Intrusive images and intrusive thoughts as different phenomena: Two experimental studies

According to the dual representation theory of PTSD, intrusive trauma images and intrusive verbal thoughts are produced by separate memory systems. In a previous article it was shown that after watching an aversive film, participants in non-movement conditions reported more intrusive images than participants in a free-to-move control condition (Hagenaars, Van Minnen, Holmes, Brewin, & Hoogduin, 2008). The present study investigates whether the experimental conditions of the Hagenaars et al. study had a different effect on intrusive thoughts than on intrusive images. Experiment 2 further investigated the image–thoughts distinction by manipulating stimulus valence (trauma film versus neutral film) and assessing the subsequent development of intrusive images and thoughts. In addition, both experiments studied the impact of peri-traumatic emotions on subsequent intrusive images and thoughts frequency across conditions. Results showed that experimental manipulations (non-movement and trauma film) caused higher levels of intrusive images relative to control conditions (free movement and neutral film) but they did not affect intrusive thoughts. Peri-traumatic anxiety and horror were associated with subsequent higher levels of intrusive images, but not intrusive thoughts. Correlations were inconclusive for anger and sadness. The results suggest intrusive images and thoughts can be manipulated independently and as such can be considered different phenomena.     

The relationship between suppression and subsequent intrusions: the mediating role of peritraumatic dissociation and anxiety

Background and objectives: Although previous studies showed that thought and emotion suppression represent risk factors for intrusions development, the mechanisms that explain these relations were less explored. This study aims to examine the relationships between thought and emotion suppression and the symptoms of intrusion following the exposure to a trauma-related event. Moreover, we explored if these relationships would be mediated by peritraumatic state dissociation and state anxiety.

Design and methods: The trauma film paradigm was used and the participants were students (N?=?148) experimentally exposed to an aversive film to model a traumatic experience. Thought and emotion suppression were measured before the trauma exposure. After exposure, the participants completed scales for measuring state dissociation and state anxiety. Intrusive images and thoughts of the film were recorded in the subsequent week using an intrusion diary.

Results: Thought suppression predicted intrusive thoughts frequency, and this effect was mediated by the peritraumatic anxiety. State anxiety predicted both intrusive images and thoughts, while state dissociation only predicted intrusive images.

Conclusions: Intrusive images and intrusive thoughts are different phenomena and they are predicted by different variables. The practical implications of these results for posttraumatic stress disorder treatment and secondary traumatization are discussed.     

Retrieval-induced forgetting and unwanted thought intrusions

The act of retrieving an existing memory has been found to inhibit the recall of related memories, a phenomenon known as retrieval-induced forgetting (RIF). The purpose of the present study was to investigate the hypothesis that individuals with a strong RIF effect might be better at suppressing unwanted intrusive thoughts. In Experiment 1 the relationship between RIF and the prevalence of intrusive thoughts was investigated using a sample of 58 normal British participants, who completed three different questionnaires to measure their susceptibility to intrusive thoughts, obsessional thoughts, and impulsive thoughts. Their susceptibility to RIF was also measured, using the standard procedure introduced by Anderson, Bjork, and Bjork (1994). The results showed a significant RIF effect, and, although no significant correlations were found between RIF strength and any of the three measures of intrusive thoughts, there was some evidence to suggest a possible relationship between RIF and intrusive thoughts. In an effort to clarify these inconclusive findings, Experiment 2 investigated the relationship between RIF and intrusive thoughts in a different and more varied population sample, consisting of 90 normal members of the Greek population. Experiment 2 confirmed the RIF effect, but no significant association was found between RIF and intrusive thoughts. These findings therefore offer no support for the hypothesis that RIF assists the suppression of intrusive thoughts in normal individuals.     

Hunger-related intrusive thoughts reflect increased accessibility of food items

The elaborated intrusion model (Kavanagh, Andrade, & May, 2005) argues that a craving episode begins with a desire-related intrusive thought. This study tests the assumption that such intrusive thoughts, during hunger, reflect an increase in accessibility of food-related information in memory. Fifty-six undergraduates were randomly assigned to hungry or satiated conditions. Hunger was manipulated by asking the “hungry” group to abstain from eating breakfast and snacks prior to testing before lunch, while the “satiated” group was asked to eat normally and attend testing after lunch. Participants completed a lexical decision task containing food-related and neutral words, an intrusive thoughts questionnaire and a hunger questionnaire. Priming for food-related items relative to neutral on the lexical decision task was higher for hungry participants than satiated participants. Priming correlated strongly with frequency of food-related intrusive thoughts during the task. We conclude that desire-related lexical decision priming could provide a useful objective correlate of proneness to desire-related intrusions.     

