An experimental investigation of reassurance and responsibility

Repeated reassurance-seeking is a common phenomenon in obsessive-compulsive disorder (OCD). This behaviour may exacerbate compulsive urges (e.g., to check, to seek additional reassurance) by undermining confidence (Dar, 2004; Hout & Kindt, 2004), and preventing the disconfirmation of irrational threat-relevant thoughts and beliefs. The current investigation examined the effects of repeated reassurance and perceived responsibility/threat on anxiety, checking behaviour, memory and confidence. Volunteer undergraduate participants were randomly assigned to one of four conditions: high responsibility-high reassurance, high responsibility-low reassurance, low responsibility-high reassurance, or low responsibility-low reassurance, and were asked to perform several trials of a sorting task. On two separate occasions (i.e., before and after a critical trial, in which only members of the high reassurance groups received reassurance regarding their performance), participants were asked to rate their current anxiety, their urges to check their performance, their urges to be reassured that they had sorted correctly, and their confidence in the accuracy of their performance. They also completed a test to assess their memory accuracy (i.e., their ability to recall details of the experimental task). Results revealed that higher levels of perceived responsibility were associated with the maintenance of compulsive urges (to check and to seek reassurance) and performance-related doubt. Manipulations of reassurance did not significantly affect participants' ratings of the above-listed variables. The results of this study are discussed in terms of cognitive and behavioural models of OCD, and methodological issues are examined. Directions for future research are also suggeste

An investigation of excessive reassurance seeking in OCD

Excessive reassurance-seeking (ERS) is a common problem among individuals dealing with emotional and/or psychological difficulties. Prior research on ERS has focused almost exclusively on the potential consequences of this behaviour in the contexts of Depression and Hypochondriasis, and this research has shown that ERS contributes to interpersonal difficulties and emotional distress. Despite anecdotal evidence that ERS is a hallmark feature of Obsessive-Compulsive Disorder (OCD), comparatively few studies have examined OCD-related ERS. The goal of the present research was to examine various cognitive, behavioural and affective processes that may be involved in the perpetuation of ERS, specifically within the contexts of OCD and Depression. Given the purported functional equivalence between OCD-related reassurance seeking and compulsive checking (Rachman, 2002), the current investigations also aimed to compare ERS and repeated checking activity across a number of important domains (i.e., content, precipitating factors, function and termination criteria). Toward these goals, Study I employed a semi-structured interview with clinical (OCD and Depression) and non-clinical individuals to examine factors involved in the onset, maintenance and termination of ERS and repeated checking. Results revealed that individuals with OCD tend to seek reassurance about perceived general threats (e.g., fire, theft), whereas ERS tends to be focused on perceived social threats (e.g., abandonment, loss of support) among depressed individuals. Clinical participants reported greater anxiety, sadness and perceived threat in association with ERS and repeated checking than healthy control participants. Study 2 examined how manipulations of threat, responsibility, and ambiguity of feedback impacted upon non-clinical participants' anxiety and compulsive urges (to seek reassurance and to check) in a series of experimental vignettes. Consistent with hypotheses, higher levels of perceived threat, responsibility and ambiguity of feedback were associated with greater anxiety and compulsive urges. Results also suggested that perceived threat and responsibility partially mediated the effects of ambiguity of feedback on anxiety, urges to check, and (for threat) urges to seek reassurance. The collective results of these studies are discussed in terms of cognitive and behavioural models of OCD, and directions for future research are suggested

ENST 411: Merrill W. Linn Conservancy - Dale’s Ridge

Collaborative community-based project working on developing an ecological management and trail maintenance plan alongside updating the trail brochure for the Dale’s Ridge property managed by the Merrill W. Linn Conservancy in East Buffalo Township, Pennsylvania. This is a collaborative project between the Conservancy & the ENST 411 culminating experience course

Space Warps II. New Gravitational Lens Candidates from the CFHTLS Discovered through Citizen Science

We report the discovery of 29 promising (and 59 total) new lens candidates from the CFHT Legacy Survey (CFHTLS) based on about 11 million classifications performed by citizen scientists as part of the first Space Warps lens search. The goal of the blind lens search was to identify lens candidates missed by robots (the RingFinder on galaxy scales and ArcFinder on group/cluster scales) which had been previously used to mine the CFHTLS for lenses. We compare some properties of the samples detected by these algorithms to the Space Warps sample and find them to be broadly similar. The image separation distribution calculated from the Space Warps sample shows that previous constraints on the average density profile of lens galaxies are robust. SpaceWarps recovers about 65% of known lenses, while the new candidates show a richer variety compared to those found by the two robots. This detection rate could be increased to 80% by only using classifications performed by expert volunteers (albeit at the cost of a lower purity), indicating that the training and performance calibration of the citizen scientists is very important for the success of Space Warps. In this work we present the SIMCT pipeline, used for generating in situ a sample of realistic simulated lensed images. This training sample, along with the false positives identified during the search, has a legacy value for testing future lens finding algorithms. We make the pipeline and the training set publicly available.Comment: 23 pages, 12 figures, MNRAS accepted, minor to moderate changes in this versio

Space Warps: I. Crowd-sourcing the Discovery of Gravitational Lenses

We describe Space Warps, a novel gravitational lens discovery service that yields samples of high purity and completeness through crowd-sourced visual inspection. Carefully produced colour composite images are displayed to volunteers via a web- based classification interface, which records their estimates of the positions of candidate lensed features. Images of simulated lenses, as well as real images which lack lenses, are inserted into the image stream at random intervals; this training set is used to give the volunteers instantaneous feedback on their performance, as well as to calibrate a model of the system that provides dynamical updates to the probability that a classified image contains a lens. Low probability systems are retired from the site periodically, concentrating the sample towards a set of lens candidates. Having divided 160 square degrees of Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) imaging into some 430,000 overlapping 82 by 82 arcsecond tiles and displaying them on the site, we were joined by around 37,000 volunteers who contributed 11 million image classifications over the course of 8 months. This Stage 1 search reduced the sample to 3381 images containing candidates; these were then refined in Stage 2 to yield a sample that we expect to be over 90% complete and 30% pure, based on our analysis of the volunteers performance on training images. We comment on the scalability of the SpaceWarps system to the wide field survey era, based on our projection that searches of 10$^5$ images could be performed by a crowd of 10$^5$ volunteers in 6 days.Comment: 21 pages, 13 figures, MNRAS accepted, minor to moderate changes in this versio

Galaxy Zoo: Mergers – Dynamical models of interacting galaxies

The dynamical history of most merging galaxies is not well understood. Correlations between galaxy interaction and star formation have been found in previous studies, but require the context of the physical history of merging systems for full insight into the processes that lead to enhanced star formation. We present the results of simulations that reconstruct the orbit trajectories and disturbed morphologies of pairs of interacting galaxies. With the use of a restricted three-body simulation code and the help of citizen scientists, we sample 105 points in parameter space for each system. We demonstrate a successful recreation of the morphologies of 62 pairs of interacting galaxies through the review of more than 3 million simulations. We examine the level of convergence and uniqueness of the dynamical properties of each system. These simulations represent the largest collection of models of interacting galaxies to date, providing a valuable resource for the investigation of mergers. This paper presents the simulation parameters generated by the project. They are now publicly available in electronic format at http://data.galaxyzoo.org/mergers.html. Though our best-fitting model parameters are not an exact match to previously published models, our method for determining uncertainty measurements will aid future comparisons between models. The dynamical clocks from our models agree with previous results of the time since the onset of star formation from starburst models in interacting systems and suggest that tidally induced star formation is triggered very soon after closest approach