Enhanced priming for trauma-related material in posttraumatic stress disorder

Intrusive reexperiencing in posttraumatic stress disorder (PTSD) has been linked to perceptual priming for trauma-related material. A prospective longitudinal study (N = 69) investigated perceptual priming for trauma-related, general threat, and neutral words in assault survivors with and without PTSD, using a new version of the word-stem completion task. Survivors with PTSD showed enhanced priming for trauma-related words. Furthermore, priming for trauma-related words measured soon after the trauma was associated with subsequent PTSD severity at 3, 6, and 9 months. The enhanced priming effect was specific to trauma-related words. Enhanced perceptual priming for traumatic material appears to be one of the cognitive processes operating in PTSD.     

Conceptual and perceptual priming and dissociation in chronic posttraumatic stress disorder

Cognitive models of posttraumatic stress disorder (PTSD) assert that memory processes play a significant role in PTSD (see e.g., Ehlers & Clark, 2000). Intrusive reexperiencing in PTSD has been linked to perceptual processing of trauma-related material with a corresponding hypothesized lack of conceptual processing. In an experimental study that included clinical participants with and without PTSD (N = 50), perceptual priming and conceptual priming for trauma-related, general threat, and neutral words were investigated in a population with chronic trauma-induced complaints as a result of the Troubles in Northern Ireland. The study used a new version of the word-stem completion task (Michael, Ehlers, & Halligan, 2005) and a word-cue association task. It also assessed the role of dissociation in threat processing. Further evidence of enhanced perceptual priming in PTSD for trauma stimuli was found, along with evidence of lack of conceptual priming for such stimuli. Furthermore, this pattern of priming for trauma-related words was associated with PTSD severity, and state dissociation and PTSD group made significant contributions to predicting perceptual priming for trauma words. The findings shed light on the importance of state dissociation in trauma-related information processing and posttraumatic symptoms.     

Perceptual Implicit Memory for Trauma-related Information in Post-traumatic Stress Disorder

We used a perceptual identification paradigm to investigate whether Vietnam combat veterans with post-traumatic stress disorder (PTSD), compared to healthy combat veterans, exhibit an implicit memory bias for trauma-related information. Subjects viewed a series of trauma, positive, and neutral words, and subsequently saw these "old" words intermixed with an equivalent number of "new" distractor words of the same types. During this test phase, each word appeared for 100 milliseconds and was replaced by a visual mask. Although both groups exhibited implicit memory by accurately identifying more old words than new words, this priming effect was not enhanced for trauma words in the PTSD group. Tasks that primarily tap perceptual implicit memory may be relatively insensitive to emotional variables.     

Inhibitory control of threat remembering in PTSD

ABSTRACT

Intrusive traumatic recollections suggest an inability in Posttraumatic Stress Disorder (PTSD) to control and notably to inhibit memories for trauma-related information. Supported by inhibitory deficits found on experimental settings in PTSD, memory functioning and memory biases in the disorder were usually explained through inhibitory and control deficits in the processing of trauma-related information. The present study aimed to directly assess this hypothesis by investigating memory control abilities for emotional information in PTSD. For this purpose, 34 patients diagnosed with PTSD were compared to 37 non-PTSD controls on an item-cued directed forgetting paradigm for emotional words combined with a Remember/Know recognition procedure. Results revealed enhanced amounts of Remember recognitions for trauma-related words in PTSD. Moreover, we replicated findings of memory control impairments in the disorder. However, such impairments only occurred for non-trauma-related words. Accordingly, it appeared that PTSD patients presented preserved memory control abilities for trauma-related words, at the expenses of other emotional valences. Surprisingly, PTSD patients presented a preserved ability to control and notably to inhibit their memory functioning for trauma-related material. In addition to potential theoretical and clinical relevance, these results are discussed in the light of resource reallocation hypotheses and vigilant-avoidant theories of information processing in PTSD.     

