Invariance of the weight parameter in information integration

The relative effect of each informational dimension in an information integration task is a joint function of its weight and the range of values over which it is varied. A method is developed for separating these two factors. Weights obtained by this method were compared across variations of stimulus range. Subjects rated the performance of students on the basis of midterm exam scores and final exam scores. For some subjects, the range of scores on the final exam was twice that on the midterm and the reverse was true for other subjects. An averaging model was shown to describe the results, and weights did not differ for different stimulus ranges. This was true for each of two instructional conditions: one in which a particular weighting strategy was prescribed and one in which there was no prescribed weighting. Students who were instructed to use a 2∶1 weighting were found to assign more than twice as much weight to the final as to the midterm.     

The adrenergic receptor α-2A gene (ADRA2A) and neuropsychological executive functions as putative endophenotypes for childhood ADHD

There is resurgent interest in the psychiatric literature in endophenotypes, variables thought to more strongly reflect the effects of candidate genes than do manifest disorders. In a sample of 176 children with attention deficit hyperactivity disorder (ADHD) and 52 of their siblings, we examined the validity of several putative endophenotypes for ADHD that represent commonly used clinical measures of multiple cognitive/neuropsychological domains of executive functions (EFs). We review their distributional normality, their relations to ADHD symptoms in probands and unaffected siblings relative to nonADHD controls, and their correlation in siblings. We also tested the EF measures’ associations with the ADRA2A gene and whether they mediated or moderated the associations between ADHD and ADRA2A. Several EF measures showed association with ADRA2A, as well as moderation, but not mediation, of its association with ADHD. Implications of the results for evaluating the validity and utility of putative endophenotype measures and for finding candidate gene effects on ADHD are discussed.     

Spatial updating relies on an egocentric representation of space: Effects of the number of objects

Models of spatial updating attempt to explain how representations of spatial relationships between the actor and objects in the environment change as the actor moves. In allocentric models, object locations are encoded in an external reference frame, and only the actor’s position and orientation in that reference frame need to be updated. Thus, spatial updating should be independent of the number of objects in the environment (set size). In egocentric updating models, object locations are encoded relative to the actor, so the location of each object relative to the actor must be updated as the actor moves. Thus, spatial updating efficiency should depend on set size. We examined which model better accounts for human spatial updating by having people reconstruct the locations of varying numbers of virtual objects either from the original study position or from a changed viewing position. In consistency with the egocentric updating model, object localization following a viewpoint change was affected by the number of objects in the environment.     

Stressors, quality of the child-caregiver relationship, and children's mental health problems after parental death: the mediating role of self-system beliefs

Investigated whether three self-system beliefs, fear of abandonment, coping efficacy, and self-esteem, mediated the relations of stressors and caregiver-child relationship quality with concurrent and prospective internalizing and externalizing problems in a sample of children who had experienced parental death in the previous 2.5 years. The cross-sectional sample consisted of 340 children ages 7-16 and their surviving parent/current caregiver; the longitudinal analyses employed a subset of this sample that consisted of 100 children and their parents/caregivers who were assessed at three time points. A multirater, multimethod measure of caregiver-child relationship quality and a multirater measure of children's mental health problems were used. The cross-sectional model supported a mediational relation for fear of abandonment, coping efficacy, and self-esteem. The three-wave longitudinal model showed that fear of abandonment at Time 2 mediated the relation between stressors at Time 1 and internalizing and externalizing problems at Time 3. Implications of these findings for understanding the development of mental health problems in parentally bereaved children and designing interventions for this at-risk group are discussed.     

Relativity of judgements about sound amplitude and the asymmetry of the same-different ROC

The problem of deciding whether two things are the same or different in magnitude can be solved by judging one magnitude relative to the other, or by making absolute judgements about the magnitude of each. The shape of the resulting receiver operating characteristic depends on which solution is adopted. In order to obtain empirical receiver operating characteristics, we therefore had subjects rate their confidence that two tone amplitudes were the same or different. Four subjects each made 500 ratings of three differences in amplitude. The asymmetry in the obtained characteristics indicated that subjects made relative rather than absolute judgements of the amplitudes, despite the fact that making absolute judgements would lead to better performance on the task.     

Attentional capture and aging: implications for visual search performance and oculomotor control

Two studies examined potential age-related differences in attentional capture. Subjects were instructed to move their eyes as quickly as possible to a color singleton target and to identify a small letter located inside it. On half the trials, a new stimulus (i.e., a sudden onset) appeared simultaneously with the presentation of the color singleton target. The onset was always a task-irrelevant distractor. Response times were lengthened, for both young and old adults, whenever an onset distractor appeared, despite the fact that subjects reported being unaware of the appearance of the abrupt onset. Eye scan strategies were also disrupted by the appearance of the onset distractors. On about 40% of the trials on which an onset appeared, subjects made an eye movement to the task-irrelevant onset before moving their eyes to the target. Fixations close to the onset were brief, suggesting parallel programming of a reflexive eye movement to the onset and goal-directed eye movement to the target. Results are discussed in terms of age-related sparing of the attentional and oculomotor processes that underlie attentional capture.     

The Good's Magnetism and Ethical Realism

People support ethical antirealism with various arguments. Gilbert Harman thinks if a property of goodness existed, it would have detectable effects on objects that have it. However, Harman reasons, the good has no such detectable effects. Internalists think if good objects had some goodness property, that property would bond to desire and action in a way inconsistent with ethical realism. I defend ethical realism from the two arguments. I explain how good can both name a property and how objects with that property might dispose people to seek them. This explanation of the good's magnetism provides a reply to Harman.     

Predictive validity of the Psychopathy Checklist: Youth Version for general and violent recidivism

Several authors have expressed concern regarding the use of youth psychopathy assessments in determinations of risk for general and violent offending. The Psychopathy Checklist: Youth Version (PCL:YV) was completed with 182 male adolescent offenders in this prospective study (average 14.5 month follow-up) of general and violent recidivism. Both a two-factor and three-factor model of the PCL:YV significantly predicted general and violent recidivism at a predictive accuracy ranging from 68 to 63%. However, regression analyses indicated these associations were explained primarily by behavioral psychopathic symptoms, rather than interpersonal or affective traits. Implications for the use of psychopathy assessments for risk during adolescence are discussed.