Dissociation and pain perception : an experimental investigation

textDissociative symptoms and abnormalities in pain perception have been associated with a range of disorders. We tested whether experimentally induced increases in state dissociation would cause an analgesic response, and whether this effect would be moderated by participants' history of trauma and dissociative experiences. Participants (n=120) were classified based on their histories of traumatic and dissociative experiences: No trauma or dissociation (NN), trauma without dissociation (TN), or trauma with dissociation (TD). All participants were randomized to a dissociation induction condition via audiophotic stimulation or a credible control condition and were compared on prepost changes in subjective pain and pain tolerance in response to a standard cold-pressor test. Unexpectedly, dissociation induction did not lead to greater pain tolerance or reduced self-reported pain. However, increases in state dissociation significantly predicted increased immersion time and decreased subjective pain.Psycholog

Dilating and contracting arbitrarily

Standard accuracy-based approaches to imprecise credences have the consequence that it is rational to move between precise and imprecise credences arbitrarily, without gaining any new evidence. Building on the Educated Guessing Framework of Horowitz (2019), we develop an alternative accuracy-based approach to imprecise credences that does not have this shortcoming. We argue that it is always irrational to move from a precise state to an imprecise state arbitrarily, however it can be rational to move from an imprecise state to a precise state arbitrarily

9/11, Culture War, and the Pitfalls of History

9/11 marks one of the traumatic events of modern U. S. history. Yet its occurrence and aftermath must be placed in the context of social movements and global developments. This presentation focuses on getting past political and social divisiveness. Professor Horowitz has taught at Portland State since 1968, where he won a prize for outstanding achievement in 2007. He is co-author of a U.S. history textbook and has a number of publications to his credit. He is the author of a personal, professional, and political memoir with the title “Getting There: An American Cultural Odyssey.

The effects of emotional acceptance and suppression upon emotional processing in exposure treatment of claustrophobia

textRecent investigations have suggested that the use of emotion-avoidance or emotion- suppression strategies to cope with anxiety contributes to the development and maintenance of anxiety disorders, and that substituting these strategies with emotional acceptance can lead to effective symptom reduction. We wished to consider whether attempts to suppress the negative emotions associated with exposure therapy would serve to impede emotional processing and symptom reduction, and conversely, whether acceptance of these emotions would augment treatment efficacy. Fifty-nine participants displaying marked claustrophobic fear were assigned to receive 30 minutes of exposure (enclosure in a small chamber) while receiving, A) instructions to accept and allow the experience of unpleasant emotions (ACC), B) instructions to control and suppress the experience of unpleasant emotions (SUP), or C) no instructions regarding emotion regulation (exposure only; EO). Outcome assessments were conducted prior to treatment, immediately following treatment, and at one-month follow-up, and included fear and heart rate reactivity in response to a behavioral approach test. We predicted that ACC participants would display greater reductions in claustrophobic fear than EO participants, and that EO participants would in turn display greater reductions in claustrophobic fear than SUP participants. These hypotheses were not supported. In addition, a detailed analysis of treatment process data was conducted. Peak fear ratings, claustrophobic threat expectancies, self-efficacy, and acceptance of anxiety were collected over the course of the treatment session, and hierarchical linear modeling (HLM) was used to produce individual growth curves for these variables. Three hypotheses were formulated: 1) ACC participants would display a more rapid improvement in these measures than SUP and EO participants, 2) threat expectancies, self-efficacy and anxiety would mediate reductions in fear over the course of treatment, and 3) mediational pathways would be moderated by treatment condition. Though no support was found for our first process hypothesis, treatment specific mediation was found. Among ACC participants, self-efficacy and suffocation expectancies mediated the session-fear relationship, and among EO participants, entrapment expectancies mediated this relationship. Among SUP participants, no significant mediators were identified.Psycholog

Scattering of Several Multiply Charged Extremal D=5 Black Holes

The moduli space metric for an arbitrary number of extremal D=5 black holes with arbitrary relatively supersymmetric charges is found.Comment: 12 pages, ReVTeX. Minor typos corrected, including an unimportant sign for which the corresponding comment was removed. One reference adde

Enabling III-V-based optoelectronics with low-cost dynamic hydride vapor phase epitaxy

Silicon is the dominant semiconductor in many semiconductor device applications for a variety of reasons, including both performance and cost. III-V materials have improved performance compared to silicon, but currently they are relegated to applications in high-value or niche markets due to the absence of a low-cost, high-quality production technique. Here we present an advance in III-V materials synthesis using hydride vapor phase epitaxy that has the potential to lower III-V semiconductor deposition costs by orders of magnitude while maintaining the requisite optoelectronic material quality that enables III-V-based technologies to outperform Si. We demonstrate the impacts of this advance by addressing the use of III-Vs in terrestrial photovoltaics, a highly cost-constrained market. The emergence of a low-cost III-V deposition technique will enable III-V electronic and opto-electronic devices, with all the benefits that they bring, to permeate throughout modern society.Comment: pre-prin

String vacuum backgrounds with covariantly constant null Killing vector and 2d quantum gravity

We consider a $2d$ sigma model with a $2+N$ - dimensional Minkowski signature target space metric having a covariantly constant null Killing vector. We study solutions of the conformal invariance conditions in $2+N$ dimensions and find that generic solutions can be represented in terms of the RG flow in $N$ - dimensional ``transverse space'' theory. The resulting conformal invariant sigma model is interpreted as a quantum action of the $2d$ scalar (``dilaton") quantum gravity model coupled to a (non-conformal) `transverse' sigma model. The conformal factor of the $2d$ metric is identified with a light cone coordinate of the $2+N$ - dimensional sigma model. We also discuss the case when the transverse theory is conformal (with or without the antisymmetric tensor background) and reproduce in a systematic way the solutions with flat transverse space known before.Comment: 26 p., revised (a discussion of tachyon coupling is added at the end of section 4), DAMTP-92-4