Regional brain electrical activity in posttraumatic stress disorder after motor vehicle accident

This study examined whether patients with posttraumatic stress disorder (PTSD) related to motor vehicle accidents (MVAs) would show an abnormal pattern of electroencephalographic (EEG) alpha asymmetries, which has been proposed for particular types of anxiety. Patients with PTSD (n = 22) or subsyndromal PTSD (n = 21), traumatized controls without PTSD (non-PTSD with MVA; n = 21), and healthy controls without MVA (n = 23) underwent measurement of EEG activity during baseline and exposure to a neutral, a positive, a negative, and an accident-related picture. Differences in brain asymmetry between groups were observed only during exposure to trauma-related material. PTSD and subsyndromal PTSD patients showed a pattern of enhanced right anterior and posterior activation, whereas non-PTSD with MVA participants showed the opposite pattern. Furthermore, posterior asymmetry in nontraumatized healthy controls varied with gender, with female participants showing a pattern of higher right posterior activation. The results support the hypothesis that symptomatic MVA survivors are characterized by a pattern of right hemisphere activation that is associated with anxious arousal and symptoms of PTSD during processing of trauma-specific information.     

Attentional biases in PTSD: More evidence for interference

Attentional biases to trauma-related stimuli have been widely demonstrated in individuals with posttraumatic stress disorder (PTSD). However, the majority of these studies used methods not suited to differentiating difficulty disengaging attention from threatening stimuli (interference) from facilitated detection of threat. In the current study, a visual search task (VST) with a lexical decision component was used to differentiate between attentional interference and facilitation. Forty-six sexual assault survivors with High PTSD or Low PTSD symptoms completed the VST with three types of stimuli (trauma-related, general threat-related, and semantically-related neutral words), to examine the specificity of attentional biases associated with PTSD symptoms. High PTSD participants showed increased interference to trauma-related words relative to Low PTSD participants. Furthermore, the increased attentional interference in High PTSD participants was specific to trauma-related stimuli. No evidence was found for facilitated detection of threatening stimuli in PTSD. These results provide additional support for attentional biases in PTSD relating to attentional interference with trauma-related cues rather than facilitated detection of threat. The implications for this pattern of results are discussed in relation to anxiety disorders that are characterized by rumination and/or intrusions (e.g., PTSD, GAD) rather than those more circumscribed to fight or flight response (e.g., phobias).     

Cognitive interference for trauma cues in sexually abused adolescent girls with posttraumatic stress disorder

Investigated cognitive processing of fear-relevant information in sexually abused adolescent girls with posttraumatic stress disorder (PTSD) using a modified Stroop procedure (MSP). Participants were 20 sexually abused girls with PTSD, 13 sexually abused girls without PTSD, and 20 nonvictimized girls who served as controls, 11 to 17 years old. Word conditions included abuse-related threat, developmentally relevant (related to the experience of sexual abuse, e.g., trust, secrecy, and intimacy), general threat, positive, and neutral. Girls with PTSD were expected to show cognitive interference for trauma-related words as well as for developmentally relevant words, relative to adolescents without PTSD. Overall color naming was significantly slower in the PTSD group than in the nonabused controls. Contrary to expectation, all participants demonstrated cognitive interference for trauma-related words. Relevant theoretical and methodological issues are highlighted.     

Emotional working memory capacity in posttraumatic stress disorder (PTSD)

Participants with a lifetime history of posttraumatic stress disorder (PTSD) and trauma-exposed controls with no PTSD history completed an emotional working memory capacity (eWMC) task. The task required them to remember lists of neutral words over short intervals while simultaneously processing sentences describing dysfunctional trauma-related thoughts (relative to neutral control sentences). The task was designed to operationalise an everyday cognitive challenge for those with mental health problems such as PTSD; namely, the ability to carry out simple, routine tasks with emotionally benign material, while at the same time tackling emotional laden intrusive thoughts and feelings. eWMC performance, indexed as the ability to remember the word lists in the context of trauma sentences, relative to neutral sentences, was poorer overall in the PTSD group compared with controls, suggestive of a particular difficulty employing working memory in emotion-related contexts in those with a history of PTSD. The possible implications for developing affective working memory training as an adjunctive treatment for PTSD are explored.     

