Contextualized hippocampal-cortical dynamics underlying traumatic memory

In a recent study, Clancy et al. elucidate a connection between activity patterns of the hippocampus (HC) and the broader functional connectivity networks associated with trauma-related intrusive memories (TR-IMs). This neurophenomenological methodology situates the HC within a larger neural framework and provides a nuanced exploration of the neurobiological underpinnings of distinct characteristics of TR-IMs.

Exploring semantic verbal fluency patterns and their relationship to age and Alzheimer's disease in adults with Down syndrome

INTRODUCTION

Adults with Down syndrome (DS) are at ultra-high risk of developing Alzheimer's disease (AD), characterized by poor episodic memory and semantic fluency in the preclinical phase in the general population. We explored semantic fluency performance in DS and its relationship to age, AD, and blood biomarkers.

METHODS

A total of 302 adults with DS at baseline and 87 at follow-up from the London Down Syndrome Consortium cohort completed neuropsychological assessments. Blood biomarkers were measured with the single molecule array technique in a subset of 94 participants.

RESULTS

Poorer verbal fluency performance was observed as age increases. Number of correct words declined in those with AD compared to those without over 2 years and was negatively correlated with neurofilament light (r = -0.37, P = .001) and glial fibrillary acidic protein (r = -0.31, P = .012).

DISCUSSION

Semantic fluency may be useful as an early indicator of cognitive decline and provide additional information on AD-related change, showing associations with biomarkers in DS.

What makes an obsession? A systematic-review and meta-analysis on the specific characteristics of intrusive cognitions in OCD in comparison with other clinical and non-clinical populations

The Diagnostic and Statistical Manual 5th ed. defines obsessions in obsessive-compulsive disorder (OCD) as frequent, persistent, intrusive, unwanted thoughts that provoke anxiety and distress and lead to attempts to neutralize them with either thoughts or actions. However, no systematic review has yet evaluated characteristics that are specific to obsessions occurring in OCD. The aim of the current systematic review and meta-analysis was to investigate the specific features of obsessions occurring in OCD by comparing them to both obsessionally and non-obsessionally-themed intrusions in non-clinical and other clinical populations. Based on a registered protocol, 832 records were found, of which 15 were included in the systematic review and meta-analysis, with a total of 1891 participants. Obsessionally-themed intrusions that occur among those with OCD caused more distress, guilt, negative emotion and interference as compared to similarly-themed intrusions that occur within the general population. The distinction between obsessionally-themed intrusions among those with OCD as compared to those occurring in anxiety and depressive disorder primarily revolves around a higher level of persistence, pervasiveness and distress associated with their occurrence. Further, unacceptability, uncontrollability, ego-dystonicity, alienness, guilt, the form of the intrusion, association with the self and lack of any basis in reality also differentiates between obsessions and intrusions occurring in other disorders. Obsessions share many characteristics with thoughts occurring in other disorders and can be distinguished using a combination of characteristics specific to individual disorders.

Exploring Verbal Fluency Strategies among Individuals with Normal Cognition, Amnestic and Non-Amnestic Mild Cognitive Impairment, and Alzheimer's Disease

Background and Objectives: The present study explored the utilization of verbal fluency (VF) cognitive strategies, including clustering, switching, intrusions, and perseverations, within both semantic (SVF) and phonemic (PVF) conditions, across a continuum of neurocognitive decline, spanning from normal cognitive ageing (NC) to mild cognitive impairment (MCI) and its subtypes, amnestic (aMCI) and non-amnestic (naMCI), as well as AD. Materials and Methods: The study sample was derived from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD) cohort. The sample included 1607 NC individuals, 146 with aMCI (46 single-domain and 100 multi-domain), 92 with naMCI (41 single-domain and 51 multi-domain), and 79 with AD. Statistical analyses, adjusting for sex, age, and education, employed multivariate general linear models to probe differences among these groups. Results: Results showed that AD patients exhibited poorer performance in switching in both VF tasks and SVF clustering compared to NC. Similarly, the aMCI group performed worse than the NC in switching and clustering in both tasks, with aMCI performing similarly to AD, except for SVF switching. In contrast, the naMCI subgroup performed similarly to those with NC across most strategies, surpassing AD patients. Notably, the aMCI subgroup's poor performance in SVF switching was mainly due to the subpar performance of the multi-domain aMCI subgroup. This subgroup was outperformed in switching in both VF tasks by the single-domain naMCI, who also performed better than the multi-domain naMCI in SVF switching. No significant differences emerged in terms of perseverations and intrusions. Conclusions: Overall, these findings suggest a continuum of declining switching ability in the SVF task, with NC surpassing both aMCI and AD, and aMCI outperforming those with AD. The challenges in SVF switching suggest executive function impairment associated with multi-domain MCI, particularly driven by the multi-domain aMCI.

A Novel Feature-Selection Algorithm in IoT Networks for Intrusion Detection

The Internet of Things (IoT) and network-enabled smart devices are crucial to the digitally interconnected society of the present day. However, the increased reliance on IoT devices increases their susceptibility to malicious activities within network traffic, posing significant challenges to cybersecurity. As a result, both system administrators and end users are negatively affected by these malevolent behaviours. Intrusion-detection systems (IDSs) are commonly deployed as a cyber attack defence mechanism to mitigate such risks. IDS plays a crucial role in identifying and preventing cyber hazards within IoT networks. However, the development of an efficient and rapid IDS system for the detection of cyber attacks remains a challenging area of research. Moreover, IDS datasets contain multiple features, so the implementation of feature selection (FS) is required to design an effective and timely IDS. The FS procedure seeks to eliminate irrelevant and redundant features from large IDS datasets, thereby improving the intrusion-detection system's overall performance. In this paper, we propose a hybrid wrapper-based feature-selection algorithm that is based on the concepts of the Cellular Automata (CA) engine and Tabu Search (TS)-based aspiration criteria. We used a Random Forest (RF) ensemble learning classifier to evaluate the fitness of the selected features. The proposed algorithm, CAT-S, was tested on the TON_IoT dataset. The simulation results demonstrate that the proposed algorithm, CAT-S, enhances classification accuracy while simultaneously reducing the number of features and the false positive rate.

The Suicidal Intrusions Attributes Scale (SINAS): a new tool measuring suicidal intrusions

Introduction

Suicidal intrusions are uncontrollable, intrusive mental images (e. g., visualizing a future suicidal act). They may also be called suicidal "flash-forwards." Despite the importance of integrating the assessment of suicidal intrusions into a clinical routine assessment, quick self-report screening instruments are lacking. This study describes the development of a new instrument-Suicidal Intrusions Attributes Scale (SINAS)-to assess the severity and characteristics of suicidal intrusions and examines its psychometric properties.

Method

The sample included currently suicidal outpatients with elevated levels of depression recruited across mental health institutions in the Netherlands (N = 168). Instruments administered were 10-item SINAS, the Suicidal Ideation Attributes Scale (SIDAS), the Prospective Imagery Task (PIT), four-item Suicidal Cognitions Interview (SCI), and the Beck Depression Inventory (BDI-II).

Results

An exploratory factor analysis identified a one-factor structure. The resulting SINAS demonstrated good internal consistency (Cronbach's α = 0.91) and convergent validity, as expected.

Discussion

Overall, this study demonstrated acceptable levels of reliability and validity of the measure in a depressed clinical population with suicidal ideation. The SINAS may be a useful screening tool for suicidal intrusions in both research and clinical settings.

"Cinderella was attacked by the big bad wolf, but the police saved her": intrusions and confabulations on story recall in Korsakoff's syndrome and alcohol-related cognitive impairments

BACKGROUND

The relation between confabulations and intrusions in patients with Korsakoff's syndrome (KS) and patients with alcohol-related cognitive impairments (ARCI) remains under debate. This study examines (1) differences in the production of confabulations and intrusions between patients with KS and ARCI, (2) whether an altered fairy tale induces more intrusions, and (3) whether different types of intrusions were significantly related to confabulations.

