What is a visual object? Evidence from target merging in multiple object tracking

The notion that visual attention can operate over visual objects in addition to spatial locations has recently received much empirical support, but there has been relatively little empirical consideration of what can count as an 'object' in the first place. We have investigated this question in the context of the multiple object tracking paradigm, in which subjects must track a number of independently and unpredictably moving identical items in a field of identical distractors. What types of feature clusters can be tracked in this manner? In other words, what counts as an 'object' in this task? We investigated this question with a technique we call target merging: we alter tracking displays so that distinct target and distractor locations appear perceptually to be parts of the same object by merging pairs of items (one target with one distractor) in various ways - for example, by connecting item locations with a simple line segment, by drawing the convex hull of the two items, and so forth. The data show that target merging makes the tracking task far more difficult to varying degrees depending on exactly how the items are merged. The effect is perceptually salient, involving in some conditions a total destruction of subjects' capacity to track multiple items. These studies provide strong evidence for the object-based nature of tracking, confirming that in some contexts attention must be allocated to objects rather than arbitrary collections of features. In addition, the results begin to reveal the types of spatially organized scene components that can be independently attended as a function of properties such as connectedness, part structure, and other types of perceptual grouping.     

Morphological priming: the role of prime duration, semantic transparency, and affix position.

Patterns of facilitation in three lexical decision studies reveal several properties of morphologically complex words that influence processing. In one study, effects of morphological (VOWED-VOW) similarity are contrasted with effects of either semantic (PLEDGE-VOW) or orthographic (VOWEL-VOW) similarity at two prime durations to show the distinctiveness of morphological processing. In a second study, we compare morphologically complex forms that are semantically transparent (CASUALLY-CASUALNESS) with opaque forms (CASUALTY-CASUALNESS) and show that opaque relatives are more similar to VOWEL-VOW type pairs than to transparent relatives. In the third study, we examine facilitation for complex targets (CALCULATION) preceded by prefixed (MISCALCULATE) and suffixed (CALCULATOR) relatives and show that the position of the base morpheme influences processing under cross-modal but not under purely visual presentation conditions. Taken collectively, under comparable presentation conditions, semantic transparency but not base morpheme position constrains morphological processing.     

Ethnicity and Social Support During Pregnancy

Data from two multi-ethnic prospective studies of African American, Latina, and non-Hispanic White pregnant women were used to examine the influence of contextual factors on social support processes during pregnancy. Multiple types of support (perceived support, received support, support satisfaction, network support) and sources of support (baby's father, family, friends) were assessed. The role of ethnicity in social support was examined after controlling for the contribution of related contextual factors (SES, marital status, age, parity, employment) to these processes. The impact of ethnicity and related contextual factors differed across sources of social support. Ethnic differences in support from family and friends, but not from the baby's father, emerged. However, marital status was a consistent predictor of support from the baby's father, and SES was a consistent predictor of support from friends. Overall, the findings of two studies suggest that although ethnicity is associated with support from friends and family, other contextual factors, such as marital status and SES, influence support processes during pregnancy.     

Prenatal Treatment of Congenital Adrenal Hyperplasia—Not Standard of Care

Congenital adrenal hyperplasia (CAH) due to steroid 21-hydroxylase deficiency is a common autosomal recessive disorder due to mutations in the CYP21A2 gene. Since genetic counselors play a crucial role in educating families about inherited disorders, they need to have thorough knowledge regarding the pathophysiology of CAH especially the effects on the fetus, the complex genetics of this disorder, and the controversies surrounding experimental prenatal dexamethasone treatment. Affected female fetuses may have varying degree of virilization of the external genitalia. Starting in the 1980's, supraphysiologic glucocorticoid treatment was used to decrease the virilization of the external genitalia of affected female fetuses. However, recent clinical observations, animal studies and greater awareness of the details of human fetal adrenal physiology raise concerns regarding the safety of this prenatal treatment. We review the pathophysiology of CAH, the safety and ethical considerations of prenatal dexamethasone treatment and the views of multiple medical societies that conclude that this experimental therapy should only be done in prospective trials approved by ethical review boards.     

An index of prenatal steroid exposure predicts adult face perception skills

Face perception skills are fundamental to social cognition, yet they vary markedly across individuals. This diversity has stimulated controversy over the relative contributions of genetic factors, prenatal environment, and postnatal experience to face perception. Recent twin studies have found that face perception is heritable, highlighting the potential for substantial prenatal determination of these skills. In contrast, previous work on potential influences of the prenatal hormonal environment on social cognition have found no association between 2D:4D, a marker for prenatal androgen exposure, and processing of facial emotional expressions, apparently precluding a major role for prenatal hormones in governing face perception. We propose that substantial predictive relationships between 2D:4D and face perception may have been masked in previous work because the task employed required both face perception and processing of others?? emotions, the latter component being greatly influenced by circulating hormones in adults. To assess prenatal hormone influences on face perception without requiring emotion processing, we related 2D:4D to the face inversion effect (FIE), a measure of the recruitment of specialist face processes to visual perception. The magnitude of the resulting predictive relationship (r = .52) compared surprisingly well with that found between identical twins?? face perception (rs = .27?C.61), suggesting that mechanisms of 2D:4D may account for a substantial proportion of perinatal influences on face processing. Furthermore, we employed 2D:4D as a common scale to map individual differences in the FIE onto prenatal testosterone:estrogen ratios, assayed by Lutchmaya, Baron-Cohen, Raggatt, Knickmeyer, and Manning (Early Human Development 77:23?C28, 2004). The substantial overlap between the two data sets further implicates prenatal steroids in adult face perception skills.     

Is the Continuity of Externalizing Psychopathology the Same in Adolescents and Middle–Aged Adults? A Test of the Externalizing Spectrum’s Developmental Coherence

Externalizing psychopathology (EXT) is a framework for understanding diagnostic comorbidity and etiology of antisocial and substance-use behaviors. EXT indicates continuity in adulthood but the structure of adolescent EXT is less clear. This report examines whether adolescent EXT is trait-like, as has been found with adults, or categorical. We use tests of measurement invariance to determine how diagnostic indicators of EXT differ in adolescents compared to adults. The EXT measures employed were DSM-IIIR diagnoses of adult antisocial behavior, conduct disorder, and alcohol, marijuana, and drug dependence. Latent trait, latent class, and hybrid models were fit to two separate data sets: 2,769 seventeen-year-old adolescents and 2,619 adults from the Minnesota Twin Family Study. The best model in both samples was a single-trait LT model. Parameters from the adolescent and adult models were equivalent for all disorders except alcohol dependence. It appears that EXT in adolescence can be accurately represented by a single-trait model, and the measurement properties of EXT are similar during these time periods with the exception of alcohol dependence.     

Development and validation of a revised measure of codependency

This study assessed the factor structure, internal consistency, and concurrent validity of a revised instrument, the Composite Codependency Scale (CCS), a 19‐item measure designed to assess codependent traits. Exploratory factor analysis of the CCS, using data from 301 adults from the general population and 49 attending members of Codependents Anonymous (CoDA), yielded three factors: self‐sacrifice, interpersonal control, and emotional suppression. The scale and its subscales exhibited good internal consistency. Consistent with the tenets of the codependency model, higher codependency scores were significantly associated with higher levels of depression, anxiety, stress, and familial dysfunction and lower levels of narcissistic tendencies, self‐esteem, and emotional expressivity. Furthermore, the revised measure effectively discriminated members of CoDA from those in the general population.