Causal inferences with group based trajectory models

A central theme of research on human development and psychopathology is whether a therapeutic intervention or a turning-point event, such as a family break-up, alters the trajectory of the behavior under study. This paper lays out and applies a method for using observational longitudinal data to make more confident causal inferences about the impact of such events on developmental trajectories. The method draws upon two distinct lines of research: work on the use of finite mixture modeling to analyze developmental trajectories and work on propensity scores. The essence of the method is to use the posterior probabilities of trajectory group membership from a finite mixture modeling framework, to create balance on lagged outcomes and other covariates established prior to t for the purpose of inferring the impact of first-time treatment at t on the outcome of interest. The approach is demonstrated with an analysis of the impact of gang membership on violent delinquency based on data from a large longitudinal study conducted in Montreal. The research has been supported by the National Science Foundation (NSF) (SES-99113700) and the National Institute of Mental Health (RO1 MH65611-01A2). It also made heavy use of data collected with the support from Québec’s CQRS and FCAR funding agencies, Canada’s NHRDP and SSHRC funding agencies, and the Molson Foundation. We thank Stephen Fienberg, Susan Murphy, Paul Rosenbaum, the editor, Paul De Boeck, and two anonymous reviewers for their insightful suggestions.     

Eye movements, not hypercompatible mappings, are critical for eliminating the cost of task set reconfiguration

Residual switch costs are notoriously difficult to eliminate. Yet Hunt and Klein (2002) eliminated them in a task that required observers to alternate between 8 trials of prosaccades and 8 trials of antisaccades, as long as there was at least 1 sec between the task cue and the onset of the saccade target. It was proposed that the elimination of residual switch costs occurred because prosaccade responses are computed very rapidly. These so-calledhypercompatible responses bypass memory retrieval stages of the response process, thereby eliminating the source of residual switch costs. Here we tested this hypothesis by requiring observers to alternate between responding with the finger that was vibrated (another task that meets the criteria for hypercompatibility) and responding with the finger of the opposite hand. Residual switch costs were not eliminated, suggesting that their elimination in Hunt and Klein (2002) was due to special properties of the prosaccade—antisaccade task.     

Premonitory urges are associated with decreased grey matter thickness within the insula and sensorimotor cortex in young people with Tourette syndrome

Tourette syndrome (TS) is a neurological disorder characterized by vocal and motor tics and is associated with cortical–striatal–thalamic–cortical circuit (CSTC) dysfunction and hyperexcitability of cortical limbic and motor regions, which are thought to lead to the occurrence of tics. Importantly, individuals with TS often report that their tics are preceded by ‘premonitory sensory phenomena’ (PSP) that are described as uncomfortable cognitive or bodily sensations that precede the execution of a tic, and are experienced as a strong urge for motor discharge. While the precise role played by PSP in the occurrence of tics is controversial, PSP are nonetheless of considerable theoretical and clinical importance in TS, not least because they form the core component in many of the behavioural therapies that are currently used in the treatment of tic disorders. In this study, we investigated the brain structure correlates of PSP. Specifically, we conducted a whole‐brain analysis of cortical (grey matter) thickness in 29 children and young adults with TS and investigated the association between grey matter thickness and PSP. We demonstrate for the first time that PSP are inversely associated with grey matter thickness measurements within the insula and sensorimotor cortex. We also demonstrate that grey matter thickness is significantly reduced in these areas in individuals with TS relative to a closely age‐ and gender‐matched group of typically developing individuals and that PSP ratings are significantly correlated with tic severity.     

Inducing Knowledgeability From Niceness: Children Use Social Features for Making Epistemic Inferences

In many ways, evaluating informants based on their features is a problem of induction: Children rely on the assumption that observable informant characteristics (e.g., traits, behaviors, social categories) will predict unobservable characteristics (e.g., future behavior, knowledge states, intentions). Yet to make sensible inferences, children must recognize what informant features are relevant for what types of inferences. The current research investigated whether preschoolers use social features (e.g., niceness) for making epistemic inferences and, conversely, whether they use intellectual features (e.g., expertise) for making social inferences. In the study, 96 preschoolers (M_age = 4.96 years) were asked to attribute knowledge and behaviors to a mean informant, a nice informant, and a neutral informant. Between subjects, we varied which informant had expertise. We found that when attributing knowledge, children used both features: attributing more knowledge to nicer informants, but also attributing more knowledge to an informant when he had expertise. In contrast, when making social inferences, children relied primarily on social features.     