Weak evidence for increased motivated forgetting of trauma-related words in dissociated or traumatised individuals in a directed forgetting experiment

Motivated forgetting is the idea that people can block out, or forget, upsetting or traumatic memories, because there is a motivation to do so. Some researchers have cited directed forgetting studies using trauma-related words as evidence for the theory of motivated forgetting of trauma. In the current article subjects used the list method directed forgetting paradigm with both trauma-related words and positive words. After one list of words was presented subjects were directed to forget the words previously learned, and they then received another list of words. Each list was a mix of positive and trauma-related words, and the lists were counterbalanced. Later, subjects recalled as many of the words as they could, including the ones they were told to forget. Based on the theory that motivated forgetting would lead to recall deficits of trauma-related material, we created eight hypotheses. High dissociators, trauma-exposed, sexual trauma-exposed, and high dissociators with trauma-exposure participants were hypothesised to show enhanced forgetting of trauma words. Results indicated only one of eight hypotheses was supported: those higher on dissociation and trauma recalled fewer trauma words in the to-be-forgotten condition, compared to those low on dissociation and trauma. These results provide weak support for differential motivated forgetting.     

Emotional-processing in posttraumatic stress disorder II: startle reflex modulation during picture processing

This study examined the impact of a trauma-related stressor on subsequent emotional behavior in veterans with (n = 35) and without (n = 24) posttraumatic stress disorder (PTSD). Self-report and physiological responses, including acoustic startle, were recorded during viewing of emotionally evocative photographs at baseline and following exposure to trauma-related and non-trauma-related stressors. The 2 groups exhibited equivalent patterns of emotional response across self-report and physiological measures at baseline. In contrast, following the trauma challenge, participants with PTSD showed a pattern of startle modulation suggestive of greater defensive reactivity and reduced visual perceptual engagement. These findings, along with augmented corrugator EMG reactivity during the same interval, suggest that trauma-related reexperiencing primes subsequent negative emotional responding in individuals with PTSD.     

Is Acoustic Startle a Viable Exposure Protocol for Posttraumatic Stress Disorder? A Clinical Case Study

Exaggerated startle is a common symptom (based on Diagnostic and Statistical Manual of Mental Disorders [fourth edition] Criterion D) for many patients with posttraumatic stress disorder (PTSD). Findings from previous studies suggest that exaggerated startle may be due to trauma exposure or pretrauma vulnerability factors for PTSD development. The present clinical case study reports on a patient with PTSD characterized by a very prominent startle response and preference against standard trauma-related exposure strategies. On the basis of recent findings that interoceptive exposure exercises (e.g. shaking head side to side, hyperventilation) elicit trauma-related memories (Wald & Taylor, 2008), the authors sought to determine whether repeated application of an acoustic startle stimulus would serve to diminish the prominent startle response and facilitate exposure and overall symptom reduction by eliciting trauma-related memories. The protocol was successful in eliciting vivid and distressing trauma-related memories. Over the course of seven exposure trials, the patient demonstrated a decrease in distress elicited during the protocol, improved mood, and reduced general anxiety and trauma-related distress. He also reported significantly decreased startle response to loud noises encountered during activities of daily living. Although preliminary, these finding suggest that the acoustic startle protocol may be a viable (interoceptive) exposure strategy for individuals with PTSD, particularly those with exaggerated startle responses and those who are not amenable to standard trauma-related exposure strategies.     

False Memory Susceptibility in OEF/OIF Veterans With and Without PTSD

False memory susceptibility was measured in 80 Iraq/Afghanistan veterans with (n = 32) and without posttraumatic stress disorder (PTSD; n = 48) using a modified Deese-Roediger-McDermott (DRM) word list task that included trauma-related critical (nonpresented) lures. PTSD was classified using medical record diagnoses. Participants completed a variety of self-report assessments, including the Beck Depression Inventory, the Anxiety and Stress subscales of the Depression Anxiety Stress Scales, the Dissociative Experiences Scale, and the Tellegen Absorption Scale. Veterans with PTSD displayed global memory impairments on all types of items, except for trauma-related critical lures; on these critical lures, they exhibited false memory levels equal to those seen in veterans without PTSD. The magnitude of most effects were reduced, but not entirely eliminated, when controlling for depression, suggesting that neither PTSD nor co-occurring depression entirely explain these findings. The potential effects of other mental health conditions, such as alcohol dependence, could not be ruled out. Our results support explanations of PTSD that emphasize differential processing of trauma-related information.     