METHODS

Twenty-three patients with KS and twenty-two patients with ARCI recalled three different types of stories: a novel story, a fairy tale, and a modified fairy tale. Different types of intrusions were correlated with confabulation measures.

RESULTS

Patients with KS produced more intrusions in the modified fairy tale condition than patients with ARCI, but these were unrelated to confabulations. Only unrelated intrusions were related to provoked confabulations.

CONCLUSIONS

The results of this study indicate that researchers and clinicians must be aware that in general, intrusions on memory tests should not be interpreted as confabulations. Especially spontaneous confabulations appear to be something completely different from intrusions on any type of story recall. When measuring confabulations it is crucial to use validated instruments.

Obsessional intrusive thoughts in children: An interview based study

OBJECTIVES

We aimed to investigate the experience of obsessional intrusive thoughts (OITs) in a sample of children aged 8 to 10 years old and to test the main tenets of the cognitive model of OCD. Specifically, we assessed: (1) the prevalence of OITs experienced by young children; (2) their frequency and content; (3) the emotions they evoke; (4) the reasons why they are upsetting; (5) how they are appraised (6) and what control strategies they use.

METHODS

Forty-nine children (28 girls, 21 boys; mean age 9.1 years) from the community completed two self-report questionnaires assessing anxiety and obsessive-compulsive symptoms. Children were interviewed using the Children's Anxious Thoughts Interview, which assessed their experiences of OITs.

RESULTS

From the 49 participants, 71.43% reported having experienced at least one OIT. The most frequent contents related to harm and doubt. Of the total sample, 28.6% reported having experienced one OIT recently with at least moderate frequency; these participants reported higher anxiety and obsessive-compulsive interference, described feeling nervous and anxious when experiencing their OIT, and rated their OIT as highly important and distracting. The most frequently reported control strategies were cognitive - suppression, distraction and thought replacement.

CONCLUSIONS

Almost two thirds of community children reported experiencing OITs. The findings from this study provide preliminary support for the application of the cognitive model of OCD in children. Subtle differences from previous research with adults are discussed.

The effect of sleep on intrusive memories in daily life: a systematic review and meta-analysis of trauma film experiments

STUDY OBJECTIVES

To synthesize the literature on the effect of sleep versus wake on the frequency and distress of intrusive memories in everyday life after watching film clips with distressing content as a proxy for traumatic experiences.

METHODS

We conducted a systematic review by searching PubMed and PsychInfo. The last search was conducted on January 31, 2022. We included experimental studies comparing sleep and wake groups on intrusions using ecological diary methods, whereas studies lacking a wake control condition or relying solely on intrusion-triggering tasks or retrospective questionnaires were excluded. Meta-analyses were performed to evaluate the results. Risks of biases were assessed following the Cochrane guidelines.

RESULTS

Across 7 effect sizes from 6 independent studies, sleep (n = 192), as compared to wake (n = 175), significantly reduced the number of intrusive memories (Hedges' g = -0.26, p = .04, 95% CI [-0.50, -0.01]), but not the distress associated with them (Hedges' g = -0.14, p = .25, 95% CI [-0.38, 0.10]).

CONCLUSIONS

Although the results suggest that sleep reduces the number of intrusions, there is a strong need for high-powered pre-registered studies to confirm this effect. Risks of biases in the reviewed work concern the selection of the reported results, measurement of the outcome, and failure to adhere to the intervention. Limitations with the current meta-analysis include the small number of studies, which comprised only English-language articles, and the fact that it was not pre-registered.

Echoes of shame: a comparison of the characteristics and psychological sequelae of recalled shame experiences across the voice hearing continuum

BACKGROUND

Voice hearing occurs across a number of psychiatric diagnoses and appears to be present on a continuum within the general population. Previous research has highlighted the potential role of past experiences of shame in proneness to voice hearing in the general population.

AIMS

This study aimed to extend this past research and compare people with distressing voices, people with voices but no distress, and a non-voice hearing control group, on various dimensions of shame and shame memory characteristics.

METHOD

In a cross-sectional, online study 39 distressed voice hearers, 31 non-distressed voice hearers and 50 non-voice hearers undertook a shame memory priming task in which they were prompted to recall a memory of a shaming experience from their past. They then completed questionnaires assessing the characteristics of the recalled shame event and the psychological sequalae of this event (i.e. intrusions, hyperarousal, avoidance, the centrality of shame memories, external shame, and self-criticism).

RESULTS

The majority of recalled shame memories involved experiences such as interpersonal criticism or experiences of being devalued. Univariate analyses found no significant differences between the three groups with regard to the shame events that were recalled, but the distressed voice hearer group reported significantly more hyperarousal, intrusions, self-criticism, and external shame in relation to their experience.

CONCLUSIONS

The findings suggest that voice hearers recall similar types of shame experiences to non-voice hearers, but that problematic psychological sequelae of these shame experiences (in the form of intrusive memories, hyperarousal, external shame, and self-criticism) may specifically contribute to distressing voice hearing.

Sleep and day-to-day PTSD symptom variability: an ecological momentary assessment and actigraphy monitored study in trauma-exposed young adults

BACKGROUND

Disrupted sleep and post-traumatic stress disorder (PTSD) are bi-directionally linked and have been found to mutually reinforce each other on a day-to-day basis. However, most of the previous research has focused on subjective measures of sleep only.

OBJECTIVE

Here, we investigated the temporal relationship between sleep and PTSD symptoms using both subjective (sleep diary) and objective measures of sleep (actigraphy).

METHODS

Forty-one non-treatment seeking, trauma exposed young adults (age M = 24.68, SD = 8.15) with a range of PTSD symptom severities (PTSS, 0-53 on PCL-5) were recruited. Participants completed two surveys per day over four weeks to measure day-time PTSD symptoms (i.e. PTSS and number of intrusions) and night-time sleep subjectively, while wearing an actigraphy watch to measure sleep objectively.

RESULTS

Linear mixed models revealed that subjectively reported sleep disruptions were associated with elevated next-day PTSS and increasing number of intrusive memories both within and between participants. Similar results were found for daytime PTSD symptoms on night-time sleep. However, these associations were not found using objective sleep data. Exploratory moderator analyses including sex (male vs. female) found that these associations differed in strength between sexes but were generally in the same direction.

DISCUSSION

These results were in line with our hypothesis with regards to the sleep diary (subjective sleep), but not actigraphy (objective sleep). Several factors which have implications on both PTSD and sleep, such as the COVID-19 pandemic and/ or sleep-state misperception, may be potential reasons behind those discrepancies. However, this study had limited power and needs to be replicated in larger samples. Nonetheless, these results add to the current literature about the bi-directional relationship between sleep and PTSD and have clinical implications for treatment strategies.

Qualitative Verbal Fluency Components as Prognostic Factors for Developing Alzheimer's Dementia and Mild Cognitive Impairment: Results from the Population-Based HELIAD Cohort

Background and Objectives: The aim of the present study was to investigate the prognostic value of the qualitative components of verbal fluency (clustering, switching, intrusions, and perseverations) on the development of mild cognitive impairment (MCI) and dementia. Materials and Methods: Participants were drawn from the multidisciplinary, population-based, prospective HELIAD (Hellenic Longitudinal Investigation of Aging and Diet) cohort. Two participant sets were separately analysed: those with normal cognition and MCI at baseline. Verbal fluency was assessed via one category and one letter fluency task. Separate Cox proportional hazards regressions adjusted for important sociodemographic parameters were performed for each qualitative semantic and phonemic verbal fluency component. Results: There were 955 cognitively normal (CN), older (72.9 years ±4.9), predominantly female (~60%) individuals with available follow-up assessments after a mean of 3.09 years (±0.83). Among them, 34 developed dementia at follow-up (29 of whom progressed to Alzheimer's dementia (AD)), 160 developed MCI, and 761 remained CN. Each additional perseveration on the semantic condition increased the risk of developing all-cause dementia and AD by 52% and 55%, respectively. Of note, participants with two or more perseverations on the semantic task presented a much more prominent risk for incident dementia compared to those with one or no perseverations. Among the remaining qualitative indices, none were associated with the hazard of developing all-cause dementia, AD, and MCI at follow-up. Conclusions: Perseverations on the semantic fluency condition were related to an increased risk of incident all-cause dementia or AD in older, CN individuals.

