Imagery rescripting: The value of an added positive emotion component

BACKGROUND AND OBJECTIVES

Imagery Rescripting (ImRs) aims to reduce trauma-related negative emotions and intrusions. Positive emotions during ImRs may aid coping with the consequences of trauma, but protocols vary in the extent to which they explicitly target such positive emotions. We used a multiple-day design with a trauma film paradigm to investigate whether adding an explicit positive emotion component to ImRs improved intervention effects in a non-clinical sample. In addition, we explored potentially differential effects on high, medium, and low arousal positive affect.

METHODS

Participants (n = 105) were randomly assigned to either a standard ImRs condition, to an ImRs condition with an added explicit positive emotion component targeting joy (ImRs+), or to a non-intervention control (NIC) condition. Participants watched a trauma film on day 1, received the condition-specific intervention on day 2, and completed additional post-assessments of positive and negative affect on day 3. In addition, participants recorded intrusions from the trauma film from day 1 until day 3.

RESULTS

Compared to standard ImRs and NIC, ImRs + significantly increased positive affect. Exploratory analyses showed that this increase concerned medium and high, but not low arousal positive affect. No significant between-group differences were found for negative affect and intrusion-related outcomes.

LIMITATIONS

Floor effects for intrusions and negative affect limited our ability to fully investigate the potential benefits of targeting positive affect.

CONCLUSIONS

Adding a positive emotion component to ImRs reliably improved positive affect. More research is needed to determine whether explicitly targeting positive affect improves efficacy of ImRs for intrusion-related outcomes.

Posttraumatic Growth in U.S. Military Veterans: Results from the National Health and Resilience in Veterans Study

Despite increasing recognition that positive psychological changes or posttraumatic growth (PTG) may develop after highly stressful or traumatic events, contemporary population-based data on the epidemiology of PTG in high-risk samples such as U.S. military veterans are lacking. Additionally, in light of emerging evidence suggesting an 8-factor model of posttraumatic stress disorder (PTSD) symptoms, an up-to-date characterization of how these symptom clusters relate to PTG can help inform efforts to help promote PTG. Data were analyzed from the 2019-2020 National Health and Resilience in Veterans Study (NHRVS), which surveyed a nationally representative sample of 3,847 trauma-exposed U.S. veterans. Participants completed assessments of potentially traumatic events, PTSD symptoms, and PTG, as well as a broad range of sociodemographic, military, trauma, health, personality, and psychosocial characteristics. Results revealed that 63.2% of trauma-exposed veterans and 86.4% of veterans who screened positive for PTSD endorsed moderate-or-greater PTG; these prevalences are higher than those reported in an independent U.S. veteran sample in 2011 (50.1% and 72.0%, respectively). An inverted U-shaped association was observed between PTSD symptom severity and PTG levels, with scores of 31 to 51 on the PTSD Checklist for DSM-5 associated with the highest likelihood of PTG. Intrinsic religiosity and internally- and externally-generated intrusive symptoms of PTSD were identified as the strongest correlates of PTG. Results suggest that prevention and treatment efforts to mitigate severe PTSD symptoms, and help promote intrinsic religiosity, and more deliberate and organized rumination about traumatic experiences may help foster PTG in veterans.

Using experience sampling methodology (ESM) to improve our understanding of day-to-day intrusion frequency and related distress in survivors of trauma

BACKGROUND AND OBJECTIVES

Cognitive models of posttraumatic stress disorder (PTSD) suggest that appraisals of traumatic sequelae and subsequent distress drive the development and maintenance of PTSD. Posttraumatic research has relied heavily on macro-longitudinal designs, with weeks or months between assessments of trauma-related cognitions and symptoms. The present study uses experience sampling methodology (ESM) better understand the day-to-day experiences of trauma exposed individuals.

METHODS

One-hundred trauma exposed adults reported their posttraumatic symptoms, interpretations, and behaviours four times a day over a 10-day ESM period.

RESULTS

As anticipated, within-person fluctuations in negative appraisals of intrusions and maladaptive coping strategies (e.g., thought suppression) were significantly positively associated with intrusion frequency and related distress. In all cases, the associations for negative appraisals and maladaptive coping were stronger with intrusion related distress than intrusion frequency.

LIMITATIONS

The observed contemporaneous associations only demonstrate that variables reliably fluctuated together and cannot indicate causality.

CONCLUSIONS

The findings demonstrate that day-to-day fluctuations in trauma related perceptions and sequelae are significant and should be explored alongside broader individual differences to advance our understanding of the development, maintenance, and treatment of PTSD.

The effectiveness of two novel approaches to prevent intrusions: A pilot study comparing Tetris_dualtask and imagery rescripting to control

BACKGROUND AND OBJECTIVES

Post-traumatic stress disorder (PTSD) is a global health problem. Although effective treatments for it exist, early interventions that prevent PTSD from developing are lacking. The aim of this pilot analogue trauma study was to compare the effects of two potential early intervention strategies, namely Tetris_dualtask and imagery rescripting (IR) to a no-intervention control group on intrusion frequency and the vividness and emotionality of aversive film memory.

METHODS

Sixty healthy students were subjected to the trauma film paradigm and randomly allocated to either: Tetris_dualtask, IR or no-intervention. Main outcomes were the number of film-related intrusions at one week and vividness and emotionality ratings of the most aversive film memory. Secondary outcomes were PTSD-like symptoms, intrusion intensity, and explicit film memory.

RESULTS

The Tetris_dualtask group reported significant fewer intrusions compared to the no-intervention group; whereas the IR group did not. No effect was found on vividness and emotionality ratings, PTSD-like symptoms, intrusion intensity, and explicit memory.

LIMITATIONS

The sample size was small, and analogue trauma in healthy individuals was examined, thus generalizability may be limited. Also, to increase comparability between interventions, the duration of Tetris_dualtask and IR was standardized. As a result, the IR intervention was shorter compared to other studies, which might have decreased its efficacy.

CONCLUSIONS

The results of this pilot study suggest that playing Tetris during retrieval of traumatic images, might hold potential as an early intervention strategy to reduce intrusions in the early aftermath of trauma and adversity. However, future large-scale replication research is needed.

Functional correlates of a novel 8-factor model of PTSD in U.S. military veterans: Results from the National Health and Resilience in Veterans Study

Emerging evidence indicates that more nuanced models of posttraumatic stress disorder (PTSD) may better capture the condition's symptom structure. Recent theoretical and empirical work suggest that an 8-factor model of PTSD with separate internally- (e.g. flashbacks) and externally- (e.g. trauma-cue related physiological reactivity) generated intrusive symptom clusters may advance understanding of PTSD and its treatment and course. However, the model's functional and clinical significance still requires evaluation. To this end, we analyzed data from the National Health and Resilience in Veterans Study, a nationally representative sample of 3847 trauma-exposed U.S. military veterans. Multivariable regressions were performed to assess the relationship between the 8 PTSD symptom clusters, assessed using the PTSD Checklist for DSM-5, and clinical and functional measures. Results revealed that externally-generated intrusions were associated with higher odds of current depression and anxiety and worse mental, cognitive, and psychosocial functioning. Anhedonia (e.g., loss of interest in enjoyable activities) symptoms were associated with all the correlates tested, while negative affect (e.g., having strong negative feelings such as fear) symptoms were associated with all measures except depression. Avoidance symptoms were associated with lower odds of current anxiety while externalizing behavior symptoms were linked to higher odds of suicidal ideation. Anxious arousal symptoms were associated with lower odds of suicidal ideation but higher odds of PTSD-related impairment/distress, while dysphoric arousal symptoms were associated with higher odds of current depression, PTSD-related impairment/distress and worse mental and cognitive functioning. Results suggest that a more nuanced 8-factor model of PTSD symptoms may help inform understanding of the clinical and functional correlates of this multi-faceted disorder.