Is acoustic startle a viable exposure protocol for posttraumatic stress disorder? A clinical case study

Exaggerated startle is a common symptom (based on Diagnostic and Statistical Manual of Mental Disorders [fourth edition] Criterion D) for many patients with posttraumatic stress disorder (PTSD). Findings from previous studies suggest that exaggerated startle may be due to trauma exposure or pretrauma vulnerability factors for PTSD development. The present clinical case study reports on a patient with PTSD characterized by a very prominent startle response and preference against standard trauma-related exposure strategies. On the basis of recent findings that interoceptive exposure exercises (e.g. shaking head side to side, hyperventilation) elicit trauma-related memories (Wald & Taylor, 2008), the authors sought to determine whether repeated application of an acoustic startle stimulus would serve to diminish the prominent startle response and facilitate exposure and overall symptom reduction by eliciting trauma-related memories. The protocol was successful in eliciting vivid and distressing trauma-related memories. Over the course of seven exposure trials, the patient demonstrated a decrease in distress elicited during the protocol, improved mood, and reduced general anxiety and trauma-related distress. He also reported significantly decreased startle response to loud noises encountered during activities of daily living. Although preliminary, these finding suggest that the acoustic startle protocol may be a viable (interoceptive) exposure strategy for individuals with PTSD, particularly those with exaggerated startle responses and those who are not amenable to standard trauma-related exposure strategies.     

Attention, heart rate, and startle response during exposure to trauma-relevant pictures: a comparison of recent trauma victims and patients with posttraumatic stress disorder

Victims of a recent trauma were compared with posttraumatic stress disorder (PTSD) patients and healthy controls to assess whether a specific anxiety response and an attentional bias were evident initially or only in chronic PTSD. Heart rate (HR) and startle response were measured, and a dot-probe task was carried out using trauma-relevant pictures. Severely affected recent trauma victims and chronic PTSD patients showed HR acceleration to trauma-related material, which was the only significant group difference. A bias away from trauma-related material was related to severity of intrusions in recent trauma victims, and the bias toward trauma-related material increased with amplitude of the HR response in PTSD patients. A specific anxiety reaction is present initially in severely affected trauma victims.     

The Relationship between Personality Disorder Features and Symptom Improvement at an Inpatient Treatment Program for Posttraumatic Stress Disorder

This study examined the association between personality disorder (PD) features and symptom improvement among adult survivors of childhood trauma in an inpatient program for posttraumatic stress disorder (PTSD). Participants completed questionnaires at admission, discharge, and six months following discharge. Multiple regression analyses were used to assess the combined effects of personality features on symptom improvement. Results indicated that improvement in trauma-related symptoms was not related to PD features. By contrast, the PD features were associated with change in other Axis I symptoms often comorbid with PTSD. Overall, results suggested that PD features do not impede improvement in trauma-related symptoms; however, specific accommodations might be needed to address comorbid disorders among individuals with PTSD.     

The Driving Behavior Survey as a Measure of Behavioral Stress Responses to MVA-Related PTSD

Numerous treatments are available that address the core symptoms of posttraumatic stress disorder (PTSD). However, there are a number of related behavioral stress responses that are not assessed with PTSD measures, yet these behavioral stress responses affect quality of life. The goal of the current study was to investigate whether a recently developed measure of behavioral stress response, the Driving Behavior Survey (DBS), was sensitive to change associated with treatment among a group of participants diagnosed with PTSD. The DBS indexes anxious driving behavior, which is frequently observed among individuals with motor vehicle accident-related PTSD. Participants (n = 40) were racially diverse adults (M age = 40.78, 63% women) who met diagnostic criteria for motor vehicle accident-related PTSD. Hierarchical linear modeling analyses indicated that participants who were assigned to a brief, exposure-based intervention displayed significant reductions on the DBS subscales relative to participants assigned to the wait-list control condition (r = .41–.43). Moreover, mediational analyses indicated that the observed reductions on the DBS subscales were not better accounted for by reductions in PTSD. Taken together, these findings suggest that the DBS subscales are sensitive to changes associated with PTSD treatment and can be used to augment outcome assessment in PTSD treatment trials.     

