Post Traumatic Stress,Context, and the Lingering Effects of the Hurricane Katrina Disaster among Ethnic Minority Youth

This study examined the stability of post traumatic stress disorder (PTSD) symptoms in a predominantly ethnic minority sample of youth exposed to Hurricane Katrina. Youth (n = 191 grades 4th thru 8th) were screened for exposure to traumatic experiences and PTSD symptoms at 24 months (Time 1) and then again at 30 months (Time 2) post-disaster. PTSD symptoms did not significantly decline over time and were higher than rates reported at earlier time points for more ethnically diverse samples. Younger age, female sex, and continued disrepair to the child’s home predicted stable elevated PTSD symptoms. Findings are consistent with predictions from contextual theories of disaster exposure and with epidemiological data from adult samples suggesting that the incidence of PTSD post Katrina is showing an atypical pattern of remittance. Theoretical, applied, and policy implications are discussed.     

Memory-enhancing corticosterone treatment increases amygdala norepinephrine and Arc protein expression in hippocampal synaptic fractions

Considerable evidence indicates that glucocorticoid hormones enhance the consolidation of memory for emotionally arousing events through interactions with the noradrenergic system of the basolateral complex of the amygdala (BLA). We previously reported that intra-BLA administration of a β-adrenoceptor agonist immediately after inhibitory avoidance training enhanced memory consolidation and increased hippocampal expression of the protein product of the immediate early gene activity-regulated cytoskeletal-associated protein (Arc). In the present experiments corticosterone (3 mg/kg, i.p.) was administered to male Sprague-Dawley rats immediately after inhibitory avoidance training to examine effects on long-term memory, amygdala norepinephrine levels, and hippocampal Arc expression. Corticosterone increased amygdala norepinephrine levels 15 min after inhibitory avoidance training, as assessed by in vivo microdialysis, and enhanced memory tested at 48 h. Corticosterone treatment also increased expression of Arc protein in hippocampal synaptic tissue. The elevation in BLA norepinephrine appears to participate in corticosterone-influenced modulation of hippocampal Arc expression as intra-BLA blockade of β-adrenoceptors with propranolol (0.5 μg/0.2 μL) attenuated the corticosterone-induced synaptic Arc expression in the hippocampus. These findings indicate that noradrenergic activity at BLA β-adrenoceptors is involved in corticosterone-induced enhancement of memory consolidation and expression of the synaptic-plasticity-related protein Arc in the hippocampus.     

Alleviating women’s mathematics stereotype threat through salience of group achievements

Stereotype threat impairs performance in situations where a stereotype holds that one’s group will perform poorly. Two experiments investigated whether reminding women of other women’s achievements might alleviate women’s mathematics stereotype threat. In Experiment 1, college women performed significantly better on a difficult mathematics test when they were first told that women in general make better participants than men in psychology experiments. In Experiment 2, college women performed significantly better on a difficult mathematics test when they first read about four individual women who had succeeded in architecture, law, medicine, and invention. The results are seen as having implications for theories of stereotype threat, self-evaluation, and performance expectations.     

Different practice effects for males and females by psychometric and chronometric mental-rotation tests

Gender differences in the psychometric mental-rotation test are usually larger than in the chronometric version. In both tests, practice effects appear for males and females. In this study, 104 participants (54 females, 50 males, age: 21.72 years) completed both tests in counterbalanced order. In the chronometric test, only males reacted and rotated significantly faster after the practice with the psychometric test. A strong practice effect independently of gender was found in the psychometric test and a gender difference in accuracy in favour of males. Males reported more confidence and females rated the perceived pressure of the time limit of the psychometric test higher than males. Consequently, differences in confidence after the practice could partly explain the gender differences in the improvements of reaction time and rotational speed. Practice from one mental-rotation test on the performance in another seems to be dependent of participants’ gender and the type of the test.     

“R U Mad?”: Computerized text analysis of affect in social media relates to stress and substance use among ethnic minority emerging adult males

Objective: This study examined the interactive role of affectivity and stress in substance use severity among ethnic minority, emerging adult males, using linguistic indicators of affect obtained through social media.

Method: Participants were 119 emerging adult, ethnic minority males (ages 18–25) who provided access to their mobile phone text messaging and Facebook activity for 6-months. Computerized text analysis (LIWC2015) was used to obtain linguistic indices of positive and negative affect from texts and Facebook posts. The Perceived Stress Scale was used to measure stress, and items from the Drug Abuse Screening Test were used to measure substance use severity.

Results: Generalized estimating equations showed that higher negative affect in texts was associated with greater substance use severity. Stress moderated the relationship between positive affect expressed in Facebook posts and substance use such that higher positive affect in Facebook posts was associated with less substance use at higher stress and greater substance use at lower stress.

Conclusions: Findings highlight the complexities of interactions between stress and affectivity. Findings could inform development of substance use interventions for young males that employ social technologies.     

A Latent Block Distance-Association Model for Profile by Profile Cross-Classified Categorical Data

Abstract

Distance association models constitute a useful tool for the analysis and graphical representation of cross-classified data in which distances between points inversely describe the association between two categorical variables. When the number of cells is large and the data counts result in sparse tables, the combination of clustering and representation reduces the number of parameters to be estimated and facilitates interpretation. In this article, a latent block distance-association model is proposed to apply block clustering to the outcomes of two categorical variables while the cluster centers are represented in a low dimensional space in terms of a distance-association model. This model is particularly useful for contingency tables in which both the rows and the columns are characterized as profiles of sets of response variables. The parameters are estimated under a Poisson sampling scheme using a generalized EM algorithm. The performance of the model is tested in a Monte Carlo experiment, and an empirical data set is analyzed to illustrate the model.