The Index of Intrusion Control (IIC): Capturing individual variability in intentional intrusion control in the laboratory

Intrusive memories can be downregulated using intentional memory control, as measured via the Think/No-Think paradigm. In this task, participants retrieve or suppress memories in response to an associated reminder cue. After each suppression trial, participants rate whether the association intruded into awareness. Previous research has found that repeatedly exerting intentional control over memory intrusions reduces their frequency. This decrease is often summarised with a linear index, which may miss more complex patterns characterising the temporal dynamics of intrusion control. The goal of this paper is to propose a novel metric of intrusion control that captures those dynamic changes over time as a single index. Results from a mega-analysis of published datasets revealed that the change in intrusion frequencies across time is not purely linear, but also includes non-linear dynamics that seem best captured by a log function of the number of suppression attempts. To capture those linear and non-linear dynamics, we propose the Index of Intrusion Control (IIC), which relies on the integral of intrusion changes across suppression attempts. Simulations revealed that the IIC best captured the linear and non-linear dynamics of intrusion suppression when compared with other linear or non-linear indexes of control, such as the regression slope or Spearman correlation, respectively. Our findings demonstrate how the IIC may therefore act as a more reliable metric to capture individual differences in intrusion control, and examine the role of non-linear dynamics characterizing the conscious access to unwanted memories.

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.

Exploring intrusions without awareness: A preliminary study of the characteristics and influences of meta-awareness failures

BACKGROUND AND OBJECTIVES

Research shows that people can lack meta-awareness (i.e., being explicitly aware) of their trauma-related thoughts, which impacts our understanding of re-experiencing symptoms, a key symptom type in posttraumatic stress disorder (PTSD), assessed through self-report. This preliminarily study explored differences between (meta-)aware and unaware intrusion characteristics to understand why some intrusions are not immediately apparent to individuals.

METHODS

Trauma-exposed participants (N = 78) were recruited from online crowd-sourcing platforms to complete an online meta-awareness task. During a reading task, participants were intermittently probed to index the occurrence of unreported (i.e., unaware) trauma-related intrusions. Once participants indicated trauma-related intrusions were present, they then completed a questionnaire that indexed intrusion characteristics.

RESULTS

Although unaware intrusions did occur in a subset of the sample, there were no fundamental differences between aware and unaware intrusions in terms of modality of experience (imagery vs. non-imagery), meaningfulness, accessibility, or other characteristics (e.g., vividness).

LIMITATIONS

There was potential for lower participant engagement and attention due to the online delivery of the meta-awareness task, which may have minimized meta-awareness failure. Future research could consider using a continuous measure to index levels of meta-awareness. In addition, recruiting clinical samples (e.g., individuals with PTSD) who typically experience multiple daily intrusions would allow generalizability of the current findings to be tested.

CONCLUSIONS

Our findings from this preliminary study suggest that unaware and aware intrusions show more commonality than not in their characteristics, with further research required to improve our understanding of the mechanisms leading to meta-awareness or lack of in PTSD.

Controlling intrusive thoughts of future fears under stress

Negative outlooks of our future may foster unwanted and intrusive thoughts. To some extent, individuals have control over their ability to suppress intrusions and downregulate their frequency. Acute stress impairs intentional suppression, leading to an increased frequency of intrusions. The aim of this study was to gain insight into the mechanism underlying stress-induced impairments in intentional suppression of intrusions by investigating the combined and independent roles of the two major stress hormones, noradrenaline and cortisol. Healthy participants (N = 181) were administered propranolol (to block the noradrenergic response), metyrapone (to block the cortisol response), or a placebo before being exposed to the Maastricht Acute Stress Test. Intrusive thoughts of autobiographical future fears were then measured via the Imagine/No-Imagine task. Results demonstrated that the stress response was successfully altered because of the drug and stress manipulations. In all groups, repeated suppression of future fears reduced intrusions. Across the sample, an enhanced decrease over time was associated with greater attenuation of anxiety towards the related fears. The groups did not differ in the total frequency of intrusions. Though, trait anxiety increased the total number of intrusions. Our findings show that stress hormones did not influence the ability to suppress intrusions. However, our results do add support to previous research linking anxiety to memory control deficits. When using autobiographical content, future research should focus on the quality and characteristics of the individual memories to explain more of the variation observed in intentional memory control.

Clinical significance of novel 8-factor model of DSM-5 PTSD in national VA PTSD residential treatment data: Internally- v. externally-cued intrusions

BACKGROUND

Intrusion symptoms are a core defining feature of posttraumatic stress disorder (PTSD). It was recently proposed that intrusions may be comprised of two distinct underlying processes: internally-cued intrusions (e.g., trauma-related memories), and externally-cued intrusions (e.g., reactivity to trauma-related cues in one's environment). This is the first study to examine the functional correlates of these two intrusion clusters.

METHODS

Participants included 7460 veterans discharged from 40 Veterans Affairs PTSD residential programs across the United States in fiscal years 2018 through 2020. Latent network modeling and structural equation modeling were used to assess the fit of an 8-factor model of PTSD symptoms, which were assessed using the PTSD Checklist for DSM-5 (PCL-5) PTSD symptoms at admission, and its association with symptoms of depression and generalized anxiety, and emotional and physical functioning.

RESULTS

The 8-factor model, with separate intrusion factors, showed superior model fit to the DSM-5 4-factor, 5-factor dysphoric arousal, 6-factor anhedonia, and 7-factor hybrid models of PTSD. Internally-cued intrusions were uniquely associated with dysphoric arousal, decreased avoidance, and worse physical health functioning; whereas, externally-cued intrusions were uniquely associated with greater avoidance, anxious arousal, negative affect, increased generalized anxiety symptoms, and worse emotional functioning.

LIMITATIONS

Limitations include the cross-sectional design and use of self-report measures.

CONCLUSIONS

Findings provide initial support for the clinical utility of a novel 8-factor model of PCL-5 PTSD symptoms, which distinguishes internally- and externally-cued intrusions. These separate intrusion symptom clusters may offer greater specificity and utility in informing the prognosis of and tailored interventions for PTSD.

A systematic review and meta-analysis of the effect of cognitive interventions to prevent intrusive memories using the trauma film paradigm

There is an unmet need for effective early interventions that can relieve initial trauma symptoms and reduce symptoms of posttraumatic stress disorder (PTSD). We evaluated the efficacy of cognitive interventions compared to control in reducing intrusion frequency and PTSD symptoms in healthy individuals using the trauma film paradigm, in which participants view a film with aversive content as an experimental analogue of trauma exposure. A systematic literature search identified 41 experiments of different cognitive interventions targeting intrusions. In the meta-analysis, the pooled effect size of 52 comparisons comparing cognitive interventions to no-intervention controls on intrusions was moderate (g = -0.46, 95% CI [-0.61 to -0.32], p < .001). The pooled effect size of 16 comparisons on PTSD symptoms was also moderate (g = -0.31, 95% CI [-0.46 to -0.17], p < .001). Both visuospatial interference and imagery rescripting tasks were associated with significantly fewer intrusions than controls, whereas verbal interference and meta-cognitive processing tasks showed nonsignificant effect sizes. Interventions administered after viewing the trauma film showed significantly fewer intrusions than controls, whereas interventions administered during film viewing did not. No experiments had low risk of bias (ROB), 37 experiments had some concerns of ROB, while the remaining four experiments had high ROB. To the best of our knowledge, this is the first meta-analysis investigating the efficacy of cognitive interventions targeting intrusions in non-clinical samples. Results seem to be in favour of visuospatial interference tasks rather than verbal tasks. More research is needed to develop an evidence base on the efficacy of various cognitive interventions and test their clinical translation to reduce intrusive memories of real trauma.

Disgust and fear reactions uniquely affect intrusions and posttraumatic stress symptoms

Disgust reactions commonly occur during/following trauma and predict posttraumatic stress (PTS) symptoms. Yet, disgust is not mentioned in DSM-5 PTSD criteria. To investigate disgust's clinical significance in PTSD, we measured the relationship between disgust (and fear) reactions to a personal trauma, and problematic intrusion characteristics (e.g., distress) and intrusion symptom severity. We focused on intrusions because they are a transdiagnostic PTSD symptom, though we also measured overall PTS symptoms to replicate prior work. Participants (N = 471) recalled their most traumatic/stressful event from the past six months. They then rated disgust and fear reactions to this event and completed the Posttraumatic Stress Disorder Checklist-5. Participants who had experienced intrusions about their event in the past month (n = 261) rated these intrusions on several characteristics (e.g., distress, vividness). We found stronger traumatic event-related disgust reactions were associated with more problematic intrusion characteristics, higher intrusion symptom severity, and higher overall PTS symptom severity. Notably, disgust reactions uniquely predicted these variables after statistically controlling for fear reactions. We conclude disgust reactions to trauma may be similarly pathological to fear reactions for intrusion and broader PTS symptoms. Therefore, PTSD diagnostic manuals and treatments should recognize disgust as a trauma-relevant emotion.

