An analogue study of intrusions

Examining the role of trait anxiety and attentional bias to negative information in intrusion vulnerability following an emotionally negative event

BACKGROUND AND OBJECTIVES

Research shows that individuals with heightened trait anxiety are more likely to experience intrusions; however, the mechanism that accounts for this relationship is unclear. Two alternative hypotheses were tested to determine the nature of the associations between trait anxiety, attentional bias to negative information, and intrusion vulnerability.

METHODS

Intrusions were elicited using the trauma film paradigm, and post-event attentional bias to negative information was assessed using the dot-probe task. Participants then completed a week-long intrusions diary.

RESULTS

Results showed that attentional bias to negative information mediated the effect of heightened trait anxiety on elevated intrusion frequency. It was also revealed that heightened trait anxiety was associated with elevated intrusion-related distress, though attentional bias to negative information did not mediate this relationship.

LIMITATIONS

Our sample was comprised of undergraduate students who were not selected based on a previous pathology. Replication in clinical samples is warranted.

CONCLUSIONS

These findings provide new insight regarding individual differences in the experience of intrusions and suggest that both the frequency and distress associated with intrusions could represent clinical targets.

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.

Can't get it out of my mind: A systematic review of predictors of intrusive memories of distressing events

Intrusive memories, when persistent and distressing, are theorized to underlie a range of transdiagnostic psychological symptoms and associated impairment. However, little is known about factors predicting the development and persistence of intrusive memories. The aim of this systematic review is to evaluate the literature on pre-event, event-based, and post-event predictors of intrusive memories. A systematic review was conducted, searching for studies that examined intrusive, event-based memories. One hundred and six articles were identified from PsycInfo, PubMed, and Medline databases. Experimental and prospective studies with clinical (N = 14) and nonclinical (N = 92) samples were critically reviewed, provided the inclusion of an analogue stressor with nonclinical samples, and that intrusive memories frequency and/or distress were assessed as primary dependent variables. Pre-existing psychopathology and pre-event appraisal style appear to predict intrusive memories (small to medium effects), whereas trait dissociation did not predict intrusive memories. Of studies examining event-based predictors, higher data-driven processing appears to predict intrusive memories with generally large effects. Post-event negative appraisals consistently predicted intrusive memories (medium to large effects), and preliminary evidence suggests higher post-event conceptual processing predicting fewer intrusive memories. This review synthesizes findings regarding a broad range of pre-event, event-based, and post-event factors that may influence the development of intrusive memories. Methodological issues of current paradigms and the lack of emphasis on memory retrieval processes limit our understanding of what predicts intrusive memory persistence. These limitations are particularly important given that individuals typically seek treatment for distressing intrusive memories once a memory has been fully consolidated, where retrieval processes are of utmost importance. (PsycINFO Database Record

A prospective examination of risk factors in the development of intrusions following a trauma analog

Several factors have been linked to the severity of posttraumatic distress, although retrospective designs in much of the literature limit conclusions regarding the temporal relation between risk factors and corresponding symptoms. To address these concerns, the current project employed an analog trauma paradigm to assess the impact of background characteristics, stress response, and post-stressor affect regulation on subjective distress and intrusive memories experienced during the subsequent processing of emotional stimuli. University students (N = 184; 56% female, 42% White/Non-Hispanic) were shown graphic scenes of a televised suicide. Physiological activation was recorded during exposure with emotion ratings collected following the film. Participants then viewed a sadness- or humor-eliciting prime under instructions to inhibit or naturally express emotion. Intrusions experienced during the priming film and residual distress at study's conclusion were rated prior to debriefing. Hierarchical regression identified reductions in emotional valence as a robust predictor of intrusions and distress. Sympathetic activation and exposure to the sadness prime were associated with intrusion frequency, whereas attenuated parasympathetic response predicted intrusion intensity. Expressive inhibition demonstrated a unique association with residual distress. Results suggest peritraumatic processes and post-exposure factors may hold more prominent relations with immediate trauma-related distress as compared to pre-existing survivor characteristics.

The impact of dissociation on perceptual priming and intrusions after listening to auditory narratives

This study investigates the causal role of dissociation in intrusive memory development and possible underlying aberrant memory processes (e.g., increased perceptual priming). Using an audio-only adaption of the trauma film paradigm, we divided 60 participants into 3 conditions and presented them with different visual tasks-mirror staring, dot staring, or neutral images. The former 2 conditions were hypothesized to induce dissociation. Postaudio, a number of factors were assessed, including state dissociation, perceptual priming and conceptual priming, as well as intrusions over 3 days. Participants in the dissociation conditions displayed an increase in perceptual priming compared to those in the control condition and reported more distressing intrusions. No differences were found in conceptual priming and the overall number of intrusions between conditions. Findings contribute to the growing knowledge on the impact of dissociation and cognitive processing in the etiology of posttraumatic stress disorder intrusions.

