Glutamate-mediated neuroplasticity in a limbic input to the hypothalamus

Emotionally-salient stressors are processed by cortical and limbic circuits that provide important regulatory input to the hypothalamic-pituitary-adrenal (HPA) axis. However, exposure to chronic or severe stress may cause disregulation of the axis and a variety of physiological and psychological symptoms. The mechanisms that underlie stress-induced alterations in HPA axis function are not well characterized, but one possibility is that severe stress causes plastic changes in limbic inputs to the hypothalamus. We examined plasticity within the bed nucleus of stria terminalis (BNST) and the hypothalamic paraventricular nucleus (PVN) with a stimulating electrode in the BNST and a recording electrode in the PVN. High-frequency BNST stimulation produced long-lasting suppression of evoked field potentials recorded from the PVN, and this effect was blocked by administration of MK-801. Accordingly, rapid glutamate-mediated neuroplasticity in the BNST to PVN neurocircuitry may contribute to plasticity in limbic regulation of the HPA axis.     

Automatic activation of categorical and abstract analogical relations in analogical reasoning

We examined activation of concepts during analogical reasoning. Subjects made either analogical judgments or categorical judgments about four-word sets. After each four-word set, they named the ink color of a single word in a modified Stroop task. Words that referred to category relations were primed (as indicated by longer response times on Stroop color naming) subsequent to analogical judgments and categorical judgments. This finding suggests that activation of category concepts plays a fundamental role in analogical thinking. When colored words referred to analogical relations, priming occurred subsequent to analogical judgments, but not to categorical judgments, even though identical four-word stimuli were used for both types of judgments. This finding lends empirical support to the hypothesis that, when people comprehend the analogy between two items, they activate an abstract analogical relation that is distinct from the specific content items that compose the analogy.     

Stress versus discrete negative emotions in the prediction of physical complaints: does predictive utility vary across ethnic groups?

Reports of stress and negative emotion are important predictors of health. However, whether discrete emotions or stress measures are more useful, whether they contribute independently to outcome, and whether they relate to health equally across ethnic groups remain unclear. In the current study, 207 US-born European American, US-born African American, Black English-speaking Caribbean, and Dominican men aged 40 years and older completed measures of somatic symptoms, trait emotions, and stress. Sadness and stress independently predicted symptom reports, even when examined concurrently, and with demographics controlled; trait anger did not predict symptoms. Moreover, the relations between trait emotions and symptoms varied across groups. Levels of sadness were associated with greater symptoms among US-born European American and Dominican men, but negatively associated among Black English-speaking Caribbean men, and the relations for anger also differed marginally across groups. The results underscore the importance of differentiating among discrete emotions and stress and considering ethnic interactions when examining reports of somatic symptomology. We suggest that the impact of psychological characteristics on health must be considered within cultural and ethnic contexts to be fully understood.     

An open letter to institutional review boards considering Northfield Laboratories' PolyHeme trial

At the time of this writing, a widely publicized, waived-consent trial is underway. Sponsored by Northfield Laboratories, Inc. (Evanston, IL) the trial is intended to evaluate the emergency use of PolyHeme, an oxygen-carrying resuscitative fluid that might prevent deaths from uncontrolled bleeding. The protocol allows patients in hemorrhagic shock to be randomized between PolyHeme and saline in the field and, still without consent, randomized between PolyHeme and blood after arrival at an emergency department. The Federal regulations that govern the waiver of consent restrict its applicability to circumstances where proven, satisfactory treatments are unavailable. Blood-the standard treatment for hemorrhagic shock-is not available in ambulances but is available in hospitals. The authors argue that the in-hospital stage of the study fails to meet ethical and regulatory standards.     

Distinct mechanisms for planning keypress and reaching responses: a developmental study

This study examined developmental effects in the ability to use precue information for the planning of keypress and reaching responses. Participants from four age groups (7, 9, 13, and 21 year olds) performed a spatial precuing task either by pressing one of four response keys (keypress task) or by reaching directly toward one of the four target locations on the screen (reaching task). Reaction time data revealed striking age differences in the ability to use advance information in the keypress task, not in the reaching task. This dissociation confirms the hypothesis that distinct and separate mechanisms govern the planning of indirect keypress and direct reaching responses.     