Validity of the counter-app method in the assessment of intrusions

BACKGROUND AND OBJECTIVES

The counter-app method is often used to assess the frequency of intrusions. The method requires the participants to press a button on a smartphone whenever an intrusion occurs during a predefined time period. We evaluated the convergent, discriminant, and predictive validity of the counter-app method in two studies.

METHODS

In the first study, we assessed the frequency of intrusions with a counter-app method, thought-sampling method, and a retrospective measure in N = 77 students. Additionally, we assessed retrospectively-estimated duration, percentage of time, intensity, and intrusiveness of intrusions. The second study (N = 65) was identical to the first except the thinking-aloud method replaced the thought-sampling method, and additionally we assessed behavioral neutralizing.

RESULTS

The counter-app frequency was positively correlated with the convergent (thought-sampling and thinking-aloud frequencies, and retrospectively-estimated frequencies of intrusions) and predictive (behavioral neutralizing) validity criteria. The correlations between counter-app frequency and discriminant validity criteria (retrospectively-estimated duration, percentage of time, intensity, and intrusiveness of intrusions) were not smaller than the correlations between counter-app frequency and convergent validity criteria.

LIMITATIONS

We evaluated the predictive validity of the counter-app method using a criterion typical of obsessive-compulsive disorder research. Thus, the result for predictive validity might not transfer to other areas.

CONCLUSIONS

Our findings support convergent and predictive, but not discriminant, validity of the counter-app method. The counter-app method can validly assess the frequency of intrusions but is not appropriate if the study requires the differentiation of frequency from other constructs such as duration.

The Eyes Have It: A Meta-analysis of Oculomotor Inhibition in Attention-Deficit/Hyperactivity Disorder

BACKGROUND

Diminished inhibitory control is one of the main characteristics of attention-deficit/hyperactivity disorder (ADHD), and impairments in oculomotor inhibition have been proposed as a potential biomarker of the disorder. The present meta-analysis summarizes the effects reported in studies comparing oculomotor inhibition in ADHD patients and healthy control subjects.

METHODS

Inhibitory outcomes were derived from oculomotor experimental paradigms including the antisaccade (AS), memory-guided saccade, and prolonged fixation tasks. Temporal and spatial measures were also extracted from these tasks and from visually guided saccade tasks as secondary outcomes. Data were available from k = 31 studies (N = 1567 participants). Summary effect sizes were computed using random-effects models and a restricted maximum-likelihood estimator.

RESULTS

Among inhibitory outcomes, direction errors in AS, after correcting for publication bias, showed a moderate effect and large between-study heterogeneity (k = 18, n = 739, g = 0.57, 95% confidence interval [CI] [0.27, 0.88], I²= 74%); anticipatory saccades in memory-guided saccade showed a large effect and low heterogeneity (k = 11, n = 487; g = 0.86, 95% CI [0.64, 1.08], I² = 17.7%); and saccades during prolonged fixation evidenced large effect size and heterogeneity (k = 6, n = 325 g = 1.11, 95% CI [0.56, 1.65], I² = 79.1%) partially related to age. Among secondary outcomes, saccadic reaction time in AS (k = 22, n = 932, g = 0.34, 95% CI [0.06, 0.63], I² = 53.12%) and coefficient of variability in visually guided saccade (k = 5, n = 282, g = 0.53, 95% CI [0.28, 0.78], I² = 0.01%) indicated significant effects with small to moderate effects sizes.

CONCLUSIONS

ADHD groups commit more oculomotor inhibition failures than control groups. The substantial effects support the conclusion that oculomotor disinhibition is a relevant ADHD-related mechanism. Moderate effects observed in saccadic reaction time variability suggest that fluctuant performance in oculomotor tasks is another relevant characteristic of ADHD.

The effects of computerised metacognitive cognitive bias modification training on the development of adaptive metacognitive beliefs and post-traumatic stress disorder symptoms

BACKGROUND AND OBJECTIVES

Maladaptive metacognitive beliefs are associated with the development of post-traumatic stress disorder (PTSD) symptoms following trauma, however it remains unclear whether training people to adopt healthy metacognitive beliefs helps to protect against the development of PTSD symptoms. We developed and tested a new cognitive bias modification training protocol (CBM_Metacog) that aimed to prevent analogue PTSD by training people to adopt healthy metacognitive beliefs prior to watching a distressing film.

METHODS

Participants (N = 135) received CBM_Metacog or a control CBM training and then watched a trauma film. We assessed participants' metacognitive appraisal style/beliefs, analogue PTSD symptoms, including intrusions and meta-awareness of their intrusions.

RESULTS

CBM_Metacog led participants to adopt healthier metacognitive beliefs relative to the control training. Importantly, CBM_Metacog participants reported fewer film intrusions over a 7-day period compared to the control group. CBM_Metacog did not increase participants' meta-awareness of their intrusions.

LIMITATIONS

As this was the first study to manipulate metacognitive beliefs related to an analogue trauma via CBM, we chose to use a healthy participant sample. Therefore, further research is needed before these results can be generalised to clinical samples.

CONCLUSIONS

Overall, these results suggest that training people to adopt healthy metacognitive beliefs, prior to trauma exposure, may help reduce vulnerability to PTSD.

Salient Cognitive Paradigms to Assess Preclinical Alzheimer's Disease

Despite the growing emphasis to identify early biological markers that can detect the progressive accumulation of brain pathology in the complex pathophysiologic cascade that occurs in Alzheimer's disease (AD), we continue to employ the same neuropsychological paradigms that were developed to detect dementia or frank cognitive impairment. It has become increasingly clear that we cannot expect to measure clinically meaningful change in relationship to these emerging preclinical biomarkers using these traditional cognitive assessment paradigms, nor will we advance the efforts to identify the earliest cognitive changes that emerge in AD. Over the last decade, a few novel promising cognitive assessment paradigms have emerged that have shown promise in identifying subtle cognitive deficits in AD which aids in early detection and monitoring of meaningful cognitive change over time. Some of these cognitive assessment paradigms are reviewed here, including semantic interference, semantic intrusion errors, memory binding, and binding of face and name associations. These paradigms may be useful for AD clinical trials focused on secondary prevention if there is sufficient rigor to suggest that they correlate with AD biomarkers, having robust sensitivity, specificity, and predictive utility among culturally and linguistically diverse populations at-risk for AD.

Cardiorespiratory fitness as protection against the development of memory intrusions: A prospective trauma analogue study

Intrusive and distressing memories are at the core of post-traumatic stress disorder (PTSD). Since cardiorespiratory fitness (CRF) has been linked with improved mental health, emotion regulation, and memory function, CRF may, by promoting these capabilities, protect against the development of intrusions after trauma. We investigated the CRF-intrusion relationship and its potential mediators in 115 healthy individuals, using a trauma film to induce intrusions. As potential mediators, we assessed indices of pre-trauma mental health such as heart rate variability, subjective and psychobiological peri-traumatic responses, and memory. Critically, results showed that higher CRF was related to fewer intrusions, but no mediators emerged for the CRF-intrusion relationship. These results indicate that individuals displaying higher CRF are less prone to develop traumatic memory intrusions. Future studies may want to investigate whether promoting fitness prior to possible trauma exposure can boost resilience against the development of debilitating re-experiencing symptoms of PTSD.

Trajectories of fear learning in healthy participants are able to distinguish groups that differ in individual characteristics, chronicity of fear and intrusions

BACKGROUND AND OBJECTIVES

Studies on the development and treatment of anxiety disorders mostly focus on the comparison of predefined groups. An alternative approach is to use data-driven latent class growth analyses (LCGA) to determine differentiation between groups based on particular mechanistic factors. This study validated the use of LCGA on responses in a compact fear conditioning task and whether specific characteristics are associated with maladaptive fear learning trajectories.

METHODS

Healthy subjects (N = 300) completed a fear conditioning task that included uninstructed and instructed acquisition and extinction phases. Subjective fearfulness and US expectancy were used as outcome measures. Latent classes in the responses to the CS+ (coupled with a scream) and the CS- (control stimulus) were determined based on trajectories across the experimental phases. State and trait anxiety were measured during testing, and return of fear and intrusions were measured one and six weeks later.

