Examining the utility of the PCL:SV as a screening measure using competing factor models of psychopathy

The correspondence between the Hare Psychopathy Checklist: Screening Version (PCL:SV; S. D. Hart, D. N. Cox, & R. D. Hare, 1995) and the Hare Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 1991, 2003) was examined in forensic (N = 175) and correctional (N = 188) samples. Intermeasure correlations for Total scores (.95 forensic, .94 correctional) and the original 2-factor, D. J. Cooke and C. Michie's (2001) 3-factor, and R. D. Hare's (2003) 4-facet models (range = .87-.95) were high. Area under the curve values for the PCL:SV were .98 in both samples (cutoff = PCL-R Total score of 25). The PCL:SV performed well as a screen, maximizing false positive relative to false negative errors. Close correlations for prediction of violent recidivism in the correctional sample were obtained for the PCL-R (.42) and PCL:SV (.37). Results indicate the robust relation between the measures is maintained whether they are completed on the basis of file review only or file plus interview and whether the same or different raters score the measures.     

Comparative analysis of movement characteristics during dead-reckoning-based navigation in humans and rats

Human and rat movement organization was investigated as they searched for randomly located rewards without access to visual information. Under dark conditions, rats foraged for randomly located food pellets (Experiment 1). Blindfolded humans were instructed to search for an ostensible hidden coin using a metal detector (Experiment 2). After locating the food pellet, rats carried it back to the refuge, and after a designated searching time, humans were instructed to return to the start location. Although both species exhibited a high degree of similarity in searching path movement organization and ability to return to the start location, disruption of human searching path organization was associated with impairments in returning to the start location. These results support the vestibular "gain" account of movement organization during dead-reckoning-based navigation.     

Self-control and tool use in tufted capuchin monkeys (Cebus apella)

Self-control is defined as forgoing immediate gratification to obtain a greater reward. Tool use may relate to self-control because both behaviors may require foresight and deliberate control over one's actions. The authors assessed 20 capuchin monkeys (Cebus apella) for the ability to delay gratification in a tool task. Subjects were given rod-shaped food items that could either be consumed immediately or be carried to an apparatus and used to extract a more preferred food. The authors found that some monkeys were able to exhibit self-control. Monkeys with relatively more tool use experience demonstrated the greatest levels of self-control. These results indicate that capuchins are capable of delaying gratification when a higher quality reinforcer is present and that tool experience can influence levels of self-control in this task.     

Pharmacotherapy of delusional disorders in the context of offending and the potential for compulsory treatment

Delusional disorder is an uncommon mental illness with an estimated prevalence of 0.03%. Its low prevalence has likely contributed to the paucity of research interest in this area, leading to substantial gaps in knowledge concerning its treatment and management. In the absence of a robust literature, most clinicians rely on their experience and guidelines for treating schizophrenia when treating patients with delusional disorder. This article reviews the available literature that is specific to the treatment of delusional disorder. In addition, it focuses on specific forensic and medicolegal aspects of managing patients with delusional disorder.     

Exploration in outbred mice covaries with general learning abilities irrespective of stress reactivity, emotionality, and physical attributes

Across multiple learning tasks (that place different sensory, motor, and information processing demands on the animals), we have found that the performance of mice is commonly regulated by a single factor ("general learning") that accounts for 30-40% of the variance across individuals and tasks. Furthermore, individuals' general learning abilities were highly correlated with their propensity to engage in exploration in an open field, a behavior that is potentially stress-inducing. This relationship between exploration in the open field and general learning abilities suggests the possibility that variations in stress sensitivity/responsivity or related emotional responses might directly influence individuals' general learning abilities. Here, the relationship of sensory/motor skills and stress sensitivity/emotionality to animals' general learning abilities were assessed. Outbred (CD-1) mice were tested in a battery of six learning tasks as well as 21 tests of exploratory behavior, sensory/motor function and fitness, emotionality, and stress reactivity. The performances of individual mice were correlated across six learning tasks, and the performance measures of all learning tasks loaded heavily on a single factor (principal component analysis), accounting for 32% of the variability between animals and tasks. Open field exploration and seven additional exploratory behaviors (including those exhibited in an elevated plus maze) also loaded heavily on this same factor, although general activity, sensory/motor responses, physical characteristics, and direct measures of fear did not. In a separate experiment, serum corticosterone levels of mice were elevated in response to a mild environmental stressor (confinement on an elevated platform). Stress-induced corticosterone levels were correlated with behavioral fear responses, but were unsystematically related to individuals' propensity for exploration. In total, these results suggest that although general learning abilities are strongly related to individuals' propensity for exploration, this relationship is not attributable to variations in sensory/motor function or the individuals' physiological or behavioral sensitivity to conditions that promote stress or fear.     