Updating versus Exposure to Prevent Consolidation of Conditioned Fear

Targeting the consolidation of fear memories following trauma may offer a promising method for preventing the development of flashbacks and other unwanted re-experiencing symptoms that characterise Posttraumatic Stress Disorder (PTSD). Research has demonstrated that performing visuo-spatial tasks after analogue trauma can block the consolidation of fear memory and reduce the frequency of flashbacks. However, no research has yet used verbal techniques to alter memories during the consolidation window. This is surprising given that the most effective treatments for PTSD are verbally-based with exposure therapy and trauma-focused cognitive behavioural therapy gaining the most evidence of efficacy. Psychological therapies aim to reduce the conditioned fear response, which is in keeping with the preliminary finding that an increased propensity for fear conditioning may be a vulnerability factor for PTSD. Our research had two aims. We investigated the degree to which individual differences in fear conditioning predict the development of PTSD symptoms. We also compared the preventative effects of two clinically informed psychological techniques administered during the consolidation window: exposure to the trauma memory and updating the meaning of the trauma. 115 healthy participants underwent a fear conditioning paradigm in which traumatic film stimuli (unconditioned stimuli) were paired with neutral stimuli (conditioned stimuli). Participants were randomly allocated to an updating, exposure or control group to compare the effects on the conditioned fear response and on PTSD symptomatology. The results showed that stronger conditioned responses at acquisition significantly predicted the development of PTSD symptoms. The updating group, who verbally devalued the unconditioned stimulus within the consolidation window, experienced significantly lower levels of PTSD symptoms during follow-up than the exposure and control groups. These findings are consistent with clinical interventions for chronic PTSD and have important implications for identifying those at risk as well as for designing novel early interventions to prevent the development of PTSD.

Expressive inhibition in response to stress: implications for emotional processing following trauma

Expressive inhibition--the willful restriction of expressed emotion--is documented in individuals reporting trauma-related distress, but its impact on global affective functioning remains unclear. Theoretical models propose that chronic activation of negative emotion and deliberate restriction of affect operate synergistically to produce trauma-related emotional deficits. The current project examined the impact of these factors on subjective experience and physiological activation following exposure to an analog trauma. University students (N=192; Mage=20, 57% female, 42% White/Non-Hispanic) viewed a graphic film depicting scenes of a televised suicide. Participants then viewed either a sadness- or humor-eliciting film under instructions to inhibit [nsadness=45, nhumor=52] or naturally express emotion [nsadness=48, nhumor=47]. Expressive inhibition was associated with restricted amusement specifically among participants viewing the humor film. Inhibition also produced attenuated sympathetic and parasympathetic recovery, irrespective of film assignment. Evidence of disruptions in emotional processing supports models identifying inhibition as a possible mechanism in post-trauma affect dysregulation.

False memories for missing aspects of traumatic events

Can people come to remember an event as being more traumatic than they initially experienced? Participants watched a highly structured and emotionally disturbing film depicting a car accident in which five people, including a baby, are killed. We broke the film down into a series of short clips; some of which we removed. Later, we tested participants' memory for what they had and had not seen. While participants were highly accurate identifying what they had and definitely had not seen, they also falsely claimed to have seen 26% of the missing clips, clips that fitted with the film but were removed before screening. Moreover, participants were particularly likely to recall the missing clips that were considered to be the most critical and traumatic. Importantly, they did so with high confidence. We discuss both intentional and unintentional recall mechanisms that may promote the observed memory distortion.

The prediction of intrusions following an analogue traumatic event: peritraumatic cognitive processes and anxiety-focused rumination versus rumination in response to intrusions

Intrusions are often considered the hallmark of posttraumatic stress disorder (PTSD). Despite this, relatively little is known about factors that give rise to intrusions. Cognitive models of PTSD highlight the importance of pre-existing cognitive vulnerabilities, cognitive processing and anxiety during a traumatic event, as well as negative responses to trauma sequelae. However, few studies have examined multiple forms of peritraumatic processes, and rumination in response to trauma intrusions using analogue trauma tasks, and none have examined whether broader anxious ruminative processes contribute to intrusion development. In addition, little work has investigated the role of post-state anxiety in intrusions, and anxiety may be related to both peritraumatic processing and rumination. The current study employed a distressing film paradigm to examine key tenets of cognitive models of PTSD. Ninety-one female university students completed measures of anxiety, rumination in response to anxious symptoms, peritraumatic dissociation, data driven processing, lack of self referent processing, intrusions, and rumination in response to intrusions of the distressing film. Results revealed that peritraumatic dissociation, data driven processing, and self referent processing were associated with intrusion development, with lack of self referent processing being a strong predictor of intrusion development. Post-state anxiety and rumination in response to intrusions also predicted intrusion development. Discussion focuses on implications of cognitive processes and anxiety in theories of intrusion development.

