Processing In Posttraumatic Stress Disorder Research Articles

The role of trauma-related distractors on neural systems for working memory and emotion processing in posttraumatic stress disorder

The relevance of emotional stimuli to threat and survival confers a privileged role in their processing. In PTSD, the ability of trauma-related information to divert attention is especially pronounced. Information unrelated to the trauma may also be highly distracting when it shares perceptual features with trauma material. Our goal was to study how trauma-related environmental cues modulate working memory networks in PTSD. We examined neural activity in participants performing a visual working memory task while distracted by task-irrelevant trauma and non-trauma material. Recent post-9/11 veterans were divided into a PTSD group ( n = 22) and a trauma-exposed control group ( n = 20) based on the Davidson trauma scale. Using fMRI, we measured hemodynamic change in response to emotional (trauma-related) and neutral distraction presented during the active maintenance period of a delayed-response working memory task. The goal was to examine differences in functional networks associated with working memory (dorsolateral prefrontal cortex and lateral parietal cortex) and emotion processing (amygdala, ventrolateral prefrontal cortex, and fusiform gyrus). The PTSD group showed markedly different neural activity compared to the trauma-exposed control group in response to task-irrelevant visual distractors. Enhanced activity in ventral emotion processing regions was associated with trauma distractors in the PTSD group, whereas activity in brain regions associated with working memory and attention regions was disrupted by distractor stimuli independent of trauma content. Neural evidence for the impact of distraction on working memory is consistent with PTSD symptoms of hypervigilance and general distractibility during goal-directed cognitive processing.

Attention, Memory, Intrusive Thoughts, and Acceptance in PTSD: An Update on the Empirical Literature for Clinicians

Information processing theory suggests that cognitive changes following trauma are common and hypothesized to have an impact on attention, memory, and intrusive thoughts. There is an ever-expanding empirical literature where cognitive features of posttraumatic stress disorder (PTSD) are being explored. However, it can sometimes be difficult for front-line clinicians to stay abreast of this literature and how it impacts the treatment s/he provides. The goal of this paper is to provide an overview of some recent basic and applied research on information processing in PTSD and the implications of these findings for cognitive-behavioral clinicians. In particular, we explore recent findings regarding attention, memory, intrusive thoughts/thought suppression, and acceptance as they relate to clinical work in patients with PTSD.

Information Processing Bias in Post-traumatic Stress Disorder.

This review considers theory and evidence for abnormal information processing in post-traumatic stress disorder (PTSD). Cognitive studies have indicated sensitivity in PTSD for traumatic information, more so than general emotional information. These findings were supported by neuroimaging studies that identify increased brain activity during traumatic cognition, especially in affective networks (including the amygdala, orbitofrontal and anterior cingulate cortex). In theory, it is proposed that traumatic cognition may interfere with neutral cognition and there is evidence of abnormal neutral stimulus processing in PTSD. Firstly, PTSD patients perform poorly on a variety of neuropsychology tasks that involve attention and memory for neutral information. The evidence from event-related potentials and functional neuroimaging also indicates abnormal results in PTSD during neutral stimulus processing. The research evidence generally provides support for theories of trauma sensitivity and abnormal neutral stimulus processing in PTSD. However, there is only tentative evidence that trauma cognition concurrently interferes with neutral cognition. There is even some evidence that traumatic or novelty arousal processes can increase the capacity for attentive processing, thereby enhancing cognition for neutral stimulus information. Research on this topic has not yet fully explored the mechanisms of interaction between traumatic and neutral content in the cognitive dynamics of PTSD.

