspartate receptor antagonism, migraine aura, and rapid eye movement sleep; hypothesizes that thanatosis (aka. death-feigning, a common behavioral trait in the animal kingdom) represents the evolutionary origin of near-death experiences; and speculates about the future implications of recent attempts of brain resuscitation in an animal model. The aim is to provide the reader with a thorough understanding that the boundaries within the neurology of death and the dying brain are being pushed just like everywhere else in the clinical neurosciences.

Zebra finches bi-directionally selected for personality differ in repeatability of corticosterone and testosterone

Consistent between-individual differences in behaviour have been documented across the animal kingdom. Such variation between individuals has been shown to be the basis for selection and to act as a pacemaker for evolutionary change. Recently, equivocal evidence suggests that such consistent between-individual variation is also present in hormones. This observation has sparked interest in understanding the mechanisms shaping individual differences, temporal consistency and heritability of hormonal phenotypes and to understand, if and to what extent hormonal mechanisms are involved in mediating consistent variation in behaviour between individuals. Here, we used zebra finches of the fourth generation of bi-directionally selected lines for three independent behaviours: aggression, exploration and fearlessness. We investigated how these behaviours responded to artificial selection and tested their repeatability. We further tested for repeatability of corticosterone and testosterone across and within lines. Moreover, we are presenting the decomposed variance components for within-individual variance (i.e. flexibility) and between-individual variance (i.e. more or less pronounced differences between individuals) and investigate their contribution to repeatability estimates. Both hormones as well as the exploration and fearlessness but not aggressiveness, were repeatable. However, variance components and hence repeatability differed between lines and were often lower than in unselected control animals, mainly because of a reduction in between-individual variance. Our data show that artificial selection (including active selection and genetic drift) can affect the mean and variance of traits. We stress the importance for understanding how variable a trait is both between and within individuals to assess the selective value of a trait.

Coronavirus Anxiety Scale: A brief mental health screener for COVID-19 related anxiety

Mental health concerns of people impacted by the coronavirus pandemic have not been adequately addressed. The objective of this study was to develop and evaluate the properties of the Coronavirus Anxiety Scale (CAS), which is a brief mental health screener to identify probable cases of dysfunctional anxiety associated with the COVID-19 crisis. This 5-item scale, which was based on 775 adults with anxiety over the coronavirus, demonstrated solid reliability and validity. Elevated CAS scores were found to be associated with coronavirus diagnosis, impairment, alcohol/drug coping, negative religious coping, extreme hopelessness, suicidal ideation, as well as attitudes toward President Trump and Chinese products. The CAS discriminates well between persons with and without dysfunctional anxiety using an optimized cut score of ≥ 9 (90% sensitivity and 85% specificity). These results support the CAS as an efficient and valid tool for clinical research and practice.

Advancing Theory, Methods, and Dissemination in Sexual Violence Research to Build a More Equitable Future: An Intersectional, Community-Engaged Approach

Sexual violence is a devastating trauma with long-lasting effects on survivors' health and well-being. Despite the substantial impacts of the last 25 years of research, the prevalence of sexual violence has remained stable. It will be necessary to reconceptualize our work, challenging our theories, methods, and strategies for dissemination and implementation moving forward. We outline an intersectional, community-engaged approach for sexual violence research to center the stories of survivors who face systemic oppression and inequity. Finally, we suggest applications of this approach for justice, healing, and prevention to inform our collective work to end sexual violence.

The effects of trauma on brain and body: A unifying role for the midbrain periaqueductal gray

Post-traumatic stress disorder (PTSD), a diagnosis that may follow the experience of trauma, has multiple symptomatic phenotypes. Generally, individuals with PTSD display symptoms of hyperarousal and of hyperemotionality in the presence of fearful stimuli. A subset of individuals with PTSD; however, elicit dissociative symptomatology (i.e., depersonalization, derealization) in the wake of a perceived threat. This pattern of response characterizes the dissociative subtype of the disorder, which is often associated with emotional numbing and hypoarousal. Both symptomatic phenotypes exhibit attentional threat biases, where threat stimuli are processed preferentially leading to a hypervigilant state that is thought to promote defensive behaviors during threat processing. Accordingly, PTSD and its dissociative subtype are thought to differ in their proclivity to elicit active (i.e., fight, flight) versus passive (i.e., tonic immobility, emotional shutdown) defensive responses, which are characterized by the increased and the decreased expression of the sympathetic nervous system, respectively. Moreover, active and passive defenses are accompanied by primarily endocannabinoid- and opioid-mediated analgesics, respectively. Through critical review of the literature, we apply the defense cascade model to better understand the pathological presentation of defensive responses in PTSD with a focus on the functioning of lower-level midbrain and extended brainstem systems.

