Adolescents Prefer More Immediate Rewards When in the Presence of their Peers

Adolescents take more risks in the presence of their peers, but the mechanism through which peer presence affects risky decision-making is unknown. We propose that the presence of peers increases the salience of the immediate rewards of a risky choice. The current study examined the effect of peer presence on reward sensitivity in a sample of 100 late adolescents ages 18 through 20 (M=18.5) using a delay discounting task, which assesses an individual\u27s preference for immediate versus delayed rewards. Participants were randomly assigned to complete the task alone or with 2 same-age, same-sex peers observing. Consistent with our prediction, adolescents demonstrated a greater preference for immediate rewards when with their peers than when alone. Heightened risk taking by adolescents in the company of their friends may be due in part to the effect that being with one\u27s peers has on reward sensitivity

Adolescents Prefer More Immediate Rewards When in the Presence of their Peers

Adolescents take more risks in the presence of their peers, but the mechanism through which peer presence affects risky decision-making is unknown. We propose that the presence of peers increases the salience of the immediate rewards of a risky choice. The current study examined the effect of peer presence on reward sensitivity in a sample of 100 late adolescents ages 18 through 20 (M=18.5) using a delay discounting task, which assesses an individual\u27s preference for immediate versus delayed rewards. Participants were randomly assigned to complete the task alone or with 2 same-age, same-sex peers observing. Consistent with our prediction, adolescents demonstrated a greater preference for immediate rewards when with their peers than when alone. Heightened risk taking by adolescents in the company of their friends may be due in part to the effect that being with one\u27s peers has on reward sensitivity

At risk of being risky: The relationship between "brain age" under emotional states and risk preference.

Developmental differences regarding decision making are often reported in the absence of emotional stimuli and without context, failing to explain why some individuals are more likely to have a greater inclination toward risk. The current study (N=212; 10-25y) examined the influence of emotional context on underlying functional brain connectivity over development and its impact on risk preference. Using functional imaging data in a neutral brain-state we first identify the "brain age" of a given individual then validate it with an independent measure of cortical thickness. We then show, on average, that "brain age" across the group during the teen years has the propensity to look younger in emotional contexts. Further, we show this phenotype (i.e. a younger brain age in emotional contexts) relates to a group mean difference in risk perception - a pattern exemplified greatest in young-adults (ages 18-21). The results are suggestive of a specified functional brain phenotype that relates to being at "risk to be risky.

Smooth Loops and Fiber Bundles: Theory of Principal Q-bundles

A nonassociative generalization of the principal fiber bundles with a smooth loop mapping on the fiber is presented. Our approach allows us to construct a new kind of gauge theories that involve higher ''nonassociative'' symmetries.Comment: 20 page

A randomized, placebo-controlled trial of prednisone in early Henoch Schönlein Purpura [ISRCTN85109383]

BACKGROUND: Henoch Schönlein Purpura (HSP) is the most common systemic vasculitis of childhood. There is considerable controversy over whether children with HSP should be treated with corticosteroids. The goal of this study was to investigate whether early corticosteroid administration could reduce the rate of renal or gastrointestinal complications in children with HSP. METHODS: Forty children with HSP, seen in the emergency room of a tertiary-care, paediatric centre, entered a randomized, double-blind, placebo controlled study. The treatment group (n = 21) received oral prednisone, 2 mg/kg/day for one week, with weaning over a second week, while the placebo group (n = 19) received an identical appearing placebo. Co-primary outcomes were the rate of renal involvement at one year and the rate of acute gastrointestinal complications. Co-primary outcomes were analysed using Fisher's Exact test. RESULTS: At one year, there was no difference in the rate of renal involvement (3/21 prednisone group vs. 2/19 placebo group, P = 1.0). There was also no statistically significant difference in the rate of acute gastrointestinal complications (2/21 prednisone group vs. 3/19 placebo group, P = 0.7). Two children in the placebo group did experience intussusceptions compared with none in the prednisone group (P = 0.2). CONCLUSIONS: Early prednisone therapy in HSP does not appear to reduce the risk of renal involvement at one year, or the risk of acute gastrointestinal complications. There may be a reduced risk of intussusception. The routine, early use of prednisone in uncomplicated HSP cannot be recommended at this time

Failure of Working Memory Training to Enhance Cognition or Intelligence

Fluid intelligence is important for successful functioning in the modern world, but much evidence suggests that fluid intelligence is largely immutable after childhood. Recently, however, researchers have reported gains in fluid intelligence after multiple sessions of adaptive working memory training in adults. The current study attempted to replicate and expand those results by administering a broad assessment of cognitive abilities and personality traits to young adults who underwent 20 sessions of an adaptive dual n-back working memory training program and comparing their post-training performance on those tests to a matched set of young adults who underwent 20 sessions of an adaptive attentional tracking program. Pre- and post-training measurements of fluid intelligence, standardized intelligence tests, speed of processing, reading skills, and other tests of working memory were assessed. Both training groups exhibited substantial and specific improvements on the trained tasks that persisted for at least 6 months post-training, but no transfer of improvement was observed to any of the non-trained measurements when compared to a third untrained group serving as a passive control. These findings fail to support the idea that adaptive working memory training in healthy young adults enhances working memory capacity in non-trained tasks, fluid intelligence, or other measures of cognitive abilities.National Institutes of Health (U.S.) (Blueprint for Neuroscience Research (T90DA022759/R90DA023427)United States. Defense Advanced Research Projects Agency (government contract no. NBCHC070105)United States. Dept. of Defense (National Defense Science and Engineering Fellowship)Massachusetts Institute of Technology (Sheldon Razin (1959) Fellowship

Does working memory training have to be adaptive?

This study tested the common assumption that, to be most effective, working memory (WM) training should be adaptive (i.e., task difficulty is adjusted to individual performance). Indirect evidence for this assumption stems from studies comparing adaptive training to a condition in which tasks are practiced on the easiest level of difficulty only [cf. Klingberg (Trends Cogn Sci 14:317-324, 2010)], thereby, however, confounding adaptivity and exposure to varying task difficulty. For a more direct test of this hypothesis, we randomly assigned 130 young adults to one of the three WM training procedures (adaptive, randomized, or self-selected change in training task difficulty) or to an active control group. Despite large performance increases in the trained WM tasks, we observed neither transfer to untrained structurally dissimilar WM tasks nor far transfer to reasoning. Surprisingly, neither training nor transfer effects were modulated by training procedure, indicating that exposure to varying levels of task difficulty is sufficient for inducing training gains