The effect of the Müller-Lyer illusion on map reading

One important reason for studying visual illusions is that they can influence real-world perception as people interact with human-made displays. Three experiments examined how the Müller-Lyer illusion affects distance judgments and decision-making in the complex graphical context of a map by having subjects estimate the lengths of road segment lines framed by inward-going or outward-going wings in actual maps, in control displays that had the map context removed, and in simulated maps. The experiments showed that (1) outward-going wings led to higher distance estimates than did inward-going wings to the same extent both with and without the map context, (2) decisions based on distances determined from maps were affected by Müller-Lyer elements in the maps, and (3) map readers’ measurement behavior influenced the effect of the Müller-Lyer elements in maps. The discussion focuses on how certain display manipulations and task manipulations affect the Müller-Lyer illusion. In addition, the discussion addresses the instances in which using a map might be affected by misestimation due to Müller-Lyer elements.     

Effects of anxiety sensitivity on anxiety and pain during a cold pressor challenge in patients with panic disorder

Fear of anxiety symptoms, or anxiety sensitivity (AS), has been extensively studied in anxiety disorders and more recently has been linked to other psychopathological conditions including pain. Asmundson and colleagues have suggested that AS may act as a risk factor for chronic pain and several studies have demonstrated an association between AS, avoidance behaviors and pain. The present study assessed whether AS levels would be predictive of pain and anxiety during a brief pain induction task. Clinical participants meeting DSM-IV criteria for panic disorder (n = 22) were age and sex matched with nonclinical controls (n = 22) and exposed to a 2-min cold pressor challenge. Diagnostic status and AS were significantly predictive of pain and anxiety during the cold pressor task. Moreover, AS appears to mediate the relationship between diagnostic status and pain. However, AS appears to be only indirectly associated with pain through its contribution to anxiety.     

Prospective evaluation of anxiety sensitivity in the pathogenesis of panic: replication and extension.

Increasing evidence suggests that anxiety sensitivity (AS) may be a premorbid risk factor for the development of anxiety pathology. The principal aim of this study was to replicate and extend a previous longitudinal study evaluating whether AS acts as a vulnerability factor in the pathogenesis of panic (N. Schmidt, D. Lerew, & R. Jackson, 1997). A large nonclinical sample of young adults (N = 1,296) was prospectively followed over a 5-week, highly stressful period of time (i.e., military basic training). Consistent with the authors' initial study, AS predicted the development of spontaneous panic attacks after controlling for a history of panic attacks and trait anxiety, and AS was found to possess symptom specificity with respect to anxiety versus depression symptoms. AS 1st-order factors differentially predicted panic attacks, with the Mental Concerns factor being the best predictor of panic in this sample.     

Panic Disorder: Cognitive Behavioral and Pharmacological Treatment Strategies

The past decade has seen significant advances in both psychosocial, notably cognitive behavioral (CBT), and pharmacological treatments for panic disorder. Given the widely acknowledged efficacy of both forms of treatment, it is reasonable to consider that the combination of approaches should yield an extremely potent strategy to treating panic disorder. The present report summarizes scientific evidence for the singular and combined treatment approaches to panic disorder. Data across studies indicate that combined treatments yield immediate and short-term benefits above those provided by either pharmacologic treatment or CBT alone. In the long-term, however, these benefits disappear. In fact, the combination of benzodiazepines and CBT appears to produce poorer end-state functioning than CBT alone. Other data indicate that the sequencing of pharmacotherapy and CBT may be useful for benzodiazepine fading. Although these data are preliminary, combined treatments do not appear to be the treatment of choice for patients with panic disorder. Treatment algorithms are suggested based on existing data.     

Effects of Response Probability on Response Force in Simple RT

Response force (RF) was measured in a simple reaction time (RT) experiment varying response uncertainty by cuing the probability of the response on each trial. In all cases, RF decreased as response probability increased. The dependence of RF on response probability was insensitive to foreperiod length and to the use of loud auditory response signals, although the dependence of RT on response probability was sensitive to both of these manipulations. In combination with previous findings, these results provide evidence that RT and RF can be dissociated. We describe an extension of Naatanen's readiness model that can account for the effects of response probability on RF and RT. According to this model, the distance between motor activation and a threshold for action is relatively large when subjects are unprepared, and a large increment is needed to exceed this threshold, resulting in slow but foreceful responses. A possible neurophysiological implementation of this model is suggested.     

Development of a tool to assess suicide risk factors in urban adolescents

Dramatic increases in the adolescent suicide rate over the past three decades have underscored the need for risk-assessment tools. The tools that do exist are oriented to older populations and their application to adolescents is questionable. A project was initiated at the University of Utah's Health Education Department to develop a pilot instrument to examine the differences between adolescents who have attempted suicide and other teenagers. Eighty-two subjects between the ages of 14 and 19 participated in the test of this instrument. Twenty-five subjects were identified by a physician or psychologist as having failed in a sincere suicide attempt within the previous 18 months. Fifty-seven nonsuicide attempters with similar demographic profiles served as a comparison group. An 86-item questionnaire was administered to both groups. Questions were generated from a review of the literature of the past three decades for problems associated with suicide in this population. Questions were sorted into three domains (family environment, social environment, and self-perceptions), with each domain having several subdomains. Statistical analysis revealed significant differences for each of the three domains and on 55 of 86 questions. The results were used to create a streamlined instrument for assessing suicide risk that can be administered in 20 minutes.