Using stressful films to analyze risk factors for PTSD in analogue experimental studies – which film works best?

Abstract

To understand mental disorders, analogue paradigms provide an indispensable contribution. In posttraumatic stress disorder (PTSD), the stressful film paradigm is a frequently used analogue approach: Films depicting traumatic events are shown to non-clinical participants in order to elicit stress responses analogue to responses to traumatic events in real life. Previous studies used a large variety of films, which is problematic with regard to the comparability of results. The main goal of this study was to identify a film clip that (a) consistently provokes stress reactions and (b) provokes reactions that are as similar as possible to traumatic stress.

We randomly exposed 105 male and female participants to one of four stressful films, differing, e.g., in content and origin. Intrusive memories of the film, reported immediately after the film and during a diary phase of three days, as well as distress, heart rate, and several mood states were measured. A film clip depicting rape elicited the most consistent reactions that were characterized by a higher heart rate, more distress and more intrusive memories, compared to the other three clips. Intrusive memories across all films were especially related to an increase in heart rate and disgust in response to the film.     

Obsessional beliefs and the implicit and explicit morality of intrusive thoughts

Cognitive models of obsessive-compulsive disorder (OCD) suggest that misinterpreting intrusive thoughts exacerbates obsessional thinking. To evaluate this hypothesis, healthy participants (N=91) were prompted to recollect their unwanted thoughts, and then beliefs about the immorality of these thoughts were manipulated. Next, participants completed implicit and explicit measures of self-evaluation and appraisals of unwanted thoughts. Results from structural regression analyses indicated that explicit responses to unwanted thoughts, such as evaluations of the significance of intrusive thoughts and state self-esteem, were predicted by pre-existing obsessional beliefs, but not by the morality instruction manipulation. In contrast, implicit responses, such as appraisals of unwanted thoughts as relatively important and evaluations of the self as relatively immoral and dangerous, were predicted by the interaction between specific obsessional beliefs (e.g., intolerance of uncertainty) and the morality instructions. Findings largely support cognitive models of OCD and suggest unique predictors of implicit and explicit responses to unwanted thoughts.     

Intrusive thoughts mediate the association between neuroticism and cognitive function

Although research has established a negative association between trait neuroticism and cognition, little is known about the mechanisms that underlie this relationship. We examined the tendency to experience intrusive thoughts and negative affect as potential mediators of the relationship between neuroticism and cognitive performance. We hypothesized that the tendency to experience intrusive thoughts reflects ineffective attentional control and would account for the relationship between neuroticism and cognitive performance over and above the mediating effect of negative affect. Three hundred seventeen adults (M_age = 49.43) completed a series of attention-demanding cognitive tasks as well as self-report measures of intrusive thoughts, negative affect, and neuroticism. Intrusive thoughts mediated the association between trait neuroticism and cognitive performance beyond negative affect. These findings are consistent with the hypothesis that the tendency to experience intrusive thoughts is a mechanism through which trait neuroticism influences cognitive performance.     

闯入性思维对网络成瘾的影响:一个有调节的中介模型

本研究基于有限自制力理论考察闯入性思维对网络成瘾的影响及自我控制的中介作用和认知重评的调节作用。以371名大学生为被试,采用闯入性思维量表、自我控制量表、认知重评量表和网络成瘾量表进行测试,结果发现:(1)闯入性思维和自我控制呈显著负相关,与网络成瘾呈显著正相关;自我控制与网络成瘾呈显著负相关。(2)闯入性思维通过自我控制的中介作用对网络成瘾产生影响。(3)“闯入性思维—自我控制—网络成瘾”这一中介效应的前半段受到认知重评的影响;与低认知重评的个体相比,闯入性思维对高认知重评个体自我控制的影响更小。表达抑制不能调节闯入性思维对自我控制的影响。本研究的结果表明,闯入性思维会通过降低自我控制来增加网络成瘾的风险,而且认知重评会削弱闯入性思维对自我控制的影响。     

