Brain-imaging studies of posttraumatic stress disorder

Brain-imaging studies of posttraumatic stress disorder (PTSD) have rapidly increased in recent years. Structural studies have identified potential smaller volumes of the hippocampus of traumatized and/or PTSD subjects. Functional activation studies have implicated hyperactive or altered functioning of brain regions, such as the amygdala and the insula, and a failure to engage emotional regulatory structures, such as the medial prefrontal and anterior cingulate cortex. Recent neurochemical investigations have suggested that neuromodulatory systems (eg, gamma-aminobutyric acid, micro-opioid) may underlie these aberrant brain activation patterns. This article reviews the literature on structural, functional, and neurochemical brain-imaging studies of PTSD.     

Sex-role imitation in children: Effects of sex of child,sex of model,and sex-role appropriateness of modeled behavior

The qualifying influence of the sex-role appropriateness of observed behavior on children's same-sex imitation was investigated. In each of two studies employing a 2×2×2 design, girls and boys observed a live male or female model display appropriate (to the child's sex) or inappropriate behavior. Results that were consistent in both studies indicated an interaction between sex of child and appropriateness. Boys imitated less when exposed to the inappropriate than to the appropriate sequence. An interaction between sex of child and sex of observer was obtained on only one measure in Experiment I (girls responded more quickly to a female than to a male model). In this study, girls also displayed greater opposite-sex imitation than boys; in Experiment II, there were no differences between boys and girls in either same- or opposite-sex imitation. The results are discussed with regard to the same-sex hypothesis and the differential impact of sex-role factors on boys and girls.The authors wish to thank the children, parents, and staff of Forest Park Elementary School for their participation and cooperation in the conduct of this study. Special thanks are extended to Mr. Paul H. Daby, Principal. The contribution of the undergraduate models and experimenters is also acknowledged.     

A Plea For Plurealism

In contrast to monistic realism (as represented by Peirce) and pluralistic irrealism (as represented by Goodman) I argue for what I call plurealism, a view which is both pluralistic and realist, recognizing different worlds that are not only independent of one another, but also independent of us.     

Effect of inversion on the recognition of external and internal facial features

The purpose of the present study was to find out whether inversion affects recognition of external and internal facial features. 24 participants matched, under two experimental conditions (pair and multiple-choice matchings), upright target faces with three categories of facial test stimuli: full faces, external features and internal features, which were presented in either upright or inverted orientations. Data analysis showed that matching of facial stimuli was faster, more accurate and more consistent under upright than under inverted orientations for all stimulus categories; mostly for full faces, and least for internal features. As a rule, there were no speed-accuracy trade-offs. Implications of the data for accounts of the inversion effect in face recognition in terms of a shift from configurational to componential processing were discussed.     

Directional tendencies of Hebrew, Japanese, and English readers.

Consistent left-right and right-left reading habits are associated with corresponding directional tendencies in the reproduction of horizontally displayed visual stimuli. Inconsistent reading habits should therefore be associated with inconsis tent directional tendencies. This hypothesis was tested on Japanese readers whose reading habits were inconsistent by asking them to reproduce four series of 12-item horizontal stimulus arrays. The hypothesis was partially supported by the data which showed that, like Hebrew readers who also have inconsistent reading habits, the directional tendencies shown by the 68 Japanese readers were significantly weaker on some tasks that those shown by the 16 English readers whose left-right reading habits were consistent. The data were interpreted as showing that acquired reading habits may affect directionality in perception of visual stimuli.     

Post-traumatic stress symptoms of children and adolescents exposed to the 2008 Wenchuan Earthquake: A longitudinal study of 5-HTTLPR genotype main effects and gene–environment interactions

Experiencing disasters causes severe mental disorders, among which post-traumatic stress disorder (PTSD) is the most common. We conducted a longitudinal study to examine the effect of 5-hydroxyl tryptamine transporter gene-linked polymorphic region (5-HTTLPR) genotype on child and adolescent PTSD symptom course after the 2008 Wenchuan Earthquake. We genotyped 963 participants who personally experienced the earthquake. PTSD symptoms were measured by University of California, Los Angeles PTSD reaction index at 2.5, 3.5, 4.5 and 5.5 years after the earthquake, respectively. Latent growth model was utilised to examine the main effect and gene–environment interaction effect of 5-HTTLPR on PTSD's symptom course. 5-HTTLPR genotype predicted initial PTSD symptom severity (β = 0.108, p = .019) and rates of symptom recovery (β = −0.120, p = .031) between 2.5 and 5.5 years. Compared with L′ allele carriers, those with S′S′ genotype showed higher initial symptom severity but also faster recovery rate. 5-HTTLPR genotype only predicted symptom severity at 2.5 years after the earthquake, after controlling for sex, age, ethnicity and trauma severity (β = 0.108, p = .019). This is the first evidence of the effect of 5-HTTLPR genotype on child and adolescent PTSD symptoms longitudinally, offering a novel perspective on the effect of 5-HTTLPR on PTSD symptom development following trauma exposure.