Are Fear of Cancer Recurrence and Fear of Progression Equivalent Constructs?

Background

The predominant definition of fear of cancer recurrence (FCR) conflates FCR with fear of progression (FOP). However, this assumption has never been tested. Importantly, if FCR and FOP are distinct and have different predictors, existing interventions for FCR may not be equally effective for survivors who fear progression rather than recurrence of their disease. The present study aimed to determine whether FCR and FOP are empirically equivalent; and whether they are predicted by the same theoretically derived variables.

Methods

Three hundred and eleven adults with a history of breast or ovarian cancer were analysed (n = 209, 67% in remission). Exploratory factor analysis was conducted on the items of the FCR Inventory severity subscale and short‐form FOP Questionnaire together. Structural equation modelling was conducted to predict FCR and FOP and determine whether theoretical models accounted equally well for both constructs, and whether models were equally relevant to those with and without current disease.

Findings

The factor analysis demonstrated that the FCR Inventory severity subscale and the short‐form FOP Questionnaire loaded onto distinct, but related, factors which represented FCR and FOP. Structural modelling indicated that risk perception and bodily threat monitoring were more strongly associated with FCR than FOP. However, both FCR and FOP were associated with metacognitions and intrusions.

Interpretation

These findings suggest that whilst FCR and FOP are related with some overlapping predictors, they are not the same construct. Hence, it is necessary to ensure that in clinical practice and research these constructs are considered separately.

Evaluation of Error Production in Animal Fluency and Its Relationship to Frontal Tracts in Normal Aging and Mild Alzheimer's Disease: A Combined LDA and Time-Course Analysis Investigation

Semantic verbal fluency (VF), assessed by animal category, is a task widely used for early detection of dementia. A feature not regularly assessed is the occurrence of errors such as perseverations and intrusions. So far, no investigation has analyzed the how and when of error occurrence during semantic VF in aging populations, together with their possible neural correlates. The present study aims to address the issue using a combined methodology based on latent Dirichlet allocation (LDA) analysis for word classification together with a time-course analysis identifying exact time of errors' occurrence. LDA is a modeling technique that discloses hidden semantic structures based on a given corpus of documents. We evaluated a sample of 66 participants divided into a healthy young group (n = 24), healthy older adult group (n = 23), and group of patients with mild Alzheimer's disease (AD) (n = 19). We performed DTI analyses to evaluate the white matter integrity of three frontal tracts purportedly underlying error commission: anterior thalamic radiation, frontal aslant tract, and uncinate fasciculus. Contrasts of DTI metrics were performed on the older groups who were further classified into high-error rate and low-error rate subgroups. Results demonstrated a unique deployment of error commission in the patient group characterized by high incidence of intrusions in the first 15 s and higher rate of perseverations toward the end of the trial. Healthy groups predominantly showed very low incidence of perseverations. The DTI analyses revealed that the patients with AD committing high-error rate presented significantly more degenerated frontal tracts in the left hemisphere. Thus, our findings demonstrated that the appearance of intrusions, together with left hemisphere degeneration of frontal tracts, is a pathognomic trait of mild AD. Furthermore, our data suggest that the error commission of patients with AD arises from executive and working memory impairments related partly to deteriorated left frontal tracts.

COVID-19-related distress is associated with analogue PTSD symptoms after exposure to an analogue stressor

Background: The COVID-19 outbreak in early 2020 was associated with an immediate increase in mental health problems in a significant percentage of the general population. Therefore, it is crucial to investigate how the COVID-19 pandemic - as a psychosocial stressor - affected the aetiological processes of mental disorders. Previous research has shown that stress potentiates associative (fear) learning and analogue symptoms of posttraumatic stress disorder (PTSD) and that analogue PTSD symptoms can emerge in response to associative learning. Objective: We investigated whether distress in response to the COVID-19 outbreak support the development of intrusions and rumination after exposure to a non-COVID-19-related analogue trauma. Moreover, we examined if these effects are mediated by the strength of associative learning during analogue trauma. Method: 122 undergraduate university students participated in an online experiment between March and July 2020. They completed questionnaires measuring distress and rumination related to the COVID-19 outbreak. On a subsequent day, they went through an associative learning task, in which neutral stimuli were paired with the appearance of a highly aversive film clip. Subjective ratings were assessed as indicators of associative learning. On the next day, participants documented film-related intrusions and rumination. Results: COVID-19-related distress but not rumination was associated with post-film intrusion and rumination load. These effects were mediated by associative learning. Conclusions: The current findings are in line with the assumptions that stress enhanced both associative learning and PTSD symptoms. Specifically, they indicate that prolonged psychosocial stress - like during the COVID-19 outbreak - is linked to individual differences in memory processing of aversive events. Further confirmatory research is needed to replicate these results.

How rich are false memories in a naturalistic context in healthy aging?

The recall of factual and contextual information is a core characteristic of episodic memory sensitive to aging effects. The innovative aim of the present study was to assess in a naturalistic context the quantity and quality of correct and false free recalls among younger and older adults considering feature binding (What-Where-When-Details) and recollection (Remembering vs. Knowing). Thanks to virtual reality, we designed a multimodal environment simulating a lively town in which we implemented a variant of a DRM task rich in sets of semantically related items (e.g., fruits on a market stall). We asked 30 young and 30 older participants to navigate in the virtual environment, paying attention to the items, and then recall as many items and as much contextual information as possible and indicate the presence of recollection. As expected, older adults produced fewer correct recall but more intrusions than younger adults, and their correct recall was more deficient in binding and recollection. In both age groups, false recall was associated with the correct context inferred from a related set of items. However, the intrusions produced by older adults were highly recollected compared to those of the younger adults, and they were associated with false item-related contextual information.

The relationship between obsessions and the self: Feared and actual self-descriptions in a clinical obsessive-compulsive disorder sample

Cognitive models of obsessive-compulsive disorder (OCD) posit the relevance of the self in OCD, although the nature of this association is still unclear. We aimed to explore actual and feared selves and its association with obsessions and intrusions in a group of OCD patients. A group of 58 patients with OCD identified their most upsetting obsession and intrusion (non-clinical obsession) experienced in the past 3 months. These cognitions were classified as either moral-based or autogenous (obsessions n = 32; intrusions n = 26) or non-moral-based or reactive, depending on their content. Next, patients described their actual self and their feared self, that is, the person they feared being or becoming, and whether they believed these descriptions were associated with their obsessions/intrusions. Results indicate that individuals with OCD described themselves as insecure, anxious and fearful, but also as good and nice. They particularly feared a selfish, aggressive, bad, liar, coward, insecure and arrogant self. Two-thirds of the patients believed that their obsessions said something about their actual self (65.52%) and that their obsessions brought them closer to the person they do not want to be (62.06%). A third of patients believed their intrusions said something about their actual self (actual self: 30.35%; feared self: 25%), which was a significantly lower percentage than for obsessions. These associations existed independent from the content of the obsession and/or intrusion, although patients with obsessions with moral-based contents more often tended to believe that their obsessions brought them closer to the person they do not want to be. Results suggest the relevance of the real and feared selves in the maintenance of obsessions.

Are Individuals Always Aware of Their Trauma-Related Intrusive Thoughts? A Study of Meta-Awareness

Individuals are not always aware of their mental content. We tested whether lack of awareness occurs in those who have experienced trauma, with and without posttraumatic stress disorder (PTSD). We also examined the role of proposed cognitive mechanisms (working memory and inhibition) in explaining unnoticed intrusions. Individuals with PTSD (n = 44), and varying levels of symptoms (high posttraumatic stress [PTS]: n = 24; low PTS: n = 37) reported on intrusive thoughts throughout a reading task. Intermittently, participants responded to probes about whether their thoughts were trauma related. Participants were "caught" engaging in unreported trauma-related thoughts (unnoticed intrusions) for between 24 and 27% of the probes in the PTSD and high PTS groups, compared with 15% of occasions in the low PTS group. For trauma-related intrusions only, participants lacked meta-awareness for almost 40% of probes in the PTSD group, which was significantly less than that observed in the other groups (∼60%). Contrary to predictions, working memory and response inhibition did not predict unnoticed intrusions. The results suggest that individuals who have experienced significant trauma can lack awareness about the frequency of their trauma-related thoughts. Further research is warranted to identify the mechanisms underpinning the occurrence of unnoticed intrusions.