The effect of visualization on visual search performance

Striking results recently demonstrated that visualizing search for a target can facilitate visual search for that target on subsequent trials (Reinhart et al. 2015). This visualization benefit was even greater than the benefit of actually repeating search for the target. We registered a close replication and generalization of the original experiment. Our results show clear benefits of repeatedly searching for the same target, but we found no benefit associated with visualization. The difficulty of the search task and the ability to monitor compliance with instructions to visualize are both possible explanations for the failure to replicate, and both should be carefully considered in future research exploring this interesting phenomenon.     

Kea cooperate better with sharing affiliates

Controlled studies that focus on intraspecific cooperation tasks have revealed striking similarities, but also differences, in abilities across taxa as diverse as primates, fish, and birds. Such comparisons may provide insight into the specific socio-ecological selection pressures that led to the evolution of cooperation. Unfortunately, however, compared to primates data on birds remain relatively scarce. We tested a New Zealand psittaciform, the kea, in a dyadic cooperation task using the loose-string design. During trials our subjects were in separate compartments, but obtained a common reward that could be divided multiple ways, allowing the examination of reward division effects. Ten individuals were tested twice in 44 combinations of partners. Dyads with a high affiliation score attempted to cooperate more often and were also more often successful in doing so. Furthermore, dyads that shared rewards more equally seemed to be more likely to attempt cooperation in the next trial. Like other bird and some monkey species, but unlike, for example, chimpanzees, kea did not spontaneously show understanding of either the role of the partner or the mechanism behind the cooperation task. This may point to true disparities between species, but may also be due to differences in task design and/or the amount of exposure to similar tasks and individual skills of the subjects.     

Introduction to the Special Section: Toward Implementing Physiological Measures in Clinical Assessments of Adult Mental Health

This article serves as the introduction to the Special Section called “Toward Implementing Physiological Measures in Clinical Assessments of Adult Mental Health.” As such, it provides an overview of the importance of integrating assessments of physiological and subjective processes in mental health assessments and discusses the Research Domain Criteria (RDoC) initiative. In addition, it summarizes the findings from the four empirical studies published in the Special Section. Collectively, these studies sought to illustrate how physiological assessments can be incorporated in mental health assessments conducted in applied research and clinic settings. In all, we hope that this Special Section will inspire the type of interdisciplinary research spanning basic and applied work that will be critical to advancing the RDoC initiative.     

Sex differences in the assignment of responsibility for an accident

Two experiments examined the proposition that females assign less responsibility than males to a perpetrator in a feminine occupation and males assign less responsibility than females to a perpetrator in a masculine occupation. The results from Experiment 1 indicated that females assigned less responsibility than males to a perpetrator in a feminine occupation, whereas males and females assigned equal responsibility to a perpetrator in a masculine occupation. These results did not generalize to measures of causality, foreseeability, intent, or justification. Therefore, they suggest that responsibility may have been assigned on the basis of reliability of the perpetrator's behavior and that a measure of reliability may be more appropriate than a measure of responsibility. The results from Experiment 2 supported the contention. Females judged the behavior of a perpetrator in a feminine occupation to be more reliable than did males, and males judged the behavior of a perpetrator in a masculine occupation to be more reliable than did females.     

The visual influence of ostracism

Reflecting the fundamental human need to establish and maintain positive connections with others, it has been suggested that an Ostracism Detection System is sensitized to targets by which one has been ostracized. Evidence supporting the operation of this system has yet to be provided, however. Accordingly, using binocular rivalry to explore attentional processing, here, we considered the extent to which targets previously associated with ostracism dominate visual awareness. Participants initially performed a virtual ball‐tossing game (i.e., Cyberball) in which they were “ostracized” or “included” by the other players. Afterwards, the faces of these players were presented together with houses in a binocular rivalry task. The results revealed that targets associated with ostracism (vs. inclusion) dominated longest in visual awareness.