When effect sizes disagree: the case of r and d

The increased use of effect sizes in single studies and meta-analyses raises new questions about statistical inference. Choice of an effect-size index can have a substantial impact on the interpretation of findings. The authors demonstrate the issue by focusing on two popular effect-size measures, the correlation coefficient and the standardized mean difference (e.g., Cohen's d or Hedges's g), both of which can be used when one variable is dichotomous and the other is quantitative. Although the indices are often practically interchangeable, differences in sensitivity to the base rate or variance of the dichotomous variable can alter conclusions about the magnitude of an effect depending on which statistic is used. Because neither statistic is universally superior, researchers should explicitly consider the importance of base rates to formulate correct inferences and justify the selection of a primary effect-size statistic.     

Clustering, seriation, and subset extraction of confusion data

The study of confusion data is a well established practice in psychology. Although many types of analytical approaches for confusion data are available, among the most common methods are the extraction of 1 or more subsets of stimuli, the partitioning of the complete stimulus set into distinct groups, and the ordering of the stimulus set. Although standard commercial software packages can sometimes facilitate these types of analyses, they are not guaranteed to produce optimal solutions. The authors present a MATLAB *.m file for preprocessing confusion matrices, which includes fitting of the similarity-choice model. Two additional MATLAB programs are available for optimally clustering stimuli on the basis of confusion data. The authors also developed programs for optimally ordering stimuli and extracting subsets of stimuli using information from confusion matrices. Together, these programs provide several pragmatic alternatives for the applied researcher when analyzing confusion data. Although the programs are described within the context of confusion data, they are also amenable to other types of proximity data.     

Assessing family-of-origin functioning in Mexican American adults: retrospective application of the family environment scale

Although both theoretical and empirical literature suggests that individuals' family-of-origin experiences affect subsequent relationship functioning as adults, few studies have examined the appropriateness of family assessment techniques when applied retrospectively for use in either theory development or clinical applications. This study examined psycho-metric characteristics of the Family Environment Scale (FES) when used retrospectively with Mexican Americans to assess their families-of-origin. Findings provided qualified support for the internal consistency of the FES and showed significant mean profile differences for this population across gender and when compared to the normative sample for this measure. Retrospective reports on the FES related to independent measures of family history of distress and, to a lesser extent, with current relationship functioning, providing preliminary support for the criterion-related validity of the FES when adapted for retrospective assessment. Limitations and implications of findings for further research are discussed.     

Incremental validity analyses of the violence risk appraisal guide and the psychopathy checklist: screening version in a civil psychiatric sample

This study compares two instruments frequently used to assess risk for violence, the Violence Risk Appraisal Guide (VRAG) and the Psychopathy Checklist: Screening Version (PCL:SV), in a large sample of civil psychiatric patients. Despite a strong bivariate relationship with community violence, the VRAG could not improve on the predictive validity of the PCL:SV alone, even though the VRAG includes several ostensible violence risk factors other than psychopathy. Moreover, incremental validity analyses indicated that the remaining VRAG items accounted for little or no variance in violent outcomes once psychopathy scores were controlled. Conversely, the PCL:SV continued to account for considerable variance after controlling for the VRAG. These results reflect the limited validity of the VRAG items in civil psychiatric samples beyond the variance that is explained by the PCL:SV alone.