Reward-based contextual learning supported by anterior cingulate cortex

The anterior cingulate cortex (ACC) is commonly associated with cognitive control and decision making, but its specific function is highly debated. To explore a recent theory that the ACC learns the reward values of task contexts (Holroyd & McClure in Psychological Review, 122, 54–83, 2015; Holroyd & Yeung in Trends in Cognitive Sciences, 16, 122–128, 2012), we recorded the event-related brain potentials (ERPs) from participants as they played a novel gambling task. The participants were first required to select from among three games in one “virtual casino,” and subsequently they were required to select from among three different games in a different virtual casino; unbeknownst to them, the payoffs for the games were higher in one casino than in the other. Analysis of the reward positivity, an ERP component believed to reflect reward-related signals carried to the ACC by the midbrain dopamine system, revealed that the ACC is sensitive to differences in the reward values associated with both the casinos and the games inside the casinos, indicating that participants learned the values of the contexts in which rewards were delivered. These results highlight the importance of the ACC in learning the reward values of task contexts in order to guide action selection.     

自然分娩与剖宫产的比较研究

剖宫产不是一种分娩方式,而是解决难产的手段。日益增高的剖宫产率成为人们关注的热点话题,自然分娩和剖宫产对母婴的健康和卫生资源的影响,有很多的研究和争议,对于没有医学指征要求剖宫产目前倾向于在知情同意的情况下尊重患者的自主权和选择权,但控制剖宫产率在一个理性的范围之内,是一个系统工程,值得全社会的关注。     

Moving Toward Comprehensiveness and Sustainability in a Social Ecological Approach to Youth Violence Prevention: Lessons from the Asian/Pacific Islander Youth Violence Prevention Center

Youth violence is a serious public health problem affecting communities across the United States. The use of a social ecological approach has helped reduce its prevalence. However, those who have put the approach into practice often face challenges to effective implementation. Addressing social ecology in all its complexity presents one obstacle; the ability of private non-profit and public agencies to sustain such comprehensive efforts presents another. Here, we provide an example of our efforts to prevent youth violence. We worked with the Asian/Pacific Islander Youth Violence Prevention Center (APIYVPC) and two communities on O`ahu. We provide a case example from the Asian/Pacific Islander Youth Violence Prevention Center (APIYVPC) of our work, in collaboration with two communities on O`ahu, to develop and implement a youth violence prevention initiative that is becoming both comprehensive and sustainable. We illustrate the incremental nature of what it means to be comprehensive and we underscore the importance of reaching sustainability as the project unfolds.     

自然分娩与剖宫产的比较研究

剖宫产不是一种分娩方式,而是解决难产的手段.日益增高的剖宫产率成为人们关注的热点话题,自然分娩和剖宫产对母婴的健康和卫生资源的影响,有很多的研究和争议,对于没有医学指征要求剖宫产目前倾向于在知情同意的情况下尊重患者的自主权和选择权,但控制剖宫产率在一个理性的范围之内,是一个系统工程,值得全社会的关注.     

Essential Elements for Community Engagement in Evidence-Based Youth Violence Prevention

In the field of youth violence prevention, there has been increasing emphasis on “evidence based” programs and principles shown through scientific research as reaching their intended outcomes. Community mobilization and engagement play a critical role in many evidence‐based programs and strategies, as it takes a concerted effort among a wide range of people within a community to alter behavior and maintain behavioral change. How do concerned individuals and groups within a community engage others within and outside of that community to effectively plan, develop and implement appropriate EB programs as well as evaluate the outcomes and impacts of locally developed programs yet to be proven? The authors discuss five elements essential for community engagement in evidence‐based youth violence prevention based on their work in a university‐community partnership through the Asian/Pacific Islander Youth Violence Prevention Center (API Center), a National Academic Center for Excellence on Youth Violence Prevention Center supported by the Centers for Disease Control and Prevention. They include: (a) aligning EBPs with a community's shared vision and values; (b) establishing an inclusive environment for the planning, implementation and evaluation of EBPs; (c) nurturing collaboration for increased effectiveness and efficacy of EBPs; (d) building adequate leadership and community capacity to develop and sustain EBPs; and (e) building a learning community for evaluation and self‐reflection. The authors propose placing greater emphasis on “evaluative thinking” and organizational capacity for evaluation as we pursue evidence‐based practices for youth violence prevention. This is especially important for ethnic groups for which an evidence base is not well established.     

Impaired reward processing by anterior cingulate cortex in children with attention deficit hyperactivity disorder

Decades of research have examined the neurocognitive mechanisms of cognitive control, but the motivational factors underlying task selection and performance remain to be elucidated. We recently proposed that anterior cingulate cortex (ACC) utilizes reward prediction error signals carried by the midbrain dopamine system to learn the value of tasks according to the principles of hierarchical reinforcement learning. According to this position, disruption of the ACC–dopamine interface can disrupt the selection and execution of extended, task-related behaviors. To investigate this issue, we recorded the event-related brain potential (ERP) from children with attention deficit hyperactivity disorder (ADHD), which is strongly associated with ACC–dopamine dysfunction, and from typically developing children while they navigated a simple “virtual T-maze” to find rewards. Depending on the condition, the feedback stimuli on each trial indicated that the children earned or failed to earn either money or points. We found that the reward positivity, an ERP component proposed to index the impact of dopamine-related reward signals on ACC, was significantly larger with money feedback than with points feedback for the children with ADHD, but not for the typically developing children. These results suggest that disruption of the ACC–dopamine interface may underlie the impairments in motivational control observed in childhood ADHD.