RESULTS

Fear learning trajectories of poor extinction in responding to the CS+ and generalization of fear to the CS- were associated with higher state and trait anxiety. Individuals belonging to these trajectories reported more intrusions, fear and had higher US expectancy ratings after 1 week.

LIMITATIONS

Only 56% of participants completed the six weeks follow-up measures.

CONCLUSION

Fear learning trajectories are associated with individual characteristics, return of fear and intrusions. Next, this task will be implemented in clinical practice to assess its predictive power for the extent to which patients benefit from exposure treatments.

The effect of attachment security priming and oxytocin on physiological responses to trauma films and subsequent intrusions

To further understand protective mechanisms to prevent post-traumatic stress disorder or assist recovery from psychological trauma, this study investigated whether pharmacological and psychological activation of a secure attachment representation elicits higher felt-security and a related response pattern of reduced physiological arousal and increased parasympathetic activation; and whether it protects individuals from developing intrusions and experiencing distress in the week following exposure to a trauma film. Using a double-blind, experimental mixed factorial design, 101 volunteers received either oxytocin or placebo and either secure attachment or neutral priming before watching a trauma film. We measured felt security as an indicator of the strength of activation of a secure attachment representation, skin conductance and heart rate as indicators of physiological arousal, and high frequency heart rate variability as an indicator of parasympathetic activation during the priming and the film. Participants then completed a seven-day intrusion diary. Secure attachment priming, but not oxytocin administration or the combination of both, was associated with reduced physiological arousal and increased parasympathetic activity during priming. Although secure attachment priming was not related to the absolute number of intrusions or to less perceived distress or physiological arousal during the trauma film, it was associated with lower intrusion-related distress in the 7-days post-testing. Our findings extend previous research that suggests the importance of interventions that address intrusion-related distress for recovery from trauma, and suggest a promising role for secure attachment priming in trauma-focused psychological therapies. We contribute to the growing literature that finds that higher subjective distress during a trauma is associated with higher intrusion-related distress. We discuss theoretical implications and possible mechanisms through which secure attachment priming may exert potential beneficial effects.

The production of false recognition and the associated state of consciousness following encoding in a naturalistic context in aging

Using virtual reality, we implemented a naturalistic variant of the DRM paradigm in young and older adults to evaluate false recall and false recognition. We distinguished false recognition related to the highest semantic association (the critical lures), semantic similarity (i.e. items that belong to the same semantic category), and perceptual similarity (i.e. items that are similar, but not identical in terms of shape or color). The data revealed that younger adults recalled and recognized more correct elements than older adults did while the older adults intruded more critical items than younger adults. Both age groups produced false recognition related to the critical items, followed by perceptually and then semantically related items. False recognitions were highly recollective as they were mainly associated with a sense of remembering, even more so in older adults than in young adults. The decline of executive functions and working memory predicted age-related increases in false memories.

Prospective associations between intelligence, working memory capacity, and intrusive memories of a traumatic film: Potential mediating effects of rumination and memory disorganization

BACKGROUND AND OBJECTIVES

Field research indicates that lower intelligence may predispose trauma-exposed individuals towards the development of re-experiencing symptoms. However, this assumption requires further testing in controlled prospective studies. In the current analog study, we tested whether lower fluid intelligence and lower working memory capacity (WMC) independently contribute to intrusion development. Moreover, we investigated potential mediating effects of trauma memory characteristics and trait rumination.

METHODS

118 healthy participants completed tests measuring fluid intelligence and WMC. Two days later, they were exposed to a film clip depicting traumatic events (i.e., so-called trauma film). After exposure to the film, intrusions were assessed using a diary and an intrusion triggering task.

RESULTS

Our analyses revealed a negative correlation between fluid intelligence and intrusions during the intrusion triggering task. WMC did not correlate with any intrusion measure. Moreover, planned analyses did not yield any mediation effects.

LIMITATIONS

We used the trauma film paradigm to examine analog posttraumatic stress symptoms. This approach limits the generalizability of our findings with regard to symptom development following real-life traumatic events.

CONCLUSIONS

Our results show for the first time that higher fluid intelligence is associated with fewer intrusions of a trauma film. This association was evident for laboratory but not for ambulatory intrusions. By demonstrating this association using a prospective experimental design, our study importantly corroborates previous field research.

Intrusion Errors and Progression of Cognitive Deficits in Older Adults with Mild Cognitive Impairment and PreMCI States

INTRODUCTION

Among persons with amnestic mild cognitive impairment (aMCI), intrusion errors on subscales that measure proactive semantic interference (PSI) may be among the earliest behavioral markers of elevated Alzheimer's disease brain pathology. While there has been considerable cross-sectional work in the area, it is presently unknown whether semantic intrusion errors are predictive of progression of cognitive impairment in aMCI or PreMCI (not cognitively normal but not meeting full criteria for MCI).

METHODS

This study examined the extent to which the percentage of semantic intrusion errors (PIE) based on total responses on a novel cognitive stress test, the Loewenstein-Acevedo Scales for Semantic Interference and Learning (LASSI-L), could predict clinical/cognitive outcomes over an average 26-month period in older adults initially diagnosed with aMCI, PreMCI, and normal cognition.

RESULTS

On the LASSI-L subscale sensitive to PSI, a PIE cut point of 44% intrusion errors distinguished between those at-risk individuals with PreMCI who progressed to MCI over time compared to individuals with PreMCI who reverted to normal on longitudinal follow-up. Importantly, PIE was able to accurately predict 83.3% of aMCI individuals who later progressed to dementia.

DISCUSSION

These preliminary findings indicate that PIE on LASSI-L subscales that measure PSI may be a useful predictor of clinical progression overtime in at-risk older adults.

Condensed internet-delivered prolonged exposure provided soon after trauma: A randomised pilot trial

Exposure to trauma is common and may have detrimental psychological consequences. Brief exposure therapy provided early after trauma has shown encouraging results in promoting recovery. To scale up treatment availability, we developed a 3-week internet-delivered intervention comprised of four modules based on prolonged exposure (condensed internet-delivered prolonged exposure; CIPE) with therapist support. In this pilot study, we assessed the feasibility, acceptability, and preliminary efficacy of CIPE delivered within 2 months after the index event. Thirty-three participants were randomised to CIPE or a waiting list (WL). The frequency, vividness and distress of intrusive recollections or flashback memories of the traumatic event were assessed using an intrusive memory smartphone app. Symptoms of post-traumatic stress were assessed by the PTSD Symptom Checklist for DSM-5 (PCL-5). The most common index traumas in the sample were rape, interpersonal violence and life-threatening accidents. A majority of participants (82%) randomised to CIPE completed all modules, and the number of logins per participant to the Internet platform was high during the three-week intervention (M = 19.6, SD = 11.8). At post-treatment, the CIPE participants had a more favourable reduction than the WL group on the vividness and distress ratings, as well as on the PCL-5 sum score (bootstrapped d = 0.85; 95% CI [0.25-1.45]). Treatment effects were sustained at 6-months follow up and no severe adverse events associated with the intervention were found. CIPE seems to be a feasible and possibly efficacious early intervention after trauma. Large-scale trials are needed to assess its efficacy and long-term benefits.

Short and Long-Term Effects of Cannabis on Symptoms of Post-Traumatic Stress Disorder

BACKGROUND

Many individuals use cannabis to manage symptoms of post-traumatic stress disorder (PTSD), and evidence indicates that the endocannabinoid system represents a viable target for treating these symptoms.

METHOD

Data from 404 medical cannabis users who self-identified as having PTSD were obtained from Strainprint®, a medical cannabis app that patients use to track changes in symptoms as a function of different strains and doses of cannabis across time. This sample collectively used the app 11,797 times over 31 months to track PTSD-related symptoms (intrusive thoughts, flashbacks, irritability, and/or anxiety) immediately before and after inhaling cannabis. Latent change score models were used to examine changes in symptom severity and predictors of these changes (gender, dose, cannabis constituents, time). Multilevel models were used to explore long-term consequences of repeatedly using cannabis to manage these symptoms.

RESULTS

All symptoms were reduced by more than 50% immediately after cannabis use. Time predicted larger decreases in intrusions and irritability, with later cannabis use sessions predicting greater symptom relief than earlier sessions. Higher doses of cannabis predicted larger reductions in intrusions and anxiety, and dose used to treat anxiety increased over time. Baseline severity of all symptoms remained constant across time.