Functional Neuroimaging of Anxiety: A Meta-Analysis of Emotional Processing in PTSD, Social Anxiety Disorder, and Specific Phobia

The study of human anxiety disorders has benefited greatly from functional neuroimaging approaches. Individual studies, however, vary greatly in their findings. The authors searched for common and disorder-specific functional neurobiological deficits in several anxiety disorders. The authors also compared these deficits to the neural systems engaged during anticipatory anxiety in healthy subjects. Functional magnetic resonance imaging and positron emission tomography studies of posttraumatic stress disorder (PTSD), social anxiety disorder, specific phobia, and fear conditioning in healthy individuals were compared by quantitative meta-analysis. Included studies compared negative emotional processing to baseline, neutral, or positive emotion conditions. Patients with any of the three disorders consistently showed greater activity than matched comparison subjects in the amygdala and insula, structures linked to negative emotional responses. A similar pattern was observed during fear conditioning in healthy subjects. Hyperactivation in the amygdala and insula were, of interest, more frequently observed in social anxiety disorder and specific phobia than in PTSD. By contrast, only patients with PTSD showed hypoactivation in the dorsal and rostral anterior cingulate cortices and the ventromedial prefrontal cortex-structures linked to the experience and regulation of emotion. This meta-analysis allowed us to synthesize often disparate findings from individual studies and thereby provide neuroimaging evidence for common brain mechanisms in anxiety disorders and normal fear. Effects unique to PTSD furthermore suggested a mechanism for the emotional dysregulation symptoms in PTSD that extend beyond an exaggerated fear response. Therefore, these findings help refine our understanding of anxiety disorders and their interrelationships.

Decreased cerebral blood flow of thalamus in PTSD patients as a strategy to reduce re‐experience symptoms

To investigate alterations of regional cerebral blood flow (rCBF) in subjects with post-traumatic stress disorder (PTSD). Using [99Tcm]-hexamethyl propylenamino oxime single photon emission computed tomography, the rCBF under resting condition was compared between 19 survivors of the Taegu subway fire with PTSD and 19 comparison subjects. PTSD patients showed a decreased rCBF in the right thalamus and an increased rCBF in the right superior parietal lobe relative to comparison subjects (corrected P < 0.05). The rCBF in the right thalamus positively correlated with the severity of current re-experience symptoms in PTSD subjects. Our finding of the thalamic rCBF decrease in PTSD patients may be a strategy to reduce re-experience symptom, by evading the process of external and internal information which can evoke traumatic memory. In addition, the parietal rCBF increase in our PTSD patients might be related to altered information processing in PTSD.

Interpretation biases in victims and non-victims of interpersonal trauma and their relation to symptom development

Previous studies examining information processing in posttraumatic stress disorder (PTSD) have focused on attention and memory biases, with few studies examining interpretive biases. The majority of these studies have employed lexically based methodologies, rather than examining the processing of visual information. In the present study, victims ( N = 40) and non-victims ( N = 41) of interpersonal trauma viewed a series of short positive, neutral, and threatening filmstrips of social situations with ambiguous endings. Participants were then asked about their perceptions and interpretations of the situations. Victims perceived threatening situations as more predictable and more quickly increasing in risk than non-victims. Trauma status interacted with the perceived predictability of positive situations and the perceived speed with which neutral situations reached their conclusion to predict anxious symptoms. In addition, trauma status interacted with the perceived increase in risk of positive situations to predict PTSD symptoms. The implications of these findings for theories of PTSD are discussed.

Neural Networks of Information Processing in Posttraumatic Stress Disorder: A Functional Magnetic Resonance Imaging Study

