The role of inhibitory control and ADHD symptoms in the occurrence of involuntary thoughts about the past and future: An individual differences study

In everyday life, people often experience involuntary thoughts about their personal past and future events in response to incidental cues in the environment. Yet, despite the abundance of such cues, our consciousness is not constantly flooded by these involuntary autobiographical memories (IAMs) and involuntary future thoughts (IFTs). The main goal of the present study was to further investigate the possibility that cognitive inhibitory control keeps these involuntary cognitions at bay. To test this inhibition hypothesis, we conducted a large-scale study (n = 157) in which groups of participants with different levels of inhibitory control (low, medium, high) and individuals with ADHD spectrum symptoms were engaged in a laboratory vigilance task in which the frequency of IFTs and IAMs was assessed. Contrary to predictions, although participants across groups differed significantly in terms of their individual inhibitory control capacity, the number of IFTs and IAMs reported during the vigilance task was comparable. In addition, individuals with the ADHD spectrum symptoms did not report more spontaneous thoughts compared to other groups. Together, these findings lend little support for the idea that inhibition is a key mechanism that regulates the occurrence of IAMs and IFTs in everyday life. Other possible mechanisms and avenues for future research are discussed.     

The impact of depression and PTSD symptom severity on trauma memory

Posttraumatic stress disorder (PTSD) and depression frequently co-occur following a traumatic event. Differences in the processing of autobiographical memory have been observed in both disorders in the form of overgeneralised memories and negative intrusive memories. The current study examined how symptoms of PTSD and depression influence the phenomenological characteristics of trauma memories. Undergraduate students who had experienced a traumatic event (n?=?696) completed questionnaires online including measures of PTSD and depressive symptom severity. They rated their trauma memory on several phenomenological characteristics using the Memory Experiences Questionnaire [Sutin, A. R., &; Robins, R. W. (2007). Phenomenology of autobiographical memories: The memory experiences questionnaire. Memory.]. Moderated multiple regression was used to examine how PTSD and depressive symptom severity related to each phenomenological characteristic. Symptoms of PTSD and depression were related separately and uniquely to the phenomenological characteristics of the trauma memory. PTSD severity predicted trauma memories that were more negative, contained higher sensory detail, and were more vivid. In contrast, depressive symptom severity predicted trauma memories that were less accessible and less coherent. These findings suggest that depressive and PTSD symptomatology affect traumatic memory differently and support a distinction between these two disorders.     

On the advantage of autobiographical memory pliability: implantation of positive self-defining memories reduces trait anxiety

This paper is devoted to the mechanism of the positive construction of autobiographical memory. Positive construction consists of the spontaneous transformation of memories in the direction of the subjective enhancement of self-competence in past activities to anticipate improvement over time. We speculated that trait anxiety may indicate a failure to exhibit this mechanism that results in a deficit of affirmative self-esteem. We hypothesised that the implantation of positive self-defining memories in anxiety-evoking domains would decrease trait anxiety. One hundred twenty adults recollected three negative self-defining memories. Then, half of the participants imagined episodes of desired behaviour that differed from the originally recollected ones either in discussion or in hypnosis. Thirty participants experienced a hypnotic state without any references to memories, and the rest formed the control group. Subjects from the “Memory Implantation in Hypnosis” group became unable to distinguish the originally reported memories from the imagined ones, exhibited decreased trait anxiety scores after a 4-month delay, and reported enhanced self-esteem. In contrast, the participants from the “Hypnosis with no reference to the past” group exhibited decreased scores at a short delay but later returned to their original scores. These findings highlight the power of cured episodic-like autobiographical memory for updating the self.     

Intrusive thoughts mediate the association between neuroticism and cognitive function

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

Preferential processing of visual trauma-film reminders predicts subsequent intrusive memories

This study used an analogue design to test the hypothesis that preferential processing of visual trauma reminders in the aftermath of a stressful or traumatic event gives rise to subsequent intrusive memories. Shortly after the presentation of a stressful film fragment, participants (n=36) were asked to detect neutral targets (rotated buildings or nature scenes) in a single target rapid serial visual presentation (RSVP) paradigm. During half of the streams, the target was preceded by a distracter. The distracters consisted of visual images extracted from an earlier presented stressful film (e.g., persons and objects that figured in the film). The degree of interference by these film reminders predicted subsequent intrusions recorded in a one-week diary. The results provide evidence that a deficient ability to obtain attentional control over perceptual “trauma” reminders during goal-directed behaviour may set people at risk for persistent intrusive memories. Implications for research investigating attentional bias and intrusive memories in context of posttraumatic stress disorder (PTSD) are discussed.     

The role of associative strength in children's false memory illusions

The effects of associative strength on rates of 7- and 11-year-old children's true and false memories were examined when category and Deese-Roediger-McDermott (DRM) lists were used to cue the same critical lure. Backward associative strength (BAS) was varied such that the category and DRM lists had the same strength (DRM=category), DRM lists had more BAS (DRM>category), or category lists had more BAS (DRM<category). If BAS drives children's false memories then BAS, not the type of relation across items in a list, should determine false memory production. The results confirmed this prediction using both recall and recognition measures: (1) both true and false memories increased with age, (2) true memory was better for category than DRM lists but there were no differences for false memory, and (3) at all ages, false memories varied predictably with changes in BAS but were unaffected by list-type manipulations. These findings are discussed in the context of models of false memory development.     

Self-defining future projections: Exploring the identity function of thinking about the future

The act of projecting oneself into meaningful future events may significantly contribute to a person's sense of self and identity. Yet if the role of memories, in particular self-defining memories (SDMs), in grounding the self is now well established, the identity function of anticipated future events has received comparatively little attention. This article introduces the construct of self-defining future projection (SDFP) to address this issue. Two studies show that people can readily identify significant future events that they frequently think about and that convey core information about who they are as individuals. Furthermore, a person's particular style of constructing SDMs is similarly manifested in SDFPs, suggesting that both types of events can be used to ground the self. Notably, people who display a stronger tendency to extract meaning from their past experiences also reflect more about the potential implications of imagined future events. The results further demonstrate that SDMs and SDFPs both give rise to a strong sense of personal continuity over time and are meaningfully related to self-esteem. Together these findings lend support to the idea that a person's sense of self and identity is in part nourished by the anticipation of significant future events.     

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

Abstract

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

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

Exploring the Nature of Traumatic Memory

Summary

For over 100 years clinicians have observed and described the unusual nature of traumatic memories. It has been repeatedly and consistently observed that these memories are characterized by fragmentary and intense sensations and affects, often with little or no verbal narrative content. Yet, possibly because traumatic memories cannot be precipitated under laboratory conditions, the organization of traumatic memories has received little systematic scientific investigation. In our laboratory we have developed an instrument, the Traumatic Memory Inventory (TMI), which systematically assesses the ways that memories of traumatic experience are organized and retrieved over time. In this article we report findings from our third study using the TMI, of 16 subjects who had the traumatic experience of awakening from general anesthesia during surgery. We assessed changes in traumatic memory characteristics over time and differences between memories of subjects with and without current Post-Traumatic Stress Disorder. Our findings suggest the need for more rigorous methods for the assessment of the evolution of traumatic memories. In order to develop a comprehensive and integrated understanding of the nature of traumatic memory, we need to combine careful clinical observations with repli-cable laboratory methods, including those of cognitive science and neuroscience.