Positive schizotypal symptoms predict treatment outcome in obsessive-compulsive disorder

Previous research has suggested that the presence of schizotypal personality disorder may represent a risk factor for treatment failure in obsessive-compulsive disorder (OCD). Relying on a dimensional approach, the present study investigated whether the predictive importance of schizotypal personality is shared by all of its features to the same extent or whether it is confined to a subset of symptoms. Fifty-three patients underwent multi-modal cognitive-behavioral therapy with or without adjunctive antidepressive medication. Therapy response was defined as a 35% decline of the Y-BOCS total score. At baseline assessment, patients were asked to fill out the schizotypal personality questionnaire, the perceptual aberration scale and the Beck depression inventory. Stepwise regression analysis and group comparisons conducted with the schizotypal and depression scales revealed that elevated scores in the positive schizotypal scales, especially perceptual aberrations, were highly predictive for treatment failure. Responders to treatment and non-responders did not significantly differ on other variables or on scores in two scales which measured response biases. The study provides evidence that positive schizotypal symptoms are antecendents for treatment failure in OCD. It needs to be evaluated whether these at-risk individuals benefit from additional intervention, such as the adminstration of low-dose atypical neuroleptics and specifically tailored behavorial intervention.     

Why cast shadows are expendable: insensitivity of human observers and the inherent ambiguity of cast shadows in pictorial art

The kinds of visual cues artists choose to use or not use in their work can offer insight into perceptual processes. On the basis of the observed paucity of the use of cast shadow in pictorial art, we hypothesized that cast shadows might be relatively expendable as pictorial cues. In this study, we investigated two potential reasons for this expendability: first, viewers might be insensitive to much of the information that cast shadows provide; and, second, ambiguities about what is shadow and what is pigment can often be resolved only through motion-something that static media are ill-equipped to deal with. In experiment 1, we used a visual-search paradigm in which viewers had to determine if there were odd cast shadows in sets of 4, 8, 16, and 32 objects. In experiment 2, viewers had to discriminate between shadow/pigment ambiguities in both still and moving images. Our results demonstrate that viewers are neither particularly sensitive to static cast-shadow incongruities, nor are they able to disambiguate cast shadow from pigment without continuous motion information. Taken together, these results may help explain why cast shadows are relatively rare in static pictorial work.     

The contribution of metamemory deficits to schizophrenia

A number of recent studies have demonstrated that individuals with schizophrenia display knowledge corruption; that is, they hold false information with strong conviction. This aberration in metamemory is thought to stem from poor memory accuracy in conjunction with impaired discrimination of correct and incorrect judgments in terms of confidence. Thirty-one participants with schizophrenia, along with 61 healthy control participants and 48 control participants with other psychiatric conditions, participated in a computerized source memory task. Whereas no differences in memory accuracy were observed between the group with schizophrenia and the group with other psychiatric diagnoses, knowledge corruption was specifically impaired in those with schizophrenia. Schizophrenia participants showed a significantly decreased confidence gap: They were more confident in errors and less confident in correct responses relative to those in the control groups. Knowledge corruption is theorized to be a potential risk factor for the emergence of delusions.     

Immigration, lack of control and psychological distress: findings from the Oslo Health Study

The aims of this study are to compare the level of psychological distress between Norwegian born and immigrants from countries with different income levels and culture, and to investigate the explanatory effect of socioeconomic and psychosocial factors, with special emphasis on lack of control (powerlessness and self-efficacy). A cross-sectional survey with self-administered questionnaire was conducted in 2000-2001 in a sample of 15,723 adults living in Oslo. Psychological distress was measured by a ten-item shortened version of Hopkins Symptom Checklist-25 items, whereas psychosocial variables were measured by various instruments. The results show that the level of psychological distress is significantly higher in immigrants from low- and middle-income countries than in the Norwegian born and the immigrants from high-income countries. They also report more powerlessness, more negative life events, less social support, less income and less paid work. It is concluded that negative life events, mainly related to social network, somatic health and economic situations, as well as lack of social support, are important mediators between immigration from low- and middle-income countries to Norway and psychological distress. Powerlessness also plays a role, but this is mainly because of a concept overlap between psychological distress and powerlessness.     