LIMITATIONS

The sample was self-selected, self-identified as having PTSD, and there was no placebo control group.

CONCLUSIONS

Cannabis provides temporary relief from PTSD-related symptoms. However, it may not be an effective long-term remedy as baseline symptoms were maintained over time and dose used for anxiety increased over time, which is indicative of development of tolerance.

A novel virtual reality paradigm: Predictors for stress-related intrusions and avoidance behavior

BACKGROUND AND OBJECTIVES

Most people are exposed to a violent or life-threatening situation during their lives, but only a minority develops a stress-related disorder. To examine risk factors for the development of stress-related symptoms, such as intrusions and avoidance, analogue trauma studies are necessary. The often-used trauma film paradigm has proven to be valuable to examine intrusions, but inherently to its technique is less suitable for assessing behavioral avoidance, a core symptom of stress-related disorders. The aim of the present study was twofold, first to further develop an analogue that explicitly addresses behavioral avoidance and second, to link previously-established risk factors for the development of stress-related symptoms.

METHOD

Eighty-two healthy participants were subjected to a trauma induction using virtual reality (VR). At follow-up, participants were placed in a similar VR environment and could approach or avoid the trauma-scene, a trauma-related scene or a neutral, unrelated scene. Several pre- and peri-trauma risk factors were measured.

RESULTS

The VR paradigm increased negative mood and heart rate, decreased positive mood and heart rate variability, and resulted in stress-related symptoms as trauma-related thoughts and beliefs, intrusions and avoidance behavior. The most prominent risk factors that contributed to the stress-related symptoms were negative emotions during the trauma induction, trait anxiety, and avoidant coping strategies.

LIMITATIONS

The stress-related symptoms were mild, resulting in a vast amount of participants without intrusions and limited avoidance behavior.

CONCLUSION

The current VR paradigm can elicit stress-related symptoms, including avoidance; risk factors contributing to these symptoms were similar to those observed in clinical research, indicating the potential of the general set up.

Rescripting experimental trauma: Effects of imagery and writing as a way to reduce the development of intrusive memories

BACKGROUND AND OBJECTIVES

Imagery rescripting is an effective treatment strategy for trauma related disorders, but its underlying mechanisms are still largely unknown. The aim of the present study was to test whether a) imagery (versus writing) is essential in the process of rescripting, and b) rescripting affects emotional memories on an implicit level.

METHODS

Healthy participants were subjected to an experimental trauma ('trauma film'), and randomly allocated to four conditions: recall of film + Imagery Rescripting (ImRs), recall of film + Writing Rescripting (WRs), recall only (ImRE), or no recall + no manipulation (NM). Next, participants recorded intrusion frequency and distress during one week, after which they executed a visual interference task (VIT) including neutral and trauma film stills, to access implicit emotional memory.

RESULTS

Main findings were that ImRs and WRs resulted in fewer intrusions than NM, with no differences between both rescripting conditions. We did not find an effect on intrusion distress and the VIT.

LIMITATIONS

Stills in the VIT were distracted from all four film scenes, whereas rescripting was done on one scene only, possibly obscuring the effect. Also, an analogue sample was used, which may limit generalizability to clinical samples.

CONCLUSIONS

We replicated previous effects of ImRs on intrusion development. Furthermore, no superior effect of imagery as key modality for rescripting was found; writing seems a viable alternative. Measures for implicit emotional memory such as the VIT may have to be applied relatively soon after the experimental session (e.g., same day as the experimental session).

A novel method of evaluating semantic intrusion errors to distinguish between amyloid positive and negative groups on the Alzheimer's disease continuum

BACKGROUND

The development and validation of clinical outcome measures to detect early cognitive decline associated with Alzheimer's disease (AD) biomarkers is imperative. Semantic intrusions on the Loewenstein Acevedo Scales of Semantic Interference and Learning (LASSI-L) has outperformed widely used cognitive measures as an early correlate of elevated brain amyloid in prodromal AD and has distinguished those with amnestic mild cognitive impairment (aMCI) and high amyloid load from aMCI attributable to other non-AD conditions.

METHODS

Since intrusion errors on memory tasks vary widely, we employed a novel method that accounts for the percentage of intrusion errors (PIE) in relation to total responses. Individuals with either high or low amyloid load across the spectrum of aMCI and dementia and amyloid negative cognitively normal older adults (CN) were studied.

RESULTS

Mean PIE on indices sensitive to proactive semantic interference (PSI) and failure to recover from proactive semantic interference (frPSI) could distinguish amyloid positive from amyloid negative aMCI and dementia groups. Number of correct responses alone, while able to differentiate the different diagnostic groups, did not differentiate amyloid positive aMCI from their counterparts without amyloid pathology.

CONCLUSIONS

PIE, a novel and sensitive index of early memory dysfunction, demonstrated high levels of sensitivity and specificity in differentiating CN from amyloid positive persons with preclinical AD. Mean levels of PIE are higher for amyloid positive aMCI and dementia participants relative to their amyloid negative counterparts.

Neural Processing During Fear Extinction Predicts Intrusive Memories

BACKGROUND

Deficient extinction learning has been suggested as an important mechanism involved in the etiology of posttraumatic stress disorder. A key feature of posttraumatic stress disorder, reexperiencing the trauma in form of intrusions, may be linked to deficient extinction learning. This link is investigated in a novel, functional magnetic resonance imaging-compatible fear conditioning procedure that uses trauma films. Based on previous results, we expected deficient fear extinction indexed by exaggerated responding in the anterior insula and dorsal anterior cingulate cortex to predict subsequent intrusions.

METHODS

A total of 58 healthy participants underwent acquisition and extinction learning with faces as conditioned stimuli (CS) and highly aversive 16-second films depicting interpersonal violence as unconditioned stimuli. During the subsequent 3 days, participants reported intrusive memories on their smartphone.

RESULTS

Successful fear acquisition was evidenced by differential (CS+ > CS-) activity (threat cues associated with trauma films > cues paired only with neutral films) of a widespread network, including the anterior insula and dorsal anterior cingulate cortex, whereas extinction was characterized exclusively by differential anterior insula activity. Differential conditioned responding during late extinction in the anterior insula and dorsal anterior cingulate cortex was positively related to intrusive memory frequency independent of unconditioned stimuli responding. Exploratory analysis also revealed intrusion sensitivity of the hippocampus, rostral anterior cingulate cortex, and ventromedial prefrontal cortex, among others.

CONCLUSIONS

Results support the role of extinction learning in intrusive memory formation; a failure to uncouple conditioned emotional responding from external threat cues was associated with subsequent intrusive memories, representing a potential risk marker for developing posttraumatic stress disorder symptomatology after trauma.

Moment-to-moment associations between posttraumatic stress symptoms and auditory hallucinations in the flow of daily life

Traumatic events are associated with increased risk of auditory hallucinations (AHs) and posttraumatic stress symptoms have been implicated in this relationship. We aimed to explore the moment-to-moment relationship between posttraumatic stress symptoms and AHs in daily-life. Twenty-eight people with persistent AHs and a history of traumatic events completed six-days of ecological momentary assessment. We assessed AHs, trauma memory intrusions, avoidance, and hyperarousal at ten time points each day. Multi-level modelling showed that the severity of trauma memory intrusions (but not avoidance or hyperarousal) within the preceding hour was associated with the occurrence of AHs. This relationship was significantly stronger for people with a direct link between the content of their AHs and trauma history. In time-lagged analyses, main effects of trauma memory intrusions, avoidance, and hyperarousal on AHs were not significant. Trauma memory intrusions have momentary associations with AHs and this relationship is stronger and more enduring for those with a direct link between their AH and the trauma. Our findings are in keeping with the proposal that intrusive trauma memories are associated with the occurrence of (some) AHs.

The effects of shame on subsequent reactions to a trauma analog

The current study examined the effects of experimentally-induced shame on subsequent reactions to a trauma analog. Participants were 88 college-aged women randomly assigned to a shame prime condition or to a control (neutral) condition. Participants then were presented with an analog trauma audiotape depicting dating violence. Participants reported intrusive thoughts relating to the trauma analog in the two days following the procedure. Negative (shame, guilt) and positive (pride, positive affect) emotions were monitored throughout the procedure. Results indicated that the shame prime successfully increased shame in the Shame condition alone. After the trauma analog, increases in shame were noted in both conditions. In contrast, guilt reduced in the Shame condition, while this emotion increased in the Control condition, contrary to hypothesis. Shame and guilt were somewhat volatile for participants in the Shame condition in the two days following the lab procedure, while individuals in the Control condition reported steadily decreasing levels of these emotions. No between-condition differences were noted in the frequency of intrusions in the two days following the laboratory procedure, contrary to hypothesis. Results are discussed in light of our current understanding of shame and its role in PTSD, with suggestions to guide future research.