Neuroimaging studies report reduced medial prefrontal cortical (particularly anterior cingulate) but enhanced amygdala response to fear signals in posttraumatic Stress Disorder (PTSD). We investigated whether anterior cingulate-amygdala dysregulation in PTSD would generalize to salient, but nonthreat related signals. Individuals with PTSD (n = 14) and age and sex-matched nontraumatized controls (n = 14) completed an auditory oddball paradigm adapted to functional magnetic resonance imaging at a 1.5-T field strength. Controls displayed bilateral activation in ventral anterior cingulate and amygdala networks, and PTSD subjects showed bilateral dorsal anterior cingulate and amygdala activation to targets relative to nontargets. Compared to controls, PTSD subjects showed enhanced responses to targets in the dorsal and rostral anterior cingulate, and left amygdala. Whole-brain analyses confirmed the expected pattern of distributed prefrontal-parietal responses to targets in the oddball task. Greater activity in posterior parietal somatosensory regions was observed in PTSD. Our findings of enhanced anterior cingulate responses in PTSD contrast with reports of reduced activity for threat stimuli, suggesting that the latter may be specific to processing of threat-related content. Activation in rostral and dorsal anterior cingulate, left amygdala and posterior parietal networks in response to salient, nonthreatening stimuli may reflect generalized hypervigilance.

Functional connectivity of the prefrontal cortex and the amygdala in posttraumatic stress disorder

Background Persistent, intrusive re-experiencing in posttraumatic stress disorder (PTSD) is commonly construed as a failure of cingulate inhibition (i.e., extinction) over a hyperresponsive amygdala, based primarily on animal research of fear conditioning and the finding of cingulate hypoperfusion in PTSD. Methods We examined functional connectivity in patients with PTSD and healthy trauma survivors during repeated symptom provocation using H 2O 15 positron emission tomography. Results Memory retrieval networks (right prefrontal cortex, hippocampus, and visual cortex) were common to both groups. Networks supporting autonomic and emotional control and preparatory motor action (amygdala, anterior cingulate, subcallosal gyrus, and premotor cortex) differed between the two groups and became progressively disparate with successive presentations of the traumatic script. Patterns of effective connectivity demonstrated the predominance of direct influences of the amygdala on visual cortex, subcallosal gyrus, and anterior cingulate in PTSD but not in control subjects. There was little evidence for failure of inhibition of cingulate or subcallosal cortex over the amygdala. Conclusions These patterns might represent excessive influences of the amygdala over regions involved in autonomic, and higher-order visual memory processing in PTSD. The present data suggest that inferences of direct correspondence between animal studies and pathophysiology of PTSD should be made with caution.

Neural Correlates of Traumatic Recall in Posttraumatic Stress Disorder

Functional activation studies of posttraumatic stress disorder (PTSD) using symptom provocation paradigms have implicated dysfunction in limbic and paralimbic brain regions. Increased or altered cerebral blood flow has been observed in amygdala and insula. Decreased or absent activity has been seen in medial prefrontal and anterior cingulate cortex (ACC). These brain regions comprise a neural circuit that has been demonstrated as important for emotional processing and emotional regulation. We studied combat veterans with PTSD (n=16), combat veterans without PTSD (combat controls, n=15 ), and age-matched healthy control subjects (n=15) with [O-15] H2O PET under a script-driven imagery paradigm of personalized traumatic/stressful and emotionally neutral events. Preliminary findings show that PTSD patients and combat controls had differential blood flow patterns during emotional recall in amygdala, insula and medial prefrontal cortex. Consistent with and extending prior findings, these preliminary results replicate differential patterns of activation in limbic and paralimbic regions of PTSD patients and trauma exposed controls suggesting that these neural substrates may be involved in the deficits in emotional processing in PTSD on one hand, and in resilience to trauma on the other.

Cultural Interpretations of Physiological Processes in Post-Traumatic Stress Disorder and Panic Disorder

Cultural Interpretations of Physiological Processes in Post-Traumatic Stress Disorder and Panic Disorder

Memory processes in post-traumatic stress disorder

The relation between emotion and memory is highly complex and, on the surface, the studies conducted are full of contradictions. A consensus is gradually emerging that emotion is likely to benefit memory for central details while disadvantaging memory for peripheral details, and that extremely high levels of emotion lead to strong conditioned responses while impairing conscious memory processes. These phenomena are illustrated well in post-traumatic stress disorder (PTSD), where intense flashbacks can co-exist with disorganized and incomplete narrative memory. These findings are related to the dual representation theory of memory in PTSD, and the implications for therapy are briefly discussed.