The role of tonic immobility and control in the development of intrusive memories after experimental trauma

Tonic immobility (TI; state of motor inhibition during threat) has been implicated in the onset of intrusive trauma memories, while controllability was associated with reduced anxiety. The present study investigated the interaction between TI and control in the development of intrusive memories of an analogue trauma. Sixty-four participants watched negative pictures while being allowed to close their eyes (InControl) or not (NoControl). They completed measures for spontaneous TI afterwards and recorded intrusive memories of the pictures in a diary in the subsequent week. Bayesian analyses were used to test informative hypotheses. Spontaneous TI during picture viewing was positively associated with increased intrusion frequency. Intrusion frequency did not differ for InControl versus NoControl. Moderation (control x TI) and non-moderation (main effect of TI only) were both adequate models, with no preference. Our results confirm the importance of TI in PTSD development. Implications of the findings regarding control merit more research.

Awe or horror: differentiating two emotional responses to schema incongruence

Experiences that contradict one's core concepts (e.g. of the world, people, the self) elicit intense emotions. Such schema incongruence can elicit awe, wherein experiences that are too vast to understand with existing cognitive schemata cause one to feel that schemata should be updated [i.e. a "need for cognitive accommodation" (NFA); Keltner & Haidt, 2003. Approaching awe, a moral, spiritual, and aesthetic emotion. Cognition and Emotion, 17(3), 297-314]. However, other emotional responses to schema incongruence, such as horror, have not been investigated. The current studies compared awe and horror to investigate if they are distinct emotional responses to schema incongruence. Study 1 observed significant differences between awe and horror in cognitive appraisals (e.g. certainty, legitimacy), indicating several areas of dissimilarity. Study 2 found evidence that awe and horror are both responses to schema incongruence, as schema incongruence and NFA were salient in awe and horror, but not a contrast emotion. However, awe and horror were elicited by different types of schema incongruence: awe by spiritual vastness, horror by extremity. Awe-eliciting experiences also appeared to be easier to assimilate than horrifying experiences, as NFA and uncertainty were significantly lower in awe than in horror. Differences in the functions of horror and awe are also discussed.

Tonic immobility during re-experiencing the traumatic event in posttraumatic stress disorder

Tonic Immobility (TI) is an evolved defence response, characterized by physical immobility. Peritraumatic TI has been linked to posttraumatic stress disorder (PTSD). However, samples sizes in clinical studies have been small, and little is known about TI reactions post trauma, for instance during trauma reminders. The prevalence of peritraumatic TI and TI during re-experiencing the traumatic event was examined by self-report in 184 patients with chronic PTSD. Moderate peritraumatic TI was reported by 26.6% of the participants (n = 49) and extreme peritraumatic TI by 52.2% (n = 96). During re-experiencing the traumatic event, 35.3% (n = 65) reported moderate TI, and 37.0% (n = 68) extreme TI. Peritraumatic TI was related to PTSD symptom severity and TI during re-experiencing mediated this relationship. In line with previous findings, reports of peritraumatic TI were high among PTSD patients. In addition, we showed that it often re-occurred during re-experiencing the traumatic event. The prevalence of TI at different stages post trauma warrants future study.

A review of thanatosis (death feigning) as an anti-predator behaviour

Abstract

Thanatosis—also known as death-feigning and, we argue more appropriately, tonic immobility (TI)—is an under-reported but fascinating anti-predator strategy adopted by diverse prey late on in the predation sequence, and frequently following physical contact by the predator. TI is thought to inhibit further attack by predators and reduce the perceived need of the predator to subdue prey further. The behaviour is probably present in more taxa than is currently described, but even within well-studied groups the precise taxonomic distribution is unclear for a number of practical and ethical reasons. Here we synthesise the key studies investigating the form, function, evolutionary and ecological costs and benefits of TI. This review also considers the potential evolutionary influence of certain predator types in the development of the strategy in prey, and the other non-defensive contexts in which TI has been suggested to occur. We believe that there is a need for TI to be better appreciated in the scientific literature and outline potentially profitable avenues for investigation. Future use of technology in the wild should yield useful developments for this field of study.

Significance statement

Anti-predatory defences are crucial to many aspects of behavioural ecology. Thanatosis (often called death-feigning) has long been an under-appreciated defence, despite being taxonomically and ecologically widespread. We begin by providing much-needed clarification on both terminology and definition. We demonstrate how apparently disparate observations in the recent literature can be synthesised through placing the behaviour within a cost-benefit framework in comparison to alternative behavioural choices, and how aspects of the ecology differentially affect costs and benefits. Extending this, we provide novel insights into why the evolution of thanatosis can be understood in terms of coevolution between predators and prey. We offer further novel hypotheses, and discuss how these can be tested, focussing on how emerging technologies can be of great use in developing our understanding of thanatosis in free-living animals.

