The location and interpretation of the bisection point

In atemporal bisectiontask with humans, the observer is required to decide whether a probe duration ( t ) is more similar to the short referent (S), an R S response, or to the long referent (L), an R L response. Temporal bisection yields a psychometric function relating the proportion of long responses, P(R L ), to probe duration t . The value of t at which R S and R L occur with equal frequency, P(RL) = .5, is referred to as the bisection point, T 1/2 . Bisection models usually interpret T 1/2 as identifying the value of t that is equally confusable with S and L, but they differ in their predictions for the location of T 1/2 . The present paper presents new data relevant to the location and interpretation of T 1/2 . The data indicate that the empirical values usually are biased, the biases being influenced by duration range, L:S ratio, and probe spacing. Moreover, the biases often are not consistent across observers. It is concluded that empirical values of T 1/2 should not be interpreted as indicating the value of t that is equally confusable with S and L.     

Longitudinal Changes in Intellectual Development in Children with Fragile X Syndrome

Structural equation modeling (SEM) was used to examine the development of intellectual functioning in 145 school-age pairs of siblings. Each pair included one child with Fragile X syndrome (FXS) and one unaffected sibling. All pairs of children were evaluated on the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) at time 1 and 80 pairs of children received a second evaluation at time 2 approximately 4 years later. Compared to their unaffected siblings, children with FXS obtained significantly lower percentage correct scores on all subtests of the WISC at both time points. During the time between the first and second assessments, the annual rate of intellectual development was approximately 2.2 times faster in the unaffected children compared to the children with FXS. Levels of the fragile X mental retardation protein (FMRP) were highly associated with intellectual ability scores of the children with FXS at both time points (r=0.55 and 0.64 respectively). However, when gender, age, and the time between assessments were included as covariates in the structural equation model, FMRP accounted for only 5% of the variance in intellectual ability scores at time 1 and 13% of the variance at time 2. The results of this study suggest that slower learning contributes to the low and declining standardized IQ scores observed in children with FXS.     

Exploring epistemological beliefs of bilingual Filipino preservice teachers in the Filipino and English languages

In this study, the author investigated the epistemological beliefs of 864 bilingual Filipino preservice teachers using Filipino and English versions of the Schommer Epistemological Questionnaire (M. Schommer, 1998). The author conducted confirmatory factor analyses to determine the dimensions and structure of the epistemological beliefs. The results revealed two factors: Simple Learning and Structured Learning. The same factors were found using the Filipino and English versions of the questionnaire. The author discusses the results in terms of how they contribute to the growing evidence regarding the possible problems with particular multidimensional theories and quantitative measures of epistemological beliefs. The results also indicate how the specific epistemological beliefs of the Filipino preservice teachers may reflect features of the Philippine educational system and its tensions regarding pedagogy.     

Gender: An Intersectionality Perspective

Intersectionality, the mutually constitutive relations among social identities, is a central tenet of feminist thinking and has transformed how gender is conceptualized in research. In this special issue, we focus on the intersectionality perspective in empirical research on gender. Our goal is to offer a “best practices” resource that provides models for when and how intersectionality can inform theory and be incorporated into empirical research on psychological questions at individual, interpersonal, and social structural levels. I briefly summarize the development of the intersectionality perspective, and then review how the realization of its promise has been diverted by preoccupation with intersectionality as a methodological challenge. I conclude with a discussion of why intersectionality is an urgent issue for researchers invested in promoting positive social change.     

Yohimbine impairs extinction of cocaine-conditioned place preference in an alpha2-adrenergic receptor independent process

Extinction, a form of learning that has the ability to reshape learned behavior based on new experiences, has been heavily studied utilizing fear learning paradigms. Mechanisms underlying extinction of positive-valence associations, such as drug self-administration and place preference, are poorly understood yet may have important relevance to addiction treatment. Data suggest a major role for the noradrenergic system in extinction of fear-based learning. Employing both pharmacological and genetic approaches, we investigated the role of the alpha(2)-adrenergic receptor (alpha(2)-AR) in extinction of cocaine-conditioned place preference (CPP) and glutamatergic transmission in the bed nucleus of the stria terminalis (BNST). We found that pre-extinction systemic treatment with the alpha(2)-AR antagonist yohimbine impaired cocaine CPP extinction in C57BL/6J mice, an effect that was not mimicked by the more selective alpha(2)-AR antagonist, atipamezole. Moreover, alpha(2A)-AR knockout mice exhibited similar cocaine CPP extinction and exacerbated extinction impairing effects of yohimbine. Using acute brain slices and electrophysiological approaches, we found that yohimbine produces a slowly evolving depression of glutamatergic transmission in the BNST that was not mimicked by atipamezole. Further, this action was extant in slices from alpha(2A)-AR knockout mice. Our data strongly suggest that extinction-modifying effects of yohimbine are unlikely to be due to actions at alpha(2A)-ARs.     

Affect, Social Behavior, and the Brain in Williams Syndrome

ABSTRACT— Williams syndrome (WS) is a rare genetic disorder characterized by intellectual impairment and a distinctive physical and neuropsychological profile. Relative to their level of intellectual functioning, individuals with WS exhibit strengths in language and face recognition, with deficits in visual-spatial cognition. A heightened appetitive drive toward social interaction is a strong behavioral feature. Relative to other neurodevelopmental disorders, WS has a clearly defined genetic basis, together with a consistent neurocognitive profile of strengths and deficits. Thus, this disorder offers unique opportunities for elucidating gene–brain–behavior relationships. We focus on manifestations of the unusual social profile in WS, by examining data within and across levels of cognition, brain, and molecular genetics.     

Improving assessment of personality disorder traits through social network analysis

When assessing personality disorder traits, not all judges make equally valid judgments of all targets. The present study uses social network analysis to investigate factors associated with reliability and validity in peer assessment. Participants were groups of military recruits (N=809) who acted as both targets and judges in a round-robin design. Participants completed self- and informant versions of the Multisource Assessment of Personality Pathology. Social network matrices were constructed based on reported acquaintance, and cohesive subgroups were identified. Judges who shared a mutual subgroup were more reliable and had higher self-peer agreement than those who did not. Partitioning networks into two subgroups achieved more consistent improvements than multiple subgroups. We discuss implications for multiple informant assessments.     

Factor structure of the Schizophrenia Quality of Life Scale Revision 4 (SQLS-R4)

The Schizophrenia Quality of Life Scale Revision 4 (SQLS-R4) appears to offer excellent potential as an easily administered and patient acceptable assessment and monitoring measure of quality of life (QoL). However, a principle psychometric criterion crucial to the use and validity of the instrument concerns the underlying factor structure. The SQLS-R4 comprises two sub-scales, these being cognition and vitality QoL and psychosocial feelings QoL. However, the factor structure of the SQLS-R4 has yet to be established in a patient group in the UK. Confirmatory factor analysis was conducted on the SQLS-R4 to determine its psychometric properties in 100 patients with a primary ICD-10 diagnosis of schizophrenia. Internal reliability of the SQLS-R4 cognition and vitality QoL and psychosocial feelings QoL sub-scales was found to be excellent. Consistent with the original validation of the SQLS-R4, two correlated factors comprising cognition and vitality QoL and psychosocial feelings QoL were observed to offer the best fit to the data. In conclusion, the SQLS-R4 would appear to be suitable for use in patients with a primary diagnosis of schizophrenia in the UK. Potential clinical uses and the direction of future research with the SQLS-R4 are indicated.