Influence of brain-derived neurotrophic factor and catechol O-methyl transferase polymorphisms on effects of meditation on plasma catecholamines and stress

Meditation may show differential effects on stress and plasma catecholamines based on genetic polymorphisms in brain-derived neurotrophic factor (BDNF) and catechol O-methyl transferase (COMT). Eighty adults (40 men, 40 women; mean age 26 years) who practiced meditation regularly and 57 healthy control adults (35 men, 22 women; mean age 26 years) participated. Plasma catecholamines (norepinephrine (NE), epinephrine (E), and dopamine (DA)) concentrations were measured, and a modified form of the Stress Response Inventory was administered. The results were analyzed using two-way analysis of covariance (ANCOVA) with control and meditation subjects, gene polymorphism as factors, and meditation duration as the covariate. Two-way ANCOVA showed a significant interaction between control and meditation subjects, and BDNF Val66Met polymorphism on DA/NE+DA/E (p = 0.042) and NE/E+NE/DA (p = 0.046) ratios. A significant interaction was found for control and meditation subjects with COMT Val158Met polymorphism and plasma NE concentrations (p = 0.009). Post hoc ANCOVA in the meditation group, adjusted for meditation duration, showed significantly higher plasma NE concentrations for COMT Met carriers than COMT Val/Val subjects (p = 0.025). Significant differences of stress levels were found between the control and meditation subjects in BDNF Val/Met (p < 0.001) and BDNF Met/Met (p = 0.003), whereas stress levels in the BDNF Val/Val genotype did not differ between the control and meditation groups. This is the first evidence that meditation produces different effects on plasma catecholamines according to BDNF or COMT polymorphisms.     

Active coping with stress suppresses glucose metabolism in the rat hypothalamus

We used 18F-fluorodeoxyglucose small-animal positron-emission tomography to determine whether different styles of coping with stress are associated with different patterns of neuronal activity in the hypothalamus. Adult rats were subjected to immobilization (IMO)-stress or to a non-immobilized condition for 30 min, in random order on separate days, each of which was followed by brain-scanning. Some rats in the immobilized condition were allowed to actively cope with the stress by chewing a wooden stick during IMO, while the other immobilized rats were given nothing to chew on. Voxel-based statistical analysis of the brain imaging data shows that chewing counteracted the stress-induced increased glucose uptake in the hypothalamus to the level of the non-immobilized condition. Region-of-interest analysis of the glucose uptake values further showed that chewing significantly suppressed stress-induced increased glucose uptake in the paraventricular hypothalamic nucleus and the anterior hypothalamic area but not in the lateral hypothalamus. Together with the finding that the mean plasma corticosterone concentration at the termination of the IMO was also significantly suppressed when rats had an opportunity to chew a wooden stick, our results showed that active coping by chewing inhibited the activation of the hypothalamic-pituitary-adrenal axis to reduce the endocrine stress response.     

Bioethics committee in the university teaching hospital in Bordeaux

Set up in 2011, the ethics committee at the teaching hospital in Bordeaux, although it is now obsolete in its organisation because of the "standardisation" in early 2012 of regional ethics groups, was nevertheless an original structure which deserves to be analysed for several reasons. First of all, why have a hospital ethics committee? Then, to do what? Finally, it is interesting to give a few indications about the working of this committee.     

The nature and consequences of topic avoidance in Chinese and Taiwanese close relationships

Two studies examined topic avoidance in Chinese and Taiwanese opposite‐sex friendships and romantic relationships. Five areas of topic avoidance emerged through analytic induction and cluster analysis: negative appraisal, relational issues, sexual issues, politics, and personal experience. Partner protection, negative relational impact, and self inefficacy emerged as the most common reasons for avoidance. Results revealed that friends, relative to romantic partners, engaged in higher levels of topic avoidance. Taiwanese participants, moreover, avoided discussing politics to a greater extent than did mainland Chinese participants. Lacking closeness was the main reason behind avoidance of political discussion. Topic avoidance was also linked to relationship quality, as relational satisfaction negatively predicted relational issue avoidance and topic avoidance breadth (i.e. the number of topics regularly avoided in the relationship). The authors explain these and other findings based on Chinese cultural codes and historically‐embedded concepts that shape interpersonal interaction.     