Cognitive control of obsessional thoughts

A defining characteristic of obsessive-compulsive disorder (OCD) is unsuccessful suppression of unwanted thoughts. Recent evidence of individual differences in ability to control intrusive thoughts may inform our understanding of failures of cognitive control associated with OCD symptomatology. The current study investigated characteristics of cognitive style that are potentially associated with OCD symptoms and may influence response to unwanted thoughts, including perceived ability to control thoughts and tendency to ruminate. Undergraduate students (N = 166) completed self-report measures of OCD symptoms, perceived thought control, and ruminative thinking. They were then presented with a distressing target thought and completed a standard thought suppression paradigm. Correlational results indicated that, controlling for anxiety and depression, OCD symptoms were positively associated with rumination and inversely associated with perceived thought control ability. In addition, OCD symptoms were associated with higher levels of distress and greater spontaneous efforts to suppress the target thought during a baseline period, while perceived thought control ability predicted frequency of target thoughts during suppression. Finally, results of the experimental manipulation confirmed that participants instructed to suppress experienced more intrusions during the recovery period. Clinical implications and future directions are discussed.     

“Why” or “How”: The Effect of Concrete Versus Abstract Processing on Intrusive Memories Following Analogue Trauma

Emergency service workers, military personnel, and journalists working in conflict zones are regularly exposed to trauma as part of their jobs and suffer higher rates of posttraumatic stress compared with the general population. These individuals often know that they will be exposed to trauma and therefore have the opportunity to adopt potentially protective cognitive strategies. One cognitive strategy linked to better mood and recovery from upsetting events is concrete information processing. Conversely, abstract information processing is linked to the development of anxiety and depression. We trained 50 healthy participants to apply an abstract or concrete mode of processing to six traumatic film clips and to apply this mode of processing to a posttraining traumatic film. Intrusive memories of the films were recorded for 1 week and the Impact of Events Scale–Revised (IES-R; Weiss & Marmar, 1997) was completed at 1-week follow-up. As predicted, participants in the concrete condition reported significantly fewer intrusive memories in response to the films and had lower IES-R scores compared with those in the abstract condition. They also showed reduced emotional reactivity to the posttraining film. Self-reported proneness to intrusive memories in everyday life was significantly correlated with intrusive memories of the films, whereas trait rumination, trait dissociation, and sleep difficulties were not. Findings suggest that training individuals to adopt a concrete mode of information processing during analogue trauma may protect against the development of intrusive memories.     

Effects of suppression and appraisals on thought frequency and distress

Cognitive theories of obsessions highlight appraisals of personal significance and thought suppression in the development and maintenance of intrusive thoughts. The current study examined the role of personal significance within the context of a thought suppression paradigm. The primary aim was to examine whether suppression would have differential effects for target thoughts appraised as personally meaningful versus relatively unimportant. A blasphemous thought served as the target thought, and highly religious and nonreligious participants were recruited. Participants completed a two-interval thought suppression task; during interval 1 they were randomly assigned to suppress or not suppress the target thought and during interval 2, all participants were given “do not suppress” instructions. Suppression resulted in sustained frequency of thoughts in contrast to the decline in thought frequency observed for non-suppression. Differential effects of suppression were found across the two groups. Moreover, suppression was associated with increased negative mood and anxiety. Results suggest that suppression of personally meaningful thoughts is a counterproductive strategy.     

Appraisals of obsessional thoughts in normal samples

Cognitive theories of obsessive-compulsive disorder (OCD) posit that appraisals about the significance of thoughts are critical in the development and persistence of obsessions. Rachman [(1997). A cognitive theory of obsessions. Behaviour Research and Therapy, 35, 793-802.] proposes that appraisals of unwanted thoughts distinguish clinical obsessions from normal intrusive thoughts; thoughts appraised as important and personally significant are expected to be upsetting and recur. Appraisals are also expected to be related to symptoms of OCD. To explore the features of normal appraisals of obsession-like thoughts, nonclinical participants in two studies rated the personal significance of intrusive thoughts portrayed in vignettes containing prototypical themes associated with primary obsessions: aggressive, sexual, and blasphemous thoughts. Unwanted intrusive thoughts that were described as occurring more frequently were appraised as more personally significant, but participants appraised these socially unacceptable thoughts similarly whether they imagined having personally experienced them or a friend confiding about having experienced them. Appraisals in both studies were related to subclinical OC symptoms and OC beliefs.     