Spatial distortions induced by multiple visual landmarks: how local distortions combine to produce complex distortion patterns

Visual landmarks introduce systematic distortions into spatial short-term memory for single target positions, the exact form of the distortion depending on the spatial layout of the landmarks. In two experiments, we investigated how the combined effect of two landmarks can be predicted from the effects of individual landmarks. Participants used a mouse cursor to reproduce the positions of briefly presented targets in the context of one, the other, or both landmarks. We found that distortions near a landmark are independent of whether another landmark is present, so that remembered space is partitioned into regions dominated by single landmarks. Interestingly, the display midpoint behaves like a "virtual landmark," with its own pattern of distortion. Results are inconsistent with current models of spatial memory distortions but suggest that attentional processes can lead to enhanced fidelity of salient regions in topographical neural networks while also introducing some spatial biases.     

Superior haptic perceptual selectivity in late-blind and very-low-vision subjects

Blindfolded sighted, congenitally blind, late-blind, and very-low-vision subjects were tested on a tangible version of the embedded-figures test. The results of ANOVAs on accuracy measures yielded superior performance by the very-low-vision and late-blind subjects compared with the blindfolded sighted and congenitally blind participants. Accuracy of the congenitally blind subjects was similar to that of the blindfolded sighted participants. However, all groups of blind subjects were significantly faster than the blindfolded sighted subjects. It is suggested that experience with pictures combined with haptic skill aid perceptual selectivity in touch.     

Egocentric and geocentric frames of reference in memory of large-scale space

This experiment investigated the frames of reference used in memory to represent the spatial structure of a large-scale outdoor environment. Participants learned the locations of eight objects in an unfamiliar city park by walking through the park on one of two prescribed paths that encircled a large rectangular building. The aligned path was oriented with the building; the misaligned path was rotated by 45°. Later, participants pointed to target objects from imagined vantage points using their memories. Pointing accuracy was higher in the aligned than in the misaligned path group, and the patterns of results differed: In the aligned condition, accuracy was higher for imagined headings parallel to legs of the path and for an imagined heading oriented toward a nearby lake, a salient landmark. In the misaligned condition, pointing accuracy was highest for the imagined heading oriented toward the lake, and decreased monotonically with angular distance. These results indicated that locations of objects were mentally represented in terms of frames of reference defined by the environment but selected on the basis of egocentric experience.     

The influence of between and within-person hope among emergency responders on daily affect in a stress and coping model

This study reports on daily hope, coping, stress, and affect among 84 fire service members who completed a 21-day diary. Multilevel modeling showed that between-person hope was related to higher positive affect. Three-way interactions were found for within-person hope, stress, and daily coping in the prediction of daily affect. When under high stress and if low in hope, more emotion–expression coping predicted higher next day positive affect whereas if high in hope, more problem-focused coping predicted more positive affect. Within-person hope, stress, and emotion–expression coping interacted to predict negative affect. Findings for the prediction of negative affect necessitate further research to determine if the nature of coping under low hope and low stress is qualitatively distinct from high hope states.     

J.S. Mill's Canons of Induction: From True Causes to Provisional Ones

In this essay, my aim is twofold: to clarify how the late Mill conceived of the certainty of inductive generalisations and to offer a systematic clarification of the limited domain of application of Mill's Canons of Induction. I shall argue that Mill's views on the certainty of knowledge changed over time and that this change was accompanied by a new view on the certainty of the inductive results yielded by the Canons of Induction. The key message of the later editions of The System of Logic as conceived by the late Mill was no longer that by the Canons of Induction we can establish scientific certainty and true causes, but rather that the Canons are useful in establishing causal laws in a provisional way.

Deduction is a game and induction a grievance. (Bagehot 1913, vol. 3, p. 37)     

Does Defensiveness Account for the Relationship Between Religiosity and Psychosocial Adjustment?

Religiosity has been related to positive psychosocial adjustment across a large number of studies. Some researchers question, however, whether this relationship is an accurate finding, observing that there are many potential confounds that have not been controlled for, such as defensiveness. This study examined whether defensiveness accounted for the relationship between religiosity and psychosocial adjustment. Two samples of religious individuals were assessed on religiosity (Duke University Religion Index), defensiveness (measured using the denial of distress and repressive defensiveness subscales from the Weinberger Adjustment Inventory [WAI]), and psychosocial adjustment (Depression subscale from the WAI, the Perceived Stress Scale, and the Sarason Social Support Scale). In both studies it was found that religiosity was related to positive psychosocial adjustment as well as higher levels of defensiveness. Defensiveness, however, did not account for the relationships between religiosity and psychosocial adjustment. These findings add to the research literature by eliminating a potential confound of the relationship between religiosity and psychosocial adjustment.