Acceptance and Commitment Therapy for Treatment-Resistant Posttraumatic Stress Disorder: A Case Study

An adult woman with chronic posttraumatic stress disorder (PTSD) and major depressive disorder who was nonresponsive to 20 sessions of cognitive behavior therapy (CBT) is presented in this case study. Two months after her CBT trial, she was treated with 21 sessions of Acceptance and Commitment Therapy (ACT) for PTSD. Measurements of PTSD severity, depression, anxiety, psychological flexibility and trauma-related thoughts and beliefs were taken at pretreatment, after Sessions 8 and 16, and at posttreatment. Results showed significant reduction on all measures throughout treatment, except for trauma-related thoughts and beliefs, which did not decrease until near the end of treatment. Strengths, limitations, and future directions are discussed.     

Rebound effects following deliberate thought suppression: does PTSD make a difference?

This study was designed to examine the effects of deliberate suppression of trauma-related thoughts in 44 individuals who were PTSD+ and 26 individuals who were PTSD- following a motor vehicle accident (MVA). In an effort to resolve discrepancies in the literature, the PTSD- group was selected from the same help-seeking population as the patient group. Measures included the percentage of MVA-related thoughts, mood, perceived controllability of thoughts, and physiological arousal (heart rate, skin conductance, and two measures of facial EMG). Contrary to hypothesis, both PTSD+ and PTSD- groups showed a rebound in trauma-related thoughts following deliberate thought suppression. This rebound was associated with increases in negative affect, anxiety, and distress and diminished perceptions of controllability over thoughts. Examination of the physiological measures did not mirror the pattern noted for trauma-related thoughts, although the data suggest that suppression was associated with higher levels of frontalis EMG and possibly, reduced heart rate. The current study indicates that help-seeking individuals who are distressed about their psychological state following a serious MVA will show a rebound in MVA-related thoughts, irrespective of PTSD diagnosis. Implications for the study of thought suppression as a potential maintaining factor for trauma-related problems are discussed, with suggestions for future research.     

Written exposure as an intervention for PTSD: A randomized clinical trial with motor vehicle accident survivors

The present study examined the efficacy of a brief, written exposure therapy (WET) for posttraumatic stress disorder (PTSD). Participants were 46 adults with a current primary diagnosis of motor vehicle accident-related PTSD. Participants were randomly assigned to either WET or a waitlist (WL) condition. Independent assessments took place at baseline and 6-, 18-, and 30-weeks post baseline (WL condition not assessed at 30 weeks). Participants assigned to WET showed significant reductions in PTSD symptom severity at 6- and 18-week post-baseline, relative to WL participants, with large between-group effect sizes. In addition, significantly fewer WET participants met diagnostic criteria for PTSD at both the 6- and 18-week post-baseline assessments, relative to WL participants. Treatment gains were maintained for the WET participants at the 30-week post baseline assessment. Notably, only 9% of participants dropped out of WET and the WET participants reported a high degree of satisfaction with the treatment. These findings suggest that a brief, written exposure treatment may efficaciously treat PTSD. Future research should examine whether WET is efficacious with other PTSD samples, as well as compare the efficacy of WET with that of evidence-based treatments for PTSD.     

Perceptual and response components in repetition priming of spoken words and pseudowords

Two experiments explored repetition priming effects for spoken words and pseudowords in order to investigate abstractionist and episodic accounts of spoken word recognition and repetition priming. In Experiment 1, lexical decisions were made on spoken words and pseudowords with half of the items presented twice (～12 intervening items). Half of all repetitions were spoken in a “different voice” from the first presentations. Experiment 2 used the same procedure but with stimuli embedded in noise to slow responses. Results showed greater priming for words than for pseudowords and no effect of voice change in both normal and effortful processing conditions. Additional analyses showed that for slower participants, priming is more equivalent for words and pseudowords, suggesting episodic stimulus–response associations that suppress familiarity-based mechanisms that ordinarily enhance word priming. By relating behavioural priming to the time-course of pseudoword identification we showed that under normal listening conditions (Experiment 1) priming reflects facilitation of both perceptual and decision components, whereas in effortful listening conditions (Experiment 2) priming effects primarily reflect enhanced decision/response generation processes. Both stimulus–response associations and enhanced processing of sensory input seem to be voice independent, providing novel evidence concerning the degree of perceptual abstraction in the recognition of spoken words and pseudowords.