The joint influence of mood and a cognitively demanding task on risk-taking

This study investigates a mood regulation-based reconciliation of prior findings in the mood maintenance and information processes literatures about the impact of negative mood state on risktaking judgment. Participants were administered a negative mood state induction using a standardized film clip procedure and subsequently completed a measure of risk-taking judgment under one of three conditions: (1) immediately following the mood induction, (2) following a 5 min no-task delay period, or (3) following performance of a cognitively demanding task. As expected, participants who made risk judgments after the performance of the cognitively demanding task showed higher level of recovery from the negative mood induction (i.e., increased positive mood and decreased negative mood) and lower levels of risk-taking judgment than participants in the delayed condition. Additional analyses showed the risk-taking judgments were explained by mood change after the interpolated task. These findings reconcile previous inconsistencies between the two perspectives. Implications for future research on the restorative role of cognitive task performance as a mood regulation strategy are discussed.     

False Memories for an Analogue Trauma: Does Thought Suppression Help or Hinder Memory Accuracy?

In the current study, we investigated whether suppression can produce an amplified memory for a traumatic experience. Participants viewed a distressing film depicting a multi‐fatality car accident. We broke the film down into several short clips, some of which were removed. After viewing the film, we instructed participants to (i) suppress and monitor film‐related thoughts, (ii) think freely and monitor film‐related thoughts or (iii) just think freely. Twenty‐four hours later, participants completed a recognition test. Memory distortion was comparable across conditions; however, suppression and monitoring of trauma‐related thoughts removed the typical bias to falsely remember the most critical and traumatic clips of the film over the least critical clips. Our data suggest that suppression may be effective in reducing trauma‐related cognitions and, therefore, does not predict a more ‘amplified’ memory for trauma. Instead, suppression and thought monitoring encourage an unbiased, although inaccurate, memory for trauma.Copyright © 2016 John Wiley & Sons, Ltd.     

The role of objective versus perceived life threat in the psychological adjustment to cancer

Several studies in the oncology literature have used disease stage as a measure of life threat. According to the transactional model of stress (Lazarus and Folkman, ), however, the individual's perception of a threatening situation is more strongly related to distress than the objective event itself. Thus, the present study examined whether cancer patients’ perceived life threat (PLT) is more strongly associated with psychological adjustment than a more objective index of disease prognosis (i.e., cancer stage). In addition, based on cognitive processing theories, this study examined whether intrusive thoughts and avoidance, cognitive characteristics of posttraumatic stress disorder (PTSD), mediate the relationship between PLT and distress. Patients diagnosed with various types of cancer (N = 97) completed questionnaires assessing PLT, cancer-related intrusive thoughts and avoidance, distress, and quality of life. Consistent with theoretical predictions, regression analyses showed that PLT, but not disease stage, was significantly related to psychological distress and quality of life. In addition, intrusive thoughts and avoidance mediated the relationship between PLT and distress. Taken together, these findings suggest that cancer patients’ PLT is more strongly related to distress than is cancer stage and that this association is partly due to cognitive symptoms that are part of PTSD symptomatology. Thus, patients who appraise their illness as life threatening may benefit from cognitive interventions aimed at reducing distress associated with intrusive thoughts.     