Amnestic Mild Cognitive Impairment is Characterized by the Inability to Recover from Proactive Semantic Interference across Multiple Learning Trials

BACKGROUND

Difficulties in inhibition and self-monitoring are early features of incipient Alzheimer's disease and may manifest as susceptibility to proactive semantic interference. However, due to limitations of traditional memory assessment paradigms, recovery from interference effects following repeated learning opportunities has not been explored.

OBJECTIVE

This study employed a novel computerized list learning test consisting of repeated learning trials to assess recovery from proactive and retroactive semantic interference.

DESIGN

The design was cross-sectional.

SETTING

Participants were recruited from the community as part of a longitudinal study on normal and abnormal aging.

PARTICIPANTS

The sample consisted of 46 cognitively normal individuals and 30 participants with amnestic mild cognitive impairment.

MEASUREMENTS

Participants were administered the Cognitive Stress Test and traditional neuropsychological measures. Step-wise logistic regression was applied to determine which Cognitive Stress Test measures best discriminated between diagnostic groups. This was followed by receiver operating characteristic analyses.

RESULTS

Cued A3 recall, Cued B3 recall and Cued B2 intrusions were all independent predictors of diagnostic status. The overall predictive utility of the model yielded 75.9% sensitivity, 91.1% specificity, and an overall correct classification rate of 85.1%. When these variables were jointly entered into receiver operating characteristic analyses, the area under the curve was .923 (p<.001).

CONCLUSIONS

This novel paradigm's use of repeated learning trials offers a unique opportunity to assess recovery from proactive and retroactive semantic interference. Participants with mild cognitive impairment exhibited a continued failure to recover from proactive interference that could not be explained by mere learning deficits.

Measurement of Unwanted Thought Suppression Strategies with the Thought Control Questionnaire in the General Polish Population: A Confirmatory Factor Analysis and Validation

INTRODUCTION

Although psychological studies have suggested both the desired and paradoxical effects of unwanted thought suppression, we still know little about this mechanism. It has been proposed that individual differences in using specific strategies to suppress intrusions explain why contradictory effects of suppression are observed. The main aims of the study were to investigate the factor structure of the Polish version of Thought Control Questionnaire (TCQ) and verify whether this structure corresponds to the original version of the TCQ measurement.

METHODS

Using the TCQ, which is a 30-item self-report measure, this research investigated individual thought control strategies to suppress intrusive thoughts in the general population. We used parallel analysis and theoretical interpretability to investigate the most appropriate factor structure of the inventory. To examine the validity of the Polish version of TCQ the correlational analysis of TCQ factors with other psychometric scales: Beck Depression Inventory, The State-Trait Anxiety Inventory and The Metacognitions Questionnaire. The internal consistency of the TCQ subscales was also assessed by calculating the Cronbach's alpha reliability coefficients for each factor.

RESULTS

The resulting five-factor solution explained 51.86% of the total variance. The Polish version of TCQ consisted of five subscales yielding satisfactory reliability values: 1) Punishment (α = 0.725); 2) Distraction (α = 0.688); 3) Social Control (α = 0.780); 4) Worry (α = 0.788; 5) Re-appraisal (α = 0.70).

CONCLUSION

The five-factor solution was convergent with the dimensions that appeared in the original TCQ version and were observed in the most TCQ adaptations in various countries. Our findings support the psychological construct of thought-control strategies measured by TCQ and prove the satisfactory reliability of this self-report measure within a Polish population.

Semantic Intrusion Error Ratio Distinguishes Between Cognitively Impaired and Cognitively Intact African American Older Adults

BACKGROUND

Semantic intrusion errors on memory tests may represent very early cognitive changes associated with elevated Alzheimer's disease pathology within the brain, including amyloid-β (Aβ). Subscales that measure proactive semantic interference (PSI) and intrusions related to PSI on the Loewenstein Acevedo Scales of Semantic Interference and Learning (LASSI-L) have been associated with high levels of brain amyloid load, structural changes on brain MRI in Hispanic and non-Hispanic groups. It is presently unknown whether intrusion errors or other measures of the LASSI-L can differentiate between African-American (AA) older adults diagnosed with amnestic mild cognitive impairment (aMCI) or classified as cognitively normal (CN).

OBJECTIVE

This study examined the extent to which a high percentage of semantic intrusion errors on LASSI-L subscales susceptible to PSI and other LASSI-L measures could differentiate between AA aMCI and CN groups.

METHODS

Forty-eight AA older adults were recruited (27 CN and 21 aMCI) and received a through clinical and neuropsychological evaluation. The LASSI-L was administered independent of diagnostic classification.

RESULTS

With and without statistical adjustment for literacy, AA aMCI participants scored lower on all LASSI-L measures. ROC analyses revealed an area under the curve exceeding 90% and correctly classified 86% of AA aMCI with 82% specificity for AA CN participants.

CONCLUSIONS

Percentage of intrusion errors on the LASSI-L subscales susceptible to PSI differentiated AA aMCI from AA CN. This adds to emerging evidence indicating that the LASSI-L may be culturally appropriate and can differentiate between aMCI and CN in diverse ethnic/cultural groups.

Is context a crucial factor in distinguishing between intrusions and obsessions in patients with obsessive-compulsive disorder?

OBJECTIVE

Some cognitive models of obsessive-compulsive disorder (OCD) posit that intrusions exist on a continuum with obsessions; others consider that they may be unrelated phenomena that differ in the context where they occur. We aimed to examine and compare, at two different moments, the context of the occurrence of intrusions and obsessions.

METHOD

Sixty-eight patients with OCD completed an interview appraising their most upsetting obsession and intrusion.

RESULTS

At their onset, the obsessions/intrusions were associated with experiencing negative emotional states and life events, and they were more likely to appear in "inappropriate" contexts. The context of the obsessions/intrusions differed the last time they were experienced. Autogenous obsessions/intrusions occurred more frequently in contexts with an indirect link.

CONCLUSIONS

The context distinguishes between intrusions and obsessions, not when they emerge, but when the obsession is already established. The results support that there is a continuum or progression from intrusions to obsessions.

Investigating cultural differences in the effects of expressive suppression when processing traumatic distressing material

BACKGROUND

While suppression is associated with detrimental post-traumatic psychological adjustment, research has not considered the effect of culture on this relationship.

AIMS

This study investigated cultural differences in the effects of expressive suppression, whilst watching a traumatic film, on subjective distress, psychophysiological responses and intrusive memory.

METHOD

Australians of European heritage or East Asian Australian participants (n = 82) were randomly assigned to either a suppression group (instructed to suppress their emotions during the film) or a control group (no instructions regarding emotion management). Electrodermal activity, heart rate and heart rate variability (root mean square of the successive differences; RMSSD) were measured pre-, during and post-film. Participants reported the number of film-related intrusions in the 5 min and 7 days post-viewing.

RESULTS

While the European Australian group did not differ significantly on RMSSD, the East Asian suppression group scored significantly higher on RMSSD during the film than the East Asian control group. Second, those in the suppression groups, regardless of cultural background, reported significantly fewer intrusions immediately post-film than controls. Third, we found that for the European Australian group, change in heart rate interacted with group (control versus suppression) when predicting weekly intrusions. However, for the East Asian group change in heart rate did not interact with group when predicting weekly intrusions.

CONCLUSIONS

The findings are discussed in the context of current research on culture and emotion regulation and implications for post-traumatic stress disorder.

Targeting intrusive imagery using a competing task technique: a case study

BACKGROUND

Even in cases with complexity, simple techniques can be useful to target a specific symptom. Intrusive mental images are highly disruptive, drive emotion, and contribute to maintaining psychopathology. Cognitive science suggests that we might target intrusive images using competing tasks.

