Default Probability

A probability may be called “default” if it is neither derived from preestablished probabilities nor based on considerations of frequency or symmetry. Default probabilities presumably arise through reasoning based on causality and similarity. This article advances a model of default probability based on a featural approach to similarity. The accuracy of the model is assessed by comparing its predictions to the probabilities provided by undergraduates asked to reason about mammals.     

Anxiety reactivity and anxiety perseveration represent dissociable dimensions of trait anxiety

Trait anxiety is an individual-difference variable reflecting variation in state-anxiety elevations resulting from exposure to a stressor. It is usually measured using questionnaire instruments, such as the Spielberger State-Trait Anxiety Inventory (STAI-T). The present research conceptually distinguishes, and independently assesses, two hypothetical dimensions of anxiety vulnerability which, it is argued, could plausibly make independent contributions to variance in trait-anxiety scores. These dimensions are anxiety reactivity, the probability of experiencing an anxiety reaction to a stressor, and anxiety perseveration, the persistence of anxiety symptoms once elicited. Participants were asked three questions about each STAI-T item. The traditional STAI-T question assessed how much of the time this symptom was experienced; the anxiety-reactivity question assessed the probability of experiencing the symptom in response to a stressor; and the anxiety-perseveration question assessed how long the symptom persisted, if elicited. Regression analysis determined that anxiety reactivity and anxiety perseveration scores both accounted for independent variance in trait-anxiety scores. It is argued that models of anxiety vulnerability should seek to differentiate both the causes and the consequences of elevated anxiety reactivity and increased anxiety perseveration. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Effects of pain acceptance and pain control strategies on physical impairment in individuals with chronic low back pain

Psychosocial treatments for chronic pain are effective. There is a need, however, to understand the processes involved in determining how these treatments contribute to behavior change. Control and acceptance strategies represent two potentially important processes involved in treatment, although they differ significantly in approach. Results from laboratory-based studies suggest that acceptance-oriented strategies significantly enhance pain tolerance and behavioral persistence, compared with control-oriented strategies. There is a need, however, to investigate processes of acceptance and control directly in clinical settings. The present study investigated the effects of three brief instructional sets (pain control, pain acceptance, continued practice) on demonstrated physical impairment in 74 individuals with chronic low back pain using an analogue experimental design. After controlling for baseline performance, the pain acceptance group demonstrated greater overall functioning on a set of 7 standardized physical tasks relative to the other two groups, which did not differ from one another. Further, the acceptance group exhibited a 16.3% improvement in impairment, whereas the pain control group worsened by 8.3% and the continued practice group improved by 2.5%. These results suggest that acceptance may be a key process involved in behavior change in individuals with chronic pain.     

Accuracy of Self-Reported Personal History of Cancer in an Outpatient Breast Center

The self-reporting of cancer history is becoming increasingly important, as it frequently guides medical decision-making. We studied the accuracy of personal cancer history using a self-administered questionnaire, comparing the results with the Tumor Registry at our institution. Among 39,662 records, we identified 3614 women with a single cancer in the Tumor Registry who reported none or one cancer on their questionnaire. The sensitivity in self-reporting cancers was 85.7%, ranging from 92.1% for breast cancer to 42.9% for leukemia. The accuracy for breast cancer and Hodgkin's Lymphoma was significantly better than other cancers (p=0.00027, CI: 1.4–3.88). Analysis of patient's characteristics showed that Caucasians reported breast cancer more accurately than Asian/Pacific Islanders (p=0.008), and those with Jewish ancestry more accurately than non-Jewish (p=0.0435). These results will help us to improve data collection and thus improve medical decision-making.