Test of Alternative Hypotheses Explaining the Comorbidity Between Attention-Deficit/Hyperactivity Disorder and Conduct Disorder

There is significant comorbidity between attention-deficit/hyperactivity disorder (ADHD) and conduct disorder (CD). The conclusions of studies that examined the causes of comorbidity between ADHD and CD conflict, with some researchers finding support for the three independent disorders model and others finding support for the correlated risk factors model. We tested these models and eleven alternative hypotheses using the same analytical approach. The participants were 110 monozygotic twin pairs and 181 dizygotic twin pairs recruited from the Colorado Learning Disabilities Research Center Twin Study. The three independent disorders model did not fit the data, whereas the correlated risk factors model fit the data well. Several other comorbidity models fit the data as well as or better than the correlated risk factors model. The results suggest that correlated risk factors are a better explanation for the comorbidity between ADHD and CD than a third, independent ADHD+CD subtype.     

Initial validation of a virtual environment for assessment of memory functioning: virtual reality cognitive performance assessment test.

The current project is an initial attempt at validating the Virtual Reality Cognitive Performance Assessment Test (VRCPAT), a virtual environment-based measure of learning and memory. To examine convergent and discriminant validity, a multitrait-multimethod matrix was used in which we hypothesized that the VRCPAT's total learning and memory scores would correlate with other neuropsychological measures involving learning and memory but not with measures involving potential confounds (i.e., executive functions; attention; processing speed; and verbal fluency). Using a sequential hierarchical strategy, each stage of test development did not proceed until specified criteria were met. The 15-minute VRCPAT battery and a 1.5-hour in-person neuropsychological assessment were conducted with a sample of 30 healthy adults, between the ages of 21 and 36, that included equivalent distributions of men and women from ethnically diverse populations. Results supported both convergent and discriminant validity. That is, findings suggest that the VRCPAT measures a capacity that is (a) consistent with that assessed by traditional paper-and-pencil measures involving learning and memory and (b) inconsistent with that assessed by traditional paper-and-pencil measures assessing neurocognitive domains traditionally assumed to be other than learning and memory. We conclude that the VRCPAT is a valid test that provides a unique opportunity to reliably and efficiently study memory function within an ecologically valid environment.     

Adult modelling facilitates young children's generation of novel pretend acts

The present work investigated the effect of modelling on children's pretend play behaviour. Thirty‐seven children aged between 27 and 41 months were given 4 min of free play with a dollhouse and associated toy props (pre‐modelling phase). Using dolls, an experimenter then acted out a series of vignettes involving object substitutions, imaginary play and attribution of properties. Children were subsequently provided with an additional 4 min free play (post‐modelling phase). Consistent with past research, more pretence was exhibited after modelling than before. Furthermore, in the post‐modelling phase, children were as likely to generate their own novel pretence as they were to copy the actions demonstrated by the experimenter. They also increased the number of novel symbolic acts involving imaginary play from the pre‐ to the post‐modelling phase. This study highlights how young children will not only imitate a model's demonstration of pretend acts but also use this demonstration to catalyze the creation of their own pretence. Copyright © 2008 John Wiley & Sons, Ltd.     

Integrating haptic-tactile feedback into a video-capture-based virtual environment for rehabilitation.

Video-capture virtual reality (VR) systems are gaining popularity as intervention tools. To date, these platforms offer visual and audio feedback but do not provide haptic feedback. We contend that adding haptic feedback may enhance the quality of intervention for various theoretical and empirical reasons. This study aims to integrate haptic-tactile feedback into a video capture system (GX VR), which is currently applied for rehabilitation. The proposed multi-modal system can deliver audio-visual as well as vibrotactile feedback. The latter is provided via small vibratory discs attached to the patient's limbs. This paper describes the system, the guidelines of its design, and the ongoing usability study.     

A controlled clinical comparison of attention performance in children with ADHD in a virtual reality classroom compared to standard neuropsychological methods.

In this initial pilot study, a controlled clinical comparison was made of attention perforance in children with attention deficit-hyperactivity disorder (ADHD) in a virtual reality (VR) classroom. Ten boys diagnosed with ADHD and ten normal control boys participated in the study. Groups did not significantly differ in mean age, grade level, ethnicity, or handedness. No participants reported simulator sickness following VR exposure. Children with ADHD exhibited more omission errors, commission errors, and overall body movement than normal control children in the VR classroom. Children with ADHD were more impacted by distraction in the VR classroom. VR classroom measures were correlated with traditional ADHD assessment tools and the flatscreen CPT. Of note, the small sample size incorporated in each group and higher WISC-III scores of normal controls might have some bearing on the overall interpretation of results. These data suggested that the Virtual Classroom had good potential for controlled performance assessment within an ecologically valid environment and appeared to parse out significant effects due to the presence of distraction stimuli.     