Freeze for action: neurobiological mechanisms in animal and human freezing

Upon increasing levels of threat, animals activate qualitatively different defensive modes, including freezing and active fight-or-flight reactions. Whereas freezing is a form of behavioural inhibition accompanied by parasympathetically dominated heart rate deceleration, fight-or-flight reactions are associated with sympathetically driven heart rate acceleration. Despite the potential relevance of freezing for human stress-coping, its phenomenology and neurobiological underpinnings remain largely unexplored in humans. Studies in rodents have shown that freezing depends on amygdala projections to the brainstem (periaqueductal grey). Recent neuroimaging studies in humans have indicated that similar brain regions may be involved in human freezing. In addition, flexibly shifting between freezing and active defensive modes is critical for adequate stress-coping and relies on fronto-amygdala connections. This review paper presents a model detailing these neural mechanisms involved in freezing and the shift to fight-or-flight action. Freezing is not a passive state but rather a parasympathetic brake on the motor system, relevant to perception and action preparation. Study of these defensive responses in humans may advance insights into human stress-related psychopathologies characterized by rigidity in behavioural stress reactions. The paper therefore concludes with a research agenda to stimulate translational animal–human research in this emerging field of human defensive stress responses.

This article is part of the themed issue ‘Movement suppression: brain mechanisms for stopping and stillness’.

Does persisting fear sustain catatonia?

OBJECTIVE

To examine the psychological substrate of catatonia.

METHOD

Reviewing the historical descriptions and explanations of catatonic behaviours by clinicians from its delineation in the 19th century to the present.

RESULTS

Patients with catatonia are often haunted by fears and terrors; this has not been widely appreciated, and certainly was lost from view in the days when catatonia was considered a subtype of schizophrenia. The report contributes to resolving a major question in catatonia: is the mind in stupor inactive, as the blank state that we picture in anesthetized patients, or is the mind active, so preoccupied as to exclude all other influences.

THE MAIN FINDING

Persistent fear occupies the mind of catatonic patients.

CONCLUSION

The signs of catatonia are adaptations to persistent fear, akin to tonic immobilization. The relief afforded by sedation supports this interpretation.

Incident experience predicts freezing-like responses in firefighters

Freezing is a defensive response to acute stress that is associated with coping and alterations in attentional processing. However, it remains unclear whether individuals in high risk professions, who are skilled at making rapid decisions in emergency situations, show altered threat-induced freezing. Here we investigated the effect of incident experience in a high risk profession on freezing. Additionally, we explored whether any effect of incident experience on freezing would be different for profession-related and -unrelated threat. Forty experienced and inexperienced firefighters were presented neutral, pleasant, related-unpleasant, and unrelated-unpleasant pictures in a passive viewing task. Postural sway and heart rate were assessed to determine freezing. Both postural and heart rate data evidenced reduced freezing upon unpleasant pictures in the experienced versus the inexperienced group. Relatedness of the unpleasant pictures did not modulate these effects. These findings indicate that higher incident experience relates to decreased threat-induced freezing, at least in a passive task context. This might suggest that primary defense responses are malleable through experience. Finally, these findings demonstrate the potential of using animal to human translational approaches to investigate defensive behaviors in relation to incident experience in high risk professions and stimulate future research on the role of freezing in resilience and coping.

Childhood trauma and lifetime syncope burden among older adults

OBJECTIVE

Vasovagal syncope is governed by the autonomic nervous system and often precipitated by highly salient emotional situations. We hypothesized that a lifetime tendency towards vasovagal syncope may be precipitated by exposure to childhood trauma.

METHODS

We examined data from the first wave of The Irish Longitudinal Study on Ageing (TILDA) of adults aged 50+ (n=6497) who were asked to report lifetime syncope frequency and any history of childhood sexual or physical abuse. Mediation analysis was used to assess the relative importance of pathways via which childhood trauma could plausibly increase risk of later life recurrent syncope including via depression, mid-life cardiovascular disease and frequent syncope in youth.

RESULTS

18.2% reported a lifetime syncopal event: 4.0% frequent syncope in youth and 1.5% recurrent syncope in the last year. 10.9% reported childhood sexual or physical abuse, rising to 14.2% among those reporting any lifetime syncopal event, 21.0% with frequent syncope in youth and 20.2% with recurrent syncope in later life. In fully adjusted logistic regression models the report of childhood sexual or physical abuse was independently associated with frequent syncope in youth (OR 1.85 (CI 95% 1.27-2.71); p=0.001; OR 2.14 (1.48-3.10); p<0.001 respectively). A history of frequent syncope in youth and depression partially mediated the relationship between childhood sexual and physical abuse and recurrent syncope in later life, while mid-life cardiovascular disease was less important.

