Fear and the Defense Cascade

Abstract

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Mindfulness-based treatments for posttraumatic stress disorder: a review of the treatment literature and neurobiological evidence

“…Here, according to the defence cascade model of dissociation, when an organism deems the level of threat in a given situation to be insurmountable, they may engage in tonic or collapsed immobility (states of reduced arousal that may promote survival by mimicking death), whereby "functional sensory de-afferentation" mediated by the thalamus leads to reduced sensory integration and input to the cortex, a process thought to be mirrored by dissociation in traumatized individuals. 127,128 Thus, restoration of thalamic connectivity with the ARAS as a consequence of decreased thalamic connectivity with the DMN may promote decreased dissociation among patients with PTSD+DS. Indeed, mindfulness-based skills have been suggested as strategies to shift out of dissociative states by improving awareness of mind-body states (possibly via the thalamus) through focus on interoceptive, proprioceptive and touch sensations (e.g., during a body scan).…”

The role of automatic defensive responses in the development of posttraumatic stress symptoms in police recruits: protocol of a prospective study

“…First, we will focus on the role of automatic defensive reactions in the development of trauma-related psychopathology. Although automatic defensive responses, such as freeze – fight – flight tendencies, are suggested to form a major maintaining factor of PTSD (Kozlowska et al, 2015), the role these responses in the development and persistence of PTSD symptoms remains largely unknown. Another characteristic of our study is that we adopt a transdiagnostic approach, investigating intermediate phenotypes of posttraumatic anxiety and aggressive symptoms, rather than relying on a full-blown PTSD diagnosis according to distinct diagnostic categories.…”

“…Stress-induced lack of control over automatic defensive responses is especially problematic for people in high-risk professions, such as police officers, whose control over automatic responses is essential for optimal performance under threat (Nieuwenhuys, Savelsbergh, & Oudejans, 2012). Moreover, difficulties controlling automatic defensive responses may not only affect split-second decisions under acute threat, but also increase the risk for development and persistence of posttraumatic stress disorder (PTSD) symptoms (Kozlowska, Walker, McLean, & Carrive, 2015). PTSD symptoms are highly prevalent among police officers: it was estimated that over 34% of Dutch police officers experienced PTSD or subsyndromal PTSD symptoms within one year of experiencing a critical incident (Carlier, Lamberts, & Gersons, 1997).…”

“…Moreover, self-reported tonic immobility during trauma exposure was predictive for the development of PTSD symptoms after sexual assault (Bovin, Jager-Hyman, Gold, Marx, & Sloan, 2008). Of note, however, tonic immobility and freezing are distinct defensive states: freezing prepares an individual for future defensive responses; tonic immobility takes place later in the defensive cascade, when threat is inescapable and no alternative defensive responses remain (Kozlowska et al, 2015; Roelofs, 2017). It has been suggested that aggression is associated with facilitated approach of (social) threat, possibly indicating increased fight behaviour, whereas anxiety is related to increased freeze and flight responses (Niermann, Figner, & Roelofs, 2017).…”

Heart Rate Changes in Pet and Lab Dogs as Response to Human Facial Expressions

“…The arousal-valence model [40] proposes that anger is an emotion that elicits high arousal and valence. A possible explanation would be that in lab dogs, like in pet dogs, angry facial expressions are perceived as threat and dogs undergo the defense cascade [47,48]. According to the defense cascade model an individual undergoes cardiac deceleration when still being in early stages of the defense.…”