The effects of verbal consequences for rule-following on sensitivity to programmed contingencies of reinforcement

This study examined the effects of two types of verbal consequences for rule-following and their impact on subject's responses to programmed schedules of reinforcement. The first type of consequence involved feedback on the correspondence between the subject's behavior and the behavior specified in an antecedent rule. A second type of consequence involved this same feedback plus feedback on the number of points earned for task performance. Some subjects were given accurate feedback with respect to rule-following and some were told that the rule was being followed regardless of behavior. The task involved moving a circle through a grid on a video screen using telegraph keys operating on a multiple schedule of reinforcement. Successful task performance resulted in the delivery of a point, exchangeable for chances at a cash prize. The subjects were given an accurate rule that specified the appropriate behavior for a DRL 6/FR 18 multiple schedule of reinforcement with two-minute components. After 32 minutes of responding, this schedule was changed, without announcement, to a FR 1/FI Yoked schedule of reinforcement. The change from the DRL 6 to the FR 1 enabled an increase in effectiveness (more points could be earned in a given unit of time) and the change from the FR 18 to the FI Yoked enabled an increase in efficiency (fewer responses could earn the same number of points). The changed contingencies were kept in place for 64 minutes

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Genetic influences on schizophrenia and subcortical brain volumes:Large-scale proof of concept

Schizophrenia is a devastating psychiatric illness with high heritability. Brain structure and function differ, on average, between people with schizophrenia and healthy individuals. As common genetic associations are emerging for both schizophrenia and brain imaging phenotypes, we can now use genome-wide data to investigate genetic overlap. Here we integrated results from common variant studies of schizophrenia (33,636 cases, 43,008 controls) and volumes of several (mainly subcortical) brain structures (11,840 subjects). We did not find evidence of genetic overlap between schizophrenia risk and subcortical volume measures either at the level of common variant genetic architecture or for single genetic markers. These results provide a proof of concept (albeit based on a limited set of structural brain measures) and define a roadmap for future studies investigating the genetic covariance between structural or functional brain phenotypes and risk for psychiatric disorders