Etiology of strokes in children with sickle cell anemia

The most devastating complication of sickle cell anemia is cerebral infarction, affecting approximately 30% of all individuals with sickle cell anemia. Despite being one of the most common causes of stroke in infants and children, the mechanism of cerebral infarction in this population has not been extensively studied and is poorly understood. Multiple, synergistic factors are important in the pathogenesis of stroke including the hemodynamic effects of cerebral arterial occlusive disease, viscosity, chronic and acute anemia and acute medical events. This review focuses on the relationship between these factors in order to provide a foundation for further study of the etiology of strokes in this high-risk population.     

The influence of prior knowledge and repeated questioning on children's long-term retention of the details of a pediatric examination

Children's recall of the details of pediatric examinations was examined over the course of a 6-month interval. Although the 83 4- to 7-year-old participants reported a substantial amount of information at each assessment, performance declined over time, dropping sharply over the course of 3 months but then remaining constant out to the final interview at 6 months. As expected, older children provided more total information than younger children did and reported a greater proportion of the event components in response to general rather than specific questions. However, comparable patterns of remembering and forgetting over time were observed at each age level. In addition, no effects of repeated questioning--in the form of an interview at 3 months for half of the children--were observed on performance at the 6-month assessment. Moreover, children's prior knowledge about routine doctor visits was assessed before the checkup for half of the participants at each age and was associated with initial but not delayed recall. Although knowledge increased with age as expected, it nonetheless affected recall over and above the influence of age.     

Facilitated cognitive disengagement in depression

The present study was conducted to test predictions derived from the hypothesis that depression may serve the purpose of adaptively facilitating disengagement from obsolete cognitive plans. Groups of students with either low or high depression scores were contrasted using a procedure that featured an initial learning phase, within which participants learned to perform a task, followed by a relearning phase within which they needed to disengage from initial learning in order to relearn to perform an altered task. It was assumed that performance in the relearning phase would be affected by the degree to which participants could readily disengage from their initial learning. As predicted, participants in the high depression group, relative to those in the low depression group, demonstrated superior performance in the relearning phase alone. The theoretical and applied implications of this finding are discussed.     

Asymmetric cultural effects on perceptual expertise underlie an own-race bias for voices

The own-race bias in memory for faces has been a rich source of empirical work on the mechanisms of person perception. This effect is thought to arise because the face-perception system differentially encodes the relevant structural dimensions of features and their configuration based on experiences with different groups of faces. However, the effects of sociocultural experiences on person perception abilities in other identity-conveying modalities like audition have not been explored. Investigating an own-race bias in the auditory domain provides a unique opportunity for studying whether person identification is a modality-independent construct and how it is sensitive to asymmetric cultural experiences. Here we show that an own-race bias in talker identification arises from asymmetric experience with different spoken dialects. When listeners categorized voices by race (White or Black), a subset of the Black voices were categorized as sounding White, while the opposite case was unattested. Acoustic analyses indicated listeners’ perceptions about race were consistent with differences in specific phonetic and phonological features. In a subsequent person-identification experiment, the Black voices initially categorized as sounding White elicited an own-race bias from White listeners, but not from Black listeners. These effects are inconsistent with person-perception models that strictly analogize faces and voices based on recognition from only structural features. Our results demonstrate that asymmetric exposure to spoken dialect, independent from talkers’ physical characteristics, affects auditory perceptual expertise for talker identification. Person perception thus additionally relies on socioculturally-acquired dynamic information, which may be represented by different mechanisms in different sensory modalities.     

Does group efficacy increase group identification? Resolving their paradoxical relationship

Although group identification and group efficacy are both important predictors of collective action against collective disadvantage, there is mixed evidence for their (causal) relationship. Meta-analytic and correlational evidence suggests an overall positive relationship that has been interpreted as consistent with the idea that group identification leads to group efficacy. However, experimental evidence has not supported this causal relationship. To resolve this paradox, we show in an experiment that it is group efficacy that leads to increased group identification because group efficacy puts individuals' identity into action. We discuss the theoretical and practical implications of these findings.     

Bifactor models and rotations: exploring the extent to which multidimensional data yield univocal scale scores

The application of psychological measures often results in item response data that arguably are consistent with both unidimensional (a single common factor) and multidimensional latent structures (typically caused by parcels of items that tap similar content domains). As such, structural ambiguity leads to seemingly endless "confirmatory" factor analytic studies in which the research question is whether scale scores can be interpreted as reflecting variation on a single trait. An alternative to the more commonly observed unidimensional, correlated traits, or second-order representations of a measure's latent structure is a bifactor model. Bifactor structures, however, are not well understood in the personality assessment community and thus rarely are applied. To address this, herein we (a) describe issues that arise in conceptualizing and modeling multidimensionality, (b) describe exploratory (including Schmid-Leiman [Schmid & Leiman, 1957] and target bifactor rotations) and confirmatory bifactor modeling, (c) differentiate between bifactor and second-order models, and (d) suggest contexts where bifactor analysis is particularly valuable (e.g., for evaluating the plausibility of subscales, determining the extent to which scores reflect a single variable even when the data are multidimensional, and evaluating the feasibility of applying a unidimensional item response theory (IRT) measurement model). We emphasize that the determination of dimensionality is a related but distinct question from either determining the extent to which scores reflect a single individual difference variable or determining the effect of multidimensionality on IRT item parameter estimates. Indeed, we suggest that in many contexts, multidimensional data can yield interpretable scale scores and be appropriately fitted to unidimensional IRT models.     

Why Leibniz thinks Descartes was wrong and the Scholastics were right

The bundle theory is a theory about the internal constitution of individuals. It asserts that individuals are entirely composed of universals. Typically, bundle theorists augment their theory with a constitutional approach to individuation entailing the thesis ‘identity of constituents is a sufficient ground for numerical identity’ (CIT). But then the bundle theory runs afoul of Black’s duplication case—a world containing two indiscernible spheres. Here I propose and defend a new version of the bundle theory that denies ‘CIT’, and which instead conjoins it with a structural diversity thesis, according to which being separated by distance is a sufficient ground for numerical diversity. This version accommodates Black’s world as well as the three-spheres world—a world containing three indiscernible spheres, arranged as the vertices of an equilateral triangle. In this paper, I also criticize Rodriguez-Pereyra’s alternative attempt to defend the bundle theory against Black’s case and the case of the three-spheres world.     

Justice through consensus: Shared identity and the preference for a restorative notion of justice

We propose a concept of restorative justice as a sense of justice deriving from consensus about, and the reaffirmation of, values violated by an offence (in contrast to punishment‐based retributive justice). Victims should be more likely to seek restorative justice (and less likely retributive justice) when they perceive to share a relevant identity with the offender. In Study 1, when the relevant identity (university affiliation) shared with the offender was made salient (vs. not), participants found a consensus‐based response more justice‐restoring. In Study 2, when the group (company) shared with the offender was cohesive (vs. not), participants more strongly endorsed a restorative justice philosophy and, mediated by this, responded in consensus‐restoring ways. In Study 3, when the offender was an ingroup (vs. outgroup) member, participants more strongly endorsed a restorative justice philosophy, fully mediated by sadness emotions. Copyright © 2009 John Wiley & Sons, Ltd.