Hypnosis,hypnotic suggestibility,memory, and involvement in films

Our research extends studies that have examined the relation between hypnotic suggestibility and experiential involvement and the role of an hypnotic induction in enhancing experiential involvement (e.g., absorption) in engaging tasks. Researchers have reported increased involvement in reading (Baum & Lynn, 1981) and music-listening (Snodgrass & Lynn, 1989) tasks during hypnosis. We predicted a similar effect for film viewing: greater experiential involvement in an emotional (The Champ) versus a non-emotional (Scenes of Toronto) film. We tested 121 participants who completed measures of absorption and trait dissociation and the Harvard Group Scale of Hypnotic Susceptibility and then viewed the two films after either an hypnotic induction or a non-hypnotic task (i.e., anagrams). Experiential involvement varied as a function of hypnotic suggestibility and film clip. Highly suggestible participants reported more state depersonalization than less suggestible participants, and depersonalization was associated with negative affect; however, we observed no significant correlation between hypnotic suggestibility and trait dissociation. Although hypnosis had no effect on memory commission or omission errors, contrary to the hypothesis that hypnosis facilitates absorption in emotionally engaging tasks, the emotional film was associated with more commission and omission errors compared with the non-emotional film.     

Role of prior negative cognitions on the development of intrusive thoughts

This analogue study examined how individuals' prior negative cognitions influenced intrusion frequency, intrusion‐related distress and thought suppression. Participants at high (HR) and low risk (LR) for interpreting their intrusive thoughts in a negative manner viewed a graphic trauma film and their subsequent intrusion development was assessed. HR participants experienced a greater frequency of intrusions and intrusion‐related distress compared to LR participants. Trait thought suppression moderated the relationship between risk for the negative interpretation of intrusions and intrusion frequency. The findings suggest that pre‐existing negative cognitions are influential in the development of intrusions following exposure to an analogue trauma.     

An examination of trait,spontaneous and instructed emotion regulation in dysphoria

Depression is thought to be characterised by impaired emotion regulation, although the mechanisms of that regulation are not yet well understood. The present study examined trait, spontaneous and instructed emotion regulation in dysphoric (n = 66) and non-dysphoric (n = 86) participants. Participants were randomly assigned to use reappraisal while watching a sadness-inducing film clip (instructed emotion regulation condition) or were not given specific viewing instructions (spontaneous emotion regulation condition). Participants also completed trait measures of emotion regulation. Dysphoric individuals reported greater spontaneous use of rumination and suppression than non-dysphoric individuals, and these strategies were associated with greater negative emotional reactivity to the sadness-inducing film clip. Both participant groups were able to effectively use reappraisal when instructed to do so. The clinical implications of these findings and future research directions are discussed.     

The cognitive mediation of thought-control strategies

Research suggests that people use various strategies to control their normally occurring intrusive thoughts. Strategies that involve worrying about the thought and self punishment appear to be associated with certain forms of psychopathology, such as obsessive-compulsive (OC) symptoms. The present study sought to examine whether dysfunctional beliefs associated with OC symptoms (e.g., beliefs that intrusive thoughts are highly significant) underlie the use of such thought control strategies. Ninety-three non-clinical participants completed self-report questionnaires measuring cognitive variables, thought-control strategies, and OC symptoms. Analyses revealed that overestimates of threat and responsibility, beliefs about the significance and need to control intrusions, the need for perfection and certainty, and scrupulosity were associated with the use of punishment, but not worry thought control strategies. These cognitive phenomena also mediated the relationship between OC symptoms and the use of punishment as a thought-control strategy. Results are discussed in terms of cognitive models of OC symptoms and their implications for cognitive-behavioral therapy.     

Implicit and explicit appraisals of the importance of intrusive thoughts

To evaluate cognitive theories of obsessions, the current study experimentally manipulated appraisals of the importance of intrusive thoughts. Undergraduate students (N = 156) completed measures of obsessive-compulsive disorder (OCD) symptoms and beliefs and were primed with a list of commonly reported unwanted thoughts. Participants were then informed that unwanted thoughts are either (1) significant and indicative of their personal values, or (2) meaningless, or participants (3) received no instructions about unwanted thoughts. Participants then completed implicit and explicit measures of self-evaluation and interpretations of their unwanted thoughts. Results indicated that the manipulation shifted implicit appraisals of unwanted thoughts in the expected direction, but not self-evaluations of morality or dangerousness. Interestingly, explicit self-esteem and beliefs about the significance of unwanted thoughts were associated with measures of OCD beliefs, whereas implicit self-evaluations of dangerousness were better predicted by the interaction of pre-existing OCD beliefs with the manipulation. Results are discussed in terms of divergent predictors of implicit and explicit responses to unwanted thoughts.