AIMS

We describe an imagery competing task technique within cognitive behavioural therapy (CBT) with a patient with bipolar disorder and post-traumatic stress disorder (PTSD) symptoms. The intervention - including Tetris computer game-play - was used (1) to target a specific image within one therapy session, and (2) to manage multiple images in daily life.

METHOD

A single case (AB) design was used. (1) To target a specific image, the patient brought the image to mind and, after mental rotation instructions and game-play practice, played Tetris for 10 minutes. Outcomes, pre- and post-technique, were: vividness/distress ratings when the image was brought to mind; reported intrusion frequency over a week. (2) To manage multiple images, the patient used the intervention after an intrusive image occurred. Outcomes were weekly measures of: (a) imagery characteristics; (b) symptoms of PTSD, anxiety, depression and mania.

RESULTS

(1) For the target image, there were reductions in vividness (80% to 40%), distress (70% to 0%), and intrusion frequency (daily to twice/week). (2) For multiple images, there were reductions from baseline to follow-up in (a) imagery vividness (38%), realness (66%) and compellingness (23%), and (b) PTSD symptoms (Impact of Events Scale-Revised score 26.33 to 4.83).

CONCLUSION

This low-intensity intervention aiming to directly target intrusive mental imagery may offer an additional, complementary tool in CBT.

Reduction in the occurrence of distressing involuntary memories following propranolol or hydrocortisone in healthy women

BACKGROUND

Pharmacological treatments targeting the neuroendocrine stress response may hold special promise in secondary prevention of posttraumatic stress disorder (PTSD). However, findings from clinical trials have been inconsistent and the efficacy of specific drugs, their temporal window of efficacy, effective doses and the characteristics of likely treatment responders remain unclear.

METHOD

Using an experimental human model of distressing involuntary memory formation, we compare the effects of two drugs that have theoretical or empirical support as secondary preventive agents in PTSD. Eighty-eight healthy women (average age: 23.5 years) received oral propranolol (80 mg), hydrocortisone (30 mg), or matched placebo immediately after viewing a 'trauma film'. They then completed daily, time-stamped intrusion diaries for 1 week, at the end of which, voluntary memory was tested.

RESULTS

While neither drug affected voluntary memory for the trauma narrative, propranolol treatment was associated with 42% fewer, and hydrocortisone with 55% fewer intrusions across the week, relative to placebo. Additionally, propranolol reduced general trauma-like symptoms, and post-drug cortisol levels were negatively correlated with intrusion frequency in the hydrocortisone group.

CONCLUSIONS

Overall, this study shows substantial reductions in intrusive memories and preserved voluntary narrative-declarative memory following either propranolol or hydrocortisone in an experimental model of psychological trauma. As such, despite some inconsistencies in clinical trials, our findings support continued investigation of propranolol and hydrocortisone as secondary preventive agents for re-experiencing symptoms of PTSD. The findings also suggest that it is critical for future research to identify the conditions governing the preventive efficacy of these drugs in PTSD.

Validation of the Interpretation of Intrusions Inventory for the Mexican Population: Cross-Cultural Discrepancies

To facilitate research on the cognitive model of obsessive-compulsive disorder (OCD), leaders in the field of OCD (Obsessive-Compulsive Cognitions Working Group [OCCWG]) developed and validated the Interpretation of Intrusions Inventory-31 (III-31). The current sought to adapt and validate this important measure for the Mexican population using a large sample of emerging adults (N = 457). Specifically, we evaluated the factor structure and convergent validity of the III-31 for the Mexican population. Based on a series of confirmatory factor analyses, previously established one-, two-, and three-factor models were found to be a poor fit with current data. However, an exploratory factor analysis yielded a two-factor solution, with one factor assessing the harmfulness and danger of intrusive thoughts (Harmfulness/Danger), and the other assessing exaggerated responsibility and efforts to control intrusions (Responsibility/Control). Satisfactory convergent validity was found with the severity of dysfunctional beliefs and OCD symptoms. Implications and limitations of study results are discussed.

Affective and cognitive factors associated with hallucination proneness in the general population: the role of shame and trauma-related intrusions

Introduction: Feelings of shame may be an important factor implicated in the onset and maintenance of hallucination (or hearing voices). Shame has been shown to increase trauma-related intrusions and avoidance and may reinforce negative beliefs about the self, which in turn may contribute to hallucinations in clinical and non-clinical populations. To our knowledge, no study has so far explored the role of shame in hallucination-proneness. Therefore, the main goal of the present study is to explore the mediation role of shame, trauma-related intrusions and avoidance in the association between childhood trauma and hallucination-proneness.Methods: Self-report questionnaires were used to assess past traumatic experiences, trauma-related symptoms, shame, and hallucination proneness in 175 participants from the general population.Results: Mediation analyses (joint-significance test and Monte Carlo test) showed that both shame and intrusions mediated the association between childhood trauma and hallucination-proneness.Conclusions: Our results reinforce the importance of considering previous experiences of trauma and trauma-related symptoms, including feelings of shame in individuals experiencing hallucinations. Moreover, this study reinforces previous studies showing some preliminary evidence that compassion-focused therapy, whose primary goal is to reduce shame by increasing self-compassion, could have a significant effect on voices whose content is hostile.

Differential Effects of Poor Recall and Memory Disjointedness on Trauma Symptoms

Clinical theories of posttraumatic stress disorder (PTSD) suggest that trauma memories are disorganized. In the present study, we examined how trauma-film exposure affects two aspects of memory disorganization, poor memory recall and memory disjointedness, and their relationship to PTSD-like symptoms. In Session 1, 90 healthy participants were exposed to a trauma (n = 60) or a neutral film (n = 30). Cognitive processing styles, memory characteristics, and intrusive memories of the film were assessed. The trauma-film group reported greater memory disjointedness of the worst moments of the film but better memory recall of the film than the neutral-film group. In the trauma-film group, cognitive processing and memory disjointedness were related to intrusive memories and PTSD-like symptoms in the week after film exposure. Memory disjointedness but not poor memory recall mediated the relationship between cognitive processing and intrusions. The findings suggest that different aspects of memory disorganization need to be distinguished to explain PTSD symptoms.

Acute Exercise on Memory Reconsolidation

Background and Objective: Once a memory is reactivated, it enters a labile state and, thus, is vulnerable to memory decay and/or distortion. Recent research demonstrates that acute, high-intensity exercise is associated with enhanced episodic memory function. Very limited research, however, has evaluated whether acute exercise can attenuate memory distortion from memory reactivation, which was the purpose of this study. Methods: A between-subject randomized controlled intervention was employed. Participants (N = 80) were randomly assigned to one of four groups, including (1) reminder with exercise, (2) reminder, (3) no reminder, and (4) interference control. For the groups, participants completed three visits (Visit 1, 2, and 3), which all occurred 48 hours apart. An exception to this was the interference control group, which did not complete Visit 2. On Visit 2, the reminder with exercise group engaged in a 15 min bout of high-intensity exercise (80% of heart rate reserve) immediately after memory reactivation. On Visit 3, participants engaged in a free recall (4 trials) of the memory task encoded on Visit 1. Results: In a 4 (groups) × 4 (learning trials) mixed-measures ANOVA, with the group as the between-subjects variable and the learning trials (1–4) as the within-subject variable, there was a significant main effect group, F(3, 76) = 4.18, p = 0.008, η²_p = 0.14, and a significant main effect for the learning trials, F(2.40, 182.59) = 49.25, p < 0.001, η²_p = 0.39, but there was no group by learning trials interaction, F(7.20, 182.59) = 1.07, p = 0.38, η²_p = 0.04. Conclusion: Our findings suggest that exercise may, potentially, attenuate memory distortion from memory reactivation. However, future work is needed to confirm these findings before any strong conclusions can be reached.