Memory processes in post-traumatic stress disorder

The relation between emotion and memory is highly complex and, on the surface, the studies conducted are full of contradictions. A consensus is gradually emerging that emotion is likely to benefit memory for central details while disadvantaging memory for peripheral details, and that extremely high levels of emotion lead to strong conditioned responses while impairing conscious memory processes. These phenomena are illustrated well in post-traumatic stress disorder (PTSD), where intense flashbacks can co-exist with disorganized and incomplete narrative memory. These findings are related to the dual representation theory of memory in PTSD, and the implications for therapy are briefly discussed.

PREDICTORS OF ANALOGUE POST-TRAUMATIC INTRUSIVE COGNITIONS

Previous research on vulnerability to Post-Traumatic Stress Disorder (PTSD) has been restricted by the absence of prospective studies that measure individual differences prior to traumatization. This study investigated the predictors of analogue post-traumatic intrusive cognitions using a fully prospective design. Non-patient participants completed a range of predictor measures before being exposed to a film about a traumatic fire. Film-induced changes in negative mood were also assessed. Subsequent intrusions were measured both within the experimental session and for a further seven days. The hypothesized predictors were: neuroticism, trait anxiety, extraversion, depression, a general tendency to suppress unpleasant thoughts, beliefs about being “at risk” from fire, mental imagery, self-rated proneness to intrusions and negative mood changes. The results showed that intrusions were predicted by film-induced increases in negative mood, thought suppression tendencies, beliefs about vulnerability to fire and self-rated proneness to intrusive cognitions. The findings are discussed in relation to the literature on thought suppression and cognitive processes in PTSD.

Traumatic stress: the effects of overwhelming experience on mind, body, and society

Part I: Background Issues and History. van der Kolk, McFarlane, The Black Hole of Trauma. McFarlane, van der Kolk, Trauma and its Challenge to Society. van der Kolk, Weisaeth, van der Hart, History of Trauma in Psychiatry. Part II: Acute Reactions. Shalev, Stress versus Traumatic Stress: From Acute Homeostatic Reactions to Chronic Psychopathology. Solomon, Laror, McFarlane, Acute Posttraumatic Reactions in Soldiers and Civilians. Part III: Defining and Diagnosing Posttraumatic Stress Disorder. Brett, The Classification of Posttraumatic Stress Disorder. McFarlane, Girolamo, The Nature of Traumatic Stressors and the Epidemiology of Posttraumatic Reaction. McFarlane, Resilience, Vulnerability and the Course of Posttraumatic Reactions. van der Kolk, The Complexity of Adaptation to Trauma: Self-regulation, Stimulus Discrimination, and Characterological Development. van der Kolk, The Body Keeps the Score: Approaches to the Psychobiology of Posttraumatic Stress Disorder. Newman, Kaloupek, Feane, Assessment of Posttraumatic Stress Disorder in Clinical and Research Settings. Part IV: Memory: Mechanisms and Processes. van der Kolk, Trauma and Memory. van der Kolk, van der Hart, Marmar, Dissociation and Information Processing in Posttraumatic Stress Disorder. Part V: Developmental, Social, and Cultural Issues. Pynoos, Steinberg, Goenjian, Traumatic Stress in Childhood and Adolescence, Recent Developments and Current Controversies. Prior Traumatization and the Process of Aging: Theory and Clinical Implications. Pitman, Sparr, Saunders, McFarlane, Legal Issues in Posttraumatic Stress Disorder. de Vries, Trauma in Cultural Perspective. Part VI: Treatment. van der Kolk, McFarlane, van der Hart, A General Approach to Treatment of Posttraumatic Stress Disorder. Ursano, Grieger, McCarroll, Prevention of Posttraumatic Stress: Consultation, Training, and Early Treatment. Raphael, Wilson, Meldrum, McFarlane, Acute Preventive Interventions. Turnbull, McFarlane, Acute Treatments. Rothbaum, Foa, Cognitive-Behavioral Therapy for Posttraumatic Stress Disorder. Davidson, van der Kolk, The Psychopharmacological Treatment of Posttraumatic Stress Disorder. Lindy, Psychoanalytic Psychotherapy of Posttraumatic Stress Disorder: The Nature of the Therapeutic Relationship. Turner, McFarlane, van der Kolk, The Therapeutic Environment and New Explorations in the Treatment of Posttraumatic Stress Disorder.