Effects of imagery rescripting on consolidated memories of an aversive film

BACKGROUND AND OBJECTIVES

Imagery rescripting (ImRs) is a promising intervention targeting emotional memory. Previous analogue studies have mainly investigated effects of ImRs during memory encoding and consolidation; experimental research on the effects and mechanisms of change in ImRs targeting consolidated memories is largely missing. The present study aimed to investigate effects of ImRs on consolidated memories using a multiple-day trauma film paradigm.

METHODS

Eighty-eight participants were randomly assigned to either ImRs, imagery rehearsal (IRE), or no intervention control (NIC). In Session 1, participants watched an aversive film. In Session 2 (24 h after Session 1), the analogue trauma memory was reactivated and the intervention took place. Participants reported intrusive memories of the aversive film for one week and then returned to the laboratory for a follow-up (Session 3).

RESULTS

Compared to IRE, ImRs was experienced as less distressing and elicited less negative emotions. In addition, ImRs accelerated the decline of intrusive memories when compared to NIC. However, ImRs, IRE, and NIC did not differ with respect to the total number of intrusive memories during the week following the intervention.

LIMITATIONS

There was a floor effect of intrusive memories, which may have obscured a potential superiority of the active interventions over NIC.

CONCLUSIONS

Adding to the current literature on ImRs as an intervention for emotional memories, the current study underscores that a multiple-day trauma film paradigm can be used to investigate the short-term efficacy and working mechanisms of ImRs, but also points toward useful modifications to the paradigm.

Investigating the effect of proactive interference control training on intrusive memories

Intrusive re-experiencing is a hallmark symptom of Posttraumatic Stress Disorder (PTSD). According to prominent models of intrusive phenomena, intrusive memories may result from impairments in the efficiency of working memory capacity (WMC), more specifically proactive interference control. Yet, experimental research is scarce. Therefore, the present study aimed to investigate experimentally the role of proactive interference control in intrusive memories. We randomly assigned 57 healthy participants to either receive a high interference control training or a low interference control training. Participants were then exposed to highly distressing film clips. WMC was assessed before and after the training. Intrusion symptoms were assessed directly post-training and after one week using an Intrusion Provocation Task (IPT), a one-week intrusions diary, and the retrospective intrusion subscale of the Impact of Event Sale - Revised (IES-R). Results indicated that both groups reported improvements in WMC and fewer intrusions on the second IPT post-training, with no differences between groups. Similarly, no group differences on intrusions were found at one-week follow-up (i.e., intrusion diary and IES-R). To conclude, these data are not consistent with the hypothesis that WMC plays a role in intrusive re-experiencing. Implications for future research are discussed.

Anxiety sensitivity and post-traumatic stress reactions: Effects of time-varying intrusive thoughts and associated distress

BACKGROUND AND OBJECTIVES

The present study examines the extent to which intrusive thoughts and associated distress explains the association between anxiety sensitivity (AS) and post-traumatic stress (PTS) using the "trauma film paradigm".

METHODS

Participants high and low in AS viewed a 10-min film of graphic scenes of fatal traffic accidents and then underwent a 10-min thought suppression period where intrusive thoughts and associated distress about the film was assessed. Participants also kept a diary of intrusions and associated distress about the film for one-week and post-traumatic stress reactions about the film were assessed after the one-week period.

RESULTS

The high AS group reported greater post-traumatic stress reactions about the film a week later than the low AS group. Although the high AS group also reported more intrusion distress than the low AS group during thought suppression in the laboratory, this difference did not mediate group differences in subsequent post-traumatic stress reactions. Furthermore, the intercept and slope of intrusions and associated distress about the film during the week generally did not differentiate those high in AS from those low in AS. However, the intercept of distress during the week mediated the association between intrusion distress during thought suppression in the laboratory and post-traumatic stress reactions at the end of the week.

LIMITATIONS

The present study is limited by use of an analogue sample as well as modeling trauma exposure with a film.

CONCLUSIONS

Distress about intrusive thoughts in proximity to the trauma and over time may be an important determinant of PTS.

The food craving experience: Thoughts, images and resistance as predictors of craving intensity and consumption

The Elaborated-Intrusion Theory of Desire (Kavanagh, Andrade, & May, 2005) suggests that cravings are made up of two distinct stages whereby an initial, seemingly spontaneous craving-related thought is sufficiently intrusive and pleasant for it then to be elaborated with vivid mental imagery. Previous questionnaire studies have investigated the craving experience with a particular focus on the role of imagery. The present study sought to provide a fuller account of the craving process by investigating the role of craving-related thoughts alongside imagery in predicting craving intensity. Further, the present study sought to investigate predictors of craving-related consumption, including spontaneous strategies used to resist cravings. Two-hundred and forty-nine women completed an online questionnaire which asked about their most recent food craving experience. Results showed that around a third of participants reported craving-related thoughts and about half reported craving-related imagery. Craving-related imagery appeared to be a more important predictor of craving intensity than craving-related thoughts; however, neither predicted craving-related consumption. One resistance strategy, 'recognised it was just a thought', was successful in decreasing the likelihood of eating in response to craving. Theoretical and practical implications are discussed in the context of the Elaborated-Intrusion Theory.

Imagining trauma: Memory amplification and the role of elaborative cognitions

BACKGROUND AND OBJECTIVES

Trauma victims, such as war veterans, often remember additional traumatic events over time: the "memory amplification effect". This effect is associated with the re-experiencing symptoms of post-traumatic stress disorder (PTSD), including frequent and intrusive images of the trauma. One explanation for memory amplification is that people gradually incorporate new, imagined information about the trauma with what they actually experienced, leading to an amplified memory for what actually happened. We investigated this proposal here.

METHODS

Participants viewed highly negative and graphic photographs and recorded their intrusions. Critically, we instructed some participants to elaborate on their intrusions-that is, we asked them to imagine details about the trauma beyond what they actually witnessed. We assessed memory for the traumatic photos twice, 24-h apart.

RESULTS

The elaboration condition experienced fewer intrusions about the photos compared to the control condition. Furthermore, the elaboration condition were less susceptible to memory amplification compared to controls.

LIMITATIONS

The use of negative photos allowed experimental control, however does not permit generalization of our findings to real-world traumatic experiences.

CONCLUSIONS

Our findings suggest that effortful imagination of new trauma-related details leads to a reduction in intrusions and an increased tendency to not endorse trauma exposure over time. One explanation for this finding is that elaboration enhanced conceptual processing of the trauma analogue, therefore reducing intrusions. Critically, this reduction in intrusions affected participants' tendency to endorse trauma exposure, which is consistent with the reality-monitoring explanation for memory amplification.

Effects of appraisal training on responses to a distressing autobiographical event

Dysfunctional appraisals are a key factor suggested to be involved in the development and maintenance of PTSD. Research has shown that experimental induction of a positive or negative appraisal style following a laboratory stressor affects analogue posttraumatic stress symptoms. This supports a causal role of appraisal in the development of traumatic stress symptoms and the therapeutic promise of modifying appraisals to reduce PTSD symptoms. The present study aimed to extend previous findings by investigating the effects of experimentally induced appraisals on reactions to a naturally occurring analogue trauma and by examining effects on both explicit and implicit appraisals. Participants who had experienced a distressing life event were asked to imagine themselves in the most distressing moment of that event and then received either a positive or negative Cognitive Bias Modification training targeting appraisals (CBM-App). The CBM-App training induced training-congruent appraisals, but group differences in changes in appraisal over training were only seen for explicit and not implicit appraisals. However, participants trained positively reported less intrusion distress over the subsequent week than those trained negatively, and lower levels of overall posttraumatic stress symptoms. These data support the causal relationship between appraisals and trauma distress, and further illuminate the mechanisms linking the two.

Can an experimental self-efficacy induction through autobiographical recall modulate analogue posttraumatic intrusions?