The role of tonic immobility and control in the development of intrusive memories after experimental trauma

Tonic immobility (TI; state of motor inhibition during threat) has been implicated in the onset of intrusive trauma memories, while controllability was associated with reduced anxiety. The present study investigated the interaction between TI and control in the development of intrusive memories of an analogue trauma. Sixty-four participants watched negative pictures while being allowed to close their eyes (InControl) or not (NoControl). They completed measures for spontaneous TI afterwards and recorded intrusive memories of the pictures in a diary in the subsequent week. Bayesian analyses were used to test informative hypotheses. Spontaneous TI during picture viewing was positively associated with increased intrusion frequency. Intrusion frequency did not differ for InControl versus NoControl. Moderation (control x TI) and non-moderation (main effect of TI only) were both adequate models, with no preference. Our results confirm the importance of TI in PTSD development. Implications of the findings regarding control merit more research.

The Prospective Influence of Trait Alexithymia on Intrusive Memories: What Is the Role of Emotional Recognition Memory?

Posttraumatic stress disorder (PTSD) is often considered to be a disorder of memory as patients suffer from fragmented uncontrollable memories (intrusions) whilst experiencing difficulties in intentionally retrieving details of the traumatic event. Recent research suggests that trait-related deficits in the identification of emotional states (alexithymia) may impact emotional memory processes in a way that promotes intrusion formation in PTSD. Therefore, we investigated the influence of alexithymia on intrusive re-experiencing and emotional recognition memory in a prospective analog study. Twenty-six healthy participants took part in a laboratory experiment, which combined two independent paradigms. Participants were exposed to a traumatic film (first session) and completed an episodic memory task comprising neutral and emotional stimuli (second session). In between sessions, participants recorded intrusive memories of the film. Individuals with higher trait alexithymia (HTA) reported an increased number of intrusions on the day of film presentation. Moreover, analyses of memory performance revealed a negative correlation between alexithymia and emotional recognition memory. Further analyses suggest that reduced emotional recognition memory, as evident in individuals with HTA, may, in turn, be associated with enhanced intrusive re-experiencing. As such, the current findings provide first indications regarding the role of alexithymia in emotional learning and PTSD. Future studies should further investigate these associations as well as potential implications for the treatment of PTSD.

Differential effects of sleep on explicit and implicit memory for potential trauma reminders: findings from an analogue study

Background: Recent findings suggest that disruptions of sleep-related memory processing are involved in the development of posttraumatic stress symptoms. More specifically, exposure to an analogue traumatic event resulted in fewer intrusive memories, when it was followed by sleep instead of continued wakefulness. However, competing evidence suggests that sleep deprivation may reduce intrusive re-experiencing. To address these conflicting accounts, we examined how sleep - as opposed to partial sleep deprivation - modulates explicit and implicit trauma memory using an analogue procedure. Methods: Healthy participants (N = 41) were assigned to a Sleep or Partial sleep deprivation group. Prior to nocturnal sleep, both groups were exposed to "traumatic" picture stories. After sleep or partial sleep deprivation, participants were subjected to tests of explicit and implicit memory for potential trauma reminders. Thereafter, participants completed an intrusion triggering task that was embedded in a distractor task. Results: Analyses revealed higher explicit memory for potential trauma reminders after sleep as compared to partial sleep deprivation. No group differences were found for implicit memory. Participants responded with fewer intrusions after sleep than following partial sleep deprivation. Conclusions: The current findings support a protective role of sleep in trauma memory processing, which may be evident after the first night of sleep post-trauma. Although more research is needed, our results corroborate the importance of promoting restful sleep in trauma-exposed individuals.

Factors influencing within-group conflict over defence against conspecific outsiders seeking breeding positions

In social species, groups face a variety of threats from conspecific outsiders. Defensive actions are therefore common, but there is considerable variation in which individuals contribute and to what extent. There has been some theoretical exploration of this variation when the defence is of shared resources, but the relative contributions when a single intruder threatens a particular breeding position have received less attention. Defensive actions are costly, both for the individual and dependent young, and contributions are likely to differ depending on individual sex, rank and size, current breeding stage, infanticide risk and relatedness levels. Here, we model analytically the relative fitness benefits of different group members to engaging in defence against individual intruders and determine when within-group conflicts of interest might arise over these defensive contributions. Conflicts of interest between the challenged breeder and other group members depend on relatedness to the brood and the potential relatedness reduction if an intruder acquires breeding status. Conflicts are more likely to occur when there is a low chance of winning the contest, low infanticide rates, inefficient defence from helpers, a long remaining brood-dependency period and high external (non-contest-related) mortality. Our work can help explain variation in defensive actions against out-group threats.

The Retro-Cue Benefit for Verbal Material and Its Influence on the Probability of Intrusions Under Dual-Task Conditions

It is well established in the working memory literature, that performance can be improved by cueing attention toward the position of a to-be-tested item, even after that item's presentation. This retro-cue benefit is often characterized as the joint outcome of two different effects: facilitation of recall and memory strengthening at the cued position. While the latter has been mainly explained by increased context-content binding, competing hypotheses exist to explain the facilitation of recall. The present study focuses on two of these hypotheses: the removal of non-cued information and the protection of cued information against interference. I replicate the retro-cue effect for verbal material and provide strong evidence for its protective effect. However, I did not find support for the removal hypothesis. This lack of support follows from two empirical findings: Retro-cueing does not decrease, rather increases the conditional probability of intrusions, and the retro-cue benefit does not interact with memory load.

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

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

Development and validation of the Workplace Interruptions Measure

In 3 studies, we developed and tested the first comprehensive, self-report measure of workplace interruptions. The Workplace Interruptions Measure (WIM) is based on a typology of interruptions that included intrusions, distractions, discrepancy detections, and breaks. The four-factor structure was reduced to a 12-item measure in Study 1 (N = 317) and confirmed in a diverse sample of employees in Study 2 (N = 160). Study 3 (N = 323) further examined the psychometric properties of the WIM in a sample of university faculty and staff. Studies 2 and 3 demonstrated that both effort-enhancing interruptions (intrusions, distractions, and discrepancy detections) and recovery-enhancing interruptions (breaks) were associated with stressors and strains. Distractions, discrepancy detections, and breaks uniquely predicted strain outcomes beyond other workplace stressors (i.e., quantitative workload, interpersonal conflict, and role conflict). We discuss implications of the WIM for the theory and practice of interruptions research.

Development and testing of TraumaGameplay: an iterative experimental approach using the trauma film paradigm

Background: Vivid trauma-related intrusions are a hallmark symptom of posttraumatic stress disorder (PTSD), and may be involved in its onset. Effective interventions to reduce intrusions and to potentially prevent the onset of subsequent PTSD are scarce. Studies suggest that playing the videogame Tetris, shortly after watching aversive film clips, reduces subsequent intrusions. Other studies have shown that taxing working memory (WM) while retrieving an emotional memory reduces the memory's vividness and emotionality. Objective: We developed TraumaGameplay (TGP), a gaming app designed to reduce intrusions. This paper describes two successive experiments to determine whether playing TGP without memory retrieval (regular TGP) or TGP with memory retrieval (dual-task TGP) reduces intrusion frequency at one week compared to a no-game control. Method: For both experiments, healthy university students were recruited. Experiment 1: 92 participants were exposed to a trauma film and randomized to (1) regular TGP1 (n = 31), (2) dual-task TGP1 (n = 31) or (3) control (n = 30). In experiment 2, 120 healthy students were exposed to a trauma film and randomized to (1) regular TGP2 (n = 30), (2) dual-task TGP2 (n = 29), (3) recall only (n = 31) or (4) control (n = 30). Results: We found no significant difference between conditions on the number of intrusions for either playing regular TGP or dual-task TGP in both experiment 1 and experiment 2. Conclusion: Our results could not replicate earlier promising findings from preceding experimental research. Several reasons may underpin this difference ranging from the visuospatial videogame used in our experiments to the method of the experiment to the difficulties of replicability in general.

