Impulsivity and paced tapping

The purpose of this study was to test the hypothesis that impulsivity is positively related to both the intraindividual variability and the rate of performance of a paced tapping task. The independent variable in the tapping task were: feedback vs. no feedback; tempo; concurrent cognitive task (counting) vs. no concurrent cognitive task. Three measures of tapping performance were computed: absolute or total error of tapping, tapping rate, and the intraindividual variability of tapping. The results confirm the hypothesis that impulsivity is positively related to rate of paced tapping, although the degree of relationship varied under different experimental conditions within the paced tapping task. Intraindividual variability of tapping was not significantly related to impulsivity, but the results were suggestive of a positive relationship.     

The polyserial correlation coefficient

The polyserial and point polyserial correlations are discussed as generalizations of the biserial and point biserial correlations. The relationship between the polyserial and point polyserial correlation is derived. The maximum likelihood estimator of the polyserial correlation is compared with a two-step estimator and with a computationally convenient ad hoc estimator. All three estimators perform reasonably well in a Monte Carlo simulation. Some practical applications of the polyserial correlation are described.By coincidence, the first author and the second and third authors learned that they were working independently on closely related problems and, consequently, decided to write a jointly authored paper.     

How Valuable Is It?

The Journal of Value Inquiry -     

Gender differences in psychopathy in a Swedish offender sample

In this study we examined gender differences in the PCL:SV employing a variety of statistical methods with two subsets of psychopathic individuals drawn from larger samples of 129 female and 499 male Swedish offenders. The larger samples included forensic psychiatric patients, forensic psychiatric evaluees and criminal offenders. We found gender differences in antisocial behavior, as defined in factor 2 of the PCL:SV, with female psychopaths (PCL:SV>or=18) displaying significantly more lying, deceitfulness and lack of control, while male psychopaths were more antisocial as measured by the PCL:SV. We conclude that it might be meaningful to use gender specific definitions in the assessment of psychopathy or, alternatively, slightly revise the diagnostic tools. Our results support the use of the three-factor model of the PCL-R and PCL:SV introduced by Cooke and Michie (2001) in female populations.     

Reliability and Validity Evaluation of the Psychopathy Checklist: Screening Version (PCL:SV) in Swedish correctional and forensic psychiatric samples

This study evaluated the structural reliability, construct-related validity, and cultural validity generalization of the Hare Psychopathy Checklist: Screening Version (PCL:SV) in a sample of more than 560 male and female Swedish forensic psychiatric treatment patients, forensic evaluation patients, and criminal offenders. Structural reliability was excellent for most indices. PCL:SV scores were higher for males than females for total and Part 1 scores (interpersonal/affective features) but not for Part 2 (behavioral features). With some exceptions, PCL:SV scores were meaningfully related to aggression to others, a measure of risk for violence, substance use problems, personality disorder (positive), and psychosis (negative). Correlations between PCL:SV and aggression were larger for females than males, although the difference was smaller when personality disorder was held constant. The structural reliability and pattern of validity coefficients were comparable in these Swedish samples to other non-North American samples. Implications for the cross-cultural manifestation and correlates of psychopathy are discussed.     

Perceptual restoration of missing sounds in a group of hallucinating schizophrenics.

17 subjects diagnosed with schizophrenia and having auditory hallucinations in their case history were compared with 15 control subjects in an experiment on perceptual restoration. A tone pattern was presented, then interrupted by noise, under conditions such that the tone pattern could be heard as going on continuously (restoration). A series of 16 stimuli with a distractor of varying amplitude (noise) were presented. Healthy controls reliably reported restoration in Presentations 9 and 10. Four schizophrenics reported no restoration at all. Three of them reported restoration earlier than controls, and four others reported it later than controls and continued to report the phenomenon after a point at which no healthy controls did. Six other presented an irregular pattern of response to the phenomenon. The results are discussed with respect to the neurophysiological functioning of the auditory pathway and schizophrenic symptoms.     

Are Callous Unemotional (CU) Traits Enough?

A guiding question for this special section, sparked by the increasing number of studies on callous –unemotional traits (CU traits) and the DSM-5 Limited Prosocial Emotion (LPE) specifier, is whether CU traits are enough to identify a clinically meaningful subgroup of youth with conduct problems or whether other psychopathic traits contribute. Seven empirical papers and two commentary papers address this question to varying degrees and in different ways with some papers “competing” various models against one another along with other papers investigating distinct correlates of the psychopathy factors. Findings across the papers suggest that there could be benefits to examining the broader construct of psychopathy in addition to examining its underpinning dimensions rather than CU traits alone. Two commentary papers also shed light on the importance of psychopathic traits in children with Conduct Disorder (CD) and provide insights for future work on this topic. It is hoped that the articles and commentary will generate new ideas for research and practice that could have implications for the treatment of those individuals with CD and psychopathic traits.     

Comparing Different Approaches for Subtyping Children with Conduct Problems: Callous-Unemotional Traits Only Versus the Multidimensional Psychopathy Construct

The aim of this study was to compare two youth psychopathy models (i.e., callous-unemotional versus multidimensional model) in their ability to predict future and stable conduct problems (CP). At baseline, mothers and fathers of 321 boys and 369 girls (ages 7–12) completed measures that tap callous-unemotional and other psychopathic traits. Parent-reported CP was collected at baseline and at 6- and 12 month follow-ups. Children were assigned to mutually exclusive groups based on their levels of CP and psychopathic traits. Children with CP who manifested callous-unemotional traits (Callous-Unemotional?+?CP) were occasionally at risk for future and stable CP. Yet, across gender, children with CP scoring high on all psychopathic trait dimensions (Psychopathic Personality?+?CP) showed the most robust and highest risk for future and stable CP. Also, Callous-Unemotional?+?CP children, and children who were only high in CP, often were at similar risk for future CP. The findings suggest that the callous-unemotional model is less sufficient than the multidimensional model in predicting future and stable CP. This can be concluded for both boys and girls and calls for more research reconsidering the multidimensional nature of psychopathy for CP subtyping purposes.