BACKGROUND AND OBJECTIVES

Research has shown a link between self-efficacy appraisals and PTSD symptoms. Less is known about the relation between perceived self-efficacy and specific PTSD symptoms such as intrusions. These two experiments tested the causal relationship between perceived self-efficacy and intrusions from a trauma film.

METHODS

In Experiment I, healthy student participants received a self-efficacy manipulation consisting of the recall of autobiographical memories of success (high self-efficacy condition), failure (low self-efficacy condition) or 'important' memories (control condition). Afterwards, they viewed a trauma film and recorded their intrusions of the film in the following week. In Experiment II the self-efficacy manipulation was given after the film.

RESULTS

In contrast to expectations, the high self-efficacy condition reported a higher number of intrusions relative to the low self-efficacy condition in both experiments.

LIMITATIONS

The trauma film provides experimental control but precludes generalization to real-life trauma. The effect of the experimental manipulation was small. The control condition also affected mood and confidence.

CONCLUSIONS

The results suggest that the relation between self-efficacy and intrusions development is causal, but not straightforward. Recalling personal memories of success before or after a traumatic event may increase the risk of developing intrusions, at least under some circumstances. Conversely, recalling past failure experiences may be protective, perhaps by preparing the individual for adversity, or prompting them to search for coping strategies that have been successful in the past. Overall, autobiographical recall involves complex processes related to the self that could be useful but need to be more fully understood.

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.

Brief exercise enhances intrusive memories of traumatic stimuli

Brief physical exercise enhances memories for neutral events, and recently has been shown to modulate fear learning in animals. To date there is no evidence pertaining to the impact of exercise on emotional memories in humans. Accordingly, this study investigated the role of brief exercise in the development of emotional intrusive memories. Forty-nine university students (18-29year olds) viewed a car accident film depicting accident and injury, and were then randomly assigned to engage in either 10min of intense exercise or easy walking. Two days following the experiment participants were assessed for both intrusive memories of the film and intentional recall of film details. Results indicated that participants in the exercise relative to the walking condition reported more intrusive memories, but not voluntarily recalled memories, of the car accident film two days later. These findings are consistent with recent evidence of exercise-induced emotional learning in animals, and point to the potential for physical activity to contribute to the development of intrusions in the context of encoding emotionally-laden information.

Visuospatial context learning and configuration learning is associated with analogue traumatic intrusions

BACKGROUND AND OBJECTIVES

Cognitive and information processing theories of Post-Traumatic Stress Disorder (PTSD) assert that trauma intrusions are characterized by poor contextual embedding of visuospatial memories. Therefore, efficient encoding of visuospatial contextual information might protect against intrusions. We tested this idea using indices of visuospatial memory embedding along with the trauma film paradigm.

METHODS

Individual differences in spatial configuration learning, as well as the degree to which visual recognition memory depends on its visual encoding context (i.e., memory contextualization), were assessed in 81 healthy participants. Next, participants viewed a distressing film. Intrusions and other PTSD analogue symptoms were assessed subsequently.

RESULTS

Participants displaying stronger memory contextualization developed fewer intrusions and PTSD analogue symptoms. Spatial configuration learning was unrelated to memory contextualization and, contrary to prior findings, predicted higher levels of intrusions.

LIMITATIONS

Due to the analogue design, our findings may not translate directly to clinical populations. Furthermore, due to the correlational design of the study, causal relations remain to be tested.

CONCLUSIONS

Our results suggest a protective role for the ability to integrate memories in their original visual learning context against the development of PTSD symptoms.

Do meta-cognitive beliefs affect meta-awareness of intrusive thoughts about trauma?

BACKGROUND AND OBJECTIVES

People exposed to trauma often experience intrusive thoughts and memories about that event. Research examining people's responses to trauma assumes that people can accurately notice the occurrence of symptoms. However, we know from the broader cognitive literature on 'mind-wandering' that people are not always aware of their current focus of attention. That lack of awareness has implications for our theoretical and practical understanding of how trauma survivors recover from their experience. In the current study we investigated whether people's meta-cognitive beliefs about controlling trauma-related intrusions influenced the occurrence and meta-awareness of those intrusions.

METHODS

We recruited participants who scored high (strong beliefs) or low (weak beliefs) on beliefs regarding the importance of controlling intrusive thoughts. Participants viewed a trauma film then-during a subsequent reading task-reported any film-related intrusions they noticed. We also intermittently asked half the participants to report what they were thinking at that particular moment, to "catch" intrusions without meta-awareness.

RESULTS

People are not always aware of their trauma intrusions, and importantly, people with strong beliefs are more likely to notice trauma related intrusions both with and without meta-awareness than people with weak beliefs.

LIMITATIONS

We used an analogue trauma, and focused on a particular metacognitive belief, both of which somewhat limit generalizability. We also cannot definitively rule out demand effects.

CONCLUSIONS

Our data add to existing research showing people may lack meta-awareness of trauma-related thoughts, and suggest that survivors with particular metacognitive characteristics may be more vulnerable to 'mind-wandering' about trauma without awareness.

Intrusions and provoked and spontaneous confabulations on memory tests in Korsakoff's syndrome

INTRODUCTION

Intrusions on verbal memory tests have been used as an index for clinical confabulation. Severe memory impairments in combination with executive dysfunction have been suggested to be the underlying mechanism of confabulation, but to date, this relation is unclear. The aim of this study was (a) to examine the relation between (different types of) intrusions and confabulations in a large sample of confabulating patients with Korsakoff's syndrome (KS) and (b) to investigate whether different measures of executive functioning and memory performance are related to provoked and spontaneous confabulation.

METHOD

The Dutch version of the California Verbal Learning Test (CVLT) and various executive function and memory tests were administered to a group of 51 confabulating patients with KS. Professional caregivers rated the severity of provoked and spontaneous confabulation behavior of the patients using the Nijmegen-Venray Confabulation List-20 (NVCL-20).

RESULTS

The total number of intrusions on the CVLT was not related to either provoked or spontaneous confabulation scores. None of the CVLT intrusion scores correlated significantly with any of the confabulation scores, but we did find small-to-medium, positive correlations between unrelated intrusions and both provoked confabulations and spontaneous confabulation. Provoked confabulation behavior was associated with executive dysfunction and poorer memory performances. Spontaneous confabulation was not related to performance on measures of executive function and memory.

CONCLUSIONS

The total number of intrusions on verbal memory tests and clinical confabulations appear to be different phenomena. Only unrelated intrusions produced on the CVLT might possibly be related to confabulations. The production of provoked, but not spontaneous, confabulation is associated with executive dysfunction and memory deficits.

Nitrous oxide speeds the reduction of distressing intrusive memories in an experimental model of psychological trauma

BACKGROUND

Post-traumatic stress disorder (PTSD) involves maladaptive long-term memory formation which underlies involuntary intrusive thoughts about the trauma. Preventing the development of such maladaptive memory is a key aim in preventing the development of PTSD. We examined whether the N-methyl d-aspartate receptor (NMDAR) antagonist gas nitrous oxide (N2O) could reduce the frequency of intrusive memories by inhibiting NMDAR-dependent memory consolidation in a laboratory analogue of psychological trauma.

METHOD

Participants were randomized to inhale N2O (N = 25) or medical air (N = 25) after viewing a negatively valenced emotional film clip ('trauma film'). Participants subsequently completed a daily diary assessing frequency of intrusive thoughts relating to the film clip. A week later, participants completed an explicit memory recall task related to the film.

RESULTS

Post-encoding N2O sped the reduction in intrusive memory frequency, with a significant reduction by the next day in the N2O group compared to 4 days later in the air group. N2O also interacted with post-film dissociation, producing increased intrusion frequency in those who were highly dissociated at baseline. Sleep length and quality the night after viewing the film did not differ between the groups.

CONCLUSION

N2O speeds the reduction of intrusive analogue trauma memory in a time-dependent manner, consistent with sleep-dependent long-term consolidation disruption. Further research with this drug is warranted to determine its potential to inoculate against enduring effects of psychological trauma; however, caution is also urged in dissociated individuals where N2O may aggravate PTSD-like symptomatology.