If it is absurd, then why do you do it? The richer the obsessional experience, the more compelling the compulsion

Mounting evidence suggests that obsessive intrusions are often accompanied and amplified by perceptual experiences of different modalities (e.g., feeling dirt on one's skin while experiencing intrusive thoughts about contamination). Pilot studies conducted online with individuals endorsing mild obsessive-compulsive symptoms have linked the co-occurrence of perceptual experiences and obsessions to the severity of subsequent compulsive behaviour as well as low insight. However, it is presently unclear whether sensory experiences accompany all types of obsessional thoughts or are restricted to certain preoccupations (e.g., contamination and aggression). The present study examined a clinical inpatient and outpatient sample with a formally diagnosed obsessive-compulsive disorder (N = 34). Perceptual properties of intrusive thoughts were assessed with the Sensory Properties of Obsessions Questionnaire. The prevalence of perception-laden obsessive thoughts was comparable with prior studies (73.5%), but the intensity was significantly greater. No association was observed between perceptual experiences and expert-rated insight. However, the severity of perception-laden obsessions predicted the frequency of and impairment associated with compulsive behaviour. This was particularly strong for obsessions about contamination. The present study confirms the high prevalence and clinical relevance of perceptual experiences that accompany obsessions and further challenges the traditional trichotomy splitting mental phenomena into thoughts, intrusions, and hallucinations.

Physiological and psychological effects of imagery techniques on health anxiety

Previous research has shown that intrusions are part of the psychopathology of mental disorders. Imagery techniques seem to be an effective treatment of negative intrusions. Since negative mental imagery is part of health anxiety, the present study investigated the impact of imagery techniques on health anxiety. A total of 159 students with elevated scores in a health anxiety questionnaire watched an aversive film concerning a cancer patient and were randomly allocated to one of three interventions (positive imagery, imagery reexperiencing, imagery rescripting) or the control group. The intervention lasted 9 min. Physiological data (heart rate and cortisol) as well as psychological measures, such as mood ratings, health anxiety scores, and intrusions, were assessed during the appointment, while psychological measures were assessed over a period of 1 week after the intervention. Cortisol levels changed over time depending on the intervention. Heart rate changed during the 9-min interventions as well, with the fastest decrease during imagery rescripting. Moreover, negative mood and distress decreased after the intervention, while intrusions were reduced 1 week after the intervention in all groups equally. The results suggest that imagery rescripting is a promising technique that seems to activate a process of deep elaboration. Therefore, it might be an adequate way to target health anxiety symptoms such as anxiety, intrusions, and avoidance or safety-seeking behavior. Further studies should focus on imagery rescripting in clinical samples with health anxiety and target individual intrusive images to increase effectiveness. Nevertheless, the development of a long-term explanatory model of rescripting is needed.

Treatment of Intrusive Suicidal Imagery Using Eye Movements

Suicide and suicidal behavior are major public health concerns, and affect 3–9% of the population worldwide. Despite increased efforts for national suicide prevention strategies, there are still few effective interventions available for reducing suicide risk. In this article, we describe various theoretical approaches for suicide ideation and behavior, and propose to examine the possible effectiveness of a new and innovative preventive strategy. A model of suicidal intrusion (mental imagery related to suicide, also referred to as suicidal flash-forwards) is presented describing one of the assumed mechanisms in the etiology of suicide and the mechanism of therapeutic change. We provide a brief rationale for an Eye Movement Dual Task (EMDT) treatment for suicidal intrusions, describing techniques that can be used to target these suicidal mental images and thoughts to reduce overall behavior. Based on the available empirical evidence for the mechanisms of suicidal intrusions, this approach appears to be a promising new treatment to prevent suicidal behavior as it potentially targets one of the linking pins between suicidal ideation and suicidal actions.

Pathways from Trauma to Psychotic Experiences: A Theoretically Informed Model of Posttraumatic Stress in Psychosis

In recent years, empirical data and theoretical accounts relating to the relationship between childhood victimization and psychotic experiences have accumulated. Much of this work has focused on co-occurring Posttraumatic Stress Disorder or putative causal mechanisms in isolation from each other. The complexity of posttraumatic stress reactions experienced in psychosis remains poorly understood. This paper therefore attempts to synthesize the current evidence base into a theoretically informed, multifactorial model of posttraumatic stress in psychosis. Three trauma-related vulnerability factors are proposed to give rise to intrusions and to affect how people appraise and cope with them. First, understandable attempts to survive trauma become habitual ways of regulating emotion, manifesting in cognitive-affective, behavioral and interpersonal responses. Second, event memories, consisting of perceptual and episodic representations, are impacted by emotion experienced during trauma. Third, personal semantic memory, specifically appraisals of the self and others, are shaped by event memories. It is proposed these vulnerability factors have the potential to lead to two types of intrusions. The first type is anomalous experiences arising from emotion regulation and/or the generation of novel images derived from trauma memory. The second type is trauma memory intrusions reflecting, to varying degrees, the retrieval of perceptual, episodic and personal semantic representations. It is speculated trauma memory intrusions may be experienced on a continuum from contextualized to fragmented, depending on memory encoding and retrieval. Personal semantic memory will then impact on how intrusions are appraised, with habitual emotion regulation strategies influencing people's coping responses to these. Three vignettes are outlined to illustrate how the model accounts for different pathways between victimization and psychosis, and implications for therapy are considered. The model is the first to propose how emotion regulation and autobiographical memory may lead to a range of intrusive experiences in psychosis, and therefore attempts to explain the different phenomenological associations observed between trauma and intrusions. However, it includes a number of novel hypotheses that require empirical testing, which may lead to further refinement. It is anticipated the model will assist research and practice, in the hope of supporting people to manage the impact of victimization on their lives.

Posttraumatic Stress Disorder and Autobiographical Memories in Everyday Life

Evidence from self-reports and laboratory studies suggests that recall of nontrauma autobiographical memories may be disturbed in posttraumatic stress disorder (PTSD), but investigations in everyday life are sparse. This study investigated unintentional nontrauma and trauma memories in trauma survivors with and without PTSD (N = 52), who kept an autobiographical memory diary for a week. We investigated whether unintentional nontrauma memories show an overgeneral memory bias and further memory abnormalities in people with PTSD, and whether unintentional trauma memories show distinct features. Compared to the no-PTSD group, the PTSD group recorded fewer nontrauma memories, which were more overgeneral, more often from before the trauma or related to the trauma, were perceived as distant, and led to greater dwelling. Trauma memories were more vivid, recurrent, and present and led to greater suppression and dwelling. Within the PTSD group, the same features distinguished trauma and nontrauma memories. Results are discussed regarding theories of autobiographical memory and PTSD.

A virtual reality paradigm as an analogue to real-life trauma: its effectiveness compared with the trauma film paradigm

Background: The trauma film paradigm (TFP) is a well-established method to study the effects of analogue psychological trauma under controlled laboratory settings. It has been used to examine pre-, peri-, and post-trauma processes, and to create and test interventions. A possible drawback is that watching films is a somewhat passive endeavour that lacks active behavioural engagement. Virtual reality (VR) may provide a better alternative. Like the TFP, VR allows for experimental control. In addition, it can induce a greater 'feeling of presence' and allows interaction with the environment, enabling research on action-reaction associations. Objective: We aimed to validate the utility of a VR paradigm as an experimental model to study psychological trauma by comparing its effectiveness with the TFP. Method: One group of participants (N = 25) was shown an aversive film, and another group (N = 25) moved through a VR scene. Main outcome measures were intrusion frequency assessed with a 7-day diary and self-rated vividness and emotionality of recalled memories related to the film or VR scene. Results: The results indicate that the film and VR scene were equally effective in inducing vivid and intrusive memories. However, self-reported emotional intensity appeared to be higher for memories related to the film than for memories related to the VR scene. Conclusions: Perhaps the film was more effective in inducing emotional memories than the VR scene due to its more aversive content. However, the VR scene seemed equally effective in inducing vivid and intrusive memories, and merits further exploration in light of ethical considerations (less aversive content) and other presumably beneficial qualities (e.g. inducing a greater feeling of presence and allowing interaction with the environment).

