A psychometric evaluation of the Rorschach comprehensive system's perceptual thinking index

In this study, we investigated evidence for reliability and validity of the Perceptual Thinking Index (PTI; Exner, 2000a, 2000b) among an adult inpatient population. We conducted reliability and validity analyses on 107 patients who met the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text revision; American Psychiatric Association, 2000) criteria for a schizophrenia-spectrum disorder (SSD) or mood disorder with no psychotic features (MD). Results provided support for interrater reliability as well as internal consistency of the PTI. Furthermore, the PTI was an effective index in differentiating SSD patients from patients diagnosed with an MD. Finally, the PTI demonstrated adequate diagnostic statistics that can be useful in the classification of patients diagnosed with SSD and MD. We discuss methodological issues, implications for assessment practice, and directions for future research.     

Object recognition in dense clutter

Observers in recognition experiments invariably view objects against a blank background, whereas observers of real scenes sometimes view objects against dense clutter. In this study, we examined whether an object's background affects the information used for recognition. Our stimuli consisted of color photographs of everyday objects. The photographs were organized either as a sparse array, as is typical of a visual search experiment, or as high density clutter, such as might be found in a toy chest, a handbag, or a kitchen drawer. The observer's task was to locate an animal, vehicle, or food target in the stimulus. We varied the information in the stimuli by convolving them with a low-pass filter (blur) or a high-pass filter (edge) or converting them to grayscale. In two experiments, we found that the blur and edge manipulations produced a modest decrement in performance with the sparse arrangement but a severe decrement in performance with the clutter arrangement. These results indicate that the information used for recognition depends on the object's background. Thus, models of recognition that have been developed for isolated objects may not generalize to objects in dense clutter.     

Tactile spatial acuity differs between fingers: a study comparing two testing paradigms

Tactile spatial acuity (TSA) is a reliable and reproducible measure of somatosensory system function that has been used to study abroad range of subject populations. Although TSA is most often assessed at the fingertip, published studies employing identical stimuli disagree on whether TSA differs between the fingers of neurologically normal subjects. Using a validated grating orientation discrimination task, we determined TSA bilaterally at the index and ring fingers of 16 healthy young adults. Motivated by earlier work, we utilized two stimulus presentation paradigms, the method of constant stimuli (MCS) and a staircase (SC) method. We found that TSA was significantly higher (the discrimination threshold was lower) at the index than at the ring finger, which was consistent with a prior study. Although mean thresholds at both fingers were higher when measured with the SC than with the MCS paradigm, this difference did not reach statistical significance (p = .14). These findings should facilitate both design and interpretation of future studies investigating TSA.     

Re-analysis of Sageman's (2004) and Pape's (2005) data predicting Al'Qaeda membership and suicide terrorism

Sageman's (2004) and Pape's (2005) arguments for the development of Al'Qaeda members and suicide terrorism are examined statistically. Presence of foreign occupying troops and foreign support for disliked local regimes appeared to be related to either the number of Al'Qaeda suicide terrorists (Pape) or the number of known Al'Qaeda members (Sageman) reported within 34 predominately Sunni nations. Results support the theory that nationalism fuels much of Middle Eastern resentment against allied nations.     

Association of pathological gambling with depression in Scotland

Is most research concerning gambling and depression has been conducted on clinical populations, the present study examined the relationship between gambling and depression across a large sample in Scotland in higher education and the community. A questionnaire-based cluster design involved the distribution of the South Oaks Gambling Screen and the Centre for Epidemiologic Studies Depression Scale mainly to students and staff of higher educational establishments, with small community and gambling samples also included. Thirty-seven colleges and universities across Scotland participated in the research, with a sample of 2259 people aged sixteen years of age or over (M = 28.9 yr., SD = 13.4) being obtained. It was found that past-year probable pathological gamblers had significantly higher depression than problem gamblers, nonproblem gamblers, and nongamblers. However, when probable pathological gamblers who had sought treatment were omitted from the analysis, the nontreatment-seeking probable pathological gambling group no longer had significantly higher depression than the problem gambling group. Female problem and probable pathological gamblers had particularly high depressive symptomatology, suggesting co-morbid depression may be a prominent feature of problematic female gambling.     

Cross-National Variations in Behavioral Profiles Among Homeless Youth

Cross-national comparisons of homeless youth in Melbourne, Australia, and Los Angeles, CA, United States were conducted. Newly (n = 427) and experienced (n = 864) homeless youth were recruited from each site. Compared to Australia, homeless youth in the United States were younger, more likely to be in school or jail, demonstrated fewer sexual and substance use risk acts, fewer suicidal acts, and reported less need for social services. Across sites, experienced homeless youth were more likely to be older, male, engage in sexual and substance use, report greater need for social services, and make greater use of work, substance use, and health-related services. Homeless youth have different behavioral profiles in Australia and the United States, reflecting differences in the effectiveness of service systems in the two countries in keeping youth with fewer problems out of homelessness.