Spatial attention does improve temporal discrimination

It has recently been stated that exogenous attention impairs temporal-resolution tasks (Hein, Rolke, & Ulrich, 2006; Rolke, Dinkelbach, Hein, & Ulrich, 2008; Yeshurun, 2004; Yeshurun & Levy, 2003). In comparisons of performance on spatially cued trials versus neutral cued trials, the results have suggested that spatial attention decreases temporal resolution. However, when performance on cued and uncued trials has been compared in order to equate for cue salience, typically speed—accuracy trade-offs (SATs) have been observed, making the interpretation of the results difficult. In the present experiments, we aimed at studying the effect of spatial attention in temporal resolution while using a procedure to control for SATs. We controlled reaction times (RTs) by constraining the time to respond, so that response decisions would be made within comparable time windows. The results revealed that when RT was controlled, performance was impaired for cued trials as compared with neutral trials, replicating previous findings. However, when cued and uncued trials were compared, performance was actually improved for cued trials as compared with uncued trials. These results suggest that SAT effects may have played an important role in the previous studies, because when they were controlled and measured, the results reversed, revealing that exogenous attention does improve performance on temporal-resolution tasks.     

Dating Violence Victimization,Dispositional Aggression,and Nonsuicidal Self‐Injury among Psychiatrically Hospitalized Male and Female Adolescents

The objective of the current study was to characterize the association between dating violence victimization and dispositional aggression in predicting nonsuicidal self‐injury (NSSI) among psychiatrically hospitalized male and female adolescents. One hundred fifty‐five adolescents (ages 13–17) and their parents completed the Schedule for Affective Disorders and Schizophrenia for School‐Age Children clinical interview to assess NSSI and child abuse; adolescents completed self‐report measures of aggression and dating violence victimization (verbal, physical, and sexual). Dating violence victimization and NSSI were found to be highly prevalent among both males and females in this psychiatric inpatient sample. Two moderational models were supported, wherein dating violence was associated with NSSI in the context of elevated trait anger in males and indirect aggression in females. Findings suggest that helping victims of dating violence acquire skills to address certain forms of dispositional aggression may attenuate NSSI.     

The Anatomy of Revolutionists

A questionnaire containing 62 items relating to the New Left and 28 items measuring anomia, authoritarianism, and Machiavellianism was given to 153 entering freshmen at Columbia in the fall of 1968. The five factors emerging from a factor analysis of responses to the items were labeled: New Left Philosophy, Revolutionary Tactics, Machiavellian Tactics, Machiavellian Cynicism, and Traditional Moralism. Students who had been politically active prior to coming to college scored higher than the rest of the group on New Left Philosophy, Revolutionary Tactics, and Machiavellian Cynicism, but scored lower on Machiavellian'Tactics and Traditional Moralism. In the spring of 1969, a revised set of items was given to students in introductory psychology classes at Columbia University and New York University. While the findings from these subjects replicated those found with the Columbia freshmen, they showed subtle differences which led to speculations about the radicalization process. Also discussed are the relationships between the nature of political participation and all of the factors, with special emphasis on the discrepancy between Machiavellian Tactics and Cynicism.     

Characteristics of Suicidality Among Adolescents

The identification of high-risk adolescent suicide attempters in a population of depressed and suicidal adolescents is of crucial importance. This retrospective study examined characteristics of suicidality (recent and lifetime, active and passive) and psychopathology (depression, aggression, impulsivity, stressful life events, SCL-90 dimensions) among four groups of depressed adolescent outpatients: (1) suicide attempters who required medical treatment (n = 84), (2) suicide attempters who did not require medical treatment (n = 57), (3) suicidal ideators who had never made a suicide attempt (n = 40), and (4) nonsuicidal patients (n = 44). Results indicate that the nonsuicidal group could be differentiated from the three suicidal groups on the basis of suicidality and psychopathology, and that the three suicidal groups could be differentiated from one another on the basis of suicidality but not psychopathology. These findings are discussed in terms of the usefulness of certain self-report measures of suicidality for identifying suicidal adolescents and for differentiating among them. Furthermore, the findings suggest that psychopathological factors do not determine which suicidal adolescents make a medically dangerous suicide attempt and which do not.