Individual differences in emotionality and peri-traumatic processing

BACKGROUND AND OBJECTIVES

Recent cognitive models propose that intrusive trauma memories arise and persist because high levels of emotional arousal triggered by the trauma disrupt conceptual processing of elements of the event, while enhancing sensory/perceptual processing. A trauma film analogue design was used to investigate if the predicted facilitating effects on intrusions from inhibiting conceptual processing and predicted attenuating effects on intrusions from inhibiting sensory processing are moderated by individual differences in emotionality.

METHODS

One hundred and five non-clinical participants viewed a traumatic film while undertaking a conceptual interference task, a sensory interference task, or no interference task. Participants recorded the frequency and intensity of intrusions over the following week.

RESULTS

There was no facilitating effect for the conceptual interference task compared to no interference task. A significant attenuation of the frequency of intrusions was evident for those undertaking sensory interference (ŋ(2) = .04). This effect, however, was only present for those with high trait anxiety (d = .82) and not for those with low trait anxiety (d = .08). Relative to high trait anxious controls, high anxious participants who undertook sensory interference also reported lower intensity of intrusions (d = .66).

CONCLUSIONS

This is the first trauma film analogue study to show that the attenuating effect of concurrent sensory/perceptual processing on the frequency and intensity of subsequent intrusions is evident only for people with high trait anxiety. The results have implications for conceptual models of intrusion development and for their application to the prevention of post traumatic distress.

Pathways to intrusive memories in a trauma analogue paradigm: a structural equation model

BACKGROUND

Structural equation modeling was used to develop and test an integrated model of how emotional and cognitive factors contribute to the development of intrusive memories after a distressing event.

METHODS

The emotional constructs included preexisting emotion and emotional reactivity to the distressing event. Cognitive constructs included peritraumatic cognitive processing and maladaptive coping strategies.

RESULTS

Using a prospective design, 148 undergraduate students viewed a distressing film and recorded their film-related intrusive memories over the following week.

RESULTS

The results indicated that emotional reactivity and, to a lesser extent, preexisting emotion, predicted peritraumatic cognitive processing during the film, which in turn predicted the use of maladaptive coping strategies (i.e., rumination, thought suppression, and safety behaviors). Furthermore, emotional reactivity and maladaptive coping strategies directly predicted intrusive memories.

CONCLUSIONS

The observed model supported the importance of cognitive variables central to cognitive models, placing them in a broader context.

The effect of pre-existing vulnerability factors on a laboratory analogue trauma experience

This study examined how pre-existing emotional and personality vulnerability factors affect responses to an analogue trauma experience. Sixty-eight undergraduate participants viewed a distressing film and completed measures of trait anxiety, intelligence, depression, trait dissociation, as well as changes in state anxiety, then recorded intrusions over the following week. Results revealed that trait anxiety, depression, trait dissociation, change in anxiety, and post-state anxiety were associated with intrusion frequency. Post-state anxiety mediated the relationship between trait anxiety, depression and trait dissociation, and intrusions. Implications for PTSD theories and laboratory trauma analogue research examining specific elements of cognitive models of PTSD are discussed.

Inducing and modulating intrusive emotional memories: a review of the trauma film paradigm

Highly affect-laden memory intrusions are a feature of several psychological disorders with intrusive images of trauma especially associated with post-traumatic stress disorder (PTSD). The trauma film paradigm provides a prospective experimental tool for investigating analogue peri-traumatic cognitive mechanisms underlying intrusion development. We review several historical papers and some more recent key studies that have used the trauma film paradigm. A heuristic diagram is presented, designed to simplify predictions about analogue peri-traumatic processing and intrusion development, which can also be related to the processing elements of recent cognitive models of PTSD. Results show intrusions can be induced in the laboratory and their frequency amplified/attenuated in line with predictions. Successful manipulations include competing task type (visuospatial vs. verbal) and use of a cognitive coping strategy. Studies show that spontaneous peri-traumatic dissociation also affects intrusion frequency although attempts to manipulate dissociation have failed. It is hoped that further use of this paradigm may lead to prophylactic training for at risk groups and an improved understanding of intrusions across psychopathologies.