Muriel A. Hagenaars

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Freezing is a common defensive response in animals threatened by predators. It is characterized by reduced body motion and decreased heart rate (bradycardia). However, despite the relevance of animal defense models in human stress research, studies have not shown whether social threat cues elicit similar freeze-like responses in humans. We investigated body(More)
Freezing is widely used as the main outcome measure for fear in animal studies. Freezing is also getting attention more frequently in human stress research, as it is considered to play an important role in the development of psychopathology. Human models on defense behavior are largely based on animal models. Unfortunately, direct translations between(More)
Facial expressions are potent social cues that can induce behavioral dispositions, such as approach–avoidance tendencies. We studied these tendencies by asking participants to make whole-body forward (approach) or backward (avoidance) steps on a force plate in response to the valence of social cues (happy or angry faces) under affect-congruent and(More)
BACKGROUND As of yet, no collective agreement has been reached regarding the precise factor structure of posttraumatic stress disorder (PTSD). Several alternative factor-models have been proposed in the last decades. OBJECTIVE The current study examined the fit of a hierarchical adaptation of the Simms et al. (2002) dysphoria model and compared it to the(More)
Human freezing has been objectively assessed using a passive picture viewing paradigm as an analog for threat. These results should be replicated for other stimuli in order to determine their stability and generalizability. Affective films are used frequently to elicit affective responses, but it is unknown whether they also elicit freezing-like defense(More)
A better understanding of psychological trauma is fundamental to clinical psychology. Following traumatic event(s), a clinically significant number of people develop symptoms, including those of Acute Stress Disorder and/or Post Traumatic Stress Disorder. The trauma film paradigm offers an experimental psychopathology model to study both exposure and(More)
Improved (n = 21) and nonimproved (n = 13) PTSD patients (a mixed trauma population) were compared for fear activation and habituation patterns during and between the 1st and 2nd prolonged exposure sessions. Drop-outs (n = 11) were also evaluated. Nonimproved patients had significantly higher ratings of anxiety at the start of the first exposure session.(More)
In the present study, we investigated the effect of prior aversive life events on freezing-like responses. Fifty healthy females were presented neutral, pleasant, and unpleasant images from the International Affective Picture System while standing on a stabilometric platform and wearing a polar band to assess body sway and heart rate. In the total sample,(More)
The present prospective study evaluates the predictive value of 2 different types of dissociation (psychological and somatoform peritraumatic dissociation), and dysfunctional cognitions on symptoms of posttraumatic stress disorder (PTSD) at 6 months. Assessment of dissociation, PTSD symptoms, and dysfunctional cognitions took place in 49 participants(More)
Intense, disorganized recollections are one of the core symptoms of posttraumatic stress disorder (PTSD), and considered to be the result of inadequate processing of trauma information. A first panic attack resembles trauma in being an unexpected frightening and subjectively life-threatening event, and like PTSD, panic disorder with agoraphobia also(More)