Mood-as-input theory and specific negative moods for perseverative checking and worrying

The mood-as-input hypothesis predicts that perseveration at an open-ended task is determined by “stop rules” for the task and by the valency of the mood. Stop rules define a person’s goals in task attainment, e.g. stopping after doing as much as they can, or stopping when they no longer feel like continuing. This thesis will examine the combined effects of stop rules and specific negative moods (sadness, anxiety, anger) on perseverative worrying and checking tasks, and the influence of specific negative moods on personal performance standards. The final study explores the impact of experimentally induced mood on a worry task when the mood source is made highly salient i.e. attributed to an obvious event or source. On a perseverative checking task, different negative mood and stop rule combinations were found not to affect participant performance. However, using a personally-relevant worry task, participants in each specific negative mood condition persevered for longer using an “as many as can” rule compared with those using a “feel like continuing” rule. The opposite was found for participants in a happy mood. The effects of sadness and anxiety on personal performance standards and stop rule preference were also examined. Findings suggest a positive relationship between sad and anxious moods and “as many as can” stop rule preference. An attempt to manipulate mood attribution after inducing an angry mood showed marginally significant differences in attribution by the high and low manipulation groups, but no effects of mood attribution on task performance. These findings suggest that with a catastrophic worry task, participants in each specific negative mood condition using an “as many as can” stop rule persevered for longer compared with those using a “feel like continuing” stop rule. The implications of this work are discussed in relation to mood-as-input accounts of perseveration and models of mood

Evaluation of a brief 4-session psychoeducation procedure for high worriers based on the mood-as-input hypothesis

Given the ubiquity of worrying as a consuming and distressing activity at both clinical and sub-clinical levels, it is important to develop theory-driven procedures that address worrying and allow worriers to manage this activity. This paper describes the development and testing of a psychoeducation procedure based on mood-as-input hypothesis, which is a transdiagnostic model that describes a proximal mechanism for perseverative worrying. The study used nonclinical participants meeting IAPT criteria indicating GAD symptomatology. In 4 sessions, participants in experimental groups received psychoeducation about the basic principles of the mood-as-input hypothesis and received guidance on how to identify and change worry-relevant goal-directed decision rules and negative moods. Participants in the psychoeducation conditions were compared with participants in a befriending control group. Psychoeducation about the model significantly reduced PSWQ scores at follow-up compared with the befriending control condition (a between-groups large effect size, Cohen's d = 1.05), and the homework tasks undertaken by the psychoeducation groups raised mood and reduced worry immediately. At follow up 48.2% of participants in the psychoeducation groups were below the recommended cut-off for identifying GAD symptomatology compared with 20% of participants in the control condition. This study was conducted on a small sample, high-worry student population, without a formal diagnosis. This brief, low-intensity procedure is potentially adaptable to online or self-help procedures, and can be integrated into fuller cognitive therapy packages

Modeling of light scattering and haze in semicrystalline polymers

This article reports a new model approach for the description of light scattering in semicrystalline polymers, to describe more precisely the influence of supermolecular structure on the optical properties. This is the first study in which light scattering of polymer films has been modeled using exact Mie scattering theory of radially anisotropic spheres. As a model material a well‐known polymer, isotactic polypropylene (iPP) was used. Samples were prepared with different sample thicknesses and crystalline structures in order to identify the key parameters of light scattering in polycrystalline polymeric systems. Validation haze measurements were carried out with a spectrophotometer equipped with a 150 mm snap‐in integrating sphere. It was found that the optical properties of the polycrystalline sample can be described using multiple light scattering on these scattering centers. Good agreement was found between the simulated and experimentally measured haze values which proves the reliability and applicability of our new approach

Alterations in amygdala-prefrontal functional connectivity account for excessive worry and autonomic dysregulation in generalized anxiety disorder

Background: Generalized anxiety disorder (GAD) is characterized by the core symptom of uncontrollable worry. Functional magnetic resonance imaging studies link this symptom to aberrant functional connectivity between the amygdala and prefrontal cortex. Patients with GAD also display a characteristic pattern of autonomic dysregulation. Although frontolimbic circuitry is implicated in the regulation of autonomic arousal, no previous study to our knowledge combined functional magnetic resonance imaging with peripheral physiologic monitoring in these patients to test the hypothesis that core symptoms of worry and autonomic dysregulation in GAD arise from a shared underlying neural mechanism. Methods: We used resting-state functional magnetic resonance imaging and the measurement of parasympathetic autonomic function (heart rate variability) in 19 patients with GAD and 21 control subjects to define neural correlates of autonomic and cognitive responses before and after induction of perseverative cognition. Seed-based analyses were conducted to quantify brain changes in functional connectivity with the right and left amygdala. Results: Before induction, patients showed relatively lower connectivity between the right amygdala and right superior frontal gyrus, right paracingulate/anterior cingulate cortex, and right supramarginal gyrus than control subjects. After induction, such connectivity patterns increased in patients with GAD and decreased in control subjects, and these changes tracked increases in state perseverative cognition. Moreover, decreases in functional connectivity between the left amygdala and subgenual cingulate cortex and between the right amygdala and caudate nucleus predicted the magnitude of reduction in heart rate variability after induction. Conclusions: Our results link functional brain mechanisms underlying worry and rumination to autonomic dyscontrol, highlighting overlapping neural substrates associated with cognitive and autonomic responses to the induction of perseverative cognitions in patients with GAD