The moderating role of dysphoria in the relationship between intrusions and alcohol use

Posttraumatic Stress Disorder (PTSD) is frequently comorbid with alcohol use disorders (AUD; Calabrese et al., 2011; McFall, Mackay, & Donovan, 1992). Among several explanations for this comorbidity, the most empirically supported is the self-medication theory which postulates that substances are used to medicate PTSD-related distress (Keane & Wolfe, 1990; Khantzian, 1985; Stewart, 1996). The current study examines the effects of trauma-related distress on alcohol use (total drinking days, drinks per drinking day, heavy drinking days) in a sample of 127 trauma-exposed Veterans following deployment to Iraq or Afghanistan. The dysphoria symptoms of PTSD were used as an indicator of distress, and examined as a moderator in the relationship between intrusion symptoms of PTSD and alcohol use. The proposed moderation model was tested using cross-sectional data from the first month following return from deployment, and at 6 months and at 12 months post-deployment. Results showed that dysphoria symptoms significantly moderated relations between intrusions and total drinking days and heavy drinking days at one month post-deployment; however, a significant pattern was not demonstrated at 6 months and 12 months. Further, dysphoria did not moderate the relation between intrusion symptoms and drinks per drinking day at the three time points. Theoretical and clinical implications are subsequently discussed.

Vantage perspective during encoding: The effects on phenomenological memory characteristics

The vantage perspective from which a memory is retrieved influences the memory's emotional impact, intrusiveness, and phenomenological characteristics. This study tested whether similar effects are observed when participants were instructed to imagine the events from a specific perspective. Fifty student participants listened to a verbal report of car-accidents and visualized the scenery from either a field or observer perspective. There were no between-condition differences in emotionality of memories and the number of intrusions, but imagery experienced from a relative observer perspective was rated as less self-relevant. In contrast to earlier studies on memory retrieval, vantage perspective influenced phenomenological memory characteristics of the memory representation such as sensory details, and ratings of vividness and distancing of the memory. However, vantage perspective is most likely not a stable phenomenological characteristic itself. Implications and suggestions for future research are discussed.

Accounting for intrusive thoughts in PTSD: Contributions of cognitive control and deliberate regulation strategies

BACKGROUND

Persistent, trauma-related intrusive thoughts are common in individuals with posttraumatic stress disorder (PTSD). Automatic aspects of cognitive functioning (including executive functioning) and maladaptive deliberate attempts at cognitive regulation have been proposed as individual difference factors that may perpetuate intrusive thoughts. The current study sought to examine the joint contribution of these two factors on intrusive thoughts in PTSD.

METHOD

Forty-two women with PTSD completed an executive functioning assessment followed by a thought suppression task. Intrusive thoughts (frequency and duration), as well as participants' use of specific cognitive regulation strategies (avoidance-based thought regulation strategies; TRS), were measured during the task. Hierarchical linear regression was used to examine the interaction of executive functioning and TRS on intrusive thoughts.

RESULTS

Greater use of TRS was associated with greater intrusive thought persistence for those with low executive functioning, but not those with high executive functioning.

LIMITATIONS

Data was collected cross-sectionally and the laboratory thought suppression task may not correspond to naturalistic thought regulation.

CONCLUSIONS

Results are consistent with prior literature suggesting that certain responses deployed by individuals to control intrusive thoughts may be unhelpful, but that a higher level of cognitive capacity may mitigate this effect. Implications of these findings for recent models of cognition in PTSD are discussed.

Re-experiencing phenomena following a disaster: The long-term predictive role of intrusion symptoms in the development of post-trauma depression and anxiety

BACKGROUND

Contention in the literature regarding the diagnostic utility of intrusion symptoms highlights that they have high sensitivity but low specificity in predicting PTSD. They are highly prevalent following a range of traumatic events, and across a range of disorders. The prevalence of intrusion symptoms in the absence of PTSD suggests their relevance to the development of other psychopathology. Therefore, the predictive role of intrusion symptoms for other post-trauma psychopathology was examined using data from an epidemiological, longitudinal sample of adults recruited in childhood.

METHOD

From 5 phases of data collection for this sample, these analyses focused on the 20 year and 28 year follow-ups (n=583). Lifetime exposure to trauma was assessed using a modified set of 10 Criterion-A events from the Composite International Diagnostic Interview (CIDI), with PTSD assessed in reference to a self-nominated worst lifetime event, and other DSM-IV disorder also assessed using the CIDI.

RESULTS

Results showed that the presence of intrusion symptoms without PTSD at the 20 year follow-up was predictive of increased risk at 28 years for depressive but not anxiety disorders.

LIMITATIONS

There was limited psychopathology in the sample, reducing the power to examine many individual disorders. Furthermore, trauma history and psychiatric symptoms were retrospectively reported, introducing the possibility of recall bias.

CONCLUSION

Together the findings suggest that intrusion symptoms may play an aetiological role in the development and/or maintenance of disorders other than PTSD.

Anxiety sensitivity and post-traumatic stress reactions: Evidence for intrusions and physiological arousal as mediating and moderating mechanisms

A growing body of research has implicated anxiety sensitivity (AS) and its dimensions in the development of post-traumatic stress disorder (PTSD). However, the mechanism(s) that may account for the association between AS and PTSD remains unclear. Using the "trauma film paradigm," which provides a prospective experimental tool for investigating analog intrusion development, the present study examines the extent to which intrusions mediate the association between AS and the development of posttraumatic stress reactions. After completing a measure of AS and state mood, unselected participants (n = 45) viewed a 10 min film of graphic scenes of fatal traffic accidents and then completed a second assessment of state mood. Participants then kept a daily diary to record intrusions about the film for a one-week period. Post-traumatic stress reactions about the film were then assessed after the one-week period. The results showed that general AS and physical and cognitive concerns AS predicted greater post-traumatic stress reactions about the film a week later. Furthermore, the number of intrusions the day after viewing the traumatic film, but not fear and disgust in response to the trauma film, mediated the association between general AS (and AS specifically for physical and cognitive concerns) and post-traumatic stress reactions a week later. Subsequent analysis also showed that physiological arousal during initial exposure to the traumatic film moderated the association between general AS and the number of intrusions reported the day after viewing the film. The implications of these analog findings for conceptualizing the mechanism(s) that may interact to explain the role of AS in the development of PTSD and its effective treatment are discussed.

Accuracy of self-reported intake of signature foods in a school meal intervention study: comparison between control and intervention period

Bias in self-reported dietary intake is important when evaluating the effect of dietary interventions, particularly for intervention foods. However, few have investigated this in children, and none have investigated the reporting accuracy of fish intake in children using biomarkers. In a Danish school meal study, 8- to 11-year-old children (n 834) were served the New Nordic Diet (NND) for lunch. The present study examined the accuracy of self-reported intake of signature foods (berries, cabbage, root vegetables, legumes, herbs, potatoes, wild plants, mushrooms, nuts and fish) characterising the NND. Children, assisted by parents, self-reported their diet in a Web-based Dietary Assessment Software for Children during the intervention and control (packed lunch) periods. The reported fish intake by children was compared with their ranking according to fasting whole-blood EPA and DHA concentration and weight percentage using the Spearman correlations and cross-classification. Direct observation of school lunch intake (n 193) was used to score the accuracy of food-reporting as matches, intrusions, omissions and faults. The reporting of all lunch foods had higher percentage of matches compared with the reporting of signature foods in both periods, and the accuracy was higher during the control period compared with the intervention period. Both Spearman's rank correlations and linear mixed models demonstrated positive associations between EPA+DHA and reported fish intake. The direct observations showed that both reported and real intake of signature foods did increase during the intervention period. In conclusion, the self-reported data represented a true increase in the intake of signature foods and can be used to examine dietary intervention effects.

Flashbacks, intrusions, mind-wandering - Instances of an involuntary memory spectrum: A commentary on Takarangi, Strange, and Lindsay (2014)

In their paper, Takarangi, Strange, and Lindsay (2014) showed in two experiments that participants who had witnessed a shocking film frequently "mind-wandered without awareness" about the content of the film. More importantly, they equated this effect with the occurrence of traumatic intrusions. In this commentary, we argue that the authors adhered to conceptually ambiguous terms, and thereby unintentionally contribute to an already existing conceptual blur in the trauma-memory field. We postulate that clear definitions are urgently needed for phenomena such as intrusions, flashbacks, and mind-wandering, when using them in the context of trauma memory. Furthermore, our proposal is that these phenomena can fall under a spectrum of different involuntary memory instances. We propose that by adopting stricter definitions and viewing them as separate, but interrelated phenomena, different lines of trauma-memory research can be reconciled, which would considerably advance the field.