A Dual-Process Discrete-Time Survival Analysis Model: Application to the Gateway Drug Hypothesis

The gateway drug model is a popular conceptualization of a progression most substance users are hypothesized to follow as they try different legal and illegal drugs. Most forms of the gateway hypothesis are that “softer” drugs lead to “harder,” illicit drugs. However, the gateway hypothesis has been notably difficult to directly test—that is, to test as competing hypotheses in a single model that licit drug use might lead to illicit drug use or the reverse. This article presents a novel statistical technique, dual-process discrete-time survival analysis, which enables this comparison. This method uses mixture-modeling software to estimate 2 concurrent time-to-event processes and their effects on each other. Using this method, support for the gateway hypothesis in the National Longitudinal Survey of Youth, 1997, was weak. However, this article was not designed as a strong test of causal direction but more as a technical demonstration and suffered from certain technological limitations. Both these limitations and future directions are discussed.     

Basal ganglia, dopamine and temporal processing: performance on three timing tasks on and off medication in Parkinson's disease

A pervasive hypothesis in the timing literature is that temporal processing in the milliseconds and seconds range engages the basal ganglia and is modulated by dopamine. This hypothesis was investigated by testing 12 patients with Parkinson's disease (PD), both 'on' and 'off' dopaminergic medication, and 20 healthy controls on three timing tasks. In a seconds range (30-120 s) time production task, patients tested 'on' medication showed a significantly different accuracy profile compared to controls and when tested 'off' medication. However, no group or on vs off medication differences in accuracy were found on a time reproduction task and a warned reaction time task requiring temporal processing within the 250-2000 ms range. Variability was measured using the coefficient of variation, with the performance of the patient group on the time reproduction task violating the scalar property, suggesting atypical temporal processing mechanisms. The data suggest that the integrity of the basal ganglia is necessary for 'typical' time production in the seconds range as well as for time reproduction at shorter intervals. Exploratory factor analysis suggested that the time production task uses neural mechanisms distinct from those used in the other two timing tasks. The dissociation of the effects of dopaminergic medication and nature of task on performance in PD raises interesting questions about the pharmacological mediation and task-specificity of deficits in temporal processing.     

Cues to deception

Do people behave differently when they are lying compared with when they are telling the truth? The combined results of 1,338 estimates of 158 cues to deception are reported. Results show that in some ways, liars are less forthcoming than truth tellers, and they tell less compelling tales. They also make a more negative impression and are more tense. Their stories include fewer ordinary imperfections and unusual contents. However, many behaviors showed no discernible links, or only weak links, to deceit. Cues to deception were more pronounced when people were motivated to succeed, especially when the motivations were identity relevant rather than monetary or material. Cues to deception were also stronger when lies were about transgressions.     

A Randomized Trial of Two Promising Computer-Based Interventions for Students with Attention Difficulties

Few studies have examined whether attention can be improved with training, even though attention difficulties adversely affect academic achievement. The present study was a randomized-controlled trial evaluating the impact of Computerized Attention Training (CAT) and Computer Assisted Instruction (CAI) on attention and academic performance in 77 inattentive first graders. Students receiving either intervention were more likely than controls to show a moderate decline in teacher rated attention problems in first grade. Students receiving CAI also showed gains in reading fluency and in teacher ratings of academic performance. Intervention effects for attention were absent by second grade largely because attention problems declined in all groups. However, post hoc analyses indicated potential longer-term benefits for children with 6 or more inattentive symptoms at baseline. Persistent attention problems were associated with poorer academic performance in multiple domains. Results provide initial evidence that CAT and CAI can improve children’s attention in the classroom - and support additional studies to determine whether more clinically significant benefits are attainable.     

Boys’ and Girls’ Relational and Physical Aggression in Nine Countries

Distinguishing between relational and physical aggression has become a key feature of many developmental studies in North America and Western Europe, but very little information is available on relational and physical aggression in more diverse cultural contexts. This study examined the factor structure of, associations between, and gender differences in relational and physical aggression in China, Colombia, Italy, Jordan, Kenya, the Philippines, Sweden, Thailand, and the United States. Children ages 7–10 years (N = 1,410) reported on their relationally and physically aggressive behavior. Relational and physical aggression shared a common factor structure across countries. In all nine countries, relational and physical aggression were significantly correlated (average r = .49). Countries differed in the mean levels of both relational and physical aggression that children reported using and with respect to whether children reported using more physical than relational aggression or more relational than physical aggression. Boys reported being more physically aggressive than girls across all nine countries; no consistent gender differences emerged in relational aggression. Despite mean‐level differences in relational and physical aggression across countries, the findings provided support for cross‐country similarities in associations between relational and physical aggression as well as links between gender and aggression. Aggr. Behav. 38:298‐308, 2012. © 2012 Wiley Periodicals, Inc.     

Facial affect recognition deficits: A potential contributor to aggression in psychotic illness

The current literature suggests a relationship between psychosis and the likelihood of engaging in aggressive behavior, though the factors involved are unclear. In this paper we use a social information processing framework to consider mediators of aggressive behavior in psychosis, especially facial affect recognition (FAR) deficits. The theoretical underpinnings of aggressive behavior are explored using the General Aggression Model (GAM) and FAR deficits are posited as a possible contributor to increased aggression in psychosis. Current research investigating the relationship between FAR, psychosis, and aggression is critically examined, and the role of potential confounding variables including positive symptoms, psychopathic personality traits, childhood trauma, and substance use briefly explored. In conclusion, we argue that socioemotional processing deficits, such as impaired FAR, are a fruitful area for research aimed at understanding, and hence reducing the risk of violence in psychosis.