CONCLUSION

Childhood trauma may contribute to a lifelong vasovagal tendency. Early attention should be given to the potential precipitating and perpetuating psychosocial factors affecting recurrent syncope.

Immobility reactions under threat: A contribution to human defensive cascade and PTSD

Violence exacts a burden on public health. Gun violence is a major trigger for motor defensive reactions in humans and post-traumatic stress disorder (PTSD) is its main psychiatric sequela. However, studies of the human defensive cascade, especially the motor reactions, are at an early stage. This review focuses on studies that employ stabilometry, a methodology that assesses whole body motor reactions, to address defensive behaviors to violence-related threats. Special attention is given to three reactions: "attentive immobility", "immobility under attack" and "tonic immobility", with emphasis on the latter - a peritraumatic reaction which has been strongly associated with the severity of PTSD. These reactions are characterized by reduced body sway and bradycardia, except tonic immobility that presents robust tachycardia. The advances made by investigations into the immobility reactions of the human defensive cascade contribute to helping to bridge the gap between human and non-human species. Furthermore, progresses in basic research to objectively monitor motor defensive reactions under threat can help to develop a dimensional, trans-diagnostic approach to PTSD.

Reduced Freezing in Posttraumatic Stress Disorder Patients while Watching Affective Pictures

Besides fight and flight responses, animals and humans may respond to threat with freezing, a response characterized by bradycardia and physical immobility. Risk assessment is proposed to be enhanced during freezing to promote optimal decision making. Indeed, healthy participants showed freezing-like responses to threat cues. Posttraumatic stress disorder (PTSD) patients are characterized by hypervigilance and increased threat responsiveness. We propose that threat responses will be characterized by decreased freezing in PTSD, eliminating possibilities for rejecting cognitive distortions, such as harm expectancy, and thereby contributing to the maintenance of the disorder. However, freezing responses have hardly been investigated in PTSD. Using a stabilometric platform to assess body sway as an indicator of freezing-like behavior, we examined whether veterans with PTSD would show diminished freezing responses to unpleasant versus neutral and pleasant pictures. Fourteen PTSD patients and 14 healthy matched controls watched the pictures, while body sway and heart rate (HR) were continuously assessed. Replicating previous findings, healthy controls showed decreased body sway and HR in response to unpleasant pictures, indicative of freezing-like behavior. In contrast, this response pattern was not observed in PTSD patients. The results may indicate a reduced freezing response in PTSD. As reduced freezing may hinder appropriate risk assessment, it may be an important factor in the maintenance of PTSD. Future research might clarify whether impaired freezing is a PTSD-specific or a transdiagnostic symptom, being present in threat-related disorders.

Individual personality differences in Port Jackson sharks Heterodontus portusjacksoni

This study examined interindividual personality differences between Port Jackson sharks Heterodontus portusjacksoni utilizing a standard boldness assay. Additionally, the correlation between differences in individual boldness and stress reactivity was examined, exploring indications of individual coping styles. Heterodontus portusjacksoni demonstrated highly repeatable individual differences in boldness and stress reactivity. Individual boldness scores were highly repeatable across four trials such that individuals that were the fastest to emerge in the first trial were also the fastest to emerge in subsequent trials. Additionally, individuals that were the most reactive to a handling stressor in the first trial were also the most reactive in a second trial. The strong link between boldness and stress response commonly found in teleosts was also evident in this study, providing evidence of proactive-reactive coping styles in H. portusjacksoni. These results demonstrate the presence of individual personality differences in sharks for the first time. Understanding how personality influences variation in elasmobranch behaviour such as prey choice, habitat use and activity levels is critical to better managing these top predators which play important ecological roles in marine ecosystems.

Personality over ontogeny in zebra finches: long-term repeatable traits but unstable behavioural syndromes

A crucial assumption of animal personality research is that behaviour is consistent over time, showing a high repeatability within individuals. This assumption is often made, sometimes tested using short time intervals between behavioural tests, but rarely thoroughly investigated across long time intervals crossing different stages of ontogeny. We performed such a longitudinal test across three life stages in zebra finches (Taeniopygia guttata), representing about 15-20% of their life span in captivity, and found repeatabilities ranging from 0.03 to 0.67. Fearlessness and exploration were the most repeatable traits both within and across life stages. Activity and aggression were repeatable across, but not or only partly within life stages. Boldness was not repeatable. Furthermore, we found no evidence for a consistent behavioural syndrome structure across ontogeny. Our results indicate that the consistency of behavioural traits and their correlations might be overestimated and suggest that life-long stability of animal personality should not simply be assumed.