Cognitive processing in post-traumatic stress disorder.

Recent research has suggested an abnormal attentional bias to threat in anxiety disorders. We have assessed the processing of thoughts of trauma, panic attacks, general fear and positive affect in a cohort of 15 war veterans with post-traumatic stress disorder (PTSD) and an age- and sex-matched normal control group. Subjects with PTSD showed delayed processing of self-referential sentences when the themes of the sentences were traumatic experiences or positive affect, compared with controls. However, they were more efficient than control subjects in the processing of sentences describing situations of panic attacks and general fear. It would therefore appear that in patients with PTSD, cognitive processing is hindered by personally relevant themes of past traumatic experiences, whereas it may be facilitated by information related to general threat or internal body sensations of panic.

Information processing in post-traumatic stress disorder

Previous research has established that patients suffering from anxiety disorders, including post-traumatic stress disorder (PTSD), exhibit a cognitive bias that selectively favours the processing of threat material. This information processing bias has frequently been demonstrated by subjects' performance on the Stroop colour-naming task. The current experiment investigated the selective processing of threat information in people with PTSD using a modified Stroop procedure. Subjects were 13 ferry disaster survivors with high PTSD symptomatology, 20 survivors of the same disaster with low PTSD symptomatology, and 12 non-traumatized control subjects. All were asked to colour-name five types of words: ferry disaster words, general threat words, neutral semantically-unrelated words, neutral semantically-related words, and positive words. The disaster survivors with high levels of PTSD symptomatology evidenced a significantly longer response latency for colour-naming disaster-related words than for other word types. The results of the low-PTSD survivors and non-traumatized controls showed no significant difference between response latencies for general threat words and disaster word, although all 3 groups showed increased latencies for threat words compared with neutral words. The mechanisms proposed to underlie this response pattern are discussed, and clinical implications are considered.

Emotional numbing in combat-related post-traumatic stress disorder: A critical review and reformulation

Emotional numbing symptoms are considered in the clinical literature as cardinal signs of Post-Traumatic Stress Disorder (PTSD) and have been formally codified in DSM-III-R. However, the term has not been consistently defined nor adequately researched. The present paper critically reviews the extant empirical and theoretical literature in combat-related PTSD that has explored emotional numbing symptoms. A theoretical framework, based on Levanthal's (1984) perceptual-motor theory of emotion, is posited to account for the parameters of emotional processing in PTSD, and specific hypotheses concerning selective or differential emotional processing deficits in PTSD are described in order to clarify empirical issues about the development and maintenance of emotional processing deficits in PTSD and to stimulate future research in this underexplored, yet clinically important area.

Information processing in anxiety disorders: Application to the understanding of post-traumatic stress disorder

Several of the key defining features of post-traumatic stress disorder (PTSD) are symptoms that reflect problems related to perception, attention, and memory processes (hypervigilance, flashbacks, nightmares, psychogenic amnesia, and concentration difficulties). Although there have been several recent attempts to explain such phenomena through facets of cognitive psychology, little empirical work has been completed to confirm or explicate such processes in PTSD. This paper critically reviews the theoretical and empirical work done to date in the area of information processing in anxiety disorders, so as to provide a context for future empirical work to identify the specific psychological mechanisms and controlling variables responsible for symptoms of PTSD. A working theoretical model of information processing variables in PTSD is also proposed to stimulate future research in this area.