Tetris and Word games lead to fewer intrusive memories when applied several days after analogue trauma

Background: Intrusive trauma memories are a key symptom of posttraumatic stress disorder (PTSD), so disrupting their recurrence is highly important. Intrusion development was hindered by visuospatial interventions administered up to 24 hours after analogue trauma. It is unknown whether interventions can be applied later, and whether modality or working-memory load are crucial factors. Objectives: This study tested: (1) whether a visuospatial task would lead to fewer intrusions compared to a reactivation-only group when applied after memory reactivation four days after analogue trauma exposure (extended replication), (2) whether both tasks (i.e. one aimed to be visuospatial, one more verbal) would lead to fewer intrusions than the reactivation-only group (intervention effect), and (3) whether supposed task modality (visuospatial or verbal) is a critical component (modality effect). Method: Fifty-four participants were randomly assigned to reactivation+Tetris (visuospatial), reactivation+Word games (verbal), or reactivation-only (no task). They watched an aversive film (day 0) and recorded intrusive memories of the film in diary A. On day 4, memory was reactivated, after which participants played Tetris, Word games, or had no task for 10 minutes. They then kept a second diary (B). Informative hypotheses were evaluated using Bayes factors. Results: Reactivation+Tetris and reactivation+Word games resulted in relatively fewer intrusions from the last day of diary A to the first day of diary B than reactivation-only (objective 1 and 2). Thus, both tasks were effective even when applied days after analogue trauma. Reactivation-only was not effective. Reactivation+Word games appeared to result in fewer intrusions than reactivation+Tetris (objective 3; modality effect), but this evidence was weak. Explorative analyses showed that Word games were more difficult than Tetris. Conclusions: Applying a task four days after the trauma film (during memory reconsolidation) was effective. The modality versus working-memory load issue is inconclusive.

The role of guilt in Posttraumatic Stress Disorder

Background: A growing body of evidence supports the notion that the emotional profile of Posttraumatic Stress Disorder (PTSD) may be more diverse than traditional accounts presume. PTSD's image as an anxiety-based disorder is undergoing change as the significance of other emotions in its development becomes more evident. Experimental research is needed in order to expand the understanding of underlying processes driving the development of PTSD. Objective: Experimentally test the influence of stressor-related guilt on the occurrence of PTSD symptomatology. Method: A non-clinical student sample faced an analogue trauma, a stressor in the form of a computer crash and related loss of data. We either personally blamed participants for causing the incident (blame group) or told them that it was a technical failure and therefore not their fault (no-blame group). Levels of guilt before and after the incident as well as number and associated distress of incident-related intrusions were assessed using a one-day diary and compared between groups. Results: The guilt manipulation was successful: feelings of guilt significantly increased in the blame group but not in the no-blame group. Furthermore, the blame group showed a significantly higher number of intrusions and associated distress compared to the no-blame group at one-day follow-up. Conclusions: These laboratory findings indicate that feelings of guilt may lead to increased PTSD symptomatology, supporting the view that guilt experienced in reaction to a traumatic event may be part of a causal mechanism driving the development of PTSD.

Influence of the noradrenergic system on the formation of intrusive memories in women: an experimental approach with a trauma film paradigm

BACKGROUND

Intrusive memories of traumatic events are a core feature of post-traumatic stress disorder but little is known about the neurobiological formation of intrusions. The aim of this study was to determine whether the activity of the noradrenergic system during an intrusion-inducing stressor would influence subsequent intrusive memories.

METHOD

We conducted an experimental, double-blind, placebo-controlled study in 118 healthy women. Participants received a single dose of either 10 mg yohimbine, stimulating noradrenergic activity, or 0.15 mg clonidine, inhibiting noradrenergic activity, or placebo. Subsequently, they watched an established trauma film which induced intrusions. The number of consecutive intrusions resulting from the trauma film, the vividness of the intrusions, and the degree of distress evoked by the intrusions were assessed during the following 4 days. Salivary cortisol and α-amylase were collected before and after the trauma film.

RESULTS

A significant time × treatment interaction for the number of intrusions and the vividness of intrusions indicated a different time course of intrusions depending on treatment. Post-hoc tests revealed a delayed decrease of intrusions and a delayed decrease of intrusion vividness after the trauma film in the yohimbine group compared with the clonidine and placebo groups. Furthermore, after yohimbine administration, a significant increase in salivary cortisol levels was observed during the trauma film.

CONCLUSIONS

Our findings indicate that pharmacological activation of the noradrenergic system during an emotionally negative event makes an impact on consecutive intrusive memories and their vividness in healthy women. The noradrenergic system seems to be involved in the formation of intrusive memories.

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

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

An adapted imaginal exposure approach to traditional methods used within trauma-focused cognitive behavioural therapy, trialled with a veteran population

Trauma-focused cognitive behavioural therapy (TF-CBT) is beneficial for individuals with post-traumatic stress disorder (PTSD); however, a subset of clients struggle to engage with traditional methods, due to high levels of avoidance and dissociation. This paper aims to describe an adapted approach to imaginal reliving and prolonged exposure, to facilitate subsequent cognitive updating. The paper demonstrates the technique with veterans, who are a client group that may struggle with some aspects of traditionally implemented TF-CBT. Two case studies are described, both with PTSD symptoms stemming from traumatic military experiences. An adapted exposure technique is utilized to address the barriers of high dissociation, poor access to trauma-related cognitions and fixed intrusive imagery. The approach involved three stages: (1) reliving the trauma outdoors, (2) manipulating the perspectives of the imagery, and (3) restructuring the narrative with new perspectives. Both clients showed decreased dissociation and improved toleration of their traumatic imagery. Improvement of PTSD symptoms and quality-of-life functioning was observed for both clients on objective measures. Adapting TF-CBT to have a stronger emphasis on grounding and allocentric processing may be helpful for a subset of patients with PTSD that present with high levels of dissociation and avoidance. Further research and investigation into alternative populations is needed.

Cognitive Load Undermines Thought Suppression in Acute Stress Disorder

Thought suppression studies demonstrate that attempts to suppress can be undermined by cognitive load. We report the first instance in which this has been tested experimentally in a sample of recently traumatized individuals. Individuals with and without acute stress disorder (ASD) were recruited following recent trauma and randomized to load or no load conditions (N=56). They monitored intrusive memories during baseline, suppression, and think anything phases. The impact of suppression and load on self-reported intrusions, attention bias (dot-probe), and memory priming (word-stem task) was assessed. The ASD load group were less able to suppress memories (d=0.32, CI95 [-0.15, 0.83], p=.088) than the ASD no load group (d=0.63, CI95 [0.08, 1.24], p<.001). In the think anything phase, the ASD load group reported more intrusions than the ASD no load or non-ASD groups (with and without load). No consistent findings were observed in relation to attentional bias. ASD load individuals exhibited stronger priming responses for motor vehicle accident and assault words than all other groups (ds between 0.35-0.73). Working memory did not moderate any outcomes of interest. The findings indicate that cognitive load interferes with suppression and may enhance access to trauma memories and associated material. The study extends previous research by demonstrating these effects for the first time in a clinical sample of recent survivors of trauma.

Psychometric properties of the Greek version of the Social Constraints Scale in a sample of women with breast cancer

This study evaluated the psychometric properties of the Greek version of the Social Constraints Scale, developed in English by Lepore and Ituarte (1999). The scale was culturally adapted in Greek and was then administered, along with measures of psychological distress and intrusions, to a sample of 202 women with breast cancer, recruited from July 2012 to October 2013. Although the scale has usually been treated as a unidimensional measure, exploratory factor analysis revealed three underlying factors in the Greek Social Constraints Scale: unsupportive behaviors, avoidant behaviors, and suggestions for pretense and distraction. The three-factor solution explained 55% of the total variance. Subscale reliability was satisfactory (Cronbach's alpha coefficients ranging from 0.77 to 0.88). All subscales were significantly related to intrusions and psychological distress. Thus, the Greek Social Constraints Scale is a reliable and valid multidimensional instrument. The results of the present study show that, among all kinds of social constraints, unsupportive behaviors are the most highly correlated with distress, while distraction/pretense is most correlated with intrusiveness. Findings suggested that health professionals should aim to educate both the patient to claim her right to express feelings and thoughts and her social network to adopt disclosure-facilitating behaviors to compensate for intrusiveness and distress.