Young children can tell strategic lies after committing a transgression

This study investigated whether young children make strategic decisions about whether to lie to conceal a transgression based on the lie recipient's knowledge. In Experiment 1, 168 3- to 5-year-olds were asked not to peek at the toy in the experimenter's absence, and the majority of children peeked. Children were questioned about their transgression in either the presence or absence of an eyewitness of their transgression. Whereas 4- and 5-year-olds were able to adjust their decisions of whether to lie based on the presence or absence of the eyewitness, 3-year-olds did not. Experiments 2 and 3 manipulated whether the lie recipient appeared to have learned information about children's peeking from an eyewitness or was merely bluffing. Results revealed that when the lie recipient appeared to be genuinely knowledgeable about their transgression, even 3-year-olds were significantly less likely to lie compared with when the lie recipient appeared to be bluffing. Thus, preschool children are able to make strategic decisions about whether to lie or tell the truth based on whether the lie recipient is genuinely knowledgeable about the true state of affairs.     

Visual assessment of camouflaged targets with different background similarities

The study investigated the effectiveness of different camouflage designs using a computational image quality index. Camouflaged human targets were presented on a natural landscape and the targets were designed to be similar to the landscape background with different levels of background similarity as estimated by the image index. The targets were presented in front of the observer (central 0 degrees) or at different angles in the left (-7 degrees, -14 degrees, -21 degrees) or right (+7 degrees, +14 degrees, +21 degrees) visual fields. The observer had to detect the target using peripheral vision if the target appeared in the left and right visual fields. The camouflage effectiveness was assessed by detection hit rates, detection times, and subjective ratings on detection confidence and task difficulty. The study showed that the psychophysical measures correlated well with the image similarity index, suggesting a potentially more efficient camouflage effectiveness assessment tool if the relationship between the psychophysical results and the index can be quantified in the future.     

The reciprocal cycle of self‐concealment and trust in romantic relationships

We propose that perceived partner concealment, self‐concealment from one's partner (i.e., keeping secrets from one's partner), and trust in one's partner form a reciprocal cycle in romantic relationships. In Study 1, participants in a romantic relationship (N = 94) completed a two‐time point survey within a span of 8 to 10 weeks. Results revealed that perceived partner concealment was associated with a loss of trust in partner, and low trust in partner was associated with an increase in self‐concealment from one's partner. Furthermore, the association between perceived partner concealment and self‐concealment from one's partner was mediated by trust. In Study 2, couples (N = 50) completed daily records for 14 consecutive days. Multilevel analyses indicated that on the days the individuals reported more self‐concealment, their partners reported lower trust in them. Moreover, on the days the partners reported lower trust, the partners also reported higher self‐concealment. These findings suggest that self‐concealment in romantic relationships can create a reciprocal cycle that involves loss of trust and more self‐concealment between partners, which would slowly deteriorate the relationship well‐being. Copyright © 2012 John Wiley & Sons, Ltd.     

Neural Correlates of Bridging Inferences and Coherence Processing

We explored the neural correlates of bridging inferences and coherence processing during story comprehension using Positron Emission Tomography (PET). Ten healthy right-handed volunteers were visually presented three types of stories (Strong Coherence, Weak Coherence, and Control) consisted of three sentences. The causal connectedness among sentences in the Strong Coherence story was strong that readers would not have to generate bridging inferences, whereas the causal antecedent of the last sentence in the Weak Coherence story was not explicitly stated so that readers should draw bridging inferences to fill the gap between sentences. It was found that the left middle temporal gyrus was activated while participants read the Weak Coherence stories. In contrast, the dorsomedial prefrontal cortex (dmPFC) and posterior cingulate cortex were activated only in the Strong Coherence condition. This suggests that the dmPFC was involved in coherence processing whereas bridging inference was mediated by the left middle temporal gyrus. It was also found that anterior temporal pole and the temporo-parietal junction mediated general semantic processing.