Evaluation of a structural polymorphism in the ankyrin repeat and kinase domain containing 1 (ANKK1) gene and the activation of executive attention networks

The specificity of genetic effects on brain activation is a central issue in understanding how molecular actions at the synapse relate to anatomic patterns of brain activity. In an effort to understand the basis for the specificity of gene-associated brain activity, we explore a well-studied genetic polymorphism, TaqIA, which lies downstream of the DRD2 gene in the protein-encoding region of a neighboring gene, ANKK1, which is not expressed in the brain. We utilize the attention network test and find that carriers of the A1 allele show gene-associated functional activation in an anatomically specific, dopamine-rich region of the brain comprising the anterior cingulate gyrus, a finding partially consistent with prior data from functional imaging genetics. A review of the patterns of expression for ANKK1 and DRD2 and the extent of linkage disequilibrium between the two genes sheds light on additional criteria for the selection of candidate genes in imaging-genetic studies.     

Strange bedfellows? Reflections on bioethics' role in disaster response planning

This essay considers the potential role of bioethics in disaster response planning and preparedness. Bioethicists can make substantial contributions, by ensuring that decision-making and distribution of resources during crises is carried out in a fair and just manner, as well as by examining the assumptions upon which disaster planning are based. Bioethicists should also be aware of potential pitfalls of overly-hasty engagement with this new field.     

Students' perceptions of rewards for academic performance by parents and teachers: relations with achievement and motivation in college

In the present study, the authors examined college students' (N= 136) perceptions of the provision of extrinsic rewards given by parents and teachers for academic performance from elementary school through high school. They also examined the relations between reward history and present student motivational orientation. External rewards for students' grades were common at all levels of schooling. Reward history related significantly to students' motivational orientation and performance in college, and these relations were generally stronger for boys than for girls. The authors discuss implications of these findings.     

Thinking within the box: The relational processing style elicited by counterfactual mind-sets

By comparing reality to what might have been, counterfactuals promote a relational processing style characterized by a tendency to consider relationships and associations among a set of stimuli. As such, counterfactual mind-sets were expected to improve performance on tasks involving the consideration of relationships and associations but to impair performance on tasks requiring novel ideas that are uninfluenced by salient associations. The authors conducted several experiments to test this hypothesis. In Experiments 1a and 1b, the authors determined that counterfactual mind-sets increase mental states and preferences for thinking styles consistent with relational thought. Experiment 2 demonstrated a facilitative effect of counterfactual mind-sets on an analytic task involving logical relationships; Experiments 3 and 4 demonstrated that counterfactual mind-sets structure thought and imagination around salient associations and therefore impaired performance on creative generation tasks. In Experiment 5, the authors demonstrated that the detrimental effect of counterfactual mind-sets is limited to creative tasks involving novel idea generation; in a creative association task involving the consideration of relationships between task stimuli, counterfactual mind-sets improved performance.     

Religion and unforgivable offenses

ABSTRACT The value of forgiveness is emphasized in many religions, but little is known about how members of distinct religious cultures differ in their views of forgiveness. We hypothesized and found that Jews would agree more than Protestants that certain offenses are unforgivable and that religious commitment would be more negatively correlated with belief in unforgivable offenses among Protestants than among Jews (Studies 1 and 2). Dispositional forgiveness tendencies did not explain these effects (Studies 1 and 2). In Study 3, Jews were more inclined than Protestants to endorse theologically derived reasons for unforgivable offenses (i.e., some offenses are too severe to forgive, only victims have the right to forgive, and forgiveness requires repentance by the perpetrator). Differential endorsement of these reasons for nonforgiveness fully mediated Jew-Protestant differences in forgiveness of a plagiarism offense and a Holocaust offense.