Concurrent schedules: undermatching and control by previous experimental conditions.

Five pigeons were trained on concurrent variable-interval schedules. A series of conditions in which the ratio of reinforcement rates on two keys was progressively increased and then decreased was arranged twice. The birds were then exposed to an irregular sequence of conditions. Each condition in which reinforcement was available on both keys lasted six sessions. Performance in the first, third, and sixth sessions after a condition change was analyzed. Following a condition change, preference was biased toward the preference in the last condition, but this effect largely disappeared before the sixth session of training. The birds' preferences also appeared less sensitive to reinforcement rates in early sessions after a transition. Preference in a session was a function of both the reinforcements in that session and the reinforcements obtained in as many as four or five previous sessions. The effects of reinforcements in previous sessions could be summarized by the performance in the immediately preceding session, giving a relatively simple relation between present performance and a combination of present reinforcement and prior session performance. While such hysteresis could cause undermatching when only a small number of sessions are arranged in a condition, undermatching in a stable-state performance probably arises elsewhere.     

Reason and Faith: Themes from Richard Swinburne

International Journal for Philosophy of Religion -     

Prenatal experience and postnatal perceptual preferences: evidence for attentional-bias in bobwhite quail embryos (Colinus virginianus)

Previous studies have indicated that concurrent multimodal sensory stimulation can interfere with prenatal perceptual learning. This study further examined this issue by exposing 3 groups of bobwhite quail embryos (Colinus virginianus) to (a) no supplemental stimulation, (b) a bobwhite maternal call, or (c) a maternal call paired with a pulsating light in the period prior to hatching. Experiments differed in terms of the types of stimuli presented during postnatal preference tests. Embryos receiving no supplemental stimulation showed no preference between stimulus events in all testing conditions. Embryos receiving exposure to the unimodal maternal call preferred the familiar call over an unfamiliar call regardless of the presence or absence of pulsating light during testing. Embryos exposed to the call-light compound preferred the familiar call only when it was paired with the light during testing. These results suggest that concurrent multimodal stimulation does not interfere with prenatal perceptual learning by overwhelming the young organism's limited attentional capacities. Rather, multimodal stimulation biases what information is attended to during exposure and subsequent testing.     

Developing a Community Science Research Agenda for Building Community Capacity for Effective Preventive Interventions

Research has shown that prevention programming can improve community health when implemented well. There are examples of successful prevention in local communities, however many continue to face significant challenges, demonstrating a gap between science and practice. Common strategies within the United States to address this gap are available (e.g., trainings), but lack outcomes. Building community capacity to implement high quality prevention can help communities achieve positive health outcomes, thereby narrowing the gap. While there is ample research on the efficacy of evidence-based programs, there is little on how to improve community capacity to improve prevention quality. In order to narrow the gap, a new model of research—one based in Community Science—is suggested that improves the latest theoretical understanding of community capacity and evaluates technologies designed to enhance it. In this article, we describe this model and suggest a research agenda that can lead to improved outcomes at the local level.     

Suicide compared to other causes of mortality in physicians

Physicians frequently are early adopters of healthy behaviors based on their knowledge and economic resources. The mortality patterns of physicians in the United States, particularly suicide, have not been rigorously described for over a decade. Previous studies have shown lower all-cause mortality among physicians yet reported conflicting results about cause-specific mortality such as suicide. In this study, we compared all-cause and cause-specific mortality in a sample of physicians to the age-gender matched general U.S. population from 1948 through 1998. We also compared the mortality experience across medical specialties. The risk of all-cause mortality was 56% lower than expected in men, and 26% lower in women, compared to the general population. Standardized mortality ratios (SMRs) were markedly lower for diseases strongly linked to smoking, e.g., cardiovascular diseases, respiratory diseases, and lung cancer. Suicide was the only cause of death where risk was greater than the general population. Overall, we found that physicians are at substantially lower risk of dying compared to the general population for all causes of death except suicide. The findings for suicide are strikingly different than other causes of death and should provide impetus for new research on the mental health of physicians.     

Organizational expectations of the novice teacher

The study focuses on the teacher as an organization person, that is, a professional working in an organizational setting, and forms part of its administrative and human fabric. The purpose of the article is to describe the novice teachers expectations from teaching as a profession and from the school as a work organization. The novice teachers who participated in trainee programs at five large teacher training colleges in Israel, completed a self-report questionnaire. The questionnaire items expressed teachers expectations of their work at the outset of their professional career. Facet Theory was the methodological approach used for the study. It was found that novice teachers expectations focus on the following areas of interest and activity expectations of professional and social recognition; expectations of responsive conduct on the part of students; of involvement and support from parents, and of collegiality from other staff, parents and the principal; and expectations that teaching and those associated with it will contribute to strengthening the teachers professional sense of self. The findings were also examined based on self-psychology perspectives. The article discusses the implications of these expectations pertaining to teacher training.