Myosin II motor activity in the lateral amygdala is required for fear memory consolidation

Learning induces dynamic changes to the actin cytoskeleton that are required to support memory formation. However, the molecular mechanisms that mediate filamentous actin (F-actin) dynamics during learning and memory are poorly understood. Myosin II motors are highly expressed in actin-rich growth structures including dendritic spines, and we have recently shown that these molecular machines mobilize F-actin in response to synaptic stimulation and learning in the hippocampus. In this study, we report that Myosin II motors in the rat lateral amygdala (LA) are essential for fear memory formation. Pretraining infusions of the Myosin II inhibitor, blebbistatin (blebb), disrupted long term memory, while short term memory was unaffected. Interestingly, both post-training and pretesting infusions had no effect on memory formation, indicating that Myosin II motors operate during or shortly after learning to promote memory consolidation. These data support the idea that Myosin II motor-force generation is a general mechanism that supports memory consolidation in the mammalian CNS.     

Involving Parents in Indicated Early Intervention for Childhood PTSD Following Accidental Injury

Accidental injuries represent the most common type of traumatic event to which a youth is likely to be exposed. While the majority of youth who experience an accidental injury will recover spontaneously, a significant proportion will go on to develop Post-Traumatic Stress Disorder (PTSD). And yet, there is little published treatment outcome research in this area. This review focuses on two key issues within the child PTSD literature—namely the role of parents in treatment and the timing of intervention. The issue of parental involvement in the treatment of child PTSD is a question that is increasingly being recognized as important. In addition, the need to find a balance between providing early intervention to at risk youth while avoiding providing treatment to those youth who will recover spontaneously has yet to be addressed. This paper outlines the rationale for and the development of a trauma-focused CBT protocol with separate parent and child programs, for use with children and adolescents experiencing PTSD following an accidental injury. The protocol is embedded within an indicated intervention framework, allowing for the early identification of youth at risk within a medical setting. Two case studies are presented in order to illustrate key issues raised in the review, implementation of the interventions, and the challenges involved.     

Loss Of Trust: Correlates Of The Comorbidity Of Ptsd and Severe Mental Illness

Abstract

The prevalence of post-traumatic stress disorder (PTSD) in the general population of the United States is a topic of speculation, with estimates ranging from 0.4% to 9% (Breslau, Davis, Andreski, & Peterson, 1991; Helzer, Robins, & McEvoy, 1987; Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995). Likewise, estimates of the prevalence of PTSD within the population of persons with serious mental illness have varied widely, depending on how PTSD has been measured. While record verification of PTSD within mental health outpatient samples has routinely been very low (0%-3%), research assessments of PTSD have resulted in estimated rates of co-occurrence of 29% to 43% (Cascardi, Mueser, DeGirolomo, & Murrin, 1996; Craine, Henson, Colliver, & MacLean, 1998; Mueser et al., 1998). A lack of documentation of PTSD in clinical records and inattention to PTSD in clinical diagnoses are thought to greatly underestimate the extent of PTSD within mental health treatment populations. The general consensus among researchers has been that the occurrence of PTSD is much higher within the population of persons with diagnoses of mental illness than in the general population, particularly among those who have major depression (Friedman & Rosenheck, 1996).     

Cognitive-Behavioural Treatment of School-Refusing Children: Maintenance of improvement at 3- to 5-year follow-up

Although evidence is accumulating on the immediate or short-term efficacy of cognitive-behavioural strategies in the treatment of school refusal, no studies have been reported on the long-term efficacy of this treatment approach. An earlier randomized clinical trial conducted by the authors demonstrated the efficacy of a manual-based cognitive-behavioural treatment program for school refusal relative to waiting list controls. We now report findings of a 3- to 5-year follow-up investigation of the treatment group. In general, results support the long-term efficacy of the treatment program, with children showing maintenance of improvements in school attendance and school adjustment. Methodological limitations of the follow-up investigation are emphasized.     

College Student Cheating: The Role of Motivation,Perceived Norms,Attitudes, and Knowledge of Institutional Policy

This study provides a comparative analysis of students' self-reported beliefs and behaviors related to six analogous pairs of conventional and digital forms of academic cheating. Results from an online survey of undergraduates at two universities (N = 1,305) suggest that students use conventional means more often than digital means to copy homework, collaborate when it is not permitted, and copy from others during an exam. However, engagement in digital plagiarism (cutting and pasting from the Internet) has surpassed conventional plagiarism. Students also reported using digital “cheat sheets” (i.e., notes stored in a digital device) to cheat on tests more often than conventional “cheat sheets.” Overall, 32% of students reported no cheating of any kind, 18.2% reported using only conventional methods, 4.2% reported using only digital methods, and 45.6% reported using both conventional and digital methods to cheat. “Digital only” cheaters were less likely than “conventional only” cheaters to report assignment cheating, but the former was more likely than the latter to report engagement in plagiarism. Students who cheated both conventionally and digitally were significantly different from the other three groups in terms of their self-reported engagement in all three types of cheating behavior. Students in this “both” group also had the lowest sense of moral responsibility to refrain from cheating and the greatest tendency to neutralize that responsibility. The scientific and educational implications of these findings are discussed in this study.     

Concern-induced negative affect is associated with the occurrence and content of mind-wandering

Previous research has shown that the content and frequency of mind-wandering episodes—the occurrence of thoughts that are both stimulus-independent and task-unrelated—are closely related to an individual’s future-related concerns. Whether this relationship is shaped by the affective changes that are usually associated with future-related concerns still remains unclear, however. In this study, we induced the anticipation of a negatively valenced event and examined whether the ensuing affective changes were related to the occurrence and content of mind-wandering during an unrelated attentional task. We found that the increase in negative affect following concern induction predicted the general frequency of mind-wandering episodes. Furthermore, mind-wandering episodes specifically directed at the induced concern were related to a lower decrease in negative affect during the attentional task. These results suggest that the negative emotional impact of future-related concerns is an important factor to be taken into consideration for the subsequent occurrence of mind-wandering episodes, which might in turn be involved in the maintenance of negative affect over time.     

Preference exploration and learning: the role of intensiveness and extensiveness of experience

In this article, the authors partition the construct of experience into intensiveness (i.e., amount) and extensiveness (i.e., breadth) and examine the impact of the two specific types of experience on preference learning. In the first three studies, the authors' theory that experience can be partitioned into intensiveness (i.e., amount) and extensiveness (i.e., breadth) of experience and that extensiveness has a greater impact on preference learning is supported in environments where prior experience is measured. Further, in study 4 they demonstrate that extensiveness or breadth of experience exerts a larger influence on preference learning in an experiment where each unique type of experience is manipulated as well as measured.